Hemodynamic Response to Exercise and Quality of Life in Patients with Hypertrophic Cardiomyopathy Without Left Ventricular Outflow Tract Obstruction

In hypertrophic cardiomyopathy (HCM), impaired exercise capacity and quality of life (QoL) are indicative of a poor prognosis irrespective of left ventricular outflow tract (LVOT) obstruction. Exercise limitations are considered a substantial contributor to reduced QoL in HCM but the relationship between hemodynamic determinants of exercise capacity and QoL in HCM remains unknown. This study assessed the relationship between exercise hemodynamics and QoL in patients with HCM without LVOT obstruction. Patients underwent hemodynamic assessment via right heart catheterization, with measurements taken at rest and during exercise. Patient-reported QoL was assessed using the Kansas City Cardiomyopathy Questionnaire overall summary score (KCCQ-OSS). Hemodynamic metrics correlating with QoL were identified. Fifty-nine patients were included (27% females, mean age 58 ± 12 years). The cohort demonstrated mild to moderate QoL impairments, with a median overall summary KCCQ score of 83 (IQR: 71 to 95). At rest, QoL correlated with cardiac output (r = 0.3, p = 0.01) and mean pulmonary arterial pressure (r = -0.4, p = 0.003). During mild exercise (25 watts), an inverse correlation was observed between the KCCQ-OSS and left ventricular filling pressure (r = -0.4, p < 0.001), and at peak exercise, a positive correlation was observed between the KCCQ-OSS and cardiac output (r = 0.4, p < 0.001). In multivariate analysis, left ventricular filling pressure measured during mild exercise (β = -0.8, [95% CI: -1.49, -0.09], p = 0.035) emerged as the sole independent hemodynamic predictor of QoL. In conclusion, in patients with HCM without LVOT obstruction, QoL is significantly associated with several hemodynamic parameters, with elevated left ventricular filling pressures during mild exercise emerging as a key determinant.