The Prognostic Impact of the Evolution of RV Function in Idiopathic DCM

OBJECTIVES: In this study, the authors analyzed the prognostic role of right ventricular systolic function (RVF) longitudinal trends in a large cohort of patients affected by dilated cardiomyopathy (DCM). BACKGROUND: RVF is a known prognostic predictor in DCM; however, whether RVF changes over time to better predict the long-term disease progression has not been investigated. METHODS: From 1993 to 2008, we analyzed 512 patients with DCM (46 years of age [36 to 55 years of age], left ventricular ejection fraction 32% [25% to 41%]) with a potential follow-up of ≥72 months and available data at baseline and at least 1 pre-specified follow-up evaluation (i.e., 6, 24, 48, or 72 months). RV dysfunction was defined as RV fractional area change <35% at 2-dimensional echocardiography. The primary outcome measure was a composite of death or heart transplantation. RESULTS: At enrollment, 103 (20%) patients had RV dysfunction. During follow-up, 89 of them (86%, 17% of the overall cohort) normalized RVF at a median time of 6 months, whereas 38 of the remaining 409 patients with normal baseline RVF (9%; 7% of the overall population) exhibited a new-onset RV dysfunction (median time: 36 months). RVF normalization was significantly associated with subsequent left ventricular reverse remodeling that was observed at a median time of 24 months (odds ratio: 2.49; 95% confidence interval [CI]: 1.17 to 5.3; p = 0.018). At baseline multivariate analysis, RV dysfunction was independently associated with the primary outcome measure (hazard ratio: 1.71; 95% CI: 1.02 to 2.85; p = 0.0413). At time-dependent model, RVF revaluation over time maintained an independent predictive value (hazard ratio: 2.83; 95% CI: 1.57 to 5.11; p = 0.0006). CONCLUSIONS: Patients with DCM frequently present RV dysfunction at first evaluation. However, a complete RVF recovery is largely observed early after optimization of medical therapy and predates subsequent left ventricular reverse remodeling. Systematic revaluation of patients including RVF throughout regular follow-up conferred additive long-term prognostic value to the baseline evaluation.