The Clinical Significance of Right Coronary Artery Stenosis on the Prognosis of Patients with Unprotected Left Main Disease Undergoing Percutaneous Coronary Intervention

Background: Although coronary artery bypass grafting remains the standard treatment for unprotected left main (LM) coronary artery disease, percutaneous coronary intervention (PCI) with the use of stent has become an alternative treatment. In this study, we aimed to evaluate the real-world results of patients with LM disease treated with PCI and compare the impact of significant right coronary artery (RCA) disease on the short-term and long-term outcomes of these patients. Methods and Results: A total of 164 patients were included, with 95 patients (57.9%) with significant RCA stenosis and 69(42.1%) patients without, and were followed up over a mean period of 2.5 years. EuroSCORE >= 6 was noted in 78 patients (47.6%). Within the 30-day period after index procedure, major adverse cardiovascular events (MACE) were observed in 16 (9.9%) patients, including 15 (9.3%) deaths, and 1 non-fatal myocardial infarction (0.6%). Three patients suffered from probable sub-acute stent thrombosis (1.8%). In the stepwise multivariate Cox regression analysis, female gender, left ventricular ejection fraction < 40% and RCA disease were identified as the significant independent predictors of 30-day deaths and MACE. As for the long-term outcomes, the mean follow-up period was 2.5 years (range 1 month to 9.7 years, median 23.4 months). There were 38 deaths (23.6%), and 57 MACE (35.4%). The survival of LM patients with RCA disease remained worse than that of those without (p < 0.01), and concomitant RCA disease remained significant prognostic predictor after being adjusted by other variables. Conclusion: In this real-world practice in a single center, we found that unprotected LM stenting in patients with concomitant significant stenosis of RCA may be associated with worse early and long-term outcomes compared with those without RCA disease.