Prevalence and prognostic implications of the longitudinal changes of right ventricular systolic function on cardiac magnetic resonance in dilated cardiomyopathy.

Background: Although in many patients with dilated cardiomyopathy (DCM), right ventricular systolic dysfunction (RVSD) accompanies left ventricular SD, knowledge about the RVSD prevalence, course, and prognostic significance in DCM remains limited.

Aims: We aimed to analyze the prevalence and prognostic significance of longitudinal changes in RV ejection fraction (RVEF) in DCM.

Methods: One hundred and two stable DCM patients were included. Heart failure therapy was up-titrated every 3 months, and CMR was performed at baseline and then after 13 (12.2-13.5) months (CMR-1 and CMR-2). RVSD was defined as RVEF <51% in women and <52% in men in CMR-1, while RVEF and LVEF improved if the increase between CMR-1 and CMR-2 was ≥10%. A composite endpoint, including all-cause mortality, heart transplant, left ventricular assistant device, and urgent cardiac hospitalization, was analyzed after 32.6 (26.3-39.4) months.

Results: At baseline, RVSD was observed in 76 (75%) patients. Of 66 DCM patients with RVSD who completed CMR-2, 60% experienced an RVEF improvement. All patients without RVSD at baseline maintained normal RV systolic function at 13 months. Baseline RVSD did not affect the composite endpoint (hazard ratio, 1.241; 95% CI, 0.458-3.366; P = 0.67); however, RVEF improvement was independently associated with this outcome (hazard ratio, 0.260; 95% CI, 0.080-0.846; P = 0.03).

Conclusions: Three-quarters of DCM patients exhibited RVSD at baseline, and 60% of them experienced an RVEF improvement following proper heart failure therapy up-titration. While no relationship between outcome and RVSD was observed, RVEF improvement was associated with a 75% reduction in the composite outcome.