Exercise training in heart failure with reduced ejection fraction and permanent atrial fibrillation: A randomized clinical trial

BACKGROUND Heart failure (HF) associated with atrial fibrillation increases patients' physical inactivity, worsening their clinical condition and mortality. Exercise training is safe and has clear benefits in HF. However, little is known about the effects of exercise training on patients with HF with reduced ejection fraction and permanent atrial fibrillation (HFAF). OBJECTIVE The purpose of this study was to test the hypothesis that exercise training improves functional capacity, cardiac function, and quality of life in patients with HFAF. METHODS This randomized clinical trial was conducted at the Heart Institute. Patients with HFAF, left ventricular ejection fraction <= 40%, and resting heart rate (HR) <= 80 beats/min were included in the study. Cardiopulmonary testing, echocardiography, nervous system, and quality of life assessment were performed before and after the 12-week protocol period. RESULTS Twenty-six patients (mean age 58 +/- 1 years) were randomized to exercise training (HFAF-trained group; n = 13) or no training (HFAF-untrained group; n = 13). At baseline, no differences between the groups were found. Exercise improved peak oxygen consumption, slope of ventilation per minute/carbon dioxide production, and quality of life. The HFAF-trained group had significantly decreased resting HR (from 73 +/- 2 to 69 +/- 2 beats/ min; P = .02) and recovery HR (from 148 +/- 11 to 128 +/- 9 beats/min; P = .001). Concomitantly, left ventricular ejection fraction increased (from 31% 61% to 36% +/- 0.9%; P=.01), left atrial dimension decreased (from 52 +/- 1.2 to 47 +/- 1 mm; P = .03), and left ventricular end-systolic volume and left ventricular enddiastolic volume deceased (from 69 +/- 2 to 64 +/- 1.8 mL/m(2) and from 9962.1 to 9162 mL/m(2), respectively; P<.05). No changes were observed in the HFAF-untrained group. CONCLUSION Exercise training can improve exercise capacity, quality of life, and cardiac function in patients with HF with reduced ejection fraction and permanent atrial fibrillation.