Dilated cardiomyopathy: does the right ventricle have an impact on prognostic outcomes?
A Sousa, M Dias, S D Padrao, S Fernandes, C R Ferreira, F Vilela, B Rocha, J Faria, R Flores, V H Pereira, C M PiresAbstract
Introduction
Dilated cardiomyopathy (DCM) is characterized by ventricular dilatation and systolic dysfunction in the absence of abnormal loading conditions or significant coronary artery disease and remains an important cause of heart failure and cardiac death. Although left ventricular (LV) impairment is classically emphasized, right ventricular (RV) structure and function may have important prognostic implications in DCM.
Purpose
To assess the impact of the right ventricle on clinical outcomes in DCM patients.
Methods
We performed a retrospective, observational, single-center study including patients with DCM who underwent cardiac magnetic resonance (CMR) between 2019 and 2025. Patients were followed for a median of 37 months. RV and LV volumes, mass and ejection fraction (EF) were quantified by CMR. The primary composite endpoint (all-cause mortality, heart failure hospitalization, or ventricular arrhythmia) was analysed.
Results and discussion
A total of 153 patients were included, 66% male, with a mean age of 62.5 ± 13.8 years. In our study population, 64.7% had idiopathic DCM. Only 26% (n=40) underwent genetic testing, of which 17,5% had a pathogenic or likely pathogenic variant. Right and left ventricular ejection fractions were positively correlated, with moderate strength (ρ = 0,533, p < 0,001). A significant difference was found in median RV ejection fraction between patients who did and did not reach the composite outcome (50% vs. 57,5%, p < 0,002). RV end-diastolic volume alone was not associated with the composite outcome. In the multivariable logistic regression model including LVEF and RVEF, only RVEF remained significantly associated with the primary composite endpoint (p=0.025, odds ratio 0.95; 95% confidence interval 0.91–0.99), whereas LVEF was not significant. Thus, lower RVEF is associated with higher risk, with the odds of an adverse outcome increasing by roughly 5% for every 1% decrease in RVEF.
Conclusion
In this cohort, RVEF assessed by CMR emerged as an independent predictor of adverse outcomes beyond conventional and more frequent parameters such as LVEF. Routine RV assessment may improve risk stratification and guide follow-up and therapeutic decisions in patients with DCM.Results table