Impact of Plaque Burden in the Left Main Coronary Artery Determined by Intravascular Ultrasound on Cardiovascular Events in a Japanese Population Undergoing Percutaneous Coronary Intervention

The left main coronary artery (LMCA) is a particularly important target of atherosclerotic plaque accumulation. The aim of this study was to investigate the connection between subclinical plaque burden in the LMCA measured by intravascular ultrasound and future cardiovascular events. Two hundred eighteen consecutive patients underwent percutaneous coronary intervention for the left anterior descending coronary artery or the left circumflex coronary artery under intravascular ultrasound guidance. Plaque burden in the LMCA was analyzed for these patients, and major adverse cardiac events were also evaluated. Data were analyzed by grouping the patients into tertiles according to plaque burden values; tertile 1, <32% area stenosis; tertile 2, 32% to 45% area stenosis; and tertile 3, >45% area stenosis. During a 3-year follow-up period (average 16.1 months), 12% of tertile 1, 18% of tertile 2, and 40% of tertile 3 experienced major adverse cardiac events, mostly due to repeat revascularization (p <0.001). On Cox multivariate analysis, plaque burden in the LMCA (per percentage) detected by intravascular ultrasound remained an independent significant predictor of major adverse cardiac events (hazard ratio 1.04, 95% confidence interval 1.02 to 1.07) and future revascularization (hazard ratio 1.05, 95% confidence interval 1.02 to 1.07) (p <0.001). In conclusion, plaque burden in the LMCA is useful as an indicator of coronary atherosclerosis and may be a significant predictor of cardiovascular events, especially revascularization.