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Role of percutaneous transluminal coronary angioplasty in the treatment of patients with multivessel coronary artery disease: a review
J Piessens MD Department of Cardiology, University Hospital Gasthuisberg, Herestraat 49, B-3000 Leuven, Belgium
J J Glazier MD MRCP
Keywords: coronary balloon angioplasty; multivessel disease
Introduction The technique of percutaneous transluminal coronary balloon angioplasty (PTCA) was first introduced by Andreas Gruentzig working in Zurich in 19771. It thus constitutes a relatively new form of treatment. During the early years of its application, coronary angioplasty was confined predominantly to patients with single vessel disease with lesions that were proximal, discrete, noncalcified and subtotal2'3. Increased operator experience together with continuing refinements in angioplasty 'hardware' (guiding and dilation catheters and guidewires) and imaging equipment have led to application of the technique to an ever widening spectrum of patients2'3. A particularly important extension of angioplasty has been its widespread use in the treatment of patients with multivessel coronary artery disease2-5. Indeed, currently, in many experienced centres over 50% of patients presenting for angioplasty have multivessel disease6. Figure 1 illustrates application of the technique to a patient with multivessel disease. In the treatment of patients with single vessel coronary artery disease who are judged to require mechanical revascularization, coronary angioplasty is generally preferred to coronary bypass surgery2'3. However, the role of coronary angioplasty in patients with multivessel disease is, at present, uncertain4 5. An important consideration is that coronary artery bypass graft surgery has, in a number of well designed, large scale, controlled clinical trials, been shown to improve symptoms and prolong life in selected subsets of patients with multivessel disease6-8, whereas angioplasty has not yet been evaluated in this regard4'5. However, this situation is about to change. A number of large scale, multicentre trials, comparing the relative efficacy of angioplasty and bypass surgery in patients with multivessel disease, have been set up both in Europe and in North America, and are now in progress. Nevertheless, it will be at least several years before some guidelines will begin to emerge from these trials. Whilst awaiting the results of these trials, it is important to analyse carefully what is already known about angioplasty in the treatment of patients with multivessel disease. Particular concerns about the widespread use of angioplasty in these patients include: (1) the acute outcome, (2) the completeness of revascularization that can be achieved, (3) the high restenosis rate, and (4) the long-term outcome. Acute outcome In patients with multivessel disease, angioplasty is associated with a high immediate success rate.
Clinical success (successful dilation of all attempted lesions without any major complication) is achieved in over 90% of such patients4'5. However, in comparison to patients with single vessel disease, major complications (death, non-fatal myocardial infarction and need for emergency bypass surgery) are more common. One of the most comprehensive reports regarding the acute complications of angioplasty is that provided by the results of the 1985-1986 National Heart Lung Blood Institute (NHLBI) PTCA Registry6. This report analysed the acute outcome of 1802 consecutive patients undergoing their first angioplasty at 15 centres. Of these 1802 patients, 963 (53%) had multivessel disease. In the Registry report, in patients with multivessel disease, the mortality rate at angioplasty was 1.7%, the non-fatal myocardial infarction rate 5% and emergency bypass rate 4%. The equivalent rates for patients with single vessel disease were 0.2%, 3.5%, and 1.8% respectively6. The mortality rate of 1.7% in patients with multivessel disease is similar to the recorded 1.6% mortality rate of such patients undergoing bypass surgery at the Cleveland Clinic10, one of the most experienced and internationally acclaimed surgical centres. It appears, however, that angioplasty is becoming safer. When
the NHLBI reported the results of these 1985-1986 PTCA Registry patients they took the opportunity to compare these results with those observed in patients entered into the 1977-1981 Registry. An encouraging feature of this comparison was the observation that the rate of major complications in patients with multivessel disease undergoing angioplasty in 1985-1986 was similar to the rate observed in patients with single vessel disease in the period 1977-19816.
Completeness of revascularization that can be achieved In patients with multivessel disease, some operators attempt to dilate all accessible, significant lesions whereas others only approach the lesion deemed most likely to cause myocardial ischaemia (the so-called 'culprit' lesion)11. Experience with regard to patients with multivessel disease who undergo coronary artery bypass graft surgery suggests that complete revascularization, that is, graft insertion around all moderate and severe stenoses, leads to a superior result. Follow-up studies of patients with surgical revascularization report that complete revascularization is more effective than incomplete revascularization in protecting patients against future coronary events'2. However, although the concept of complete revascularization is intuitively appealing,
0141-0768/91/
040224-05/$02.00/0 © 1991 The Royal Society of Medicine
Journal of the Royal Society of Medicine Volume 84 April 1991
Figure 1. Diagnostic coronary arteriography in a 45-year-old man with angina refractory to medical therapy, followed by coronary balloon angioplasty. A: Right coronary arteriogram (left anterior oblique projection) showing a severe stenosis of the right coronary artery (arrow). B: Left coronary arteriogram (left anterior oblique projection) showing a severe stenosis of the left anterior descending coronary artery. C+D: The balloon (small arrows) is inflated first across the right coronary artery stenosis (C) and then across the left coronary artery stenosis (D). Note, in each case, the guidewire over which the balloon is guided to the desired inflation site (arrow). E+F: Following PTCA, there is no significant residual stenosis of either the dilated right coronary (E) or left coronary (F) segments [lTwo-years following PTCA, this man remains entirely asymptomatic]
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initially successful angioplasty2'3. This complication it may be a little too simplistic merely to classify,and compare patients according to the achievement of occurs early and is rare after 6-8 months23. The incidence of restenosis is higher in a patient with complete or incomplete revascularization. Patiedns dilatation of multiple lesions than in one with who have incomplete revascularization may havp more extensive disease to begin with and it may -single-lesion angioplasty26. This observation is of be difficult to separate the effect of adeuy of particular importance when considering patients with multivesel disease, as such patients are more likely revascularization from the influence of baline characteristics (such as severity and complexity of to have ,iultilesion angioplasty than patients with single vessel disease25. In addition to an increased coronary disease and degree of left venticular incdence of restenosis pe-r- tient, patients "with impairment) on follow-up results'. multivesel disease may have restenosis in more than The concept of completeness of revascularization one dilatted segment",4)eligoaul et aL4 performed has significant implications for patients with multiwith multivessel vessel disease undergoing coronary angioplasty, as follow-up angiography 222p iase who had s il initial angioplasty. it is often not possible to achieve complete revasculari zation in these patients'3. In recently published 1'b restenosis ratepar leionw'as 28%. The overall series concerning angioplast inM patients wit4-:- pqatientrestenosisrate w 50%;37ofpatients had re'stnosis of a single-' esioWi-and,;13%, of patients multivessel disease4-8, the pe ntage of patients achieving complete revascularization ranged between -had multiple restenosis. Mylr-et aL also reported a similarly high restenosis rate2O. They documented 32%14 and 53%15. The primary reasons for incomplete restenosis in 92 of 164 (56%) patients undergoing revascularization are the inability to dilate chronic total occlusions and the inability to dilate diffuse follow-up angiography after multivessel angioplasty. Sixty patients (36.6%) had restenosis of one or coronary lesions or lesions with excessive tortuosity or angulation'3. In the experience of the, NHLBI more segments and 32 (19.5%) had restenosis of all dilated segments. Until effective methods of PTCA Registry, a totally occluded vessel wafound rducinthe incidence of restenosis becomeavailble, at baseline in 52% of patients who had iplete revascularization by PTCA but in only 6% of pents these, prohibitively high restenosis rates -Will conwho had complete revascularization by dilation. If tinue tl>dampen enthusiasm for multives angionew technologies such as laser can improve.results plasty.in patients with chronic total occlusions, theresr.a The foriidably high restenosi# rts rep d .i patients who undergo multilesion- -agioplaty have be a pronounced increase in the frequency with wh promd considerable interest in the strategy of complete revascularization is achieved. A number of studies have examined the relative e' g gto dilate only -the 'culpri le . Supt for such a strategy is provided byLthe observations of efficacy of complete and inomplete revasculaition Breisblatt et aL21. These w rs, in their series by angioplasty in patients with multivessel disease. of patients with multivessel disease undergoing These studies have provided conflicting observations. Reeder et aL6 analysed the 1985-1986 NHLBI angioplasty, used thallium scintigraphy to identify the 'culprit' lesion in individual patients and elected patients using logistic regression analysis to adjust to dilate only this lesion initially. Following angiofor baseline differences in left ventricular function. Comparing 127 patients with complete versus 159 plasty, thallium scintigraphy showed no evidence of ischaemia in a second vascular distribution in incomplete revascularization, they found no differences the majority of these patients21. In addition, it is between the status of the two cohorts at 2-year followimportant to realize that, in patients with multivessel up. Likewise, Thomas et aL19 found no difference in clinical improvement after multivessel angioplasty disease, the greater the number of vessels attempted at angioplasty the greater is the risk of- major between patients who received incomplerath than complications2-5. complete revascularization. Ghalili .et aL reported similar findings at one year follow;-upt. Howver,-: Deligonul et aLl4 observed, at a mean follow-upperioa Long-term results of 27 months, a significantly increased incidence of The relatively recent introduction of coronary angioplasty and the lag period of several years before this coronary bypass grafting in patients with-incomplete te versus complete revascularization. It is8possible that began to be widely applied to patients With the differences between these studies can be eplained Multi disease have resulted in a paucity of long-. termf n. : up information'3. However, the results of by the degree of incomplete revascula It appears reasonable to suggest that, ifacoroary anuxber of studies suggest that, in patients with r stenosis is in a vessel serving either a small multessel disease, angioplasty is assciatd wia or an area of infarction without viable miscle, favourable long-term outcome. A follow-up study at, revascularization of this vessel might not influence.. of 605 such patients achieving initial' sc d# long-term outcome'3. The results of a study by Gaiui _,angioplasty at Emory University deMO et aL support this idea'3. In this study, patients who 3-year freedom from cardiac event rate of 83%2. had incomplete revascularization Were further.subData from the 1985-1986 NHLBI Registry show that divided into groups. Patients who had incomplete-but the outcome for patients with multivessel disease is less favourable than for patients with single vessel adequate revascularization (ie those ihout cant disease23. One year mortality after PTCA was 4.6% residual lesions serving large or viable myocardial territory) had a better outcome in terms of symptom for patients who had multivessel disease and 1.8% for relief and need for bypass surgery than patients who those who had single vessel disease. The equivalent had incomplete and inadequate revascularization'3. nonfatal myocardial infarction rates were 8.8% and 5.4% respectively. Restenosis It is likely that the results of several ongoing Restenosis remains the major drawback of angioplasty, multicentre controlled clinical trials on both sides of the Atlantic will provide useful information regarding occurring in approximately 30% of patients who had
Journal of the Royal Society of Medicine Volume 84 April 1991
the long-term outcome of patients with multivessel disease undergoing angioplasty. These trials are also likely to provide some guidelines regarding relative indications and contraindications for angioplasty in patients with multivessel disease as well as, possibly, determining the relative efficacy of angioplasty and bypass surgery in such patients. The major European trial in this respect is the CABRI (Coronary Artery Bypass Revascularization Investigation) trial. In this trial, eligible patients with multivessel disease -are randomized to either angioplasty or bypass surgery. All patients have follow-up angiography at one year and, in the interim, exercise testing to detect residual ischaemia. This trial aims to recruit 2000 patients from 25 participating European centres (3 in the UK). The major equivalent trial in the US is the BARI (Bypas/Angioplasty Revascularization Investigation) trial which aims to recruit about 2500 patients who will be followed-up for 5 years., Endpoints include survival, infarction, symptoms and exercise performance. The RITA (Randomised Intervention Treatment of Angina) trial2A in an exclusively British trial which, unlike the other trials, randomizes patients with single vessel as well as multivessel disease. Patient recruitment began in March 1988 and it is proposed to recruit at least 1000 patients from 14 participating UK centres. Patients are considered for the trial if the participating cardiologist and surgeon agree that equivalent revascularization could be achieved by either treatment method. Patients will be followed for 5 years and major trial endpoints include death, new myocardial infarction and new coronary angioplasty or coronary artery bypass procedures. Other outcome measures include symptom and employment status, quality of- life, exercise tolerance and left ventricular function. Relative roles of angioplasty and bypass surgery In the treatment of patients with multivessel disease these two forms of mechanical revascularization are complementary rather than direct competitors. Coronary balloon angioplasty when successful is less traumatic, less costly and requires a shorter hospital stay. While these features will make angioplasty an attractive therapeutic modality, enthusiasm for angioplasty should be tempered with caution. Dilatation of certain types of lesions are associated with a low success rate or a considerably increased risk of major complications". For example, in a patient who has a large area of myocardial dysfunction as a result of previous myocardial infarction, and who has arteries with high grade lesions, whose acute occlusion at dilatation would result in cumulative damage equal to approximately 40-50% of the total myocardium, surgical revascularization would appear the wiser option". Conversely, angioplasty is, at times, preferable to bypass surgery in some patients with multivessel disease. A particular example in this respect is in the treatment of patients who have undergone prior bypass surgery and who, after a variable interim, are judged to require further mechanical revascularization. Repeat bypass surgery has at least a 3-fold greater risk of mortality than the initial operation26. In contrast, there is no significant increase in mortal risk in performing angioplasty in patients with prior coronary artery bypass surgery than in those who have never had bypass surgery. However, in patients with prior bypass surgery, coronary
angioplasty has a 12-fold lower mortality and a 2 to 3 times less frequent incidence of myocardial infarction than repeat surgery3. Whether or not angioplasty improves survival in patients with multivessel disease is, as yet, unknown. In contrast, there is now compelling evidence that bypass surgery prolongs life in selected subsets of patients with obstructive coronary artery disease. Included in these subsets are patients with three-vessel disease and impaired left ventricular function7-9, three-vessel disease with inducible myocar-dial ischaemia8'9, three-vessel disease with severe angina7, threevessel disease with multiple risk factors9 and, possibly, two-vessel disease where one ofthe diseased vessels is the proximal left anterior descending artery8. One could argue that, when mechanical coronary revascularization is deemed necessary in such patients, bypass surgery should, in general, be considered more favourably than angioplasty, at least until more comprehensive data regarding PTCA becomes available.
Conclusions Since the introduction of angioplasty in 1977, improved operator experience and continuiing improvement in angioplasty equipment have resulted in this technique becoming safer and more effective, at least in the short term. Now, in 1990, angioplasty is being routinely applied to patients with multivessel disease, many of whom have complex as well as extensive coronary disease. Coronary angioplasty can be used with a high degree of clinical and angiographic success in selected symptomatic patients with multivessel disease. However, the high restenosis rates reported following multivessel angioplasty as well as the not insignificant, although declining, rates of major acute complications are a matter ofconcern and have undermined the success of the procedure. Angioplasty appears a useful alternative and, at times, preferable treatment to bypass surgery for selected groups of patients who are at high surgical risk, have had previous bypass surgery or have extensive distal coronary disease and are not suitable candidates for bypass surgery. There is a paucity of long-term follow-up data concerning multivessel PTCA. However, it is likely that a number of ongoing controlled clinical trials will provide useful information in this respect as well as providing some guidelines regarding the relative efficacy of angioplasty and bypass surgery. However, it is important to realize that these trials will not provide all ofthe answers, and that patients with multivessel disease will continue to challenge our clinical judgement. References 1 Greuntzig A. Transluminal dilation of coronary artery stenoses. Lancet 1978;i:263 2 Baim DS. Interventional catheterization techniques. In: Braunwald E, ed. Heart disease. A textbook of
cardiovascular medicine, 3rd edn. Philadelphia: WB Saunders, 1988:1379-94 3 Myler RK, Stertzer SH, Cumberland DC, Webb JG,
Shaw RE. Coronary angioplasty: indications, contraindications and limitations: historical perspectives and technological determinants. J Interv Cardiol 1989; 3:174-85 4 Stertzer SH, Shaw RE, Myler RK, et aL Coronary angioplasty in the setting of multivessel disease: current status and future directions. Cardiol Clin 1989;7:1-12
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5 Holmes DR, Reeder GS, Vliestra RE. Role of percutaneous transluminal coronary angioplasty in multivessel disease. Am J Cardiol 1988;61:9G-14G 6 Detre K, Holubkov R, Kelsey G,.et aL Percutaneous transluminal coronary angioplasty in 1985-1986 and 1977-1981. N Engl J Med 1988;318:265-70 7 CASS Principal Investigators and their Associates. Coronary Artery Surgery Study (CASS): a randomized trial of coronary artery bypass surgery. Survival data. Circulation 1983;68:939-50 8 European Coronary Surgery Study Group. Long-term results of prospective randomized study of coronary artery bypass surgery in stable angina pectoris. Lancet 1982;ii:1173-80 9 The Veterans Administration Coronary Artery Bypass Surgery Cooperative Study Group. Eleven-year survival in the Veterans Administration randomized trial of coronary bypass surgery for stable angina. NEngl JMed 1984;311:1333-41 10 Whitlow PL. Percutaneous transluminal coronary angioplasty in two and three vessel disease: information and speculation. J Am Coll Cardiol 1989;11:1180-2 11 Ryan TJ, Faxon DP, Gunnar RM, et al. Guidelines for percutaneous transluminal coronary angioplasty. Circulation 1988;78:486-502 12 Jones EL, Craver JM, Guyton RA, Bone DK, Hatcher CR, Riechwald N. Importance of complete revascularization in the performance of the coronary bypass operation. Am J Cardiol 1983;51:7-12 13 Faxon DP, Ruocco N, Jacobs AK. Long-term outcome of patients after percutaneous transluminal coronary angioplasty. Circulation 1990;81(suppl IV):IV9-IV13 14 Deligonul U, Vandormael MG, Kern MJ, Zelman R, Galan K, Chairman BR. Coronary angioplasty: A therapeutic option for symptomatic patients with two and three vessel coronary disease. J Am Coll Cardiol 1988;11:1173-9 15 Vandormael MG, Chairman BR, Ischinger T, et al. Immediate and short-term benefit of multilesion coronary angioplasty: Influence of degree of revascularization. J Am Coll Cardiol 1985;6:983-91 16 Reeder GS, Holmes DR, Detre K, Costigan T, Kelsey SF. Degree ofrevascularization in patients with multivessel
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coronary artery disease: a report from the National Heart, Lung, and Blood Institute percutaneous transluminal coronary angioplasty registry. Circulation 1988;77:638-44 Ghalili K, Varrichione TR, Christelis EM, Kellett MA, Ryan TJ, Faxon DP. The strategy of incomplete revascularization in multivessel PTCA: is it justified (abstract). J Am Coll Cardiol 1988;II(suppl):611 Mabin TA, Holmes DR, Smith HC, et al. Follow-up clinical results of inpatients undergoing percutaneous transluminal coronary angioplasty. Circulation 1985; 71:754-60 Thomas ES, Most AS, Williams DO. Coronary aDgioplasty for patients with multivessel coronary artery disease: follow-up clinical status. Am Heart J 1988;115:8-13 Myler RK, Topol EJ, Shax RE, et al. Multivessel coronary angioplasty: classification, results and patterns of restenosis in 494 consecutive patients. Cathet Cardiovasc Diagn 1987;13:1-15 Breisblatt WM, Barnes JV, Weiland F, Spacavento LJ. Incomplete revascularization in multivessel pemutaneous transluminal coronary angioplasty: the role for stress thallium-201 imaging. J Am Coll Cardiol 1988;11: 1183-90 Roubin G, Weintraub WS, Sutor C, et al. Event free survival after successful angioplasty in multivessel coronary artery disease (abstract). J Am Coll Cardiol 1987;9:15A Detre K, Hulubkov R, Kelsey S, et al. One-year followup results of the 1985-1986 National Heart, Lung and Blood Institute's PTCA Registry. Circulation 1989; 80:421-8 Henderson RA. The Randomized Intervention Treatment of Angina (RITA) trial protocol; a long-term study of coronary angioplasty and coronary artery bypass surgery in patients with angina. Br Heart J 1989; 62:411-14 Little BW, Loop FD, Cosgrove DM, et aL Fifteen hundred coronary reoperations. J Thorac Cardiovasc Surg 1987;93:847-59
(Accepted 4 October 1990. Correspondence to Professor J Piessens)
Journal of the Royal Society of Medicine Volume 84 April 1991
Role of percutaneous transluminal coronary angioplasty in the treatment of patients with multivessel coronary artery disease: a review
J Piessens MD Department of Cardiology, University Hospital Gasthuisberg, Herestraat 49, B-3000 Leuven, Belgium
J J Glazier MD MRCP
Keywords: coronary balloon angioplasty; multivessel disease
Introduction The technique of percutaneous transluminal coronary balloon angioplasty (PTCA) was first introduced by Andreas Gruentzig working in Zurich in 19771. It thus constitutes a relatively new form of treatment. During the early years of its application, coronary angioplasty was confined predominantly to patients with single vessel disease with lesions that were proximal, discrete, noncalcified and subtotal2'3. Increased operator experience together with continuing refinements in angioplasty 'hardware' (guiding and dilation catheters and guidewires) and imaging equipment have led to application of the technique to an ever widening spectrum of patients2'3. A particularly important extension of angioplasty has been its widespread use in the treatment of patients with multivessel coronary artery disease2-5. Indeed, currently, in many experienced centres over 50% of patients presenting for angioplasty have multivessel disease6. Figure 1 illustrates application of the technique to a patient with multivessel disease. In the treatment of patients with single vessel coronary artery disease who are judged to require mechanical revascularization, coronary angioplasty is generally preferred to coronary bypass surgery2'3. However, the role of coronary angioplasty in patients with multivessel disease is, at present, uncertain4 5. An important consideration is that coronary artery bypass graft surgery has, in a number of well designed, large scale, controlled clinical trials, been shown to improve symptoms and prolong life in selected subsets of patients with multivessel disease6-8, whereas angioplasty has not yet been evaluated in this regard4'5. However, this situation is about to change. A number of large scale, multicentre trials, comparing the relative efficacy of angioplasty and bypass surgery in patients with multivessel disease, have been set up both in Europe and in North America, and are now in progress. Nevertheless, it will be at least several years before some guidelines will begin to emerge from these trials. Whilst awaiting the results of these trials, it is important to analyse carefully what is already known about angioplasty in the treatment of patients with multivessel disease. Particular concerns about the widespread use of angioplasty in these patients include: (1) the acute outcome, (2) the completeness of revascularization that can be achieved, (3) the high restenosis rate, and (4) the long-term outcome. Acute outcome In patients with multivessel disease, angioplasty is associated with a high immediate success rate.
Clinical success (successful dilation of all attempted lesions without any major complication) is achieved in over 90% of such patients4'5. However, in comparison to patients with single vessel disease, major complications (death, non-fatal myocardial infarction and need for emergency bypass surgery) are more common. One of the most comprehensive reports regarding the acute complications of angioplasty is that provided by the results of the 1985-1986 National Heart Lung Blood Institute (NHLBI) PTCA Registry6. This report analysed the acute outcome of 1802 consecutive patients undergoing their first angioplasty at 15 centres. Of these 1802 patients, 963 (53%) had multivessel disease. In the Registry report, in patients with multivessel disease, the mortality rate at angioplasty was 1.7%, the non-fatal myocardial infarction rate 5% and emergency bypass rate 4%. The equivalent rates for patients with single vessel disease were 0.2%, 3.5%, and 1.8% respectively6. The mortality rate of 1.7% in patients with multivessel disease is similar to the recorded 1.6% mortality rate of such patients undergoing bypass surgery at the Cleveland Clinic10, one of the most experienced and internationally acclaimed surgical centres. It appears, however, that angioplasty is becoming safer. When
the NHLBI reported the results of these 1985-1986 PTCA Registry patients they took the opportunity to compare these results with those observed in patients entered into the 1977-1981 Registry. An encouraging feature of this comparison was the observation that the rate of major complications in patients with multivessel disease undergoing angioplasty in 1985-1986 was similar to the rate observed in patients with single vessel disease in the period 1977-19816.
Completeness of revascularization that can be achieved In patients with multivessel disease, some operators attempt to dilate all accessible, significant lesions whereas others only approach the lesion deemed most likely to cause myocardial ischaemia (the so-called 'culprit' lesion)11. Experience with regard to patients with multivessel disease who undergo coronary artery bypass graft surgery suggests that complete revascularization, that is, graft insertion around all moderate and severe stenoses, leads to a superior result. Follow-up studies of patients with surgical revascularization report that complete revascularization is more effective than incomplete revascularization in protecting patients against future coronary events'2. However, although the concept of complete revascularization is intuitively appealing,
0141-0768/91/
040224-05/$02.00/0 © 1991 The Royal Society of Medicine
Journal of the Royal Society of Medicine Volume 84 April 1991
Figure 1. Diagnostic coronary arteriography in a 45-year-old man with angina refractory to medical therapy, followed by coronary balloon angioplasty. A: Right coronary arteriogram (left anterior oblique projection) showing a severe stenosis of the right coronary artery (arrow). B: Left coronary arteriogram (left anterior oblique projection) showing a severe stenosis of the left anterior descending coronary artery. C+D: The balloon (small arrows) is inflated first across the right coronary artery stenosis (C) and then across the left coronary artery stenosis (D). Note, in each case, the guidewire over which the balloon is guided to the desired inflation site (arrow). E+F: Following PTCA, there is no significant residual stenosis of either the dilated right coronary (E) or left coronary (F) segments [lTwo-years following PTCA, this man remains entirely asymptomatic]
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initially successful angioplasty2'3. This complication it may be a little too simplistic merely to classify,and compare patients according to the achievement of occurs early and is rare after 6-8 months23. The incidence of restenosis is higher in a patient with complete or incomplete revascularization. Patiedns dilatation of multiple lesions than in one with who have incomplete revascularization may havp more extensive disease to begin with and it may -single-lesion angioplasty26. This observation is of be difficult to separate the effect of adeuy of particular importance when considering patients with multivesel disease, as such patients are more likely revascularization from the influence of baline characteristics (such as severity and complexity of to have ,iultilesion angioplasty than patients with single vessel disease25. In addition to an increased coronary disease and degree of left venticular incdence of restenosis pe-r- tient, patients "with impairment) on follow-up results'. multivesel disease may have restenosis in more than The concept of completeness of revascularization one dilatted segment",4)eligoaul et aL4 performed has significant implications for patients with multiwith multivessel vessel disease undergoing coronary angioplasty, as follow-up angiography 222p iase who had s il initial angioplasty. it is often not possible to achieve complete revasculari zation in these patients'3. In recently published 1'b restenosis ratepar leionw'as 28%. The overall series concerning angioplast inM patients wit4-:- pqatientrestenosisrate w 50%;37ofpatients had re'stnosis of a single-' esioWi-and,;13%, of patients multivessel disease4-8, the pe ntage of patients achieving complete revascularization ranged between -had multiple restenosis. Mylr-et aL also reported a similarly high restenosis rate2O. They documented 32%14 and 53%15. The primary reasons for incomplete restenosis in 92 of 164 (56%) patients undergoing revascularization are the inability to dilate chronic total occlusions and the inability to dilate diffuse follow-up angiography after multivessel angioplasty. Sixty patients (36.6%) had restenosis of one or coronary lesions or lesions with excessive tortuosity or angulation'3. In the experience of the, NHLBI more segments and 32 (19.5%) had restenosis of all dilated segments. Until effective methods of PTCA Registry, a totally occluded vessel wafound rducinthe incidence of restenosis becomeavailble, at baseline in 52% of patients who had iplete revascularization by PTCA but in only 6% of pents these, prohibitively high restenosis rates -Will conwho had complete revascularization by dilation. If tinue tl>dampen enthusiasm for multives angionew technologies such as laser can improve.results plasty.in patients with chronic total occlusions, theresr.a The foriidably high restenosi# rts rep d .i patients who undergo multilesion- -agioplaty have be a pronounced increase in the frequency with wh promd considerable interest in the strategy of complete revascularization is achieved. A number of studies have examined the relative e' g gto dilate only -the 'culpri le . Supt for such a strategy is provided byLthe observations of efficacy of complete and inomplete revasculaition Breisblatt et aL21. These w rs, in their series by angioplasty in patients with multivessel disease. of patients with multivessel disease undergoing These studies have provided conflicting observations. Reeder et aL6 analysed the 1985-1986 NHLBI angioplasty, used thallium scintigraphy to identify the 'culprit' lesion in individual patients and elected patients using logistic regression analysis to adjust to dilate only this lesion initially. Following angiofor baseline differences in left ventricular function. Comparing 127 patients with complete versus 159 plasty, thallium scintigraphy showed no evidence of ischaemia in a second vascular distribution in incomplete revascularization, they found no differences the majority of these patients21. In addition, it is between the status of the two cohorts at 2-year followimportant to realize that, in patients with multivessel up. Likewise, Thomas et aL19 found no difference in clinical improvement after multivessel angioplasty disease, the greater the number of vessels attempted at angioplasty the greater is the risk of- major between patients who received incomplerath than complications2-5. complete revascularization. Ghalili .et aL reported similar findings at one year follow;-upt. Howver,-: Deligonul et aLl4 observed, at a mean follow-upperioa Long-term results of 27 months, a significantly increased incidence of The relatively recent introduction of coronary angioplasty and the lag period of several years before this coronary bypass grafting in patients with-incomplete te versus complete revascularization. It is8possible that began to be widely applied to patients With the differences between these studies can be eplained Multi disease have resulted in a paucity of long-. termf n. : up information'3. However, the results of by the degree of incomplete revascula It appears reasonable to suggest that, ifacoroary anuxber of studies suggest that, in patients with r stenosis is in a vessel serving either a small multessel disease, angioplasty is assciatd wia or an area of infarction without viable miscle, favourable long-term outcome. A follow-up study at, revascularization of this vessel might not influence.. of 605 such patients achieving initial' sc d# long-term outcome'3. The results of a study by Gaiui _,angioplasty at Emory University deMO et aL support this idea'3. In this study, patients who 3-year freedom from cardiac event rate of 83%2. had incomplete revascularization Were further.subData from the 1985-1986 NHLBI Registry show that divided into groups. Patients who had incomplete-but the outcome for patients with multivessel disease is less favourable than for patients with single vessel adequate revascularization (ie those ihout cant disease23. One year mortality after PTCA was 4.6% residual lesions serving large or viable myocardial territory) had a better outcome in terms of symptom for patients who had multivessel disease and 1.8% for relief and need for bypass surgery than patients who those who had single vessel disease. The equivalent had incomplete and inadequate revascularization'3. nonfatal myocardial infarction rates were 8.8% and 5.4% respectively. Restenosis It is likely that the results of several ongoing Restenosis remains the major drawback of angioplasty, multicentre controlled clinical trials on both sides of the Atlantic will provide useful information regarding occurring in approximately 30% of patients who had
Journal of the Royal Society of Medicine Volume 84 April 1991
the long-term outcome of patients with multivessel disease undergoing angioplasty. These trials are also likely to provide some guidelines regarding relative indications and contraindications for angioplasty in patients with multivessel disease as well as, possibly, determining the relative efficacy of angioplasty and bypass surgery in such patients. The major European trial in this respect is the CABRI (Coronary Artery Bypass Revascularization Investigation) trial. In this trial, eligible patients with multivessel disease -are randomized to either angioplasty or bypass surgery. All patients have follow-up angiography at one year and, in the interim, exercise testing to detect residual ischaemia. This trial aims to recruit 2000 patients from 25 participating European centres (3 in the UK). The major equivalent trial in the US is the BARI (Bypas/Angioplasty Revascularization Investigation) trial which aims to recruit about 2500 patients who will be followed-up for 5 years., Endpoints include survival, infarction, symptoms and exercise performance. The RITA (Randomised Intervention Treatment of Angina) trial2A in an exclusively British trial which, unlike the other trials, randomizes patients with single vessel as well as multivessel disease. Patient recruitment began in March 1988 and it is proposed to recruit at least 1000 patients from 14 participating UK centres. Patients are considered for the trial if the participating cardiologist and surgeon agree that equivalent revascularization could be achieved by either treatment method. Patients will be followed for 5 years and major trial endpoints include death, new myocardial infarction and new coronary angioplasty or coronary artery bypass procedures. Other outcome measures include symptom and employment status, quality of- life, exercise tolerance and left ventricular function. Relative roles of angioplasty and bypass surgery In the treatment of patients with multivessel disease these two forms of mechanical revascularization are complementary rather than direct competitors. Coronary balloon angioplasty when successful is less traumatic, less costly and requires a shorter hospital stay. While these features will make angioplasty an attractive therapeutic modality, enthusiasm for angioplasty should be tempered with caution. Dilatation of certain types of lesions are associated with a low success rate or a considerably increased risk of major complications". For example, in a patient who has a large area of myocardial dysfunction as a result of previous myocardial infarction, and who has arteries with high grade lesions, whose acute occlusion at dilatation would result in cumulative damage equal to approximately 40-50% of the total myocardium, surgical revascularization would appear the wiser option". Conversely, angioplasty is, at times, preferable to bypass surgery in some patients with multivessel disease. A particular example in this respect is in the treatment of patients who have undergone prior bypass surgery and who, after a variable interim, are judged to require further mechanical revascularization. Repeat bypass surgery has at least a 3-fold greater risk of mortality than the initial operation26. In contrast, there is no significant increase in mortal risk in performing angioplasty in patients with prior coronary artery bypass surgery than in those who have never had bypass surgery. However, in patients with prior bypass surgery, coronary
angioplasty has a 12-fold lower mortality and a 2 to 3 times less frequent incidence of myocardial infarction than repeat surgery3. Whether or not angioplasty improves survival in patients with multivessel disease is, as yet, unknown. In contrast, there is now compelling evidence that bypass surgery prolongs life in selected subsets of patients with obstructive coronary artery disease. Included in these subsets are patients with three-vessel disease and impaired left ventricular function7-9, three-vessel disease with inducible myocar-dial ischaemia8'9, three-vessel disease with severe angina7, threevessel disease with multiple risk factors9 and, possibly, two-vessel disease where one ofthe diseased vessels is the proximal left anterior descending artery8. One could argue that, when mechanical coronary revascularization is deemed necessary in such patients, bypass surgery should, in general, be considered more favourably than angioplasty, at least until more comprehensive data regarding PTCA becomes available.
Conclusions Since the introduction of angioplasty in 1977, improved operator experience and continuiing improvement in angioplasty equipment have resulted in this technique becoming safer and more effective, at least in the short term. Now, in 1990, angioplasty is being routinely applied to patients with multivessel disease, many of whom have complex as well as extensive coronary disease. Coronary angioplasty can be used with a high degree of clinical and angiographic success in selected symptomatic patients with multivessel disease. However, the high restenosis rates reported following multivessel angioplasty as well as the not insignificant, although declining, rates of major acute complications are a matter ofconcern and have undermined the success of the procedure. Angioplasty appears a useful alternative and, at times, preferable treatment to bypass surgery for selected groups of patients who are at high surgical risk, have had previous bypass surgery or have extensive distal coronary disease and are not suitable candidates for bypass surgery. There is a paucity of long-term follow-up data concerning multivessel PTCA. However, it is likely that a number of ongoing controlled clinical trials will provide useful information in this respect as well as providing some guidelines regarding the relative efficacy of angioplasty and bypass surgery. However, it is important to realize that these trials will not provide all ofthe answers, and that patients with multivessel disease will continue to challenge our clinical judgement. References 1 Greuntzig A. Transluminal dilation of coronary artery stenoses. Lancet 1978;i:263 2 Baim DS. Interventional catheterization techniques. In: Braunwald E, ed. Heart disease. A textbook of
cardiovascular medicine, 3rd edn. Philadelphia: WB Saunders, 1988:1379-94 3 Myler RK, Stertzer SH, Cumberland DC, Webb JG,
Shaw RE. Coronary angioplasty: indications, contraindications and limitations: historical perspectives and technological determinants. J Interv Cardiol 1989; 3:174-85 4 Stertzer SH, Shaw RE, Myler RK, et aL Coronary angioplasty in the setting of multivessel disease: current status and future directions. Cardiol Clin 1989;7:1-12
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5 Holmes DR, Reeder GS, Vliestra RE. Role of percutaneous transluminal coronary angioplasty in multivessel disease. Am J Cardiol 1988;61:9G-14G 6 Detre K, Holubkov R, Kelsey G,.et aL Percutaneous transluminal coronary angioplasty in 1985-1986 and 1977-1981. N Engl J Med 1988;318:265-70 7 CASS Principal Investigators and their Associates. Coronary Artery Surgery Study (CASS): a randomized trial of coronary artery bypass surgery. Survival data. Circulation 1983;68:939-50 8 European Coronary Surgery Study Group. Long-term results of prospective randomized study of coronary artery bypass surgery in stable angina pectoris. Lancet 1982;ii:1173-80 9 The Veterans Administration Coronary Artery Bypass Surgery Cooperative Study Group. Eleven-year survival in the Veterans Administration randomized trial of coronary bypass surgery for stable angina. NEngl JMed 1984;311:1333-41 10 Whitlow PL. Percutaneous transluminal coronary angioplasty in two and three vessel disease: information and speculation. J Am Coll Cardiol 1989;11:1180-2 11 Ryan TJ, Faxon DP, Gunnar RM, et al. Guidelines for percutaneous transluminal coronary angioplasty. Circulation 1988;78:486-502 12 Jones EL, Craver JM, Guyton RA, Bone DK, Hatcher CR, Riechwald N. Importance of complete revascularization in the performance of the coronary bypass operation. Am J Cardiol 1983;51:7-12 13 Faxon DP, Ruocco N, Jacobs AK. Long-term outcome of patients after percutaneous transluminal coronary angioplasty. Circulation 1990;81(suppl IV):IV9-IV13 14 Deligonul U, Vandormael MG, Kern MJ, Zelman R, Galan K, Chairman BR. Coronary angioplasty: A therapeutic option for symptomatic patients with two and three vessel coronary disease. J Am Coll Cardiol 1988;11:1173-9 15 Vandormael MG, Chairman BR, Ischinger T, et al. Immediate and short-term benefit of multilesion coronary angioplasty: Influence of degree of revascularization. J Am Coll Cardiol 1985;6:983-91 16 Reeder GS, Holmes DR, Detre K, Costigan T, Kelsey SF. Degree ofrevascularization in patients with multivessel
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coronary artery disease: a report from the National Heart, Lung, and Blood Institute percutaneous transluminal coronary angioplasty registry. Circulation 1988;77:638-44 Ghalili K, Varrichione TR, Christelis EM, Kellett MA, Ryan TJ, Faxon DP. The strategy of incomplete revascularization in multivessel PTCA: is it justified (abstract). J Am Coll Cardiol 1988;II(suppl):611 Mabin TA, Holmes DR, Smith HC, et al. Follow-up clinical results of inpatients undergoing percutaneous transluminal coronary angioplasty. Circulation 1985; 71:754-60 Thomas ES, Most AS, Williams DO. Coronary aDgioplasty for patients with multivessel coronary artery disease: follow-up clinical status. Am Heart J 1988;115:8-13 Myler RK, Topol EJ, Shax RE, et al. Multivessel coronary angioplasty: classification, results and patterns of restenosis in 494 consecutive patients. Cathet Cardiovasc Diagn 1987;13:1-15 Breisblatt WM, Barnes JV, Weiland F, Spacavento LJ. Incomplete revascularization in multivessel pemutaneous transluminal coronary angioplasty: the role for stress thallium-201 imaging. J Am Coll Cardiol 1988;11: 1183-90 Roubin G, Weintraub WS, Sutor C, et al. Event free survival after successful angioplasty in multivessel coronary artery disease (abstract). J Am Coll Cardiol 1987;9:15A Detre K, Hulubkov R, Kelsey S, et al. One-year followup results of the 1985-1986 National Heart, Lung and Blood Institute's PTCA Registry. Circulation 1989; 80:421-8 Henderson RA. The Randomized Intervention Treatment of Angina (RITA) trial protocol; a long-term study of coronary angioplasty and coronary artery bypass surgery in patients with angina. Br Heart J 1989; 62:411-14 Little BW, Loop FD, Cosgrove DM, et aL Fifteen hundred coronary reoperations. J Thorac Cardiovasc Surg 1987;93:847-59
(Accepted 4 October 1990. Correspondence to Professor J Piessens)
