Right ventricular hypertrophy in apical hypertrophic cardiomyopathy

Background: Right ventricular hypertrophy (RVH+) in hypertrophic cardiomyopathy occurs in one third of patients, however, outcomes in apical hypertrophic cardiomyopathy (ApHCM) have not been described. We hypothesized that RVH+ in ApHCM is associated with more ventricular remodeling and dysfunction, and increased adverse events when compared with those without RVH (RVH-).

Methods: Ninety-one ApHCM patients were retrospectively analyzed using 2D and speckle-tracking echocardiography (64 ± 16 years old, 43% female). RVH+ was defined as wall thickness >5 mm and was present in 23 (25%). Ventricular mechanics were characterized by global longitudinal strain (GLS), RV free wall strain, and myocardial work.

Results: New York Heart Association functional class > II, atrial fibrillation, and prior stroke were more prevalent in RVH+. Left ventricular (LV) size and ejection fraction were similar between groups, with greater septal (17 vs. 14 mm, p = .001) and apical (20 vs. 18 mm, p = .04) wall thickness in RVH+. When compared with RVH- patients, RVH+ had worse LV GLS (-8.6 vs. -12.8%), global work index (820 vs. 1172 mmHg%) (both p < .001), and work efficiency (76 vs. 83%, p = .001), as well as RV GLS (-14 vs. -17.5%) and free wall strain (-17.3 vs. -21.3%) (both p = .02). At 3-year follow-up RVH+ had greater incidence of heart failure hospitalization compared with RVH- (35 vs. 7%, p = .003). RVH+ was associated with RV GLS (β = .2, p = .03), independent of clinical and echocardiographic variables.

Conclusions: RVH+ patients with ApHCM have worse biventricular mechanics and myocardial work, and more heart failure hospitalization, as RVH- at mid-term follow-up.