RESUMO
Background: The use of beta-blockers in hypertrophic obstructive cardiomyopathy (HOCM) patients after alcohol septal ablation (ASA) lacks data support. We aimed to evaluate the effect of metoprolol on exercise capacity, hemodynamic and laboratory parameters, and quality of life in HOCM patients after ASA. Methods: This was a prospective randomized single-center open-label crossover trial in 21 HOCM patients after ASA. Patients received metoprolol and no beta-blocker for two periods of three months. The endpoints were: peak oxygen uptake (pVO2), maximal left ventricular outflow tract (LVOT) pressure gradient at peak exercise, a ratio of mitral peak velocity of the early filling (E) to early diastolic mitral annular velocity (e') (E/e') at rest, Kansas City Cardiomyopathy Questionnaire (KCCQ) overall summary score, and N-terminal prohormone of brain natriuretic peptide (NT-proBNP) plasmatic concentration. Results: No significant association was found between the treatment and any of the endpoints in the assessed patients: 1) pVO2 (19.5 ± 5.3 ml/kg/min vs. 19.4 ± 4.1 ml/kg/min, p = 0.90), 2) exercise-induced pressure gradient in LVOT 32 ± 37 mmHg vs. 32 ± 30 mmHg, p = 0.84, 3) E/e' ratio at rest (11 ± 4 vs. 10 ± 4, p = 0.23), 4) KCCQ overall summary score (78 ± 11 vs. 77 te ± 15, p = 0.56), 5) NT-proBNP (215 pg/ml [121-333] vs. 153 pg/ml [102-228], p = 0.19). Conclusions: In HOCM patients after successful ASA, metoprolol treatment did not improve exercise capacity, hemodynamic and laboratory parameters, or quality of life.
