Long-term effects of cardiac rehabilitation on sleep apnea severity in patients with coronary artery disease

Abstract

Introduction: Sleep apnea (SA) is prevalent among patients with coronary artery disease (CAD) and increases cardiovascular risk. A previous study showed that 1-month of cardiac rehabilitation (CR) reduced severity of SA in CAD patients by reducing fluid accumulation in the legs during the day and the amount of fluid shifting rostrally overnight (Mendelson M. et al. ERJ 2016; 48:142-50). Aim: To evaluate whether CR will lead to longer-term (6-months) attenuation of SA in patients with CAD. Methods: Fifteen patients with CAD and SA who had participated in a 1-month randomized trial of the effects of exercise training on SA were followed up until they completed 6 months of CR (age: 65±10 years; body mass index (BMI): 27.0±3.9 kg/m2; baseline apnea-hypopnea index (AHI): 39.0±16.7 /hour; 1 with central sleep apnea, and 14 with obstructive sleep apnea). AHI was evaluated at baseline by polysomnography and then at 6 months by portable monitoring at home (BresoDx). Cardiorespiratory fitness (VO2peak) was evaluated via a graded cardiopulmonary exercise test at baseline and 6 months. The 6-month CR program included once weekly, 90-min, in-facility exercise sessions, and 4 days/week at-home exercise sessions. Results: After 6 months of CR, there was a 55% reduction in the AHI (30.5±15.2 to 13.8±8.2, P Conclusion: Participation in CR is associated with a significant long-term decrease in the severity of SA. This finding suggests that attenuation of SA by exercise could be a mechanism underlying reduced mortality following participation in CR in patients with CAD and SA.