Percutaneous coronary intervention versus optimal medical therapy for prevention of spontaneous myocardial infarction in subjects with stable ischemic heart disease.

BACKGROUND: Contemporary studies have shown that spontaneous but not procedural myocardial infarction (MI) is related to subsequent mortality. Whether percutaneous coronary intervention (PCI) reduces spontaneous (nonprocedural) MI is unknown. METHODS AND
RESULTS: PubMed, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) were searched for randomized clinical trials until October 2012 comparing PCI with optimal medical therapy (OMT) for stable ischemic heart disease and reporting MI outcomes: spontaneous nonprocedural MI, procedural MI, and all MI, including procedure-related MI. Given the varying length of follow-up between trials, a mixed-effect Poisson regression meta-analysis was used. From 12 randomized clinical trials with 37 548 patient-years of follow-up, PCI compared with OMT alone was associated with a significantly lower incident rate ratio (IRR) for spontaneous nonprocedural MI (IRR=0.76; 95% confidence interval [CI], 0.58-0.99) at the risk of a higher rate of procedural MI (IRR=4.11; 95% CI, 2.53-6.88) without any difference in the risk of all MI (IRR=0.96; 95% CI, 0.74-1.21). The point estimate for PCI versus OMT for all-cause mortality (IRR=0.88; 95% CI, 0.75-1.03) and cardiovascular mortality (IRR=0.70; 95% CI, 0.44-1.09) paralleled that for spontaneous nonprocedural MI (but not procedural or all nonfatal MI), although these were not statistically significant.
CONCLUSIONS: PCI compared with OMT reduced spontaneous MI at the risk of procedural MI without any difference in all MI. Consistent with prior studies showing that spontaneous MI but not procedural MI is related to subsequent mortality, in the present report the point estimate for reduced mortality with PCI compared with OMT paralleled the prevention of spontaneous MI with PCI. Further studies are needed to determine whether these associations are causal.