Native coronary disease progression exceeds failed revascularization as cause of angina after five years in the Bypass Angioplasty Revascularization Investigation (BARI)

OBJECTIVES: Coronary angiograms obtained five years following revascularization were examined to assess the extent of compromise in myocardial perfusion due to failure of revascularization versus progression of native disease. BACKGROUND: The Bypass Angioplasty Revascularization Investigation (BARI) randomized revascularization candidates between bypass surgery and angioplasty. Entry and five-year angiograms from 407 of 519 (78%) patients at four centers were analyzed. METHODS: Analysis of the distribution of coronary vessels and stenoses provided a measure of myocardial jeopardy that correlates with presence of angina. The extent to which initial benefits of revascularization were undone by failed revascularization versus native disease progression was assessed. RESULTS: Myocardial jeopardy fell following initial revascularization, from 60% to 17% for percutaneous coronary intervention (PCI)-treated patients compared with 60% to 7% for coronary artery bypass graft (CABG) surgery patients (p < 0.001), rebounding at five years to 25% for PCI and 20% for surgery patients (p = 0.01). Correspondingly, angina prevalence was higher at five years in PCI-treated patients than in surgery-treated patients (28% vs. 18%; p = 0.03). However, myocardial jeopardy at five years, and not initial treatment (PCI vs. surgery), was independently associated with late angina. Increased myocardial jeopardy from entry to five-year angiogram occurred in 42% of PCI-treated patients and 51% of CABG-treated patients (p = 0.06). Among the increases in myocardial jeopardy, two-thirds occurred in previously untreated arteries. CONCLUSIONS: Native coronary disease progression occurred more often than failed revascularization in both PCI- and CABG-treated patients as a cause of jeopardized myocardium and angina recurrence. These results support intensive postrevascularization risk-factor modification.     

Myocardial revascularization for chronic stable angina. Analysis of the role of percutaneous transluminal coronary angioplasty based on data available in 1989

No prospective, randomized clinical trial comparing coronary artery bypass grafting, percutaneous transluminal coronary angioplasty, and conservative therapy has been reported. To address when revascularization is indicated, we constructed a decision analytic model. Our model incorporates procedure-related mortality and morbidity, coronary artery disease-related mortality, and the benefit of revascularization. We determined the quality-adjusted life expectancy and expected costs for each strategy. Our model suggests that angioplasty is a reasonable alternative to bypass surgery in patients with favorable lesions if angioplasty would provide a comparable degree of revascularization. Our model predicts that patients treated with angioplasty will have more revascularization procedures than will patients treated with bypass surgery but predicts that both treatments will cost the same over the typical patient's lifetime. In many patients with severe angina or documented ischemia, angioplasty is indicated for stenosis of a single artery. In patients with two vessel disease that is amenable to angioplasty, angioplasty may be a reasonable alternative to bypass surgery. Even in patients whose three vessel disease can be completely revascularized by angioplasty, bypass surgery, although relatively expensive, is slightly better than angioplasty. In patients with three vessel disease and comorbidities that increase operative risk, angioplasty may be a reasonable alternative to either bypass surgery or medical therapy.     

Is a strategy of intended incomplete percutaneous transluminal coronary angioplasty revascularization acceptable in nondiabetic patients who are candidates for coronary artery bypass graft surgery? The Bypass Angioplasty Revascularization Investigation (BARI).

OBJECTIVES: Our objective was to determine whether a strategy of intended incomplete percutaneous transluminal coronary angioplasty revascularization (IR) compromises long-term patient outcome. BACKGROUND: Complete angioplasty revascularization (CR) is often not planned nor attempted in patients with multivessel coronary disease, and the extent to which this influences outcome is unclear. METHODS: Before randomization, in the Bypass Angioplasty Revascularization Investigation, all angiograms were assessed for intended CR or IR via angioplasty. Outcomes were compared among patients with IR intended if assigned to angioplasty, randomized to coronary artery bypass graft surgery (CABG) versus angioplasty; and within angioplasty patients only, among patients with IR versus CR intended. RESULTS: At 5 years, there was a trend for higher overall (88.6% vs. 84.0%) and cardiac survival (94.5% vs. 92.1%) in CABG versus angioplasty patients with IR intended. The excess mortality in angioplasty patients occurred solely in diabetic subjects; overall and cardiac survival were similar among nondiabetic CABG and angioplasty patients. Freedom from myocardial infarction (MI) at 5 years was higher in nondiabetic CABG versus angioplasty patients (92.4% vs. 85.2%, p = 0.02), vet was similar to the rate observed (85%) in nondiabetic CABG and angioplasty patients with CR intended. Five-year rates of death, cardiac death, repeat revascularization and angina were similar in all angioplasty patients with IR versus CR intended. However, a trend for greater freedom from subsequent CABG was seen in CR patients (70.3% vs. 64.0%, p = 0.08). CONCLUSIONS: Intended incomplete angioplasty revascularization in nondiabetic patients with multivessel disease who are candidates for both angioplasty and CABG does not compromise long-term survival; however, subsequent need for CABG may be increased with this strategy. Whether the risk of long-term MI is also increased remains uncertain.     

The symptomatic status of patients one year following revascularization by either coronary surgery or angioplasty

This study consisted of a one year clinical follow-up of 81 patients who had coronary revascularization. In 32 patients, this was accomplished by bypass surgery and in 49, by percutaneous angioplasty. Prior to the procedure the two groups of patients were similar with regard to age, sex, antianginal medication and angina severity with 75% of the surgical patients and 65% of the angioplasty patients in CCS Angina Class III or IV. Although most of the surgical patients had multivessel disease and most of the angioplasty patients had single vessel disease, all had complete revascularization. At one year, 78% of the surgical patients and 84% of the angioplasty patients did not have angina and few patients in either group were taking medication. However, in the intervening year 39% of the angioplasty patients had had a second revascularization procedure, whereas, only 3% of the surgical patients required a second procedure. Extracardiac sequelae were more frequent in the surgical cohort. Therefore, at one year following complete revascularization, bypass surgery and angioplasty result in comparable symptomatic and functional improvement.     

Percutaneous transluminal coronary angioplasty of the left main coronary artery in patients with rest angina

Left main coronary angioplasty may be a therapeutic revascularization procedure for a subset of patients with symptomatic coronary artery disease. The purpose of this study is to report procedural outcomes and long-term clinical follow-up of 15 patients who underwent either protected or unprotected left main angioplasty for rest angina. These patients represent a cohort of unstable angina patients who were considered high risk for coronary artery bypass surgery. Ten of 15 patients had Canadian Heart Class IV angina, and three patients were hemodynamically unstable. Balloon angioplasty was successful in 14 patients, and one patient was treated with directional atherectomy. Initial angiographic success was achieved in 14 of 15 patients (93%). Major complications (myocardial infarction, emergent coronary artery bypass graft, death) occurred in one patient (6%); 73% of the patients were asymptomatic or had stable exertional angina at 6 months follow-up. One year survival was 87% (13 of 15). During the follow-up period six patients had repeat catheterization for recurrent angina. Four of these patients had left main restenosis and underwent successful repeat left main angioplasty. No patient had coronary bypass surgery during follow-up. This report suggests that left main angioplasty can be a safe and effective revascularization procedure for critically ill patients with unstable angina who are at high risk for coronary bypass surgery. © Wiley-Liss, Inc.     

Triple vessel coronary angioplasty: acute outcome and long-term results

Triple vessel coronary angioplasty, defined as angioplasty of one or more lesions in each of the three major coronary arteries (left anterior descending, left circumflex, right coronary artery) was performed in 50 (11%) of 469 patients who had angioplasty of multiple vessels. There were 32 men and 18 women with a mean age of 56 years. All 50 patients had severe three vessel coronary disease and represent approximately 5% of patients with three vessel disease who had revascularization in this institution; 8 (16%) had previous coronary bypass surgery, and 23 (46%) had previous myocardial infarction. Unstable angina was present in 33 patients (66%) and 96% had Canadian Heart Association class III or IV angina; mean left ventricular ejection fraction was 57 +/- 11%. Angioplasty was performed in 176 vessels (3.5 vessels per patient, range 3 to 6) and in 250 lesions (5 lesions per patient, range 3 to 9); angiographic success was achieved in 240 lesions (96%) and 166 vessels (94%). Success in all vessels attempted was achieved in 40 (80%) of the 50 patients. Clinical success (angiographic success associated with clinical improvement) was obtained in all 50 patients in whom triple vessel angioplasty was performed; none of them required urgent bypass surgery and 5 patients (10%) had a non-Q wave myocardial infarction. In four other patients triple vessel angioplasty was planned but not performed because of failure to dilate the primary vessel; urgent bypass surgery was required in one of these, who developed a Q wave infarction. Thus, overall clinical success in 54 patients was 93%; the incidence rate of myocardial infarction was 11%, and that of urgent surgery 1.8%.(ABSTRACT TRUNCATED AT 250 WORDS)     

Angioplasty of internal mammary artery and saphenous vein bypasses and native coronary vessels in a patient with rapidly progressing disease

Although coronary artery bypass is an effective treatment for patients with coronary artery disease, early graft failure is sometimes observed. We report here on a patient who had triple-vessel coronary bypass surgery, and 3 subsequent coronary angioplasty procedures of grafts and native vessels in the 13 following months, because of recurrence of angina. Each procedure was followed by disappearance of signs and symptoms of myocardial ischemia. This case illustrates the complementary approach of coronary artery bypass surgery and percutaneous angioplasty to myocardial revascularization in patients with rapidly progressive coronary disease.     

Percutaneous transluminal angioplasty in patients with multivessel coronary disease: how important is complete revascularization for cardiac event-free survival?

The relative influences of revascularization status and baseline characteristics on long-term outcome were examined in 867 patients with multivessel coronary disease who had undergone successful coronary angioplasty. These patients represented 83% of a total of 1,039 patients in whom angioplasty had been attempted with an in-hospital mortality and infarction rate of 2.5% and 4.8%, respectively. Emergency coronary bypass surgery was needed in 4.9%. Of the 867 patients, 41% (group 1) were considered to have complete revascularization and 59% (group 2) to have incomplete revascularization. Univariate analysis revealed major differences between these two groups with patients in group 2 characterized by advanced age, more severe angina, a greater likelihood of previous coronary surgery and infarction, more extensive disease and poorer left ventricular function. Over a mean follow-up period of 26 months, the probability of event-free survival was significantly lower for group 2 only with respect to the need for coronary artery surgery (p = 0.004) and occurrence of severe angina (p = 0.04). The difference in mortality was of borderline significance (p = 0.051) and there were no significant differences between groups 1 and 2 in either the incidence of myocardial infarction or the need for repeat angioplasty. Multivariate analysis identified independent baseline predictors of late cardiac events that were then used to adjust the probabilities of event-free survival. This adjustment effectively removed any significant influence of completeness of revascularization on event-free survival for any of the above end points including the combination of death, myocardial infarction and need for coronary artery surgery. Therefore, late outcome in these patients is not significantly influenced by revascularization status but depends more on baseline patient characteristics.     

Comparative cost of myocardial revascularization: percutaneous transluminal angioplasty and coronary artery bypass surgery

A consecutive series of 78 patients having percutaneous transluminal coronary angioplasty for single vessel coronary artery disease and 85 patients having single vessel coronary artery bypass graft surgery were followed up prospectively for 1 year. Days in hospital and angiographic and revascularization procedures were counted in the two groups of patients and total cost of care for 12 months was calculated using current billing levels. Angioplasty was initially successful in 74% of patients; because of initial failure in 26% and late restenosis in 18%, bypass surgery was ultimately needed in 23 of 78 patients having coronary angioplasty. Nevertheless, total cost of care per patient was 43% lower for those having angioplasty as an initial procedure for single vessel coronary artery disease.     

Staged revascularization in critically ill patients with coronary artery disease

BACKGROUND: Critically ill patients undergoing bypass surgery experience a higher mortality and morbidity. HYPOTHESIS: The study was undertaken to evaluate the efficacy and value of percutaneous transluminal coronary angioplasty (PTCA) as a bridge to coronary artery bypass graft surgery (CABG) in high-risk patients with refractory unstable angina or cardiogenic shock. METHODS: We present 11 seriously unstable patients with severe multivessel coronary artery disease undergoing culprit vessel PTCA. Angioplasty was performed not as a definitive procedure but rather as a bridge to surgical revascularization. All the patients had sustained at least one myocardial infarction prior to catheterization, all had refractory unstable angina, eight patients had only a single patent coronary artery, and five patients were in cardiogenic shock. RESULTS: Following PTCA, all patients enjoyed a stable in-hospital period. One patient died 12 weeks after successful PTCA while awaiting second CABG. Seven patients subsequently underwent CABG and are doing well. The remaining three patients were also advised to undergo CABG, but elected to continue medical management. CONCLUSIONS: Coronary angioplasty of the culprit vessel may play a role as a bridge to surgery in critically ill patients.     

A prospective randomized trial comparing stenting with off-pump coronary surgery for high-grade stenosis in the proximal left anterior descending coronary artery: three-year follow-up

OBJECTIVES: This study was done to identify the best treatment for an isolated high-grade stenosis of the proximal left anterior descending coronary artery (LAD). BACKGROUND: Percutaneous transluminal coronary angioplasty with stenting (PCI) and off-pump coronary artery bypass grafting (surgery) are used to treat single-vessel disease of a high-grade stenosis of the proximal LAD. Midterm results of both treatments are compared in this prospective randomized study. METHODS: In a single-center prospective trial, we randomly assigned 102 patients with a high-grade stenosis of the proximal LAD (American College of Cardiology/American Heart Association classification type B2 or C) to PCI (n = 51) or surgery (n = 51). Primary composite end point was freedom from Major Adverse Cardiac and Cerebrovascular Events (MACCE) at follow-up, including death, myocardial infarction, cerebrovascular accident, and repeat target vessel revascularization (TVR). Secondary end points were angina pectoris class and need for antianginal medication at follow-up. Analysis was by intention-to-treat (ITT) and received treatment (RT). RESULTS: Mean follow-up time was three years (90% midrange, two to four years). Incidence of MACCE was 23.5% after PCI and 9.8% after surgery; p = 0.07 ITT (24.1% vs. 8.3%; p = 0.04 RT). After surgery a significantly lower angina pectoris class (p = 0.02) and need for antianginal medication (p = 0.01) was found compared to PCI. Target vessel revascularization was 15.7% after PCI and 4.1% after surgery (p = 0.09). CONCLUSIONS: At three-year follow-up (range, two to four years), a trend in favor of surgery is observed in regard to MACCE-free survival with a significantly lower angina pectoris status and significantly lower need for antianginal medication.     

A comparison of three-year survival after coronary artery bypass graft surgery and percutaneous transluminal coronary angioplasty

Objectives. The purpose of this study was to compare 3-year risk-adjusted survival in patients undergoing coronary artery bypass graft (CABG) surgery and percutaneous transluminal coronary angioplasty.Background. Coronary artery bypass graft surgery and angioplasty are two common treatments for coronary artery disease. For referral purposes, it is important to know the relative pattern of survival after hospital discharge for these procedures and to identify patient characteristics that are related to survival.Methods. New York’s CABG surgery and angioplasty registries were used to identify New York patients undergoing CABG surgery and angioplasty from January 1, 1993 to December 31, 1995. Mortality within 3 years of undergoing the procedure (adjusted for patient severity of illness) and subsequent revascularization within 3 years were captured. Three-year mortality rates were adjusted using proportional hazards methods to account for baseline differences in patients’ severity of illness.Results. Patients with one-vessel disease with the one vessel not involving the left anterior descending artery (LAD) or with less than 70% LAD stenosis had a statistically significantly longer adjusted 3-year survival with angioplasty (95.3%) than with CABG surgery (92.4%). Patients with proximal LAD stenosis of at least 70% had a statistically significantly longer adjusted 3-year survival with CABG surgery than with angioplasty regardless of the number of coronary vessels diseased. Also, patients with three-vessel disease had a statistically significantly longer adjusted 3-year survival with CABG surgery regardless of proximal LAD disease. Patients with other one-vessel or two-vessel disease had no treatment-related differences in survival.Conclusions. Treatment-related survival benefit at 3-years in patients with ischemic heart disease is predicted by the anatomic extent and specific site of the disease, as well as by the treatment chosen.     

Clinical trials of coronary revascularization for chronic stable angina: medical treatment versus coronary revascularization

For patients with chronic stable angina, several randomized trials have been performed comparing medical management with surgery, medical management with angioplasty, and angioplasty with surgery. Data from the medical versus revascularization trials (either surgery or angioplasty) support the following contentions: For patients with multivessel disease, particularly involving the proximal left anterior descending coronary artery, survival is superior to surgical treatment. Symptom relief with either type of revascularization is superior to medical management. The subsequent rate of myocardial infarction is not affected by the initial treatment strategy, whether medical, angioplasty, or surgery. In individual patients the potential benefits of any revascularization strategy must be weighed against its initial risks. Further study is needed, particularly with multifaceted pharmacologic therapy and with updated angioplasty techniques, to evaluate relative survival benefits in these patients. The studies supporting these conclusions are highlighted in this paper.     

The need for coronary surgery in 1993

Coronary surgery remains an important therapeutic option for coronary revascularization, particularly in the elderly with coronary disease, in whom recent studies have demonstrated improvement of quality of life and long-term survival compared with medical treatment. Morbidity and mortality in the elderly may be predicted by stratification of preoperative risk factors into scoring systems. Interim results from multicenter trials comparing coronary surgery and coronary angioplasty for the treatment of multivessel coronary disease suggest that coronary surgery may be better for symptom relief in angina, with fewer hospital admissions and therapeutic interventions. Surgery for single- or double-vessel disease is appropriate when initial attempts at revascularization by coronary angioplasty have failed. Coronary surgery may be a therapeutic option in the treatment of cardiogenic shock, particularly in the presence of three-vessel disease or the presence of complex lesions not amenable to angioplasty. Long-term survival after myocardial infarction may be improved by revascularization of the infarct-related artery. Recent studies of myocardial viability have examined the use of positron-emission tomography scanning to determine which patients may benefit most from myocardial revascularization.     

Long-term follow-up results after plain balloon coronary angioplasty.

Between September 1987 and June 1992, 571 patients of coronary artery disease underwent percutaneous transluminal coronary angioplasty in our institute. Their ages ranged from 31-82 years (mean 51 +/- 9) and majority (88.3%) were males. At baseline, 318 (55.7%) patients had chronic stable angina, 184 (32.2%) unstable angina, and 57 (10%) underwent PTCA for recurrence of angina in the post-infarction period. Single vessel angioplasty was performed in 406 (71.1%), two-vessel angioplasty in 121 (21.2%) and three or more vessels were dilated in 44 (7.7%). The procedure was successful in 524 (91.8%) patients. Follow-up was available in 438 (83.6%) patients, and ranged from 78 to 135 months (mean 89 +/- 29) with all the patients completing at least 60 months of follow-up. Using Kaplan-Meier statistical analysis, event-free survival (freedom from repeat percutaneous transluminal coronary angioplasty, myocardial infarction, coronary artery bypass surgery, or death) was 72.5 percent at three, 68.0 percent at five, 61.8 percent at seven and 55.6 percent at 10 years of follow-up. Freedom from major adverse cardiac events (myocardial infarction, coronary artery bypass surgery or death) was 88.3, 85.8, 82.0 and 75.4 percent at 3, 5, 7 and 10 years, respectively. Overall survival was 97.4 and 95.2 percent, respectively at 5 and 10 years. Subgroup analysis for all major events was done between males and females, diabetics and non-diabetics, previous history or absence of myocardial infarction, stable versus unstable angina and single versus multivessel disease. Event-free survival rates were compared between the groups using log rank test. On follow-up, the need for surgical revascularisation was more in males compared to females although statistically insignificant, and in patients with unstable angina compared to stable angina (p < 0.02). Similarly, freedom from major adverse cardiac events was significantly better in females compared to males (p < 0.05) and in stable versus unstable angina (p < 0.01). Event-free survival (repeat percutaneous transluminal coronary angioplasty, myocardial infarction, coronary artery bypass surgery, death) was also significantly better in patients with stable angina (p < 0.02). The other outcomes were comparable in all the subgroups. In conclusion, plain balloon angioplasty provides excellent long-term results in patients with coronary artery disease in terms of reduction in major adverse cardiovascular events and need for subsequent revascularisation.     

Bypass surgery versus stenting for the treatment of multivessel disease in patients with unstable angina compared with stable angina

BACKGROUND: Earlier reports have shown that the outcome of balloon angioplasty or bypass surgery in unstable angina is less favorable than in stable angina. Recent improvements in percutaneous treatment (stent implantation) and bypass surgery (arterial grafts) warrant reevaluation of the relative merits of either technique in treatment of unstable angina. Methods and Results- Seven hundred fifty-five patients with stable angina were randomly assigned to coronary stenting (374) or bypass surgery (381), and 450 patients with unstable angina were randomly assigned to coronary stenting (226) or bypass surgery (224). All patients had multivessel disease considered to be equally treatable by either technique. Freedom from major adverse events, including death, myocardial infarction, and cerebrovascular events, at 1 year was not different in unstable patients (91.2% versus 88.9%) and stable patients (90.4% versus 92.6%) treated, respectively, with coronary stenting or bypass surgery. Freedom from repeat revascularization at 1 year was similar in unstable and stable angina treated with stenting (79.2% versus 78.9%) or bypass surgery (96.3% versus 96%) but was significantly higher in both unstable and stable patients treated with stenting (16.8% versus 16.9%) compared with bypass surgery (3.6% versus 3.5%). Neither the difference in costs between stented or bypassed stable or unstable angina ($2594 versus $3627) nor the cost-effectiveness was significantly different at 1 year. CONCLUSIONS: There was no difference in rates of death, myocardial infarction, and cerebrovascular event at 1 year in patients with unstable angina and multivessel disease treated with either stented angioplasty or bypass surgery compared with patients with stable angina. The rate of repeat revascularization of both unstable and stable angina was significantly higher in patients with stents.     

Argentine Randomized Study: Coronary Angioplasty with Stenting versus Coronary Bypass Surgery in patients with Multiple-Vessel Disease (ERACI II): 30-day and one-year follow-up results. ERACI II Investigators

OBJECTIVE: The purpose of this study was to compare percutaneous transluminal coronary revascularization (PTCR) employing stent implantation to conventional coronary artery bypass graft surgery (CABG) in symptomatic patients with multivessel coronary artery disease. BACKGROUND: Previous randomized studies comparing balloon angioplasty versus CABG have demonstrated equivalent safety results. However, CABG was associated with significantly fewer repeat revascularization procedures. METHODS: A total of 2,759 patients with coronary artery disease were screened at seven clinical sites, and 450 patients were randomly assigned to undergo either PTCR (225 patients) or CABG (225 patients). Only patients with multivessel disease and indication for revascularization were enrolled. RESULTS: Both groups had similar clinical demographics: unstable angina in 92%; 38% were older than 65 years, and 23% had a history of peripheral vascular disease. During the first 30 days, PTCR patients had lower major adverse events (death, myocardial infarction, repeat revascularization procedures and stroke) compared with CABG patients (3.6% vs. 12.3%, p = 0.002). Death occurred in 0.9% of PTCR patients versus 5.7% in CABG patients, p < 0.013, and Q myocardial infarction (MI) occurred in 0.9% PTCR versus 5.7% of CABG patients, p < 0.013. At follow-up (mean 18.5 +/- 6.4 months), survival was 96.9% in PTCR versus 92.5% in CABG, p < 0.017. Freedom from MI was also better in PTCR compared to CABG patients (97.7% vs. 93.4%, p < 0.017). Requirements for new revascularization procedures were higher in PTCR than in CABG patients (16.8% vs. 4.8%, p < 0.002). CONCLUSIONS: In this selected high-risk group of patients with multivessel disease, PTCR with stent implantation showed better survival and freedom from MI than did conventional surgery. Repeat revascularization procedures were higher in the PTCR group.     

The limited impact of percutaneous coronary artery angioplasty on bypass surgery

Although percutaneous transluminal coronary angioplasty has been used successfully now for 10 years, coronary bypass surgery volumes have not diminished greatly. This paper examines the anatomic limitations of percutaneous transluminal coronary angioplasty. Using complete revascularization criteria, angioplasty could be used in only 38% of patients undergoing coronary bypass surgery at the Cleveland Clinic in 1981. The principal anatomic reason for rejecting patients for percutaneous transluminal coronary angioplasty was chronic total occlusion in a vessel suitable for bypass surgery. Angioplasty could be used more frequently in one- and two-vessel bypass patients than in patients receiving more grafts. Percutaneous transluminal coronary angioplasty is currently limited more by its inability to more completely revascularize advanced coronary artery disease than it is from the technical aspects of crossing or dilating stenoses.     

Percutaneous coronary intervention in the 1990s. Results in patients with single or multivessel disease.

The proper role of percutaneous coronary intervention in the 1990s relative to other forms of therapy remains to be defined and appears to be a continually moving target. Ongoing randomized comparative studies with bypass surgery in patients with complex disease will assist in defining the role of angioplasty and bypass surgery, but should be viewed carefully with regard to the apparent improvements in procedural outcome and demonstrated effective patient heterogeneity on outcome. It is likely that percutaneous revascularization will remain the mainstay of therapy for patients with single vessel coronary disease who have lifestyle limiting angina or can be demonstrated to have large areas of ischemia with little provocation. One exception to this generalization might be for patients with ostial or very proximal left anterior descending narrowings in whom bypass surgery might be a better long-term therapy. Unfortunately, little truly comparable data exists for patients treated with percutaneous revascularization and bypass surgery within this group. Percutaneous revascularization will also probably remain the preferred therapy for patients with relatively focal multivessel coronary disease whilst bypass surgery will remain the preferred approach for patients with more diffuse disease and possibly for those with moderate or moderate to severe left ventricular contractile impairment. It might be expected, however, that improvements in procedural outcome with percutaneous revascularization will allow interventionalists to gradually encroach upon the previous domain of cardiac surgeons.     

Coronary angioplasty for unstable angina.

Coronary angioplasty is an effective treatment for subgroups of patients with unstable angina. The procedure has a high initial success rate but there is an increased risk of major complications resulting from a higher incidence of acute closure presumably related to additional injury of the underlying plaque with augmented platelet and clotting activity, and ensuing spasm. Newer agents that inhibit platelet aggregation or thrombin may provide a safer use of coronary angioplasty in patients with unstable angina. Coronary angioplasty is indicated if a stenosis, technically suitable for dilation, is found to be responsible for the unstable state. The decision in favor of coronary angioplasty in patients with single-vessel disease is easy to make. Patients with left main stem disease or severe multivessel disease should primarily be scheduled for bypass surgery. In the presence of other multivessel disease, uncertainty remains. However, in selected patients with multivessel disease, one might prefer dilation of the ischemia-related vessel "the culprit vessel" only, rather than total revascularization by multiple dilatations or bypass surgery, since this can be performed faster and thus shorten the hospital stay. Thrombolytic treatment in the management of patients with unstable angina may be indicated in patients with pre-existing intracoronary thrombi or when procedural acute closure occurs associated with intracoronary thrombus formation.