Background: Sleep-disordered breathing (SDB) is common in patients with heart failure and carries an independent risk for poor long-term prognosis. We aimed to study the effects of supervised, aerobic exercise training for 6 months on SDB in patients with chronic heart failure.
Methods and results: We enrolled 18 patients having both systolic dysfunction (left ventricular ejection fraction <45%) and SDB (apnea-hypopnea index [AHI] >10). The exercise group comprised 10 patients who participated in our cardiac rehabilitation program for 6 months, and the remaining 8 patients served as control. AHI (median [interquartile range]) was unchanged in the control group patients at 6-month intervals (30.4 [19.9-36.3] versus 36.6 [8.6-39.4], NS). In contrast, AHI was significantly decreased in the exercise group from 24.9 [19.2-37.1] to 8.8 [5.3-10.1] (P < .01). In the exercise group, the numbers of central sleep apnea per night was significantly decreased (152 [124-244] versus 50 [24-67], P < .01) after exercise training, but those of obstructive apnea/hypopnea were unchanged (42 [7-94] versus 18 [7-54], NS). In addition, exercise training significantly increased peak oxygen consumption and decreased minute ventilation to carbon dioxide production slope (both P < .01).
Conclusions: Six-month, aerobic exercise training increased exercise capacity and improved central sleep apnea in patients with chronic heart failure from systolic dysfunction.