The prevalence and prognostic significance of right ventricular systolic dysfunction in nonischemic dilated cardiomyopathy.

BACKGROUND: Cardiovascular magnetic resonance is the gold-standard technique for the assessment of ventricular function. Although left ventricular volumes and ejection fraction are strong predictors of outcome in dilated cardiomyopathy (DCM), there are limited data regarding the prognostic significance of right ventricular (RV) systolic dysfunction (RVSD). We investigated whether cardiovascular magnetic resonance assessment of RV function has prognostic value in DCM.

METHODS AND RESULTS: We prospectively studied 250 consecutive DCM patients with the use of cardiovascular magnetic resonance. RVSD, defined by RV ejection fraction≤45%, was present in 86 (34%) patients. During a median follow-up period of 6.8 years, there were 52 deaths, and 7 patients underwent cardiac transplantation. The primary end point of all-cause mortality or cardiac transplantation was reached by 42 of 86 patients with RVSD and 17 of 164 patients without RVSD (49% versus 10%; hazard ratio, 5.90; 95% confidence interval [CI], 3.35-10.37; P<0.001). On multivariable analysis, RVSD remained a significant independent predictor of the primary end point (hazard ratio, 3.90; 95% CI, 2.16-7.04; P<0.001), as well as secondary outcomes of cardiovascular mortality or cardiac transplantation (hazard ratio, 3.35; 95% CI, 1.76-6.39; P<0.001), and heart failure death, heart failure hospitalization, or cardiac transplantation (hazard ratio, 2.70; 95% CI, 1.32-5.51; P=0.006). Assessment of RVSD improved risk stratification for all-cause mortality or cardiac transplantation (net reclassification improvement, 0.31; 95% CI 0.10-0.53; P=0.001).

CONCLUSIONS: RVSD is a powerful, independent predictor of transplant-free survival and adverse heart failure outcomes in DCM. Cardiovascular magnetic resonance assessment of RV function is important in the evaluation and risk stratification of DCM patients.