ORIGINAL ARTICLE
Prediction of success and major complications during elective coronary angioplasty: a prospective analysis of 2365 procedures A.P. Haasdijk', M.J. de Boer', H. Suryapranata', J.C.A. Hoornte', F. Zijlstral
Background. Complications from coronary angioplasty remain a concern despite improvements in technology and operator's skills. Identification of high-risk patients is important with regard to surgical standby and other precautions that have to be taken for such patients. Methods. Prior to elective coronary angioplasty, the probability of success and the risk of complications were estimated on the basis of angiographic and clinical characteristics. A total of2365 consecutive elective procedures were evaluated. Estimates for success and complications were classified into three categories: high, intermediate or low probability. Results. Angioplasty success was achieved in 1025 of 1056 (97%) procedures with high success probability; in 833 of 914 (91%) with intermediate success probability and 304 of 395 (77%) with low success probability. Complications occurred in five of 271 (2%) procedures with an anticipated low risk of complications, in 72 of 1973 (4%) procedures with a intermediate risk and in 13 of 121 (11%) procedures with a high risk ofcomplications. Out of a total of 28, 22 (80%) surgical bypass procedures were performed in the intermediate anticipated risk category. Conclusions. For groups of patients, reliable prediction of success and complications is possible. However, most emergency bypass surgery after failed angioplasty is performed in patients with a predicted intermediate risk ofcomplications. Inter-
A.P. Haasdljk. M.J. de Boer. H. Suryapranata. J.C.A. Hoomtje. F. ZlJlstra. IDepartment of Cardiology, Isala Clinics, Weezenlanden location, Groot Wezenland 20, 8011 JWZwolle. Address for correspondence: F. Zijlstra. E-mail: [email protected]
10
ventional cardiologists are not able to identify in advance the majority of patients who will need surgery for failed angioplasty. (Neth Heart J 2001; 9:10-15.)
Key words: coronary heart disease, coronary angioplasty, coronary bypass surgery Since the introduction of percutaneous transluminal coronary angioplasty (PTCA) by Gruentzig in 1977,1 PTCA has become a standard therapy for stable angina in patients with single-vessel disease. An increasing number of patients with unstable ischaemic syndromes, multivessel disease, and impaired left ventricular function are nowadays also considered candidates for PTCA.2 Despite technological improvements and increased operator skills, a percentage of complications still remains, ranging from 1 to 7%, depending on the definition used. These complications can be related to lesion-specific as well as to patient-specific characteristics.
The American College ofCardiology/American Heart Association (ACC/AHA) Task Force classification scheme categorises lesions into types A, B and C and was developed to classify patients based on lesionspecific characteristics in categories of high probability of success and low risk ofcomplications, intermediate probability of success and intermediate risk, and low probability of success and high risk of complications respectively (table 1).3 Many studies regarding success and complication rates in patients classified according to this scheme showed results outside the range ofthis classification.4-12 Furthermore, most studies regarding success rates and complications have been performed on a retrospective basis, and prospective assessments or evaluations have been scarce.'3 Therefore, in 1991 we started a prospective evaluation of success rates and complications in all patients undergoing elective PTCA in our institution.
Netherlands Heart Joumal, Volume 9, Number 1, April 2001
Prediction of success and major complications during elective coronary angioplasty: a prospective analysis of 2365 procedures
Table 1. Characteristics of lesions. 'Type A lesions (high success, >85%; low risk)' - Discrete (3 months old - Inability to protect major side branches - Degenerated vein grafts with friable lesions
Methods Between April 1991 and January 1994, 2365 consecutive elective coronary angioplasties were performed in 2096 patients at Weezenlanden Hospital. Patients had to be free of symptoms and signs of myocardial ischaemia during the 24 hours preceding the angioplasty procedure. No patients were excluded for other reasons.
Prior to elective coronary angioplasty, the probability of success and complications were estimated on the basis of angiographic as well as clinical characteristics by two experienced interventional cardiologists. Both the estimated complication risk and the probability of success were classified into three categories: low, intermediate or high probability. Predefined low risk means a 95 High Intermediate 80-95 Low 50% DS) (%) 1 60 2 or 3 40 Unstable angina (%) 56 DS=diameter stenosis; LV= left ventricular; Ml=myocardial infarction.
80 and 95% and finally a low probability is less than 80% (table 2). Success was defined as an uncomplicated procedure with a residual stenosis of less than 50% and a TIMI (Thrombolysis in Myocardial Infarction) 3 flow after the procedure.'4 Complications were defined as death, emergency bypass surgery and acute myocardial infarction during in-hospital stay. Myocardial infarction was diagnosed if at least two of three factors were present: typical chest pain lasting more than 30 minutes, and/or ST-elevations or ischaemic changes on the electrocardiogram or the development of pathological Q waves and/or an enzyme profile reflecting myocardial infarction defined as an elevation of creatinine kinase to more than two times the upper level ofthe normal value. The study protocol was seen and approved by our institutional review board. Statistical analysis Data were reported in absolute values as well as percentages, or as mean and standard deviation (SD) when appropriate. Chi-square analyses were used to test the differences in categorical variables and unpaired Student's t tests were used to assess differences in continuous variables. All calculated p values are twotailed. A p value ofless than 0.05 was considered significant. Results Baseline characteristics of the 2365 procedures are listed in table 3. These 2365 consecutive elective cor11
Prediction of success and major complications during elective coronary angioplasty: a prospective analysis of 2365 procedures
Table 4. Observed success rates for estimated success by estimated risk of complications.
Estimated risk of complications Estimated success % High [>95%] Medium [80 - 95%] Low [10hJ] (%)
10.4 12.0 10.7
10/96 3/25 13/121
The number of complicated procedures versus the total number of procedures in each category for combinations of estimated success and risk of complications is expressed in small italics.
onary angioplasties were performed in 2096 patients. The observed success rates in comparison with the preprocedural assessments are listed in table 4 including a subdivision into the various risk categories. For high (>95%) success probability 1025 out of 1056 (97.1%) procedures were carried out successfully, for intermediate (80-95%) success probability 833 out of914 (91.1%) procedures were carried out successfully and for low (
Prediction of success and major complications during elective coronary angioplasty: a prospective analysis of 2365 procedures A.P. Haasdijk', M.J. de Boer', H. Suryapranata', J.C.A. Hoornte', F. Zijlstral
Background. Complications from coronary angioplasty remain a concern despite improvements in technology and operator's skills. Identification of high-risk patients is important with regard to surgical standby and other precautions that have to be taken for such patients. Methods. Prior to elective coronary angioplasty, the probability of success and the risk of complications were estimated on the basis of angiographic and clinical characteristics. A total of2365 consecutive elective procedures were evaluated. Estimates for success and complications were classified into three categories: high, intermediate or low probability. Results. Angioplasty success was achieved in 1025 of 1056 (97%) procedures with high success probability; in 833 of 914 (91%) with intermediate success probability and 304 of 395 (77%) with low success probability. Complications occurred in five of 271 (2%) procedures with an anticipated low risk of complications, in 72 of 1973 (4%) procedures with a intermediate risk and in 13 of 121 (11%) procedures with a high risk ofcomplications. Out of a total of 28, 22 (80%) surgical bypass procedures were performed in the intermediate anticipated risk category. Conclusions. For groups of patients, reliable prediction of success and complications is possible. However, most emergency bypass surgery after failed angioplasty is performed in patients with a predicted intermediate risk ofcomplications. Inter-
A.P. Haasdljk. M.J. de Boer. H. Suryapranata. J.C.A. Hoomtje. F. ZlJlstra. IDepartment of Cardiology, Isala Clinics, Weezenlanden location, Groot Wezenland 20, 8011 JWZwolle. Address for correspondence: F. Zijlstra. E-mail: [email protected]
10
ventional cardiologists are not able to identify in advance the majority of patients who will need surgery for failed angioplasty. (Neth Heart J 2001; 9:10-15.)
Key words: coronary heart disease, coronary angioplasty, coronary bypass surgery Since the introduction of percutaneous transluminal coronary angioplasty (PTCA) by Gruentzig in 1977,1 PTCA has become a standard therapy for stable angina in patients with single-vessel disease. An increasing number of patients with unstable ischaemic syndromes, multivessel disease, and impaired left ventricular function are nowadays also considered candidates for PTCA.2 Despite technological improvements and increased operator skills, a percentage of complications still remains, ranging from 1 to 7%, depending on the definition used. These complications can be related to lesion-specific as well as to patient-specific characteristics.
The American College ofCardiology/American Heart Association (ACC/AHA) Task Force classification scheme categorises lesions into types A, B and C and was developed to classify patients based on lesionspecific characteristics in categories of high probability of success and low risk ofcomplications, intermediate probability of success and intermediate risk, and low probability of success and high risk of complications respectively (table 1).3 Many studies regarding success and complication rates in patients classified according to this scheme showed results outside the range ofthis classification.4-12 Furthermore, most studies regarding success rates and complications have been performed on a retrospective basis, and prospective assessments or evaluations have been scarce.'3 Therefore, in 1991 we started a prospective evaluation of success rates and complications in all patients undergoing elective PTCA in our institution.
Netherlands Heart Joumal, Volume 9, Number 1, April 2001
Prediction of success and major complications during elective coronary angioplasty: a prospective analysis of 2365 procedures
Table 1. Characteristics of lesions. 'Type A lesions (high success, >85%; low risk)' - Discrete (3 months old - Inability to protect major side branches - Degenerated vein grafts with friable lesions
Methods Between April 1991 and January 1994, 2365 consecutive elective coronary angioplasties were performed in 2096 patients at Weezenlanden Hospital. Patients had to be free of symptoms and signs of myocardial ischaemia during the 24 hours preceding the angioplasty procedure. No patients were excluded for other reasons.
Prior to elective coronary angioplasty, the probability of success and complications were estimated on the basis of angiographic as well as clinical characteristics by two experienced interventional cardiologists. Both the estimated complication risk and the probability of success were classified into three categories: low, intermediate or high probability. Predefined low risk means a 95 High Intermediate 80-95 Low 50% DS) (%) 1 60 2 or 3 40 Unstable angina (%) 56 DS=diameter stenosis; LV= left ventricular; Ml=myocardial infarction.
80 and 95% and finally a low probability is less than 80% (table 2). Success was defined as an uncomplicated procedure with a residual stenosis of less than 50% and a TIMI (Thrombolysis in Myocardial Infarction) 3 flow after the procedure.'4 Complications were defined as death, emergency bypass surgery and acute myocardial infarction during in-hospital stay. Myocardial infarction was diagnosed if at least two of three factors were present: typical chest pain lasting more than 30 minutes, and/or ST-elevations or ischaemic changes on the electrocardiogram or the development of pathological Q waves and/or an enzyme profile reflecting myocardial infarction defined as an elevation of creatinine kinase to more than two times the upper level ofthe normal value. The study protocol was seen and approved by our institutional review board. Statistical analysis Data were reported in absolute values as well as percentages, or as mean and standard deviation (SD) when appropriate. Chi-square analyses were used to test the differences in categorical variables and unpaired Student's t tests were used to assess differences in continuous variables. All calculated p values are twotailed. A p value ofless than 0.05 was considered significant. Results Baseline characteristics of the 2365 procedures are listed in table 3. These 2365 consecutive elective cor11
Prediction of success and major complications during elective coronary angioplasty: a prospective analysis of 2365 procedures
Table 4. Observed success rates for estimated success by estimated risk of complications.
Estimated risk of complications Estimated success % High [>95%] Medium [80 - 95%] Low [10hJ] (%)
10.4 12.0 10.7
10/96 3/25 13/121
The number of complicated procedures versus the total number of procedures in each category for combinations of estimated success and risk of complications is expressed in small italics.
onary angioplasties were performed in 2096 patients. The observed success rates in comparison with the preprocedural assessments are listed in table 4 including a subdivision into the various risk categories. For high (>95%) success probability 1025 out of 1056 (97.1%) procedures were carried out successfully, for intermediate (80-95%) success probability 833 out of914 (91.1%) procedures were carried out successfully and for low (
