Risk stratification in patients with hypertrophic cardiomyopathy: Looking beyond the left side myocardial function

Background: Patients with hypertrophic cardiomyopathy (HCM) have heterogeneous outcomes. As risk stratification mostly focuses on left-side myocardial function, we sought to investigate the prognostic value of right ventricular (RV) function in patients with HCM. Methods: This retrospective cohort study included patients with HCM. Conventional ventricular functional parameters, including left ventricular ejection fraction (LVEF), tricuspid annular plane systolic excursion (TAPSE), and fractional area change were obtained. The longitudinal strain was analyzed using the speckle tracking method. The primary endpoint was defined as a composite of hospitalization for heart failure, sustained ventricular tachycardia, or all-cause death. Results: A total of 56 patients with HCM (aged 58.0 ± 14.9 years, 64.3% male) were included. After a mean follow-up duration of 30.1 ± 17.4 months, primary endpoints developed in 10 (20%) of 50 patients who were treated medically. Patients with cardiovascular events had a more reduced LV thickest segmental strain, worse TAPSE, and more impaired RV free wall strain. After adjusting for age, sex, and LVEF, TAPSE (hazard ratio [HR], 95% confidence intervals [CIs]: 0.24, 0.06-0.93) and RV free wall strain (HR, 95% CIs:1.12, 1.03-1.21) remained independent prognostic predictors. Incorporating either TAPSE or RV free wall strain provides incremental prognostic value to the LV strain alone (net reclassification improvement by 31.4% and 34.1%, respectively, both p < 0.05). Conclusion: RV function assessed by TAPSE or RV free wall strain is predictive of subsequent cardiac events, suggesting that a comprehensive evaluation of RV function is useful for risk stratification in patients with HCM.