Right Ventricular Hypertrophy Is Associated With Cardiovascular Events in Hypertrophic Cardiomyopathy: Evidence From Study With Magnetic Resonance Imaging

Background: Although left ventricular (LV) morphology and function have been well studied in hypertrophic cardiomyopathy (HCM), few data exist regarding the right ventricle. Accordingly, we studied right ventricular (RV) morphology and function and their effect on cardiovascular events in HCM using cardiac magnetic resonance (CMR) imaging. Methods: This retrospective study included 106 HCM patients (age 61.6 +/- 14.5 years) examined using CMR imaging during January 2008 to September 2014. RV hypertrophy (RVH) was defined as RV maximal wall thickness > 5 mm. Results: RVH was observed in 30 of the 106 patients (RVH group), with the remaining 76 patients assigned to the non-RVH group. The RVH group had higher brain natriuretic peptide levels (461.6 +/- 699.8 pg/mL vs 225.3 +/- 254.5 pg/mL; P = 0.01) and also showed a reduced RV end-diastolic volume index (43.4 +/- 16.0 mL/m(2) vs 56.6 +/- 15.2 mL/m(2); P = 0.0001), in keeping with a greater LV mass index (109.1 +/- 24.9 g/m(2) vs 78.6 +/- 23.0 g/m(2); P < 0.0001). The RVH group was prominently associated with RV late gadolinium enhancement compared with the non-RVH group (33.3% vs 0%; P < 0.0001). After CMR imaging, 15 patients developed cardiovascular events that included admission for heart failure, ventricular tachyarrhythmia/fibrillation, stroke, and sudden cardiac death. Cox proportional hazard analysis revealed that RVH was an independent predictor of the occurrence of cardiovascular events after adjustments by sex, age, LV mass index, LV ejection fraction, and LV outflow tract obstruction (hazard ratio, 5.42; 95% confidence interval, 1.16-25.3; P = 0.03). Conclusions: These results suggest that HCM patients with RVH on CMR images have a greater incidence of cardiovascular events than non-RVH patients. Further work is needed to confirm this observation and assess its clinical importance.