Limited data exist regarding the incidence and long-term implications of spontaneous myocardial infarction (MI) following revascularization for left main coronary artery disease (LMCAD). A secondary analysis of the EXCEL trial evaluated the rates and prognostic impact of spontaneous and procedural MI after percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG). The study was published in the Circulation.
Among 1,882 patients undergoing LMCAD revascularization, spontaneous MI occurred in 60 patients (6.8%) after PCI and 29 patients (3.4%) after CABG during five-year follow-up. After adjustment, spontaneous MI was more frequent following PCI (adjusted hazard ratio [adjHR] 2.01; 95% CI 1.29–3.15; P=0.002).
In multivariable time-adjusted analyses, spontaneous MI was independently associated with increased five-year cardiovascular mortality (adjHR 9.39; 95% CI 5.22–16.87) and all-cause mortality (adjHR 4.77; 95% CI 2.92–7.80). These associations were consistent after PCI and CABG (interaction P=0.60 and 0.78, respectively). Procedural MI defined by extensive myonecrosis was also associated with cardiovascular (adjHR 3.02; 95% CI 1.64–5.56) and all-cause mortality (adjHR 2.38; 95% CI 1.48–3.80), with no significant interaction by treatment strategy. As a secondary analysis of a randomized trial, findings demonstrate associations rather than causation.
