Prognostic impact of right ventricular dysfunction in subacute myocardial infarction

Background Right ventricular (RV) impairment is a well-recognized risk factor associated with mortality and morbidity in various contexts such as cardiogenic shock, chronic heart failure and acute myocardial infarction (AMI), but its role in the setting of subacute myocardial infarction (SMI) has not yet been explored. Objectives This study aimed to establish whether RV dysfunction could predict in-hospital and long-term adverse cardiovascular events in the context of SMI. Methods Consecutive patients with myocardial infarction were enrolled from 2017 to 2024. Myocardial infarction with ST-segment elevation (STEMI) was defined according to the last European Guidelines on acute coronary syndromes. SMI was defined as a delay > 12 hours from symptom onset to first medical contact (FMC). RV dysfunction was defined according to European Recommendation on echocardiography. Multivariable regression analysis was performed in all STEMI patients to assess the independent role of delay > 12 hours to predict RV dysfunction at admission. Outcome of interest include in-hospital mortality and long-term MACE (a composite of all-cause mortality, re-infarction, stroke and heart failure heart failure hospitalization). Multivariable logistic and Cox regression analysis were performed to identify independent predictors of in-hospital mortality and long-term MACE respectively in SMI patients. Kaplan-Meier curves were constructed among SMI patients with and without RV dysfunction. Results 2207 patients were admitted with a diagnosis of STEMI (mean age 67.9 y ± 13.8 y; female sex 25.2%). Among them, 136 (6.2%) presented RV dysfunction and 481 (21,8%) were SMI. RV dysfunction was more common among patients with a delay > 12 hours (10.8% vs 5.0%, p<0.001). Furthermore, a delay > 12 hours was an independent predictor of RV dysfunction at admission (OR 1.64, 95% CI [1.05-2.56], p=0.032), together with high-grade AV block and systolic hypotension. Among SMI patients, those with RV involvement exhibited high in-hospital mortality (32.7% vs 10.7%, p<0.001) and RV dysfunction served as an independent predictor of in-hospital mortality (OR 4.43, 95% CI [1.87-10.47], p = 0.001) together with older age, lower hemoglobin, mechanical complication and high Killip class whereas percutaneous revascularization showed a protective effect. Moreover, during a median follow-up of 32 months, SMI with RV involvement at discharge experienced more often MACE (50% vs 29.5%, p=0.009). Furthermore, at Cox regression analysis for MACE, RV dysfunction at discharge was independently associated with a significantly high risk of MACE (HR=1.77, 95% CI [1.04-3.02], p=0.040). Conclusion Among STEMI patients, those with SMI have a significantly higher risk of RV involvement, which in turn represents a strong independent predictor of both in-hospital mortality and long-term MACE. These findings highlight the crucial need for early recognition and management of RV dysfunction to improve clinical outcomes.