Is traditionally defined complete revascularization needed for patients with multivessel disease treated by elective coronary angioplasty? Multivessel Angioplasty Prognosis Study (MAPS) Group.

OBJECTIVES

The purpose of this study was to determine the effect of incomplete revascularization by percutaneous transluminal coronary angioplasty in patients with multivessel disease on adverse long-term cardiac events (death, coronary artery bypass surgery or myocardial infarction) and to develop an optimal definition of adequate revascularization based on clinical outcome.

BACKGROUND

The effect of incomplete coronary revascularization by coronary angioplasty on long-term adverse clinical events remains controversial.

METHODS

Three hundred seventy well characterized patients were followed-up for 27 +/- 16 months after angioplasty. Mean patient age was 58 +/- 11 years; 72% were male; 70% had two-vessel disease (> or = 50% diameter stenosis by caliper measurement); and the mean left ventricular ejection fraction was 58 +/- 11% (range 20% to 85%). Angioplasty was successfully accomplished in 339 patients (91.6%), but complete revascularization by the standard definition (no residual > or = 50% stenosis in a coronary artery > or = 1.5 mm in diameter) was achieved in only 91 patients (25%).

RESULTS

Three-year event-free survival (i.e., freedom from death, myocardial infarction, coronary artery bypass surgery) in the entire cohort was 76.5%. By the standard definition, complete revascularization was strongly and negatively associated (p = 0.003) with long-term cardiac events, even after correction for the effects of other independent correlates of events, using Cox proportional hazard regression analysis. Seventeen other definitions, evaluating the severity and extent of residual stenoses and whether they were associated with contractile myocardium, were tested to find that which best stratified late event-free survival and had an outcome with complete revascularization no worse than that associated with the standard definition. The best definition for the entire cohort, having more predictive value than the standard definition, allowed < 10% of estimated left ventricular mass to be served by vessels with mild stenoses (< 60%) without being considered "incomplete."

CONCLUSIONS

Mild stenoses in coronary arteries > or = 1.5 mm in diameter serving modest amounts of myocardium do not appear to need to be revascularized to achieve good long-term outcome with coronary angioplasty. Hence, angioplasty in such lesions may not be justified except when they are documented to cause life-style-limiting angina, and the standard definition of complete revascularization by angioplasty appears to be suboptimal. The importance of optimally defined adequate revascularization should be considered in the interpretation of the results of randomized trials assessing the clinical efficacy of coronary angioplasty compared with that of other modalities of therapy.