Right ventricular function and determining factors of dysfunction in ST-segment-elevation myocardial infarction: a cross-sectional study with cardiac magnetic resonance imaging (MRI).

Background: Over the past few decades, left ventricular (LV) dysfunction in ST-segment elevation myocardial infarction (STEMI) patients has been the focus of research. Recently, co-occurring right ventricular (RV) dysfunction has received more attention in clinical practice. We aimed to assess RV function using cardiac magnetic resonance (CMR) imaging and identify factors that may contribute to RV dysfunction in STEMI patients.

Methods: We retrospectively studied 189 patients with STEMI who underwent CMR 1-7 days after successful percutaneous coronary intervention (PCI). The ejection fraction (EF), wall thickening rate (WTR), peak radial strain (RS), circumferential strain (CS) and longitudinal strain (LS) of the LV, interventricular septum (IVS) and RV were measured with cine images. The location and extent of the infarct were determined using late gadolinium enhancement (LGE) imaging. The differences of function between STEMI patients with right ventricular ejection fraction (RVEF) <50% and those with RVEF ≥50% were compared using an independent-sample t-test. Linear regression analyses were used to determine independent predictors of RVEF.

Results: RVEF <50% was observed in 32.28%% STEMI patients, who also demonstrated significantly lower left ventricular ejection fraction (LVEF), WTR, RS, CS, LS and larger infarct sizes than those with RVEF ≥50%. Patients with RVEF <50% also demonstrated a higher incidence of RV infarction, higher RV end-systolic volume (ESV) index, and lower RV RS and CS. Multivariable linear regression analysis revealed LV EF, IVS WTR and IVS RS as significant predictors for RVEF, while male gender, the culprit lesion in the right coronary artery (RCA), peak troponin were negative predictors for RVEF. Notably, peak troponin, LV EF, LV RS, LV CS, LV WTR, and IVS WTR demonstrated higher area under the curve (AUC) values for predicting RV dysfunction.

Conclusions: RV dysfunction was detected in 32.28% of STEMI patients. Patients with acute STEMI and RVEF <50% had impaired LV and IVS functions. Systolic function of the LV and IVS, peak troponin, and culprit lesions in the RCA were independent predictors of RV dysfunction in STEMI patients.