Obstructive Sleep Apnea in Cardiac Rehabilitation Patients

Study objectives: 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.

Methods: 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.

Results: 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).

Conclusions: 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.