Beyond the inferior wall: right ventricular involvement in acute myocardial infarction
R Esculudes Dos Santos Ferrao Gomes, R Montalvao, M Ramos, A Garcia, C Santos-Jorge, M Presume, A R Bello, J Presume, M Trabulo, J Ferreira, C BrizidoAbstract
Background
Inferior myocardial infarction (MI) with right ventricular (RV) involvement is frequently associated with conduction abnormalities, hemodynamic instability and adverse outcomes. This study aimed to evaluate outcomes in patients with inferior MI and RV extension.
Methods
Retrospective, single-centre study, analysing consecutive patients admitted to a cardiac intensive care unit (CICU) for inferior ST-segment elevation MI between 2015 and 2024 at a tertiary care centre. RV involvement was diagnosed by right precordial leads ST elevation ≥1 mm and/or echocardiographic evidence of dysfunction, defined by tricuspid annular plane systolic excursion (TAPSE) <18mm and RV systolic velocity on tissue Doppler (RV S′) < 10cm/s. The primary endpoint was 1-year all-cause mortality. Secondary endpoints included heart failure (HF) hospitalization, ventricular arrhythmias, recurrent ischemia and RV systolic function during follow-up. Predictors of RV systolic recovery at 12 months were explored in univariate analysis, with variables showing significant associations entered a multivariable model.
Results
From a total of 391 patients, 32% (n=127) had RV involvement, mostly identified by echocardiographic criteria (83%). The right coronary artery (RCA) was the culprit vessel in 86% of patients with RV involvement versus 68% without (p < 0.001). Cardiogenic shock occurred more frequently in the RV involvement group (18% vs. 6%, p < 0.001), and complete AV block was significantly more common (31% vs. 9%, p < 0.001), with 14% requiring permanent pacemaker implantation (p = 0.01). In-hospital mortality was higher among patients with RV involvement (7% vs. 2%, p = 0.02). At 12 months, Kaplan–Meier analysis showed increased mortality in the RV involvement group (14% vs. 6%; log-rank p = 0.01). In univariate analysis, RV involvement, age, diabetes, multivessel disease, cardiogenic shock, complete AV block, incomplete revascularization, and LVEF <40% were associated with 12-month mortality; all except diabetes remained independent predictors in multivariable analysis. Echocardiographic follow-up at 12 months (available in 85% of survivors) showed significant RV systolic recovery, with TAPSE improving from 13.6 ± 2.8 mm to 18.2 ± 3.1 mm (p < 0.001) and S′ from 8.0 ± 1.8 cm/s to 10.5 ± 1.7 cm/s (p < 0.001). Overall, 74% of patients with RV involvement achieved significant RV systolic recovery at 12 months. Baseline RV dysfunction, incomplete revascularization, multivessel disease, and reduced LVEF independently predicted incomplete RV recovery.
Conclusions
Inferior MI with RV extension poses higher risk of 1-year mortality, HF rehospitalization and ventricular arrhythmias. Despite this, RV systolic recovery occurred in most patients, with baseline RV dysfunction, delayed or unsuccessful revascularization, multivessel disease, and reduced LVEF being key predictors of RV non-recovery.For image description, please refer to the figure legend and surrounding text.