Exercise hemodynamics in hypertrophic cardiomyopathy identify risk of incident heart failure but not ventricular arrhythmias or sudden cardiac death

Abstract

Objective: To determine whether abnormal blood pressure response (ABPR), with or without left ventricular outflow tract obstruction (LVOTO), is associated with adverse heart failure and arrhythmia outcomes in hypertrophic cardiomyopathy (HCM).

Methods: A retrospective, single-center analysis was performed for adult HCM patients who underwent exercise stress testing.

Results: Of 589 patients included in the study, 192 (33%) demonstrated ABPR. A similar proportion of patients with ABPR had LVOTO compared to those without ABPR (56% vs 63%, p = 0.11). Patients with ABPR demonstrated lower percent predicted VO2 and METs achieved than those with LVOTO (16.9 ± 6.8 vs 21.6 ± 7.9, p = 0.002 and 5.3 ± 2.4 vs 7.4 ± 3.1, p < 0.001). In a subgroup of 17 patients with LVOTO and ABPR who subsequently underwent successful myectomy, 5 (30%) demonstrated persistent ABPR. 23 patients (3.8%) experienced sudden cardiac death or ventricular arrhythmias, which were not associated with ABPR, regardless of age group. In multivariable analysis, syncope (p = 0.04), left ventricular hypertrophy (p = 0.02) and left atrial diameter (p = 0.006) were significantly associated with the composite outcome of sudden death or severe ventricular arrhythmia, whereas ABPR was not (p = 0.38). In contrast, ABPR was associated with subsequent heart failure hospitalization (p = 0.002), regardless of presence or absence of LVOTO (p = 0.04, p = 0.02).

Conclusions: ABPR is associated with reduced functional capacity in HCM regardless of the presence of LVOTO but is not associated with adverse arrhythmia outcomes. Patients with ABPR have a higher incidence of subsequent heart failure hospitalization.

Keywords: Abnormal blood pressure response; Heart failure; Hypertrophic cardiomyopathy; Sudden cardiac death.