Prognostic importance of coronary anatomy and left ventricular ejection fraction despite optimal therapy: assessment of residual risk in the Clinical Outcomes Utilizing Revascularization and Aggressive DruG Evaluation Trial.

Background: It is unknown if baseline angiographic findings can be used to estimate residual risk of patients with chronic stable angina treated with both optimal medical therapy (OMT) and protocol-assigned or symptom-driven percutaneous coronary intervention (PCI).

Methods: Death, myocardial infarction (MI), and hospitalization for non-ST-segment elevation acute coronary syndrome were adjudicated in 2,275 COURAGE patients. The number of vessels diseased (VD) was defined as the number of major coronary arteries with ≥50% diameter stenosis. Proximal left anterior descending, either isolated or in combination with other disease, was also evaluated. Depressed left ventricular ejection fraction (LVEF) was defined as ≤50%. Cox regression analyses included these anatomical factors as well as interaction terms for initial treatment assignment (OMT or OMT + PCI).

Results: Percutaneous coronary intervention and proximal left anterior descending did not influence any outcome. Death was predicted by low LVEF (hazard ratio [HR] 1.86, CI 1.34-2.59, P < .001) and VD (HR 1.45, CI 1.20-1.75, P < .001). Myocardial infarction and non-ST-segment elevation acute coronary syndrome were predicted only by VD (HR 1.53, CI 1.30-1.81 and HR 1.24, CI 1.06-1.44, P = .007, respectively).

Conclusions: In spite of OMT and irrespective of protocol-assigned or clinically driven PCI, LVEF and angiographic burden of disease at baseline retain prognostic power and reflect residual risk for secondary ischemic events.