Obstructive Sleep Apnea in Cardiac Rehabilitation Patients

Although regular physical activity improves obstructive sleep apnea (OSA) in the general population, this finding has not been assessed in postmyocardial infarction (MI) patients in a rehabilitation setting (coronary artery disease, CAD). We aimed to determine whether cardiac rehabilitation may benefit post-MI patients in terms of OSA disease and associated autonomic nervous system (ANS) activity.

Consecutive post-MI patients participating in the ambulatory cardiac rehabilitation program of St-Etienne University Hospital were included in this study. The apnea-hypopnea index calculated from electrocardiogram (ECG)-derived respiration (AHIEDR) was obtained through nocturnal Holter ECG recordings. According to AHIEDR, patients were classified as normal, mild, moderate, or severe OSA (< 5, 5-14, 15-29, ≥ 30, respectively). Physiological performance (peak VO2) was established via cardiopulmonary exercise testing. ANS activity was evaluated through spontaneous baroreflex sensibility as well as heart rate variability analysis.

Of the 105 patients with CAD and OSA included (95 men, 55.2 ± 12.4 years), 100 had at least 1 cardiovascular risk factor (98%) and 52 patients (50%) had an ANS dysfunction. Surprisingly, 68 of these patients with OSA (65%) were free of classical diurnal symptoms usually associated with sleep apnea. In response to cardiac rehabilitation, AHIEDR decreased significantly (-9.3 ± 9.5, P < .0001) only in patients with severe OSA, and the decrease was even greater when peak VO2 and baroreflex sensibility improved beyond 20% compared to basal values (-11.6 ± 9.1, P < .001).

Severe OSA in patients with CAD is significantly improved after 2 months of cardiopulmonary rehabilitation. Reviving ANS activity through physical activity might be a target for complementary therapy of OSA in patients with CAD.