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

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.