Angiographic disease progression and residual risk of cardiovascular events while on optimal medical therapy: observations from the COURAGE Trial.

Background: The extent to which recurrent events in patients with stable coronary artery disease is attributable to progression of an index lesion originally ≥50% diameter stenosis (DS) but not revascularized or originally <50% DS is unknown during optimal medical therapy (OMT).
Methods and Results: In the COURAGE (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation) trial, 205 patients assigned to OMT plus percutaneous coronary intervention (PCI) and 284 patients assigned to OMT only had symptom-driven angiograms suitable for analysis. Percentages of patients in the OMT+PCI and OMT-only cohorts with index lesions originally <50% DS were 30% and 32%, respectively; 20% and 68% had index lesions originally ≥50% DS. In both groups, index lesions originally <50% or ≥50% DS represented <4% and <25% of all such lesions, respectively. The only angiographic predictor of myocardial infarction or acute coronary syndrome was the number of lesions originally ≥50% DS that had not been revascularized (odds ratio, 1.15; confidence limits, 1.01-1.31; P<0.04).
Conclusions: Lesions originally <50% DS were index lesions in one third of patients referred for symptom-driven repeat angiography, but represented <4% of all such lesions. Nonrevascularized lesions originally ≥50% DS were more often index lesions in OMT-only patients, but still represented a minority (<25%) of all such lesions. These findings underscore the need for improved therapies to arrest plaque progression and reliable strategies for selecting stenoses warranting PCI.