Trials comparing coronary artery bypass grafting with percutaneous transluminal coronary angioplasty and primary stent implantation in patients with multivessel coronary artery disease

With marked improvements in stent technology as adjunct to balloon angioplasty for multivessel coronary disease, several newer trials are currently in progress reviewing the optimal revascularization strategy. This review provides background from older studies and addresses the current progress and design of these newer trials.     

Coronary artery bypass surgery and percutaneous transluminal coronary angioplasty in patients with multivessel disease

Since its introduction in the early 1970s, coronary artery bypass grafting (CABG) surgery has been proven to relief anginal symptoms in patients with severe myocardial ischemia. Percutaneous coronary intervention (PCI) was introduced in clinical practice at the end of the 1970s and this treatment has also been established to be effective. PCI has now surpassed CABG as the most common means for treating coronary artery disease (CAD). However, restenosis remains its Achille's heel. Until the mid-1990s, a coronary reintervention was needed in 35% to 40% of the patients. Since then, interventional techniques and technology have evolved with improved success in more complex and anatomical settings, and restenosis has been now consistently decreased to around 20%. Despite all these improvements, the incidence of restenosis, especially in the 1(st) year, is still an important limitation to PCI. The major determinants of restenosis are elastic recoil, negative vessel remodeling and neointimal proliferation as a response to vessel injury induced by angioplasty devices. The use of conventional stents has provided an efficient method to face the first 2 problems, but neointimal proliferation is not affected by stenting. A new approach consists of using the stent as a drug carrier to the target site in order to inhibit restenosis. The first results of utilization of these fascinating drug-eluting stents (DES) to treat relatively simple lesions are very promising, but further analyses for more complex lesions such as those commonly found in daily practice are needed before any definitive conclusions can be made.     

Life adaptation after percutaneous transluminal coronary angioplasty and coronary artery bypass grafting

Life adaptation of 32 patients who had undergone percutaneous transluminal coronary angioplasty (PTCA) for coronary stenosis was compared with that of 15 patients who had coronary artery bypass grafting (CABG). Patients were matched for psychosocial, anatomic and cardiac functions. Life adaptation was measured at 6 and 15 months after PTCA or CABG by the Psychosocial Adjustment to Illness Scale (PAIS), a multidimensional instrument that evaluates change in 7 primary life domains. The overall PAIS scores for patients who had undergone PTCA were significantly better (p less than 0.04) than the scores for those who had undergone CABG after 6 months, and this superior functioning continued after 15 months (p less than 0.05). After 6 months patients who had undergone PTCA functioned better at work (p less than 0.005), in sexual performance (p less than 0.0001) and with their families (p less than 0.002). The improvement in work functioning continued at 15 months (p less than 0.04), but the differences in sexual and family domains became nonsignificant.     

Functional status after coronary artery bypass grafting and percutaneous transluminal coronary angioplasty

Two cohorts of consecutive patients of comparable age with similar preprocedure cardiac function who underwent either coronary artery bypass grafting (CABG; n = 106) or percutaneous transluminal coronary angioplasty (PTCA; n = 64) were entered into a prospective comparison study examining functional status and return to work during the first year of recovery. Patients were evaluated using standardized functional status instruments for activities of daily living, work performance, social activity, mental health and quality of social interaction at 1, 6 and 12 months after the procedure. Within the CABG group, statistically significant improvements of functional status on every subscale were noted over the 1-year follow-up. Patients undergoing PTCA demonstrated significant improvement in all dimensions except for the quality of interaction at 1 year as compared with baseline. When the 2 groups were compared, the PTCA group demonstrated greater participation than the CABG group in routine daily physical and social activities at 1 and 6 months, but this apparent advantage disappeared by 1 year. Measures of psychological functioning were better after CABG than after PTCA. A reduction in the number of those with employment occurred in both the CABG and PTCA groups, independent of physical functional status measures, which improved in both groups after the procedures. For those with employment, the CABG group reported the greatest improvement in work performance.     

Long-term exercise performance after percutaneous transluminal coronary angioplasty and coronary artery bypass grafting

In our first 169 consecutive patients admitted to undergo percutaneous transluminal coronary angioplasty (PTCA) serial bicycle ergometric exercise sessions were scheduled to assess long-term-exercise performance. In 160 of these 169 patients (95%) an average of seven ergometric measurements were available during a mean follow-up period of 29 months (range 1 to 60 months). Two groups were formed. One consisted of 132 patients in whom PTCA was successful and the other consisted of 28 patients with failure of PTCA who subsequently underwent coronary artery bypass grafting (CABG) either on an emergency basis (12 patients) or as an elective procedure (16 patients). Exercise performance was expressed as work capacity in watts according to the highest completed exercise stage. In the successful PTCA group the actual work capacities increased from 74 +/- 42 W (mean +/- SD) before PTCA to 122 +/- 47 W at the most recent follow-up examination. In patients who underwent emergency or elective CABG the respective figures were 73 +/- 34 or 65 +/- 37 W before surgery and 120 +/- 41 or 119 +/- 41 W at the most recent follow-up examination (p less than .005 for all preprocedure to postprocedure comparisons). Successful PTCA and CABG after failed PTCA improve work capacity significantly. Comparison of our results with those of surgical studies indicates that a failed attempt at PTCA before CABG does not compromise the functional outcome of the operation, regardless whether it is done on an emergency or on an elective basis.     

Role of percutaneous transluminal coronary angioplasty in multivessel disease

Although percutaneous transluminal coronary angioplasty (PTCA) is being widely performed in patients with multivessel disease, the eventual role it will play will depend on several factors, including the immediate and long-term results, procedural risks and restenosis. An important consideration is that of completeness of revascularization. This is based on cardiac surgical experience, which has documented that if revascularization is complete, the clinical outcome will be improved. The importance of this concept has been borne out in practice. Although complete revascularization is ideal, it cannot be achieved in a substantial number of patients with multivessel disease because of the presence of old total occlusion that cannot be dilated, diffuse and distal disease or a planned dilation strategy. However, many patients with successful dilation but incomplete revascularization do well. In these patients, attempts are made to identify and then dilate a "culprit" lesion. Dilation of these most physiologically important stenoses often results in an excellent short-term outcome. Currently, 2 studies have been initiated to compare the role of PTCA with that of coronary artery bypass grafting for the treatment of patients with multivessel disease. For these studies, initial success and long-term outcome in terms of morbidity and mortality as well as cost considerations will be assessed. The results of these studies will help to put into perspective the complementary roles of PTCA and coronary artery bypass grafting.     

Comparison of coronary artery bypass surgery and percutaneous transluminal coronary angioplasty including surgery for failed angioplasty

Selection and treatment of patients with ischemic heart disease is presently undergoing an evolutionary trend. Percutaneous transluminal coronary angioplasty (PTCA) has been recommended as the initial procedure for many patients with coronary artery disease and has thus redefined candidates for coronary artery bypass surgery. During our first years of experience with percutaneous angioplasty, 339 patients underwent the procedure and were compared with 338 patients who underwent isolated coronary artery bypass surgery. Patients who underwent PTCA had a shorter duration of angina and a lower number of prior myocardial infarctions and were found to have better left ventricular function (p less than 0.01). PTCA was considered initially successful in 87% (295 of 339) of patients. The most common finding at operation in those with failed angioplasty who underwent urgent or emergency revascularization was dissection of atheromatous plaque. Although the cumulative frequency of new Q waves in the entire 18-month angioplasty series was low (2.7%), the incidence was high (18%) in those with angioplasty failure and subsequent operation (N = 20) and significantly greater than in patients who had elective coronary artery bypass surgery (3.6%). Use of inotropic agents and lidocaine for ventricular arrhythmias was significantly higher in patients with unsuccessful PTCA who required operation than in those who underwent elective bypass surgery (10% vs 3% and 10% vs 1.5%, respectively; p less than 0.01). In an analysis of our entire experience between October 1980 and June 1982, 777 patients who had PTCA and 2068 patients who underwent coronary artery bypass surgery were analyzed for differences in clinical complications and early outcome.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of angioplasty and bypass surgery in multivessel coronary artery disease

The role of coronary angioplasty in the treatment of patient with multivessel coronary artery disease has not been fully established. We compared immediate and 1-year follow-up results in 60 patients undergoing coronary angioplasty for multivessel coronary disease in 1982 with 41 patients anatomically suitable for angioplasty but who underwent elective coronary bypass surgery during the same time period. Baseline variables were similar in both groups except for number of vessels diseased which was higher in the surgical group. Angioplasty was initially successful in 70% of cases. There were no deaths. Mean initial hospital days were lower in the angioplasty group. At follow-up there were no significant differences in survival, functional class, occurrence of subsequent myocardial infarction or use of cardiac medications. However, 33% of the successfully dilated patients required either repeat dilatation or subsequent bypass surgery because of restenosis or inadequate initial revascularization. The statistical power of the study was limited due to the small sample sizes. While demonstrating that angioplasty can be successfully performed in patients with multivessel disease, definitive conclusions about the comparability of the two treatments are hampered by possible selection bias and small patient numbers. This issue could be better addressed by a multicenter prospective randomized trial.     

Outcome of urgent percutaneous transluminal coronary angioplasty in acute myocardial infarction: comparison of single-vessel versus multivessel coronary artery disease.

Despite recent clinical trials of percutaneous transluminal coronary angioplasty (PTCA) in acute myocardial infarction, specific groups of patients that may benefit from adjunctive or alternative therapy have yet to be adequately characterized. The in-hospital outcome of 151 consecutive patients treated for acute myocardial infarction with urgent PTCA of the infarct-related artery was studied to identify a subgroup of patients at high risk. Patients were divided into two groups based on the angiographic presence of either single-vessel (n = 86) or multivessel (n = 65) coronary artery disease. Despite PTCA of only the infarct-related artery and similar baseline clinical characteristics such as age, peak serum creatine kinase concentration, left ventricular ejection fraction, and time from the onset of chest pain to arrival at the hospital, the group with multivessel disease had a lower rate of successful angioplasty (75% vs 92%, p < 0.005), with higher incidences of persistent total occlusion of the infarct-related artery (14% vs 3%, p < 0.02) and procedural complications during PTCA (28% vs 13%, p < or = 0.02), and were more likely to have multiple complications (12% vs 1%, p < 0.004). In addition, the group with multivessel disease had a higher rate of urgent (< or = 24 hours) coronary artery bypass graft surgery (13% vs 2%, p < 0.05) and a trend toward a higher in-hospital mortality rate (6% vs 1%, p < or = 0.17). By stepwise logistic regression, only the presence of single-vessel versus multivessel disease was predictive of PTCA success (p < 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)     

Long-term outcome of percutaneous transluminal coronary angioplasty and coronary artery bypass grafting in patients with end-stage renal disease

This study was conducted to investigate therapeutic methods for end-stage renal disease (ESRD) by retrospectively analyzing in-hospital outcome and long-term outcome in patients who underwent either percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass grafting (CABG). Ninety-two patients underwent PTCA and 47 underwent CABG, and the initial success rates were 87% and 85%, respectively. As major in-hospital complications, in the PTCA group 1 died (1%), 2 required emergency CABG (2%), and 2 had Q-wave myocardial infarction (2%); in the CABG group, 7 died (15%) and 3 had Q-wave myocardial infarction (6%). As for the long-term outcome, although there were no differences in the incidence of death or the incidence of cardiac death between the 2 groups, the cumulative proportion of patients free of death, myocardial infarction, CABG and repeat PTCA was lower in the PTCA group, which was mainly due to a higher incidence of repeat PTCA in that group. The incidence of cardiac death was low for both groups among the patients attaining complete revascularization. Twenty-three percent of the patients required cross-over implementation of PTCA and CABG. In conclusion, it is necessary to aim for complete revascularization using both treatments for a better prognosis in patients with ESRD.     

Percutaneous coronary intervention versus coronary artery bypass grafting: clinical outcomes in multivessel coronary artery disease

Revascularization with percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) is superior to medical management in reducing symptoms and prolonging exercise duration in patients with coronary artery disease (CAD). Ten randomized trials have compared the outcomes in percutaneous and surgically treated patients with multivessel CAD. The purpose of this article was to summarize the results of those trials to make recommendations regarding appropriate revascularization strategy.     

Complications prior to revascularization among patients waiting for coronary artery bypass grafting and percutaneous transluminal coronary angioplasty

AIM: To describe the occurrence of death, development of acute myocardialinfarction and need for hospitalization among patients on thewaiting list for coronary artery by pass grafting and percutaneoustransluminal coronary angioplasty. PATIENTS AND METHODS: All the patients on the waiting list for possible coronary revascularizationin September 1990 in western Sweden. RESULTS: Of 718 patients waiting for either coronary artery bypass graftingor percutaneous transluminal coronary angioplasty, 15 (2.1%)died between the actual week in September 1990 and prior torevascularization and 12 (1.7%) developed a non-fatal acutemyocardial infarction during the same period. All 15 patientswho died before undergoing revascularization died a cardiacdeath. Death and/or the development of an acute myocardial infarctionwas significantly more frequent among the elderly, among patientswith a low ejection fraction and among patients with a historyof diabetes mellitus. In all, 29% required hospitalization priorto the procedure. The most common reason was symptoms of anginapectoris requiring hospitalization in 23% of the patients. CONCLUSION: Among patients on the waiting list before either coronary arterybypass grafting or percutaneous transluminal coronary angioplasty,15 (2.1%) died prior to the procedure and 1.7% developed a non-fatalacute myocardial infarction. The risk of either death or developingan acute myocardial infarction was highest among patients inthe older age groups, among patients with a history of diabetesmellitus and among patients with a lower ejection fraction.     

Angiographic follow-up after multivessel percutaneous transluminal coronary angioplasty

In 100 consecutive patients undergoing multivessel percutaneous transluminal coronary angioplasty (PTCA), dilation was attempted in 207 arteries. Primary success was achieved in 85 patients. Complications occurred in 8 patients: acute myocardial infarction in 5 and need for emergency coronary artery bypass surgery in 5. Control angiography was done in 77 of 85 patients (91%) with primary success at a mean of 12 +/- 6 months. Complete revascularization had been achieved in 59 patients and incomplete revascularization in 18. Angiographic restenosis was found in 39 of 77 patients (51%) and in 47 of 143 arteries (33%) at 9 +/- 7 months. The restenosis rate was 57% for chronic total occlusions (8 of 14) and 30% for stenoses (39 of 129). The restenosis rate was significantly higher for the left anterior descending coronary artery (40%) than for the left circumflex coronary artery (21%). However, the significance was lost after exclusion of chronic total occlusions. A higher residual stenosis and a high coronary wedge pressure were predictors for restenosis. Restenosis was clinically silent in 14 patients (18%). Repeat PTCA was done in 19 patients with recurrence and elective surgery in 8. Clinical follow-up was available in all patients at 24 +/- 12 months. Patients with incomplete revascularization had less favorable clinical follow-up results than patients with complete revascularization: 44% (8 of 18) vs 81% (48 of 59) were asymptomatic (p less than 0.005), and 28% (5 of 18) vs 5% (3 of 59) had undergone elective bypass surgery during follow-up (p less than 0.005). Most patients with restenosis after multivessel PTCA had only 1-vessel restenosis and only 7% had restenosis of all lesions.     

Primary percutaneous transluminal coronary angioplasty in the setting of multivessel disease

Primary percutaneous coronary intervention of the culprit lesion is the treatment of choice for acute myocardial infarction, while treatment of the severe non culprit lesion is not indicated in the guidelines (Class III indication). More aggressive strategies that include initial treatment of the severe non culprit lesion may reduce the incidence of delayed occlusions in specific clinical settings. The two cases we describe support our point of view.     

Predictors of long-term cardiac survival in patients with multivessel coronary artery disease undergoing percutaneous transluminal coronary angioplasty

The predictors of 5-year cardiac survival in patients with multivessel coronary artery disease (CAD) undergoing percutaneous transluminal coronary angioplasty (PTCA) were analyzed in a series of 637 consecutive patients. The average age was 59 +/- 11 years in 472 men and 165 women. Diabetes mellitus, previous myocardial infarction and unstable angina were present in 119 (19%), 261 (41%) and 305 (47%) patients, respectively. Angiographically, 460 patients had 2-vessel and 177 patients had 3-vessel CAD. The left ventricular contraction score was greater than or equal to 12 in 55 patients. Angiographic success (less than 50% residual stenosis) was achieved in 85% of the 1,343 narrowings and clinical success was obtained in 526 (83%) of the 637 patients. Complete revascularization was obtained in 177 (34%) of 526 successful patients. Procedure-related complications resulted in death in 9 patients (1.4%), in Q-wave myocardial infarction only in 6 patients (0.9%) and in emergency bypass surgery in 44 patients (6.9%) (of whom 10 had Q-wave myocardial infarction). Follow-up for greater than or equal to 1 year and up to 6 years after PTCA was obtained in 608 (95%) of the 637 patients. To determine the predictors of 5-year cardiac survival, 28 clinical, angiographic and procedural variables were analyzed by Cox proportional-hazards regression. The estimated 5-year survival after PTCA was 88 +/- 2% in successful patients and 77 +/- 5% in patients in whom PTCA was unsuccessful (p less than 0.001). When clinical success was forced into the Cox regression, the left ventricular contraction score of greater than or equal to 12, diabetes mellitus and age greater than or equal to 65 years showed additional adverse effects on survival.(ABSTRACT TRUNCATED AT 250 WORDS)