Right Ventricular Enlargement and Dysfunction Are Associated With Increased All-Cause Mortality in Hypertrophic Cardiomyopathy

Objective: To assess whether right ventricular enlargement (RVE) and right ventricular dysfunction (RVD) adversely affect prognosis in hypertrophic cardiomyopathy (HCM). Patients and Methods: Data were retrieved from Mayo Clinic's prospectively collected HCM registry between January 1, 2000, and September 30, 2012. Right ventricle (RV) size and function were semiquantitatively categorized via echocardiography as normal (RV-Norm) versus abnormal (RV-Abn) (RVE or RVD). All-cause mortality was the primary endpoint. Results: Of 1878 HCM patients studied (mean age 53±15 years; 41.6% female), only 71 (3.8%) had RV-Abn (24 RVE, 28 RVD, 19 combined RVE and RVD). Compared with HCM patients with RV-Norm, RV-Abn patients were older (57±14 vs 53±15 years, P=.02), more symptomatic (New York Heart Association functional class III-IV in 62.0% vs 48.6%, P=.03), had more atrial fibrillation (53.5% vs 17.3%, P<.001), and more prior implantable cardioverter-defibrillator implantation (23.9% vs 11.3%, P=.02). Median follow-up was 9.4 years with 311 deaths. Patients who were RV-Abn had higher all-cause mortality compared with RV-Norm (log-rank P<.001); 24.1% (95% CI, 15.5% to 35.3%) vs 6.1% (95% CI, 5.1% to 7.3%) at 5 years. In multivariable Cox modeling, RV-Abn (hazard ratio, 1.89; 95% CI, 1.18 to 3.03; P=.008) was associated independently with all-cause mortality after adjusting for age, female sex, New York Heart Association functional class, atrial fibrillation, hypertension, coronary artery disease, implantable cardioverter-defibrillator implantation, beta blocker use, prior septal reduction therapy, resting LV outflow tract gradient, maximal LV wall thickness, and moderate or greater tricuspid regurgitation. Conclusion: Although perturbations in RV size and function were observed in fewer than 5% of patients with HCM, they were associated with nearly two-fold higher all-cause mortality at long-term follow-up.