Predictors of Adverse 30-Day Outcomes After Right Coronary Artery ST-Elevation Myocardial Infarction

Background: There is limited contemporary evidence on predictors of adverse outcomes in ST-elevation myocardial infarction (STEMI) involving the right coronary artery (RCA). We examined this in a single-centre retrospective cohort study, focusing on 30-day outcomes. Methods: Consecutive patients presenting to an Australian tertiary hospital between May 2022 and April 2024 with acute STEMI who underwent primary percutaneous coronary intervention (PCI) or rescue PCI were eligible. Patients were divided into STEMI due to RCA and non-RCA culprit lesions, and their characteristics were compared. The primary outcome was a composite of 30-day all-cause mortality and cardiogenic shock. Results: Among 320 included patients, the primary composite outcome was similar between the RCA and non-RCA groups (12% vs. 15%, p = 0.44), although 30-day mortality was lower in the RCA-STEMI group (2% vs. 8%, p = 0.01). In the RCA-STEMI cohort, right ventricular (RV) longitudinal dysfunction on echocardiogram, defined as a tricuspid annular plane systolic excursion (TAPSE) < 17 mm or RV tissue doppler lateral annular systolic velocity (RV S′) < 10 cm/s (p = 0.04), and Thrombolysis in Myocardial Infarction (TIMI) flow < 3 in the RV marginal branch post-PCI (p = 0.04) were independently associated with the primary outcome. The latter was also associated with a higher risk of intensive care unit admission for cardiogenic shock (p < 0.01) and heart failure requiring inpatient diuresis (p = 0.02). Conclusions: In patients with RCA-STEMI, compromised RV marginal branch flow post-PCI and impaired RV function were independently associated with the composite primary outcome of 30-day all-cause mortality and cardiogenic shock. These characteristics may assist early identification of at-risk individuals who could benefit from pro-active monitoring and early implementation of therapies for cardiogenic shock.