The beneficial impact of cardiac rehabilitation on obstructive sleep apnea in patients with coronary artery disease.

Study Objectives: To assess the impact of cardiac rehabilitation for decreasing sleep-disordered breathing in patients with coronary artery disease.

Methods: The study included 121 patients aged 60.01 ± 10.08 years, 101 of whom were men, with an increased pretest probability of OSA. The cardiac rehabilitation program lasted 21-25 days. The improvement in cardiorespiratory fitness was assessed using the changes in peak metabolic equivalents, the maximal heart rate achieved, the proportion of the age- and sex-predicted maximal heart rate, and the Six-Minute Walk Test distance. Level 3 portable sleep tests with respiratory event index assessments were performed in 113 patients on admission and discharge.

Results: Increases were achieved in metabolic equivalents (Δ1.20; 95% confidence interval [CI], 0.95-1.40; P < .0001), maximal heart rate (-Δ7.5 beats per minute; 95% CI, 5.00-10.50; P < .0001), proportion of age- and sex-predicted maximal heart rate (Δ5.50%; 95% CI, 4.00-7.50; P < .0001), and the Six-Minute Walk Test distance (Δ91.00 m; 95% CI, 62.50-120.00; P < .0001). Sleep-disordered breathing was diagnosed in 94 (83.19%) patients: moderate in 28 (24.8%) patients and severe in 27 (23.9%) patients, with a respiratory event index of 19.75 (interquartile range, 17.20-24.00) and 47.50 (interquartile range, 35.96-56.78), respectively. OSA was dominant in 90.40% of patients. The respiratory event index reduction achieved in the sleep-disordered breathing group was -Δ3.65 (95% CI, -6.30 to -1.25; P = .003) and was in parallel to the improvement in cardiorespiratory fitness in the subgroups with the highest effort load and with severe sleep-disordered breathing: -Δ6.40 (95% CI, -11.40 to -1.90; P = .03) and -Δ11.00 (95% CI, -18.65 to -4.40; P = .003), respectively.

Conclusions: High-intensity exercise training during cardiac rehabilitation resulted in a significant decrease in OSA, when severe, in parallel with an improvement in cardiorespiratory fitness in patients with coronary artery disease.