Effectiveness of percutaneous coronary intervention in patients with silent myocardial ischemia (post hoc analysis of the COURAGE trial)
Angioplasty, Balloon, Coronary
Previous studies have suggested that percutaneous coronary intervention (PCI) decreases long-term mortality in patients with silent myocardial ischemia (SMI), but whether PCI specifically decreases mortality when added to intensive medical therapy is unknown. We performed a post hoc analysis of clinical outcomes in patients in the COURAGE trial based on the presence or absence of anginal symptoms at baseline. Asymptomatic patients were classified as having SMI by electrocardiographic ischemia at rest or reversible stress perfusion imaging (exercise-induced or pharmacologic). Study end points included the composite primary end point (death or myocardial infarction [MI]); individual end points of death, MI, and hospitalization for acute coronary syndrome; and need for revascularization. Of 2,280 patients 12% (n = 283) had SMI and 88% were symptomatic (n = 1,997). There were no between-group differences in age, gender, cardiac risk factors, previous MI or revascularization, extent of angiographic disease, or ischemia by electrocardiogram or imaging. Compared to symptomatic patients, those with SMI had fewer subsequent revascularizations (16% vs 27%, p <0.001) regardless of treatment assignment and fewer hospitalizations for acute coronary syndrome (7% vs 12%, p <0.04). No significant differences in outcomes were observed between the 2 treatment groups, although there was a trend toward fewer deaths in the PCI group (n = 7, 5%) compared to the optimal medical therapy (OMT) group (n = 16, 11%, p = 0.12). In conclusion, addition of PCI to OMT did not decrease nonfatal cardiac events in patients with SMI but showed a trend toward fewer deaths. Although underpowered, given similar outcomes in other small studies, these findings suggest the need for an adequately powered trial of revascularization versus OMT in SMI patients.