ABSTRACT

BACKGROUND - Left main coronary artery (LMCA) disease is associated with high mortality and morbidity due to a large area of jeopardized myocardium. However, the optimal revascularization strategy for patients with LMCA disease and left ventricular dysfunction is still unclear.

OBJECTIVES - This study sought to examine long-term comparative outcomes after percutaneous coronary intervention (PCI) or a coronary artery bypass grafting (CABG) according to the severity of left ventricular dysfunction.

METHODS - The authors evaluated a total of 3,488 patients with LMCA disease who underwent CABG (n = 1,355) or PCI (n = 2,133) from the IRIS-MAIN (Interventional Research Incorporation Society-Left MAIN Revascularization) registry. Left ventricular function was categorized according to left ventricular ejection fraction (LVEF) as normal function (LVEF ≥55%), mild dysfunction (LVEF ≥45% to <55%), moderate dysfunction (LVEF ≥35% to <45%), or severe dysfunction (LVEF <35%). The primary outcome was a composite of death, myocardial infarction, or stroke.

RESULTS - Among the overall patient population, 2,641 (75.7%) patients had normal LVEF and 403 (11.6%), 260 (7.5%), and 184 (5.3%) had mild, moderate, and severe left ventricular dysfunction at baseline, respectively. Compared with CABG, PCI was associated with a higher adjusted risk of primary outcomes in patients with moderate (hazard ratio [HR]: 2.23; 95% confidence interval [CI]: 1.17 to 4.28) or severe (HR: 2.45; 95% CI: 1.27 to 4.73) dysfunction. In contrast, PCI and CABG had similar risks of the primary outcomes in patients with normal (HR: 0.80; 95% CI: 0.59 to 1.07) or mild (HR: 1.17; 95% CI: 0.63 to 2.17) dysfunction (p for interaction = 0.004).

CONCLUSIONS - In the revascularization of LMCA disease, PCI was associated with an inferior primary composite outcome of death, MI, or stroke compared with CABG in patients with moderate or severe left ventricular dysfunction. However, the risk for the primary outcome was comparable between PCI and CABG in those with normal or mild left ventricular dysfunction. (Observational Study for Left Main Disease Treatment; NCT01341327)