Impact of Right Ventricular Involvement on Bleeding and Mortality in Patients With Right Coronary Artery-Related Myocardial Infarction ― Insights From Nationwide Registry ―

BACKGROUND: Right ventricular involvement (RVI) in acute myocardial infarction (AMI) patients is recognized as a high-risk subset. However, its impact on bleeding and mortality is not well defined in patients with right coronary artery (RCA)-related ST-segment elevation acute myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI). METHODS AND RESULTS: Using data from the multicenter, prospective Japan AMI Registry including 3,411 patients, we analyzed 993 patients with RCA-related STEMI who underwent PCI. The incidence of all-cause mortality and major bleeding, defined as Bleeding Academic Research Consortium Type 3 or 5, was compared between patients with and without RVI. RVI was present in 9% (n=92) of patients. During a 12-month follow-up, RVI was independently associated with an increased risk of all-cause mortality (adjusted hazard ratio [HR] 2.05; 95% confidence interval [CI] 1.11-3.79) and major bleeding (adjusted HR 2.28; 95% CI 1.13-4.57) in Cox analysis, although this bleeding association was attenuated in adjusted competing-risk analysis (adjusted subdistribution HR 1.87; 95% CI 0.90-3.89). Among patients with RVI, those who experienced major bleeding had a significantly higher risk of death (HR 4.88, 95% CI 1.63-14.58). CONCLUSIONS: In patients with RCA-related STEMI treated with PCI, RVI was associated with increased mortality and appeared to be associated with a higher risk of bleeding.