Long-term outcomes in inferior ST-segment elevation myocardial infarction patients with right ventricular myocardial infarction.

Objective: To evaluate the prognostic influence of the presence of right ventricular myocardial infarction (RVMI) on patients with inferior ST-segment elevation myocardial infarction (STEMI) in the contemporary reperfusion era.

Methods: 9308 patients with inferior STEMI were included from the prospective, nationwide, multicenter China Acute Myocardial Infarction Registry, including 1745 (18.75%) patients with RVMI and 7563 (81.25%) patients without RVMI. The primary outcome was two-year all-cause mortality. The secondary outcome was major adverse cardiac and cerebrovascular event (MACCE) defined as a composite of all-cause mortality, recurrent MI, revascularization, stroke, and major bleeding.

Results: After two-year follow up, there were no significant differences between inferior STEMI patients with or without RVMI in all-cause mortality (12.0% vs 11.3%; adjusted HR: 1.05; 95% CI: 0.90 to 1.24; P = 0.5103). Inferior STEMI with RVMI was associated with higher risk of MACCE (25.6% vs 22.0%; adjusted HR: 1.17; 95% CI: 1.05 to 1.31; P = 0.0038), revascularization (10.3% vs 8.1%; adjusted HR: 1.23; 95% CI: 1.03 to 1.48; P = 0.0218), and major bleeding (4.6% vs 2.7%; adjusted HR: 1.56; 95% CI: 1.18 to 2.07; P = 0.0019). Primary percutaneous coronary intervention (PCI) and thrombolysis were independent predictors to decrease all-cause mortality. For patients who received timely reperfusion, RVMI involvement did not increase all-cause mortality, whereas for those who did not undergo reperfusion, RVMI increased all-cause mortality (20.3% vs 15.7%; HR: 1.34; 95% CI: 1.10 to 1.63).

Conclusion: RVMI did not increase all-cause mortality for inferior STEMI patients in contemporary reperfusion era, whereas the risk was increased for patients with no reperfusion treatment.