Medical
Costs of Coronary Artery in the United States
Disease
Ellison H. Wittels, MD, Joel W. Hay, PhD, and Antonio M. Gotto, Jr., MD, DPhil
A model has been developed to determine the cost of coronary artery disease (CAD) based on the 5 primary events identiied in the Framingham Study: acute myocardial infarction, angina pectoris, unstable angina pectoris, sudden death and nonsudden death. The costs for diagnostic and therapeutic service for patients wtth CAD were linked to medical decision algorithms outlining the dlagnosis and management of patients with CAD. Because CAD is a changing illness not represented by a single event, the algorithm tracked patlents for 5 years after the time of diagnosis, or until death, to develop average cost estimates. The estimated S-year costs (in 1986 United States dollars) of the 5 CAD events were: acute myocardial infarction $&211, angina pectoris $24,960, unstable angina pectoris $40,581, sudden death $9,078 and nonsudden death $19,697. The costs of major CAD surgical procedures were also cakulated because of their Impact on health care costs for patients with CAD. These inchrde: coronary artery bypass surgery per case over 5 years $32,465, and angioplasty per case over 5 years $26,916. The high cost of CAD refiects the improved technology and more effective and expensive therapies now available. (Am J Cardiol lSSOt66r432-440)
From the Department of Internal Medicine, Baylor College of Medicine, The Methodist Hospital, Houston, Texas, and the Hoover Institution, Stanford University, Stanford, California. This study was supported in part by Merck, Sharp & Dohme, Rahway, New Jersey.The views presented are solely the views of the authors. Manuscript received January 12, 1989; revised manuscript received and accepted October 23, 1989. Address for reprints: Antonio M. Gotto, Jr., MD, 6535 Fannin, Mail Station A 601, Houston, Texas 77030. Requestsfor the Appendix should be sent to Ellison H. Wittel, MD, The Methodist Hospital, 6565 Fannin, Houston, Texas 77030.
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rth United States health care costs currently exceeding $500 billion annually, there is increased interest in the determinants of expenditures. There has been little research into the total or lifetime cost of medical care for patients with coronary artery disease (CAD), although it represents a leading cause of health care expenditures. We have compiled cost figures and developed medical decision algorithms based on the diagnostic and therapeutic options and probable outcomes for the 5 primary CAD events examined in the Framingham Study. These include acute myocardial infarction (AMI), angina pectoris, unstable angina pectoris, sudden death and nonsudden death.’ We then used these algorithms to estimate the cost of CAD medical care for 5 years after diagnosis, or until death, whichever was earlier. In general, the cost was calculated by multiplying the expected frequency of the test or treatment by its price. The estimated costs often were substantially different from those previously reporte4l,2J in part because the use of medical algorithms and assessment of costs over 5 years allowed a more complete analysis of CAD expenses. This article is not intended to be a review of the efficacy or indications for specific procedures or tests, but rather an analysis of current CAD costs based on data from medical facilities with significant experience in CAD diagnosis and treatment. METHODS In developing a medical cost model, we reviewed the literature on initial CAD events as defined in the Framingham Study, and on the cost and outcome of coronary bypass surgery, thrombolytic therapy and angioplasty. Because of differences in study design, geographic regions and populations, it was difficult to consolidate published study results. Therefore, a group of knowledgeable cardiologists who represented different geographic regions of the US were selected as a consultant panel. The cardiologists generally validated the therapeutic options, projected outcomes and prices that were used. From the collected data, medical decision algorithms were developed to show expected therapies and outcomes for each CAD event. Our decision algorithms are detailed in an Appendix, available upon request. To estimate costs for each decision made in the CAD treatment algorithms, prices for approximately 70 different procedures, hospital services, medications, laboratory tests, diagnostic services and other medical services were obtained from 3 main sources that will be discussed. All prices used in our model are presented in 1986 US dollars. (A detailed list of specific tests, proce-
TABLE
I Abbreviated
List of Prices
Used
Disease
Model:
Cost
US Dollars
Annual
in 1986
in Coronary
Item
Price
AMI hospitalization Ambulance Blood sugar test CCU daily average charges Chest x-ray (2 views) Complete blood count Echocardiogram Electrocardiogram and interpretation Electrolytes Holter monitor ICU daily average charges MD outpatient visit Nineteen chemistry tests Nuclear ventricular study PTCA physrcian fee Regular care bed per diem Three chemistry tests Treadmill Urinalysis
4,134 70 7 1,120 62 8 139 49 8 285 970 47 22 700 1,412 511 3 198 6
TABLE
Heart
II Expected
Complications (8)
Cost
of Myocardial
Infarction
(in $)
Extension of infarction Congestive heart failure Pulmonary edema Cardiac arrest Cardiogenic shock therapy Medical therapy Medical therapy and aortic balloon Aortic balloon and bypass surgery Angioplasty Permanent pacemaker Temporary pacemaker
Source Houston Houston HCFA Houston Houston HCFA Houston HCFA HCFA Houston Houston HCFA HCFA Houston Houston Houston HCFA Houston HCFA
dures and medications used in each coronary event algorithm is available as part of the Appendix.) In 1985, the Health Care Financing Administration (HCFA) maintained a list of national average prices for 110 high-frequency physician services paid by Medicare. HCFA did not update this list in 1986. For all CAD medical services identified in our decision algorithms and found on this list, HCFA national average prices were used. Most drug prices were obtained from 1986 pharmaceutical price surveys from IMS America, a data resource group (Plymouth Meeting, Pennsylvania). For each category of medication (e.g., diuretics, fl blockers, angiotensin-converting enzyme inhibitors) average daily consumption and retail prices for the largest selling medication in that category were used to compute the average medication costs per patient. All other medical prices were obtained from Houston area surveys. Both HCFA and Houston hospital prices were generally considered similar to, or lower than, those prevailing in the panelists’ locales. For this reason, and because of the relatively high rate of medical inflation, the prices we have used are conservative. Table I provides a list of some of the key prices used in the analysis. A detailed pricing list is available in the Appendix. RESULTS Acute myocardial infarction: In the US, approximately 1.5 million people have an acute myocardial infarction (AMI) yearly.4 In 1983, 676,000 primary discharge diagnoses from nonfederal, short-term hospitals were for AMI. Not all cases resulted in hospitalization4,(j mostly because of sudden death and unrecognized AMI. While the Framingham Study calculated the risks of AM1 for both recognized (hospitalized) and
68 323 135 161 40 36
TABLE
III
Therapy
After Myocardial
Condition
W)
Added Expected Cost for Acute Myocardial Infarction ($)
No treatment Angina pectons Congestrve heart failure Reinfarction Death
15 35 14
4,863 1,406
25 30
7.123 2,033
Five-Year
Outcome
Receiving
of Patients
Medical
Infarction
Prevalence
AMI = acute myocardial infarction; CCU = coronary care unit: HCFA = Health Care Financing Administration; ICU = intensive care unit. PTCA = percutaneous translumlnal coronary angioplasty.
2,151 900 392 242
0.00
r
TABLE IV Framingham Five-Year
Coronary Artery Total Cost per Case
Expected
Acute myocardial infarction Angina pectoris Unstable angina pectoris Sudden death Nonsudden death
TABLE V Coronary Expected
Total
Artery Disease Cost per Case ($)
Disease
Events:
Average
Cost ($)
51,211 24,980 40,581 9,078 19,697
Procedures:
Five-Year
unrecognized (not hospitalized) AMI, we have considered only patients who were hospitalized with a recognized AMI. The costs for those who died from an AM1 and were either not brought to the hospital or died in the emergency room are considered in the section on sudden death. The costs for patients who died in the hospital after admission for an AM1 are reviewed in the section on nonsudden death. The AM1 patients considered in this section have been defined as those who were admitted and survived hospitalization. Figures 1, 2 and 3 diagram our decision algorithm. Tables II, III, IV and V list some of the specific costs of these algorithms. In 1980, the average total length of hospitalization for an AMI was 12.9 days. Patients who were subsequently discharged were in the hospital an average of 14 days, while those who died after admission were in the hospital an average 8.5 days.7 By 1983, the length of hospitalization for AM1 had decreased to approximately 11 days.5 We used 10 days as the average length of
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stay. Change in the length of hospitalization alters the cost of AMI. A decrease of 1 day in regular care lowered the expected average cost of AM1 by $5 11. Emergency room care and hospitalization in the coronary care unit for 3 days, intermediate care for 4 days and regular care for 3 days, plus inpatient cardiac rehabilitation, laboratory fees and medications added $13,670 to the expected cost of AMI. COMPLICATIONS OF INFARCTION: Approximately 60% of patients hospitalized with an AM1 experienced complications. Cardiac arrhythmias, varying degrees of left ventricular failure and continued chest pain often resulted in a more prolonged hospital course.8-io While complications from AM1 continue to be a cause of concern and extensive study by clinicians, they contributed little to the total expected cost of AMI, because of the relatively small number of patients who suffered significant costly complications (Table II). The greatest single Recognized Sudden
Unrecognized
AMI
AMI
Death
Emergency
Room J Risk Stratification
/ Medical Treatment Cardiac Surgery Angioplasty 1 Cardiac Rehabilitation No Cardiac Rehabilitation Long-Term
+
added expected cost was $2,151 for extension of an AMI, which is estimated to occur in 7% of patients. RISKSTRATIFICATION FOR INFARCTION: Holter monitoring, treadmill testing and cardiac catheterization have been used in recent years to assess the risk of future cardiac events occurring in postinfarction patients (Figure 2). Holter monitoring has been used to detect arrhythmias and both symptomatic and silent myocardial ischemia. The consultant panel estimates varied widely in the estimate of the use of Holter monitors in AM1 patients; the range was 20 to 100%. We used a 50% rate in our base case analysis. An exercise treadmill test was performed on 75% of patients either before discharge or within 6 weeks of hospitalization.* l-l3 We estimated that 60% of tests were nuclear exercise and 40% were non-nuclear exercise testing. For the AM1 patient, Holter monitoring and exercise testing added $1,7 18 to the average cost of AMI. The price of an outpatient cardiac rehabilitation was $2,430 per patient. Because only 15% of patients who had an AM1 participated, outpatient cardiac rehabilitation added a small amount to the average cost of AMI. At the initial hospitalization or within 3 months, 30% of patients who survived a recognized infarction and had not received thrombolytic therapy had heart catheterization, which added $847 to the average AM1 cost. Among these patients, 25% had coronary bypass surgery (adding $2,191 to the average cost), 33% had angioplasty (adding $2,398 to the average cost) and 42% received medical therapy (adding $860 to the average cost). THROMBOLYTIC THERAPY: Coronary thrombosis has been reported in 70 to 90% of patients with AMI.14 Successful thrombolytic therapy can limit infarct size, preserve left ventricular function and reduce hospital mortality.15-*7 The successof thrombolytic therapy with streptokinase was related to the elapsed time between the onset of AM1 and the initiation of therapy. If >6 hours elapsed between the AM1 and thrombolytic ther-
Follow-up Traditional
Thrombolytic
Care
+ ICU Holter Monitoring
+ Intermediate
Cardiac Catheterization
Treadmill
Regular
+
Therapy
Streptokinase - intravenous Streptokinase . intracoronary Tissue Plasminogen Activator
Care
J
Care
I
Pylj~~~~,
Open
Non-perfuset
+ Risk Stratification \No;:i;;r
/ \t
Cathe!erization
1
No Catheterization Risk
Stratification
Medical
/ Treatment
Medical
+ Treatment
Or Medical
Treatment + Follow-up
Surgical
Treatment # Follow-up
Surgical
Angioplasty
Treatment Or
+ Follow-up
Angioplasty I
FIGURE 2. DsicMonalgorithm*Holter~,treadmifi orcadac--ofpostfnfdonpatients. 434
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care versus
apy, then the effect of thrombolysis on mortality was significantly blunted. I8 Because the onset of the AM1 was >4 hours among most patients who presented to the hospital emergency room,19 we estimated that only 25% of patients were candidates for thrombolytic therapy, and 75% received traditional care for their AMI. Streptokinase thrombolytic therapy can be given by either the intracoronary or intravenous route to patients with an AM1 (Figure 3). Because intracoronary thrombolytic therapy required a readily available cardiac catheterization facility and trained personnel,20 10% of patients received intracoronary thrombolytic therapy and 90% received intravenous streptokinase. Seventy-five percent of patients who received intracoronary streptokinase and 50% who received intravenous streptokinase were successfully reperfused.21 A 20% reocclusion rate for intravenous streptokinase and a 17% reocclusion rate for intracoronary streptokinase were used in the algorithm. Tissue plasminogen activator, a naturally occurring human protein capable of inducing clot lysis,22,23was recently approved by the Food and Drug Administration. Intravenous tissue plasminogen activator with a reperfusion rate of 75% has appeared as effective as intracoronary streptokinase.23 Among patients successfully reperfused, 50% had angioplasty, 25% bypass surgery and 25% medical therapy. For patients not successfully reperfused, 42% received medical therapy, 25% bypass surgery and 33% angioplasty. Among patients younger than 75 years of age who received thrombolytic therapy followed by heparin, 11% had significant bleeding problems.24 Bleeding complications were reported in 7% of patients who received intravenous heparin in an amount sufficient to keep the partial thromboplastin time 2 times the control value.25 Bleeding complications from the use of streptokinase and heparin added only $31.50 to the average AM1 cost. The 5-year cost of thrombolytic therapy included the costs of the increased number of heart catheterizations, angioplasties and bypass surgeries for these patients compared to patients who received traditional care for AMI. If all patients who received thrombolytic therapy were given only streptokinase, an average of $4,197 was added to the expected cost of an AMI. The price of streptokinase was $220 per patient. If only tissue plasminogen activator therapy was used as the thrombolytic therapy, $4,733 was added to the expected cost of AMI. The price of the medication was $2,200 per patient treated. OUTCOME AFTER INFARCTION: The Framingham Study’s 5-year follow-up of men and women who had an initial AM1 and were taking medical therapy26 (Table III) was used to predict the incidence of medical events. We estimated that 92% of treated patients would be alive at 1 year and that the 5-year results among patients who received coronary bypass or angioplasty would be identical to those who had not had a previous AMI. The cost of medical therapy per patient for 5 years added $3,865 to the expected AM1 cost. In our study, the expected total cost over 5 years for a patient hospitalized with AM1 was $51,211.
Nonsudden death: Approximately 10% of the patients admitted with a diagnosis of AM1 died in the hospital. By the Framingham Study definition, they comprised the nonsudden death group. The expected cost for nonsudden death was $139 for the emergency room plus $13,254 for the hospitalization. The average length of hospitalization for those who died was 8.3 days.’ Compared to other AM1 patients, the cost of the shorter hospitalization was offset by the cost of resuscitation. Sudden death and sudden death resuscitated: In the US, 650,000 people die yearly from CAD, with sudden death accounting for 50% of deaths.4,27 We used the Framingham Study definition of a l-hour time period between the change from a stable clinical status to death.’ Among those resuscitated from sudden death, 90% had underlying CAD. 28,29Figure 4 gives an overview of the algorithm for sudden death. It has been predicted that 25 to 30% of those who suffered sudden death could be resuscitated and eventually discharged alive from the hospital. 30,31Our algorithm was more conservative. Of 100 patients with sudden death, 68 died outside the hospital and were taken to a funeral home. Of the 32 patients transported to the hospital by ambulance, 26 patients were successfully stabilized and hospitalized. Among the 26 patients hospitalized after successful resuscitation, 5 were assumed to have died in the hospital, while 21 were discharged alive. The cost of the ambulance, emergency room and hospitalization, including 3 days in the coronary care unit, 5 days in intermediate care and 4 days in regular care, added $2,840 to the expected cost of sudden death. Approximately 10 to 15% of patients resuscitated after sudden death and ultimately discharged from the hospital are left with significant morbidity.3’ The cost of care for those who did not fully recover was not included in this study. For patients who survived cardiac arrest, cardiac catheterization and electrophysiologic test-
Sudden
Death L
Hospital 1/l DOA
Resuscitation
Altempted t
Expired Emergency
\ Room AAdrn{“”
Discharged
MO?..,,
HAdmitted -coronary
Cath-Electrophysiology t P&d-Treatment ’ Supressed I MedikM
Study
>on-suppressed
Follow-up
d
I\
NO Amiodarone + Fall&-UP
FIGURE
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ing have been recommended.32 The 15% with significant morbidity had two 24-hour Holter monitors, and subsequently were given antiarrhythmic therapy. The remaining 85% of patients had heart catheterization, adding $575 to the expected cost of sudden death, and an electrophysiologic study, adding $344 to the expected cost of sudden death. Forty percent of the resuscitated patients who were catheterized had coronary bypass surgery, with a survival rate of 92%, which added $2,532 to the total cost. Patients who survived the initial surgery had a second electrophysiologic study, which added an additional $138 to the cost of sudden death. Approximately twothirds of these patients also required antiarrhythmic therapy, which added over 5 years $190 per case to the average cost of sudden death. Seventy-two percent of these patients lived for at least 5 years after bypass.33 Sixty percent of the patients who had catheterization and an electrophysiologic study after resuscitation from sudden death were treated medically. The 5-year expected cost per patient treated medically was $2,059. This cost included a follow-up electrophysiologic study to judge the effectiveness of the antiarrhythmic medication, plus additional testing and therapy. Among patients treated with antiarrhythmic therapy, only 26% experienced adequate suppression of their arrhythmias based on a follow-up electrophysiologic study.32 Approximately 10% of patients not adequately suppressed underwent antiarrhythmic surgery, which had an expected cost of $28,600 per case. Overall, because only about 1% of the total number of patients who were resuscitated after sudden death had this surgery, it added only $1,747 to the average expected cost of sudden death. Patients who were neither candidates for antiarrhythmic surgery nor adequately suppressed on antiarrhythmic therapy were given amiodarone, with a 50% successful suppression rate.34 However, after 2 years, amiodarone was discontinued in 20% of these patients because of drug toxicity. If all patients not treated surgically or suppressed on other antiarrhythmics were giv-
en amiodarone, it would add $449 to the average cost of sudden death over 5 years. Among patients resuscitated from out-of-hospital cardiac arrest who survived the initial hospitalization, the 4-year mortality ranged from 25 to 50%.3’ Overall, the average total cost per case of sudden death/sudden death resuscitated was $9,078 over a 5-year period. Angina pectoris: Approximately 5 million people in the US have angina pectoris or a history of a previous AMI. In 1983, angina pectoris was the primary diagnosis listed for 278,000 hospital discharges, and ao counted for 1,488,OOO hospital days.5 One difficulty in evaluating the prevalence of angina in the population is that it may fluctuate in intensity in the individual patient. A patient who at 1 examination had typical angina pectoris could be free of symptoms at a subsequent examination.35 During the first 8 biennial examinations in the Framingham Study, 32% of men and 44% of women had transient or nonpersistent angina. Over a 5-year period, one-half of patients with angina were assumed hospitalized for an average of 6 days because of cardiovascular disease.36The cumulative survival of patients with CAD receiving medical management was reported to be affected by the presence of left main coronary disease, left ventricular function and patient age. For patients with l- and 3-vessel CAD, the 4year survival rate was 92 and 68%, respectively. Over a 5-year period, 40% of patients with angina pectoris had heart catheterization. Catheterization added $1,255 to the expected cost of angina pectoris. The 1975 to 1979 Coronary Artery Surgery Study reported that about 5% of patients with angina pectoris had surgical intervention annually.37 This number should decrease as more patients have angioplasty. Among the patients catheterized, 25% had angioplasty, for an additional expenditure of $2,688, 50% had coronary bypass surgery, adding $6,493, and 25% continued to receive medical therapy. Among the 60% of patients in our study who did not have heart catheterization, 40% were not receiving consistent treatment for angina and no cost was ascribed.
y%y---‘-“)“I JizgTJJ No Catheterization
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The remaining 60% were taking regular daily therapy for angina, adding $4,317 to the expected angina pectoris cost. In addition, approximately 20% of medically treated patients had an AM1 during the 5 years, prompting an additional $4,091 expenditure. The total cost for each case of angina pectoris over 5 years was $24,980. Unstable angina pectoris: In 1983, 130,000 hospital discharges listed unstable angina as the primary diagnosis.5 In reality, this figure was probably larger. It is often difficult to separate unstable angina from an AMI. It is also likely that many of the hospitalizations for angina pectoris were actually for unstable angina. Patients admitted with unstable angina pectoris were in the coronary care unit for 2 days, intermediate care unit for 3 days and regular care unit for 2 days. The cost of hospitalization, including medication and noninvasive testing, added $8,093 to the expected unstable angina cost. Because of the potential for infarction or sudden death, about 90% of unstable angina patients had heart catheterization during the initial hospitalization. Heart catheterization added $2,823 to the expected cost of unstable angina. The remaining patients who did not have cardiac catheterization were given medical therapy, adding $1,169 to the cost over 5 years. The number not catheterized may increase in the future with the use of early exercise testing.38 Approximately 35% of patients diagnosed with unstable angina pectoris had coronary bypass surgery within a few weeks, with a surgical mortality rate of 4%. This surgery added an additional $9,238 to the expected cost of unstable angina. At the end of 1 year, 95% of the patients were alive, and 13% had had an AMI. An AM1 after bypass surgery added $2,097 to the expected cost. The 4-year surgical survival rate was 88%. Forty percent with unstable angina pectoris who had heart catheterization had angioplasty. The consultant panel generally felt that angioplasty would be used with increased frequency in patients with unstable angina.39 Angioplasty increased the average cost of unstable angina by $9,690. Twenty-five percent of those catheterized received medical therapy, for an added cost of $2,526. For this group, the survival rate was 93% after 1 year and at 5 years was 87%.40 Ten percent of patients had an AM1 during year 1. An additional $1,152 was added by AM1 that occurred during the 5-year follow-up. Over a period of 30 months, approximately 36% of those who were initially treated medically required bypass surgery,40 adding $3,799 to the expected cost of unstable angina. From the available data, we have used only the first year AM1 incidence rate after coronary bypass. Altogether, the average cost for unstable angina per case over 5 years was $40,581. AN~~IOPLASTYFOR ANGINA PECTORIS: Percutaneous transluminal coronary angioplasty was initially introduced in 1977 by Gruentzig for the treatment of a proximal stenosis in 1 of the 3 main coronary vessels. Subsequently, the indications for angioplasty have been extended.41 Angioplasty for CAD was initially successful 85% of the time, with 90% of the patients having no or de-
creased angina, and 10% unchanged. When angioplasty was used to treat angina pectoris, the average length of hospitalization was 2 days. The patients had heart catheterization at the time of angioplasty and were monitored for 4 hours. Successful angioplasty, including preangioplasty exercise testing, hospitalization and medication, had an expected cost of $6,706. The 5-year medical follow-up among those with successful angioplasty, including annual exercise testing and medication, added $5,381 to the expected cost of angioplasty. As experience with angioplasty has increased, the complication rate has decreased.42 We report figures from medical facilities with experience in angioplasty. Angioplasty failed in 15% of the cases. The failures reflected a 1% overall mortality rate,41 an AM1 rate of 2.5%43,44and a 14% emergency coronary bypass surgery rate, usually for coronary artery occlusion or coronary artery dissection. 41 These complications added $2,579 to the average cost of angioplasty. Surgical standby for angioplasty has been considered essential.45 Patients in whom angioplasty was not successful had coronary bypass surgery or continued medical treatment,46 adding $1,966 to the expected angioplasty cost. Among patients who had successful angioplasty, 40% had recatheterization, usually within 6 months because of either recurrent angina or a suspicion of restenosis. Among patients who had angioplasty for angina, the reported rate of restenosis at 6 months has ranged between 17 and 47%.41 We have used a restenosis rate of 30%.48 The rate of restenosis without symptoms of angina was reported to be 30%.46 Among patients with detected restenosis, we estimated that 65% had repeat angioplasty, 20% coronary bypass surgery and 15% medical therapy. With repeat angioplasty, there was an 85% successrate.49 The cost of the evaluation, including treadmill testing, catheterization and subsequent treatment with either medical therapy, repeat angioplasty or coronary bypass surgery, added $7,664 to the expected cost of angioplasty. We assumed a 15% restenosis rate over the next 5 years.48 Among those with late stenosis, 30% had bypass surgery, 60% angioplasty and 10% medical treatment. This did not include patients who had progression of disease in vessels not originally treated by angioplasty. Over a 5-year period, the average cost of angioplasty for angina pectoris was $26,916 per case. CORONARY
ARTERY
BYPASSSURGERY:COrOllary
al-tel'y
bypass surgery is an effective therapy to improve myocardial blood flow in selected patients with CAD,5o and the number of coronary heart bypass grafts has increased markedly. In 1971, 24,000 such surgeries were performed. In 1985, over 230,000 coronary artery bypass surgeries were performed.51 The reported length of hospitalization for coronary bypass surgery has varied. Readmissions, especially in the first year for postoperative surgical problems, raised the average number of hospital days per surgical case. The consultant panel believed that the length of hospitalization after surgery had decreased; we used 10 hospital days for each surgical case. Preoperative care and preoperative catheterization were not included in the cost.
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Coronary artery bypass surgical mortality has been related to factors such as patient age and status of the left ventricle.52 This algorithm used the Coronary Artery Surgery Study registry with a surgical mortality rate of 2.4%.53 By 6 months after surgery, approximately 16% of grafts were occluded, thereafter, the annual occlusion rate was about 1%.52 By 5 years, about 3% of patients had repeat coronary artery bypass surgery. By 10 years 11.4%, and by 12 years, 17.3% of the patients had repeat coronary bypass surgery.54 Compared to their preoperative symptoms, by 1 year after surgery, about 87% of patients had no angina pectoris, 10% had less angina and 3% were symptomatically unchanged. By 5 years, while about 90% of patients who had bypass surgery survived, 50% had angina pectoris.55 Patients who had recurrent angina pectoris after coronary bypass surgery added $3,588 to the average cc& of bypass surgery. If angina pectoris did not recur in the 5 years after surgery, follow-up testing and medication added $2,218 to the cost of bypass surgery. Over 5 years, the cost of repeat bypass surgery or angioplasty on occluded grafts added $1,09 1 to the expected cost of coronary bypass surgery. The percentage of patients with stenosed bypass grafts for whom angioplasty is appropriate is uncertain. Excellent successhas been reported for those who have angioplasty for occluded grafts5’j The use of angioplasty rather than repeat bypass surgery will affect the cost of bypass surgery. Overall, the average cost per case for bypass surgery over 5 years was $32,465.
and therapeutic intervention. Because of this, it is important to assessthe cost of CAD therapy over a significant period of time subsequent to the initial diagnosis. The costs included subsequent CAD events expected to occur within this time interval, adjusted for diagnosisspecific 5-year average survival probabilities. Because of continuing rapid changes in medical treatment, we did not project medical costs beyond 5 years of treatment. The reported cost was determined by multiplying the price of the expected therapy or test by the probability of occurrence for each therapy or test over the ensuing 5 years. An expensive but infrequent complication or treatment could add less to the average cost of an AM1 than less expensive but more frequently performed tests or treatments. Surgery for intractable cardiac arrhythmias among sudden death survivors had a price of $28,600; however, because of the relatively small percent who required the surgery, it added only $175 to the expected average cost of sudden death. Alternatively, unstable angina costs averaged $40,58 1 per patient over 5 years. The high cost reflected the high percent of patients who had expensive diagnostic testing and therapeutic intervention. The frequent use of angioplasty and bypass surgery added $18,928 to the average cost of unstable angina. While most medications and diagnostic tests for patients with angina pectoris were relatively inexpensive, over 5 years medical treatment added $10,634 to the expected cost of angina pectoris ($4,317 for medication and testing plus $6,317 for the cost of AMIs among the medically treated group). Medical treatment was provided to a total of 46% of patients with angina. Bypass DISCUSSION surgery added $7,746 ($1,255 for catheterization plus There is no systematic data collection source in this $6,493 for surgery) to the average cost, and was used to country that allows comprehensive, nationally represen- treat 20% of patients with angina. Although medical tative, CAD medical cost information to be obtained. therapy and bypass surgery contributed approximately We developed a cost model based on published findings the same to the total cost of angina pectoris, over twice and the consultant panel’s consensus regarding appro- as many patients received medical therapy. priate treatment and expected outcome for patients with Many tests may have little impact on the cost of CAD. We beiieve this model is generally more applica- CAD. The consultant panel suggested a wide range for ble to all sections of the country than data collected the use of Holter monitoring among patients with refrom a specific patient sample. While not attempting to cent AMI. Although it is an important therapeutic decidefine “ideal” treatment and outcome, the model does sion, Holter monitoring had only a small impact on the cost of the AM1 patient. Whether an AM1 patient had reflect current appropriate therapy and documented outcomes. Holter monitoring or not, the average net change in cost While we recognize that there is a distinction be- for an AM1 patient would be $157. tween prices (charges) and real economic resources,57 Sudden death is the least expensive of the 5 Frawe did not attempt to adjust prices to actual economic mingham coronary events. It cost $9,078, which is still a cost levels. Our cost analysis more appropriately reflects surprisingly large sum of money. While the increased what a patient or insurer would pay for medical ser- emphasis on resuscitation and rapid transportation of vices, rather than the economic costs to hospitals, physi- patients to the hospital has saved many lives, it has incians and other providers to produce these services. creased the cost of sudden death and sudden death reThis review has focused on CAD medical costs for suscitated. The percentage of patients who several years each of the 5 Framingham events, plus coronary artery ago would have been pronounced dead outside the hosbypass surgery, thrombolytic therapy and angioplasty, pital has decreased; those pronounced dead in the emerfor both the initial presentation and the 5 following gency room where resuscitation is attempted has inyears. Therefore, these costs are not estimates of the creased. Patients successfully resuscitated have a signifitotal expected lifetime costs of CAD. CAD is neither a cant number of sophisticated studies, and may have stable single event nor a static phenomenon. Effective coronary bypass surgery or surgery for the treatment of long-term treatment requires ongoing diagnostic testing arrhythmias.
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An example of a therapeutic advance that has also increased the cost of AM1 is thrombolytic therapy. Tissue plasminogen activator added $4,733 to the expected cost of an AMI, while streptokinase added $4,197. Tissue plasminogen activator was $2,000 more expensive than streptokinase; however, it added only $566 to the expected cost of an AMI. Therapy with thrombolytic agents resulted in more survivals and higher health care costs because thrombolytic therapy patients had relatively more heart catheterizations, angioplasties and bypass surgeries. Another therapy that offered less cost savings than anticipated was angioplasty. While not disputing the medical role of angioplasty, this analysis casts doubt on whether angioplasty will substantially decrease the cost of medical care. In our algorithm, the 5-year cost of angioplasty ($26,916) was only 17% less than the cost of coronary artery bypass surgery ($32,465). Kelly et al3 reported a 43% lower cost over 1 year of angioplasty compared to coronary surgery among patients with l-vessel disease. In the Coronary Artery Surgery Study, 27% of patients with angina pectoris who underwent surgery had l-vessel disease.” The cost of coronary bypass surgery accounted for $6,493 of the expected cost of angina pectoris. If we assume that angioplasty was done on every patient with l-vessel disease, using Kelly’s data the amount saved would be 43% of 27% of $6,493 or $779. This is a small amount compared to the expected total cost of angina pectoris: $24,980 per patient. Therefore, even if there were a significant difference in cost between angioplasty and coronary bypass surgery, greater use of angioplasty would have little effect on the overall expected cost of angina pectoris among patients with l-vessel disease. While the initial cost of successful angioplasty was less than that of bypass surgery, the treatment of restenosis, testing and medication over the following 5 years ($9,067) significantly added to the total cost of angioplasty. We believe that the 5-year cost reflected a more accurate estimate of the effect of angioplasty on CAD treatment costs. We have not evaluated the economic impact of quality variations reported in the outcome of CAD therapy, or focused on such issues as the relation of outcome to the volume of bypass surgery performeds8 or physician experience with angioplasty outcome.42 Our analysis shows that the major reason for the increased cost of CAD has been the ability to intervene acutely in patients with CAD with new technologies and new therapies, such as thrombolytic therapy and coronary bypass surgery. These new therapies have contributed to the decrease in CAD mortality, improved the quality of life of CAD patients, increased the number of patients who survived a Framingham event and allowed more people to live longer. We expect newer treatment and technology to continue to increase the cost of CAD. It is apparent that recent innovations in restorative therapy for CAD have substantially increased average medical costs per patient.
Acknowledgment: C. Richard Conti, MD, Albert Raizner, MD, Elliott Rapaport, MD, Thomas Ryan, MD, Rodman D. Starke, MD, and Myron L. Weisfeldt, MD, served on the consultant panel. REFERENCES 1. Kannel W, Gordon T, cds. The Framingham Study: An Epidemiological Investigation of Cardiovascular Disease. Washington, DC: DHEW Publication No. (NH?) 74-599. 1974. 2. Oster G, Epstein A. Primary prevention and coronary heart disease: the economic benefits of lowering serum cholesterol. Am J Pub1 Health 1986;76:647656. 3. Kelly M, Taylor G, Moses H, Mikell F, Dove J, Batchelder J, Wellons H, Schneider J. Comparative cost of myocardial revascularization: percutaneous transluminal angioplasty and coronary artery bypass surgery. JACC 1985;5:1620. 4. Heart Facts. American Heart Association. Dallas, Texas: 1985. 5. U.S. Department of Health and Human Services; Public Health Service. Washington,
DC:
Vital
and Health
Statistics:
Series
13 No. 82. 1983.
6. Kannel W, McNamara P, Feinleib M, Dawber T. The unrecognized myocardial infarction: fourteen-year follow-up experience in the Framingham study. Geriatrics
1970:25:75-87.
7. Gillum R. Sudden death and acute myocardial infarction in a metropolitan area. N Engl J Med
1983;309:1355-1358.
8. Wolk M, Scheidt S, Killip T. Heart failure complicating acute myocardial infarction. Circulation 1972;44:1125~1136. 9. Killip T, Kimball J. Treatment of myocardial infarction in a coronary care unit. A two year experience with 250 patients. Am J Cardiol 1967;20:457-464. 10. Jaffe A. Complications of acute myocardial infarction. Curdiol Chin 1984:2:79-94.
il. Deckers J, Fioretti P, Brewer R, Baardman T, Beelen A, Simoons M. Prediction of I-year outcome after complicated and uncomplicated myocardial infarction: Bayesian analysis of prcdischarge exercise test results in 300 patients. Am Heart
J 1987:113:90-94.
12. Crawford M, O’Rourke R. The role of cardiac catheterization in patients after myocardial infarction. Cardiol C/in 1984:2:105-l Il. 13. McHenry P. Role of exercise testing in predicting sudden death. JACC 1985;5:9B-12B.
14. Alter B, Marek M, Sperber S. Interventional therapy for the treatment of acute myocardial infarction: thrombolysis with and without angioplasty. Cardio/ C/in 1985;3:29-36.
15. Hugenholtz P, Fioretti P, Simoons M, Serruys P, Rwlandt J. Assessment for prognosis during and after myocardial infarction. Ado Cardio[ 1986;34:58-76. 16. Simoons M. Serruys P, Van Den Brand M, Res J. Early thrombolysis in acute myocardial infarction: limitation of infarct size and improved survival. JACC 1986:7:717-728.
17. Raizner A, Tortolcdo F, Verani M, Van Reet R. Intracoronary thrombolytic therapy in acute myocardial infarction: a prospective, randomized, controlled trial. Am J Cardiol 198535:301-308. 18. Rovelli F, DeVita C, Peruglio G, Lotto A, Selvini A, Tognoni G. Effectiveness of intravenous thrombolytic treatment in acute myocardial infarction. Lancef 1986;l.-397-401. 19. ISIS Steering Committee. Intravenous streptokinase given within O-4 hours of onset of myocardial infarction reduced mortality in Isis-2. Lancet 1987;1:502. 20. Braunwald E. The aggressive treatment of acute myocardial infarction. Circulation
1985;74:1087-1092.
21. Mueller H. Roberts R, Sob-e1 B. Thrombolytic therapy in acute myocardial infarction. Greenwich, Connecticut: Mason Medical Communications, 1987. 22. The TIM1 Study Group. The thrombolysis in myocardial infarction (TIMI) trial. N Engl J Med 1985:312:932-936. 23. Thrombolysis and Interventional Therapy in Acute Myocardial Infarction. New York: Biomedical
Information,
Inc. 1987.
24. Lew A, Hod H, Cercek B, Shah P, Ganz W. Mortality and morbidity rates of patients older and younger than 75 years with acute myocardial infarction treated with intravenous streptokinase. Am J Cardiol 1987;59:1-4. 25. Hull R, Raskob G, Hirsh J, Jay R, Leclerc J, Geerts W, Rosenbloom D, Sackett D. Anderson C, Harrison L, Gent M. Continuous intravenous heparin compared with intermittent subcutaneous heparin in the initial treatment of proximal-vein thrombosis. N Engl J Med 1986;315:11 J l-l 112. 26. Kannel W, Sorlie P, McNamara P. Prognosis after initial myocardial infarction. The Framingham study. Am J Cardiol 1979;44:53-59. 27. Fisch C. The role of the electrocardiogram in identifying the patient at increased risk for sudden death. JACC 1985;5:6B-88. 28. Schatzkin A, Cupples L, Heeren T, Morelock S, Kannel W. Sudden death in the Framingham heart study: differences in incidence and risk factors by sex and coronary disease status. Am J Epidemiol 1984:120:888-898. 29. Bigger J. Patients with malignant or potentially malignant ventricular arrhythmias: opportunities and limitations of drug therapy in prevention of sudden death. JACC 1985;5.238-268.
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30. Myerburg R, Kessler K, Estes D, Conde CA, Luceri R, Zaman L, Koalovskis R, Castellanos A. Long-term survival after pre-hospital cardiac arrest: analysis of outcome during an 8 year study. Circulation 1984;70:538-546. 31. Eisenberg M, Bergner L, Hallstrom A. Survivors of out-of-hospital cardiac arrest: morbidity and long-term survival. Am J Emerg Med 1984;2:189-192. 32. Scheinman M, Morady F. Invasive cardiac electrophysiologic testing: the current state of the art. Circulation 1983,67:1169-l 173. 33. Tresch D, Wetherbee J, Siegel R, Troup P, Keelan M, Olinger G, Brooks H. Long-term follow-up of survivors of pre-hospital sudden cardiac death treated with coronary bypass surgery. Am Heart J 1985;l IO:1 139-l 144. 34. Mason J. Drug therapy, amiodarone. N Engl J Med 1987;316:157-158. 35. What is angina? Julian DG, Lie KI, Wilhelmsen L, eds. In: Incidence, Prevalence, and Spontaneous Variations in Angina. Swederx A.B. Hassle, 1983. 36. Angina Pectoris. Julian D, ed. In: Epidemiology and Prognosis of Stable Angina. Edinburgh: Churchill Livingston, 1985:13-24. 37. CASS Principal Investigators and Their Associates. A randomized trial of coronary artery bypass surgery survival data. Circulation 1983,68:939-950. 38. Butman S, Olson H, Butman L. Early exercise testing after stabilization of unstable angina: correlation with coronary angiographic findings and subsequent cardiac events. Am Heart J 1986;lll:l l-18. 39. Salian R, Snyder L, Snyder B, McKay R, Lore11 B. Usefulness of percutaneous transluminal coronary angioplasty for unstable angina pectoris after non-Q wave acute myocardial infarction. Am J Cardiol 1987;59:263-266. 40. Russell R, Moraski R, Kouchoukos N, Karp R, Mantle J. Unstable angina pectoris national cooperative study group to compare surgical and medical therapy. II. In-hospital experience and initial follow-up results in patients with one, two and three vessel disease. Am J Cardiol 1978;42:839-848. 41. Giuliani E. Percutaneous transluminal coronary angioplasty. JACC 1985; 6:992-993. 42. Jacob A, Pichard A, Ohnmacht S, Lindsay J. Results of percutaneous transluminal coronary angioplasty by multiple relatively low frequency operators. Am J Cardiol
1986;57:713-716.
43. Cumberland Acta Radio1
D. The current status of percutaneous coronary angioplasty.
1985;26:497-505.
44. Meier B, Gruentzig A. Current results of coronary angioplasty-actual and future indications. Bib1 Cardiol 1985;39:25-28. 45. Wilson J, Dunn E, Wright C, Bailey W, Callard G, Melvin D, Mitts D, Will R, Flege J. The cost of simultaneous surgical standby for percutaneous transluminal coronary angioplasty. J Thorac Cardiooasc Surg 1986,91:362-370.
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46. Mabin T, Holmes D, Smith H, Vlietstra R, Reeder G, Bresnahan J, Bove A, Hammer L, Elveback L, Omzulak T. Follow-up clinical results in patients undergoing percutaneous transluminal coronary angioplasty. Circulation 1985;71:754760. 47. Leimgruber P, Roubin G, Hollman J, Cotsonis G, Meier B, Douglas J, King S, Gruentzig A. Restenosis after stressful coronary angioplasty in patients with single-vessel disease. Circulation 1986;73:710-717. 46. Gruentzig A, King S, Schlumf M, Siegenthaler W. Long-term follow-up after percutaneous transluminal coronary angioplasty. N Engl J Med 1987:316:/l 271132.
49. Williams D, Gruentzig A, Kent K, Detre K, Kelsey S, To T. Efficacy of repeat percutaneous transluminal coronary angioplasty for coronary restenosis. Am J Cardiol
1984;53:32C-35C.
50. Killip T, Ryan T. Randomized trials in coronary bypass surgery.
Circulation
1985;71:418-419.
51. Pokras R. Detailed diagnoses and procedures for patients discharged from short-stay hospitals, United States, 1985. United States Depurtment of Health and Human Services, Public tics, Hyattsuille, Maryland:
52. Lawrie disease. A 53. Myers G. Surgical Thorac
Health 1987.
Service,
National
Center/or
Health
Statis-
G, Morris G. The role of surgery in the treatment of coronary artery surgical perspective. Cardiol Series 1983,6:6-24. W, Marshtield W, Davis K, Seattle W, Foster F, Maynard C, Kaiser survival in the Coronary Artery Surgery Study (CASS) registry. Ann
Surg 1985;40:245-260.
54. Cosgrove D, Loop F, Lytle B, Gill C, Golding L, Gibson C, Stewart R, Taylor P, Goormastic M. Predictors of moperation after myocardial revascularization. J Thorac
Cardiovascular
Surg
1986,92:81
I-821.
55. Johnson W, Kayser K, Pedraza P. Angina pectoris and coronary bypass surgery: patterns of prevalence and recurrence in 3,105 consecutive patients followed up to 11 years. Am Heart J 1984;108:119t-1197. 56. Douglas J, Gruentzig A, King S, Hollman J, Ischinger T, Meier B, Carver J, Jones E, Wailer J, Bone D, Guyton R. Percutaneous transluminal coronary angioplasty in patients with prior coronary bypass surgery. JACC 1983;2;745754. 57. Finkler S. The distinction between costs and charges, Ann Intern Med 1982,96:102-109.
56. Showstack J, Rosenfeld K, Garnick D, Luft H, Schaffarzick R, Fowles J. Association of volume with outcome of coronary artery bypass graft surgery. JAMA
1987;257:785-789.
Costs of Coronary Artery in the United States
Disease
Ellison H. Wittels, MD, Joel W. Hay, PhD, and Antonio M. Gotto, Jr., MD, DPhil
A model has been developed to determine the cost of coronary artery disease (CAD) based on the 5 primary events identiied in the Framingham Study: acute myocardial infarction, angina pectoris, unstable angina pectoris, sudden death and nonsudden death. The costs for diagnostic and therapeutic service for patients wtth CAD were linked to medical decision algorithms outlining the dlagnosis and management of patients with CAD. Because CAD is a changing illness not represented by a single event, the algorithm tracked patlents for 5 years after the time of diagnosis, or until death, to develop average cost estimates. The estimated S-year costs (in 1986 United States dollars) of the 5 CAD events were: acute myocardial infarction $&211, angina pectoris $24,960, unstable angina pectoris $40,581, sudden death $9,078 and nonsudden death $19,697. The costs of major CAD surgical procedures were also cakulated because of their Impact on health care costs for patients with CAD. These inchrde: coronary artery bypass surgery per case over 5 years $32,465, and angioplasty per case over 5 years $26,916. The high cost of CAD refiects the improved technology and more effective and expensive therapies now available. (Am J Cardiol lSSOt66r432-440)
From the Department of Internal Medicine, Baylor College of Medicine, The Methodist Hospital, Houston, Texas, and the Hoover Institution, Stanford University, Stanford, California. This study was supported in part by Merck, Sharp & Dohme, Rahway, New Jersey.The views presented are solely the views of the authors. Manuscript received January 12, 1989; revised manuscript received and accepted October 23, 1989. Address for reprints: Antonio M. Gotto, Jr., MD, 6535 Fannin, Mail Station A 601, Houston, Texas 77030. Requestsfor the Appendix should be sent to Ellison H. Wittel, MD, The Methodist Hospital, 6565 Fannin, Houston, Texas 77030.
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vv
rth United States health care costs currently exceeding $500 billion annually, there is increased interest in the determinants of expenditures. There has been little research into the total or lifetime cost of medical care for patients with coronary artery disease (CAD), although it represents a leading cause of health care expenditures. We have compiled cost figures and developed medical decision algorithms based on the diagnostic and therapeutic options and probable outcomes for the 5 primary CAD events examined in the Framingham Study. These include acute myocardial infarction (AMI), angina pectoris, unstable angina pectoris, sudden death and nonsudden death.’ We then used these algorithms to estimate the cost of CAD medical care for 5 years after diagnosis, or until death, whichever was earlier. In general, the cost was calculated by multiplying the expected frequency of the test or treatment by its price. The estimated costs often were substantially different from those previously reporte4l,2J in part because the use of medical algorithms and assessment of costs over 5 years allowed a more complete analysis of CAD expenses. This article is not intended to be a review of the efficacy or indications for specific procedures or tests, but rather an analysis of current CAD costs based on data from medical facilities with significant experience in CAD diagnosis and treatment. METHODS In developing a medical cost model, we reviewed the literature on initial CAD events as defined in the Framingham Study, and on the cost and outcome of coronary bypass surgery, thrombolytic therapy and angioplasty. Because of differences in study design, geographic regions and populations, it was difficult to consolidate published study results. Therefore, a group of knowledgeable cardiologists who represented different geographic regions of the US were selected as a consultant panel. The cardiologists generally validated the therapeutic options, projected outcomes and prices that were used. From the collected data, medical decision algorithms were developed to show expected therapies and outcomes for each CAD event. Our decision algorithms are detailed in an Appendix, available upon request. To estimate costs for each decision made in the CAD treatment algorithms, prices for approximately 70 different procedures, hospital services, medications, laboratory tests, diagnostic services and other medical services were obtained from 3 main sources that will be discussed. All prices used in our model are presented in 1986 US dollars. (A detailed list of specific tests, proce-
TABLE
I Abbreviated
List of Prices
Used
Disease
Model:
Cost
US Dollars
Annual
in 1986
in Coronary
Item
Price
AMI hospitalization Ambulance Blood sugar test CCU daily average charges Chest x-ray (2 views) Complete blood count Echocardiogram Electrocardiogram and interpretation Electrolytes Holter monitor ICU daily average charges MD outpatient visit Nineteen chemistry tests Nuclear ventricular study PTCA physrcian fee Regular care bed per diem Three chemistry tests Treadmill Urinalysis
4,134 70 7 1,120 62 8 139 49 8 285 970 47 22 700 1,412 511 3 198 6
TABLE
Heart
II Expected
Complications (8)
Cost
of Myocardial
Infarction
(in $)
Extension of infarction Congestive heart failure Pulmonary edema Cardiac arrest Cardiogenic shock therapy Medical therapy Medical therapy and aortic balloon Aortic balloon and bypass surgery Angioplasty Permanent pacemaker Temporary pacemaker
Source Houston Houston HCFA Houston Houston HCFA Houston HCFA HCFA Houston Houston HCFA HCFA Houston Houston Houston HCFA Houston HCFA
dures and medications used in each coronary event algorithm is available as part of the Appendix.) In 1985, the Health Care Financing Administration (HCFA) maintained a list of national average prices for 110 high-frequency physician services paid by Medicare. HCFA did not update this list in 1986. For all CAD medical services identified in our decision algorithms and found on this list, HCFA national average prices were used. Most drug prices were obtained from 1986 pharmaceutical price surveys from IMS America, a data resource group (Plymouth Meeting, Pennsylvania). For each category of medication (e.g., diuretics, fl blockers, angiotensin-converting enzyme inhibitors) average daily consumption and retail prices for the largest selling medication in that category were used to compute the average medication costs per patient. All other medical prices were obtained from Houston area surveys. Both HCFA and Houston hospital prices were generally considered similar to, or lower than, those prevailing in the panelists’ locales. For this reason, and because of the relatively high rate of medical inflation, the prices we have used are conservative. Table I provides a list of some of the key prices used in the analysis. A detailed pricing list is available in the Appendix. RESULTS Acute myocardial infarction: In the US, approximately 1.5 million people have an acute myocardial infarction (AMI) yearly.4 In 1983, 676,000 primary discharge diagnoses from nonfederal, short-term hospitals were for AMI. Not all cases resulted in hospitalization4,(j mostly because of sudden death and unrecognized AMI. While the Framingham Study calculated the risks of AM1 for both recognized (hospitalized) and
68 323 135 161 40 36
TABLE
III
Therapy
After Myocardial
Condition
W)
Added Expected Cost for Acute Myocardial Infarction ($)
No treatment Angina pectons Congestrve heart failure Reinfarction Death
15 35 14
4,863 1,406
25 30
7.123 2,033
Five-Year
Outcome
Receiving
of Patients
Medical
Infarction
Prevalence
AMI = acute myocardial infarction; CCU = coronary care unit: HCFA = Health Care Financing Administration; ICU = intensive care unit. PTCA = percutaneous translumlnal coronary angioplasty.
2,151 900 392 242
0.00
r
TABLE IV Framingham Five-Year
Coronary Artery Total Cost per Case
Expected
Acute myocardial infarction Angina pectoris Unstable angina pectoris Sudden death Nonsudden death
TABLE V Coronary Expected
Total
Artery Disease Cost per Case ($)
Disease
Events:
Average
Cost ($)
51,211 24,980 40,581 9,078 19,697
Procedures:
Five-Year
unrecognized (not hospitalized) AMI, we have considered only patients who were hospitalized with a recognized AMI. The costs for those who died from an AM1 and were either not brought to the hospital or died in the emergency room are considered in the section on sudden death. The costs for patients who died in the hospital after admission for an AM1 are reviewed in the section on nonsudden death. The AM1 patients considered in this section have been defined as those who were admitted and survived hospitalization. Figures 1, 2 and 3 diagram our decision algorithm. Tables II, III, IV and V list some of the specific costs of these algorithms. In 1980, the average total length of hospitalization for an AMI was 12.9 days. Patients who were subsequently discharged were in the hospital an average of 14 days, while those who died after admission were in the hospital an average 8.5 days.7 By 1983, the length of hospitalization for AM1 had decreased to approximately 11 days.5 We used 10 days as the average length of
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stay. Change in the length of hospitalization alters the cost of AMI. A decrease of 1 day in regular care lowered the expected average cost of AM1 by $5 11. Emergency room care and hospitalization in the coronary care unit for 3 days, intermediate care for 4 days and regular care for 3 days, plus inpatient cardiac rehabilitation, laboratory fees and medications added $13,670 to the expected cost of AMI. COMPLICATIONS OF INFARCTION: Approximately 60% of patients hospitalized with an AM1 experienced complications. Cardiac arrhythmias, varying degrees of left ventricular failure and continued chest pain often resulted in a more prolonged hospital course.8-io While complications from AM1 continue to be a cause of concern and extensive study by clinicians, they contributed little to the total expected cost of AMI, because of the relatively small number of patients who suffered significant costly complications (Table II). The greatest single Recognized Sudden
Unrecognized
AMI
AMI
Death
Emergency
Room J Risk Stratification
/ Medical Treatment Cardiac Surgery Angioplasty 1 Cardiac Rehabilitation No Cardiac Rehabilitation Long-Term
+
added expected cost was $2,151 for extension of an AMI, which is estimated to occur in 7% of patients. RISKSTRATIFICATION FOR INFARCTION: Holter monitoring, treadmill testing and cardiac catheterization have been used in recent years to assess the risk of future cardiac events occurring in postinfarction patients (Figure 2). Holter monitoring has been used to detect arrhythmias and both symptomatic and silent myocardial ischemia. The consultant panel estimates varied widely in the estimate of the use of Holter monitors in AM1 patients; the range was 20 to 100%. We used a 50% rate in our base case analysis. An exercise treadmill test was performed on 75% of patients either before discharge or within 6 weeks of hospitalization.* l-l3 We estimated that 60% of tests were nuclear exercise and 40% were non-nuclear exercise testing. For the AM1 patient, Holter monitoring and exercise testing added $1,7 18 to the average cost of AMI. The price of an outpatient cardiac rehabilitation was $2,430 per patient. Because only 15% of patients who had an AM1 participated, outpatient cardiac rehabilitation added a small amount to the average cost of AMI. At the initial hospitalization or within 3 months, 30% of patients who survived a recognized infarction and had not received thrombolytic therapy had heart catheterization, which added $847 to the average AM1 cost. Among these patients, 25% had coronary bypass surgery (adding $2,191 to the average cost), 33% had angioplasty (adding $2,398 to the average cost) and 42% received medical therapy (adding $860 to the average cost). THROMBOLYTIC THERAPY: Coronary thrombosis has been reported in 70 to 90% of patients with AMI.14 Successful thrombolytic therapy can limit infarct size, preserve left ventricular function and reduce hospital mortality.15-*7 The successof thrombolytic therapy with streptokinase was related to the elapsed time between the onset of AM1 and the initiation of therapy. If >6 hours elapsed between the AM1 and thrombolytic ther-
Follow-up Traditional
Thrombolytic
Care
+ ICU Holter Monitoring
+ Intermediate
Cardiac Catheterization
Treadmill
Regular
+
Therapy
Streptokinase - intravenous Streptokinase . intracoronary Tissue Plasminogen Activator
Care
J
Care
I
Pylj~~~~,
Open
Non-perfuset
+ Risk Stratification \No;:i;;r
/ \t
Cathe!erization
1
No Catheterization Risk
Stratification
Medical
/ Treatment
Medical
+ Treatment
Or Medical
Treatment + Follow-up
Surgical
Treatment # Follow-up
Surgical
Angioplasty
Treatment Or
+ Follow-up
Angioplasty I
FIGURE 2. DsicMonalgorithm*Holter~,treadmifi orcadac--ofpostfnfdonpatients. 434
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3. De&ion
dpithms
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for tradiliod
care versus
apy, then the effect of thrombolysis on mortality was significantly blunted. I8 Because the onset of the AM1 was >4 hours among most patients who presented to the hospital emergency room,19 we estimated that only 25% of patients were candidates for thrombolytic therapy, and 75% received traditional care for their AMI. Streptokinase thrombolytic therapy can be given by either the intracoronary or intravenous route to patients with an AM1 (Figure 3). Because intracoronary thrombolytic therapy required a readily available cardiac catheterization facility and trained personnel,20 10% of patients received intracoronary thrombolytic therapy and 90% received intravenous streptokinase. Seventy-five percent of patients who received intracoronary streptokinase and 50% who received intravenous streptokinase were successfully reperfused.21 A 20% reocclusion rate for intravenous streptokinase and a 17% reocclusion rate for intracoronary streptokinase were used in the algorithm. Tissue plasminogen activator, a naturally occurring human protein capable of inducing clot lysis,22,23was recently approved by the Food and Drug Administration. Intravenous tissue plasminogen activator with a reperfusion rate of 75% has appeared as effective as intracoronary streptokinase.23 Among patients successfully reperfused, 50% had angioplasty, 25% bypass surgery and 25% medical therapy. For patients not successfully reperfused, 42% received medical therapy, 25% bypass surgery and 33% angioplasty. Among patients younger than 75 years of age who received thrombolytic therapy followed by heparin, 11% had significant bleeding problems.24 Bleeding complications were reported in 7% of patients who received intravenous heparin in an amount sufficient to keep the partial thromboplastin time 2 times the control value.25 Bleeding complications from the use of streptokinase and heparin added only $31.50 to the average AM1 cost. The 5-year cost of thrombolytic therapy included the costs of the increased number of heart catheterizations, angioplasties and bypass surgeries for these patients compared to patients who received traditional care for AMI. If all patients who received thrombolytic therapy were given only streptokinase, an average of $4,197 was added to the expected cost of an AMI. The price of streptokinase was $220 per patient. If only tissue plasminogen activator therapy was used as the thrombolytic therapy, $4,733 was added to the expected cost of AMI. The price of the medication was $2,200 per patient treated. OUTCOME AFTER INFARCTION: The Framingham Study’s 5-year follow-up of men and women who had an initial AM1 and were taking medical therapy26 (Table III) was used to predict the incidence of medical events. We estimated that 92% of treated patients would be alive at 1 year and that the 5-year results among patients who received coronary bypass or angioplasty would be identical to those who had not had a previous AMI. The cost of medical therapy per patient for 5 years added $3,865 to the expected AM1 cost. In our study, the expected total cost over 5 years for a patient hospitalized with AM1 was $51,211.
Nonsudden death: Approximately 10% of the patients admitted with a diagnosis of AM1 died in the hospital. By the Framingham Study definition, they comprised the nonsudden death group. The expected cost for nonsudden death was $139 for the emergency room plus $13,254 for the hospitalization. The average length of hospitalization for those who died was 8.3 days.’ Compared to other AM1 patients, the cost of the shorter hospitalization was offset by the cost of resuscitation. Sudden death and sudden death resuscitated: In the US, 650,000 people die yearly from CAD, with sudden death accounting for 50% of deaths.4,27 We used the Framingham Study definition of a l-hour time period between the change from a stable clinical status to death.’ Among those resuscitated from sudden death, 90% had underlying CAD. 28,29Figure 4 gives an overview of the algorithm for sudden death. It has been predicted that 25 to 30% of those who suffered sudden death could be resuscitated and eventually discharged alive from the hospital. 30,31Our algorithm was more conservative. Of 100 patients with sudden death, 68 died outside the hospital and were taken to a funeral home. Of the 32 patients transported to the hospital by ambulance, 26 patients were successfully stabilized and hospitalized. Among the 26 patients hospitalized after successful resuscitation, 5 were assumed to have died in the hospital, while 21 were discharged alive. The cost of the ambulance, emergency room and hospitalization, including 3 days in the coronary care unit, 5 days in intermediate care and 4 days in regular care, added $2,840 to the expected cost of sudden death. Approximately 10 to 15% of patients resuscitated after sudden death and ultimately discharged from the hospital are left with significant morbidity.3’ The cost of care for those who did not fully recover was not included in this study. For patients who survived cardiac arrest, cardiac catheterization and electrophysiologic test-
Sudden
Death L
Hospital 1/l DOA
Resuscitation
Altempted t
Expired Emergency
\ Room AAdrn{“”
Discharged
MO?..,,
HAdmitted -coronary
Cath-Electrophysiology t P&d-Treatment ’ Supressed I MedikM
Study
>on-suppressed
Follow-up
d
I\
NO Amiodarone + Fall&-UP
FIGURE
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I Anti-arrythmia
4. Algorithm JOURNAL
Amiodarone
L
Non-sudden
Fle::::ed
Bypass surgery t t Die Live t Electrophysiology Study t/ 1 No Treatment Treatment
surgery \r, Live\ Follow-up
for sudden OF CARDIOLOGY
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ing have been recommended.32 The 15% with significant morbidity had two 24-hour Holter monitors, and subsequently were given antiarrhythmic therapy. The remaining 85% of patients had heart catheterization, adding $575 to the expected cost of sudden death, and an electrophysiologic study, adding $344 to the expected cost of sudden death. Forty percent of the resuscitated patients who were catheterized had coronary bypass surgery, with a survival rate of 92%, which added $2,532 to the total cost. Patients who survived the initial surgery had a second electrophysiologic study, which added an additional $138 to the cost of sudden death. Approximately twothirds of these patients also required antiarrhythmic therapy, which added over 5 years $190 per case to the average cost of sudden death. Seventy-two percent of these patients lived for at least 5 years after bypass.33 Sixty percent of the patients who had catheterization and an electrophysiologic study after resuscitation from sudden death were treated medically. The 5-year expected cost per patient treated medically was $2,059. This cost included a follow-up electrophysiologic study to judge the effectiveness of the antiarrhythmic medication, plus additional testing and therapy. Among patients treated with antiarrhythmic therapy, only 26% experienced adequate suppression of their arrhythmias based on a follow-up electrophysiologic study.32 Approximately 10% of patients not adequately suppressed underwent antiarrhythmic surgery, which had an expected cost of $28,600 per case. Overall, because only about 1% of the total number of patients who were resuscitated after sudden death had this surgery, it added only $1,747 to the average expected cost of sudden death. Patients who were neither candidates for antiarrhythmic surgery nor adequately suppressed on antiarrhythmic therapy were given amiodarone, with a 50% successful suppression rate.34 However, after 2 years, amiodarone was discontinued in 20% of these patients because of drug toxicity. If all patients not treated surgically or suppressed on other antiarrhythmics were giv-
en amiodarone, it would add $449 to the average cost of sudden death over 5 years. Among patients resuscitated from out-of-hospital cardiac arrest who survived the initial hospitalization, the 4-year mortality ranged from 25 to 50%.3’ Overall, the average total cost per case of sudden death/sudden death resuscitated was $9,078 over a 5-year period. Angina pectoris: Approximately 5 million people in the US have angina pectoris or a history of a previous AMI. In 1983, angina pectoris was the primary diagnosis listed for 278,000 hospital discharges, and ao counted for 1,488,OOO hospital days.5 One difficulty in evaluating the prevalence of angina in the population is that it may fluctuate in intensity in the individual patient. A patient who at 1 examination had typical angina pectoris could be free of symptoms at a subsequent examination.35 During the first 8 biennial examinations in the Framingham Study, 32% of men and 44% of women had transient or nonpersistent angina. Over a 5-year period, one-half of patients with angina were assumed hospitalized for an average of 6 days because of cardiovascular disease.36The cumulative survival of patients with CAD receiving medical management was reported to be affected by the presence of left main coronary disease, left ventricular function and patient age. For patients with l- and 3-vessel CAD, the 4year survival rate was 92 and 68%, respectively. Over a 5-year period, 40% of patients with angina pectoris had heart catheterization. Catheterization added $1,255 to the expected cost of angina pectoris. The 1975 to 1979 Coronary Artery Surgery Study reported that about 5% of patients with angina pectoris had surgical intervention annually.37 This number should decrease as more patients have angioplasty. Among the patients catheterized, 25% had angioplasty, for an additional expenditure of $2,688, 50% had coronary bypass surgery, adding $6,493, and 25% continued to receive medical therapy. Among the 60% of patients in our study who did not have heart catheterization, 40% were not receiving consistent treatment for angina and no cost was ascribed.
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The remaining 60% were taking regular daily therapy for angina, adding $4,317 to the expected angina pectoris cost. In addition, approximately 20% of medically treated patients had an AM1 during the 5 years, prompting an additional $4,091 expenditure. The total cost for each case of angina pectoris over 5 years was $24,980. Unstable angina pectoris: In 1983, 130,000 hospital discharges listed unstable angina as the primary diagnosis.5 In reality, this figure was probably larger. It is often difficult to separate unstable angina from an AMI. It is also likely that many of the hospitalizations for angina pectoris were actually for unstable angina. Patients admitted with unstable angina pectoris were in the coronary care unit for 2 days, intermediate care unit for 3 days and regular care unit for 2 days. The cost of hospitalization, including medication and noninvasive testing, added $8,093 to the expected unstable angina cost. Because of the potential for infarction or sudden death, about 90% of unstable angina patients had heart catheterization during the initial hospitalization. Heart catheterization added $2,823 to the expected cost of unstable angina. The remaining patients who did not have cardiac catheterization were given medical therapy, adding $1,169 to the cost over 5 years. The number not catheterized may increase in the future with the use of early exercise testing.38 Approximately 35% of patients diagnosed with unstable angina pectoris had coronary bypass surgery within a few weeks, with a surgical mortality rate of 4%. This surgery added an additional $9,238 to the expected cost of unstable angina. At the end of 1 year, 95% of the patients were alive, and 13% had had an AMI. An AM1 after bypass surgery added $2,097 to the expected cost. The 4-year surgical survival rate was 88%. Forty percent with unstable angina pectoris who had heart catheterization had angioplasty. The consultant panel generally felt that angioplasty would be used with increased frequency in patients with unstable angina.39 Angioplasty increased the average cost of unstable angina by $9,690. Twenty-five percent of those catheterized received medical therapy, for an added cost of $2,526. For this group, the survival rate was 93% after 1 year and at 5 years was 87%.40 Ten percent of patients had an AM1 during year 1. An additional $1,152 was added by AM1 that occurred during the 5-year follow-up. Over a period of 30 months, approximately 36% of those who were initially treated medically required bypass surgery,40 adding $3,799 to the expected cost of unstable angina. From the available data, we have used only the first year AM1 incidence rate after coronary bypass. Altogether, the average cost for unstable angina per case over 5 years was $40,581. AN~~IOPLASTYFOR ANGINA PECTORIS: Percutaneous transluminal coronary angioplasty was initially introduced in 1977 by Gruentzig for the treatment of a proximal stenosis in 1 of the 3 main coronary vessels. Subsequently, the indications for angioplasty have been extended.41 Angioplasty for CAD was initially successful 85% of the time, with 90% of the patients having no or de-
creased angina, and 10% unchanged. When angioplasty was used to treat angina pectoris, the average length of hospitalization was 2 days. The patients had heart catheterization at the time of angioplasty and were monitored for 4 hours. Successful angioplasty, including preangioplasty exercise testing, hospitalization and medication, had an expected cost of $6,706. The 5-year medical follow-up among those with successful angioplasty, including annual exercise testing and medication, added $5,381 to the expected cost of angioplasty. As experience with angioplasty has increased, the complication rate has decreased.42 We report figures from medical facilities with experience in angioplasty. Angioplasty failed in 15% of the cases. The failures reflected a 1% overall mortality rate,41 an AM1 rate of 2.5%43,44and a 14% emergency coronary bypass surgery rate, usually for coronary artery occlusion or coronary artery dissection. 41 These complications added $2,579 to the average cost of angioplasty. Surgical standby for angioplasty has been considered essential.45 Patients in whom angioplasty was not successful had coronary bypass surgery or continued medical treatment,46 adding $1,966 to the expected angioplasty cost. Among patients who had successful angioplasty, 40% had recatheterization, usually within 6 months because of either recurrent angina or a suspicion of restenosis. Among patients who had angioplasty for angina, the reported rate of restenosis at 6 months has ranged between 17 and 47%.41 We have used a restenosis rate of 30%.48 The rate of restenosis without symptoms of angina was reported to be 30%.46 Among patients with detected restenosis, we estimated that 65% had repeat angioplasty, 20% coronary bypass surgery and 15% medical therapy. With repeat angioplasty, there was an 85% successrate.49 The cost of the evaluation, including treadmill testing, catheterization and subsequent treatment with either medical therapy, repeat angioplasty or coronary bypass surgery, added $7,664 to the expected cost of angioplasty. We assumed a 15% restenosis rate over the next 5 years.48 Among those with late stenosis, 30% had bypass surgery, 60% angioplasty and 10% medical treatment. This did not include patients who had progression of disease in vessels not originally treated by angioplasty. Over a 5-year period, the average cost of angioplasty for angina pectoris was $26,916 per case. CORONARY
ARTERY
BYPASSSURGERY:COrOllary
al-tel'y
bypass surgery is an effective therapy to improve myocardial blood flow in selected patients with CAD,5o and the number of coronary heart bypass grafts has increased markedly. In 1971, 24,000 such surgeries were performed. In 1985, over 230,000 coronary artery bypass surgeries were performed.51 The reported length of hospitalization for coronary bypass surgery has varied. Readmissions, especially in the first year for postoperative surgical problems, raised the average number of hospital days per surgical case. The consultant panel believed that the length of hospitalization after surgery had decreased; we used 10 hospital days for each surgical case. Preoperative care and preoperative catheterization were not included in the cost.
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Coronary artery bypass surgical mortality has been related to factors such as patient age and status of the left ventricle.52 This algorithm used the Coronary Artery Surgery Study registry with a surgical mortality rate of 2.4%.53 By 6 months after surgery, approximately 16% of grafts were occluded, thereafter, the annual occlusion rate was about 1%.52 By 5 years, about 3% of patients had repeat coronary artery bypass surgery. By 10 years 11.4%, and by 12 years, 17.3% of the patients had repeat coronary bypass surgery.54 Compared to their preoperative symptoms, by 1 year after surgery, about 87% of patients had no angina pectoris, 10% had less angina and 3% were symptomatically unchanged. By 5 years, while about 90% of patients who had bypass surgery survived, 50% had angina pectoris.55 Patients who had recurrent angina pectoris after coronary bypass surgery added $3,588 to the average cc& of bypass surgery. If angina pectoris did not recur in the 5 years after surgery, follow-up testing and medication added $2,218 to the cost of bypass surgery. Over 5 years, the cost of repeat bypass surgery or angioplasty on occluded grafts added $1,09 1 to the expected cost of coronary bypass surgery. The percentage of patients with stenosed bypass grafts for whom angioplasty is appropriate is uncertain. Excellent successhas been reported for those who have angioplasty for occluded grafts5’j The use of angioplasty rather than repeat bypass surgery will affect the cost of bypass surgery. Overall, the average cost per case for bypass surgery over 5 years was $32,465.
and therapeutic intervention. Because of this, it is important to assessthe cost of CAD therapy over a significant period of time subsequent to the initial diagnosis. The costs included subsequent CAD events expected to occur within this time interval, adjusted for diagnosisspecific 5-year average survival probabilities. Because of continuing rapid changes in medical treatment, we did not project medical costs beyond 5 years of treatment. The reported cost was determined by multiplying the price of the expected therapy or test by the probability of occurrence for each therapy or test over the ensuing 5 years. An expensive but infrequent complication or treatment could add less to the average cost of an AM1 than less expensive but more frequently performed tests or treatments. Surgery for intractable cardiac arrhythmias among sudden death survivors had a price of $28,600; however, because of the relatively small percent who required the surgery, it added only $175 to the expected average cost of sudden death. Alternatively, unstable angina costs averaged $40,58 1 per patient over 5 years. The high cost reflected the high percent of patients who had expensive diagnostic testing and therapeutic intervention. The frequent use of angioplasty and bypass surgery added $18,928 to the average cost of unstable angina. While most medications and diagnostic tests for patients with angina pectoris were relatively inexpensive, over 5 years medical treatment added $10,634 to the expected cost of angina pectoris ($4,317 for medication and testing plus $6,317 for the cost of AMIs among the medically treated group). Medical treatment was provided to a total of 46% of patients with angina. Bypass DISCUSSION surgery added $7,746 ($1,255 for catheterization plus There is no systematic data collection source in this $6,493 for surgery) to the average cost, and was used to country that allows comprehensive, nationally represen- treat 20% of patients with angina. Although medical tative, CAD medical cost information to be obtained. therapy and bypass surgery contributed approximately We developed a cost model based on published findings the same to the total cost of angina pectoris, over twice and the consultant panel’s consensus regarding appro- as many patients received medical therapy. priate treatment and expected outcome for patients with Many tests may have little impact on the cost of CAD. We beiieve this model is generally more applica- CAD. The consultant panel suggested a wide range for ble to all sections of the country than data collected the use of Holter monitoring among patients with refrom a specific patient sample. While not attempting to cent AMI. Although it is an important therapeutic decidefine “ideal” treatment and outcome, the model does sion, Holter monitoring had only a small impact on the cost of the AM1 patient. Whether an AM1 patient had reflect current appropriate therapy and documented outcomes. Holter monitoring or not, the average net change in cost While we recognize that there is a distinction be- for an AM1 patient would be $157. tween prices (charges) and real economic resources,57 Sudden death is the least expensive of the 5 Frawe did not attempt to adjust prices to actual economic mingham coronary events. It cost $9,078, which is still a cost levels. Our cost analysis more appropriately reflects surprisingly large sum of money. While the increased what a patient or insurer would pay for medical ser- emphasis on resuscitation and rapid transportation of vices, rather than the economic costs to hospitals, physi- patients to the hospital has saved many lives, it has incians and other providers to produce these services. creased the cost of sudden death and sudden death reThis review has focused on CAD medical costs for suscitated. The percentage of patients who several years each of the 5 Framingham events, plus coronary artery ago would have been pronounced dead outside the hosbypass surgery, thrombolytic therapy and angioplasty, pital has decreased; those pronounced dead in the emerfor both the initial presentation and the 5 following gency room where resuscitation is attempted has inyears. Therefore, these costs are not estimates of the creased. Patients successfully resuscitated have a signifitotal expected lifetime costs of CAD. CAD is neither a cant number of sophisticated studies, and may have stable single event nor a static phenomenon. Effective coronary bypass surgery or surgery for the treatment of long-term treatment requires ongoing diagnostic testing arrhythmias.
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An example of a therapeutic advance that has also increased the cost of AM1 is thrombolytic therapy. Tissue plasminogen activator added $4,733 to the expected cost of an AMI, while streptokinase added $4,197. Tissue plasminogen activator was $2,000 more expensive than streptokinase; however, it added only $566 to the expected cost of an AMI. Therapy with thrombolytic agents resulted in more survivals and higher health care costs because thrombolytic therapy patients had relatively more heart catheterizations, angioplasties and bypass surgeries. Another therapy that offered less cost savings than anticipated was angioplasty. While not disputing the medical role of angioplasty, this analysis casts doubt on whether angioplasty will substantially decrease the cost of medical care. In our algorithm, the 5-year cost of angioplasty ($26,916) was only 17% less than the cost of coronary artery bypass surgery ($32,465). Kelly et al3 reported a 43% lower cost over 1 year of angioplasty compared to coronary surgery among patients with l-vessel disease. In the Coronary Artery Surgery Study, 27% of patients with angina pectoris who underwent surgery had l-vessel disease.” The cost of coronary bypass surgery accounted for $6,493 of the expected cost of angina pectoris. If we assume that angioplasty was done on every patient with l-vessel disease, using Kelly’s data the amount saved would be 43% of 27% of $6,493 or $779. This is a small amount compared to the expected total cost of angina pectoris: $24,980 per patient. Therefore, even if there were a significant difference in cost between angioplasty and coronary bypass surgery, greater use of angioplasty would have little effect on the overall expected cost of angina pectoris among patients with l-vessel disease. While the initial cost of successful angioplasty was less than that of bypass surgery, the treatment of restenosis, testing and medication over the following 5 years ($9,067) significantly added to the total cost of angioplasty. We believe that the 5-year cost reflected a more accurate estimate of the effect of angioplasty on CAD treatment costs. We have not evaluated the economic impact of quality variations reported in the outcome of CAD therapy, or focused on such issues as the relation of outcome to the volume of bypass surgery performeds8 or physician experience with angioplasty outcome.42 Our analysis shows that the major reason for the increased cost of CAD has been the ability to intervene acutely in patients with CAD with new technologies and new therapies, such as thrombolytic therapy and coronary bypass surgery. These new therapies have contributed to the decrease in CAD mortality, improved the quality of life of CAD patients, increased the number of patients who survived a Framingham event and allowed more people to live longer. We expect newer treatment and technology to continue to increase the cost of CAD. It is apparent that recent innovations in restorative therapy for CAD have substantially increased average medical costs per patient.
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