Background: Diabetes mellitus (DM), low ejection fraction (EF), and the extent of coronary artery disease (CAD) have all been identified as predictors of cardiovascular events in multivessel disease, but their comparative contributions to future risk remain unclear in patients with unprotected left main coronary artery (ULMCA) disease. Through this study we aimed to categorize the risk for cardiovascular events in patients with ULMCA disease using simple clinical descriptors.
Patients and methods: Our study included a total of 5975 patients with ULMCA disease from the Interventional Research Incorporation Society-Left MAIN Revascularization registry who were treated with percutaneous coronary intervention (n=2850), coronary artery bypass grafting (n=2337), or medical therapy alone (n=608). We categorized the risk for cardiovascular events using simple clinical descriptors (DM, low EF, and the extent of CAD). The primary outcome was a major adverse cardiac or cerebrovascular event (MACCE) (i.e. death from any cause, stroke, myocardial infarction, or repeat revascularization).
Results: Overall, the 5-year rate of MACCE was highest in the medical group, lower in the percutaneous coronary intervention group, and lowest in the coronary artery bypass grafting group (42.5, 25.7, and 19.9%, respectively; P<0.001). In multivariable modeling, the presence of DM [hazard ratio (HR): 1.25; 95% confidence interval (CI): 1.12-1.40; P<0.001], low EF of 40% or less (HR: 1.83; 95% CI: 1.56-2.15; P<0.001), and the extent of CAD (HR: 1.14; 95% CI: 1.08-1.21; P<0.001) were independent predictors of MACCE; in addition, these factors were consistently associated with a significantly higher risk for MACCE, regardless of index treatment strategies.
Conclusion: Simple clinical descriptors can assist clinicians in identifying high-risk patients and in predicting future cardiovascular events within the broad range of risk factors for ULMCA disease.