Meta-Analysis of Cardiovascular Outcomes With Continuous Positive Airway Pressure Therapy in Patients With Obstructive Sleep Apnea.

Obstructive sleep apnea (OSA) is associated with increased cardiovascular morbidity and mortality. Continuous positive airway pressure (CPAP) is the main treatment of OSA. The present study explores the impact of CPAP on cardiovascular outcomes. A systematic search of electronic databases for randomized controlled trials comparing CPAP with medical therapy alone in patients with OSA who reported cardiovascular outcomes of interest was performed. The main outcome was major adverse cardiac events. Other outcomes included cardiac mortality, myocardial infarction, angina pectoris, stroke, and transient ischemic attack. Fixed effect model was used in all analyses except for subgroup analysis in which the random effect DerSimonian and Laird's model was used. Four randomized controlled trials with a total of 3,780 patients were included. Compared with medical therapy alone, CPAP use was not associated with reduced risk of major adverse cardiac events (relative risk [RR] 0.94, 95% confidence interval [CI] 0.78 to 1.15, p = 0.93, I2  = 0%) except in the subgroup that wore CPAP >4 hours (RR 0.70, 95% CI 0.52 to 0.94, p = 0.02, I2  = 0%). Furthermore, no reduction in the risk of cardiac mortality (RR 1.14, 95% CI 0.66 to 1.97, p <0.36, I2  = 2%), myocardial infarction (RR 0.96, 95% CI 0.64 to 1.44, p <0.15, I2  = 47%), angina pectoris (RR 1.16, 95% CI 0.9 to 1.50, p <0.51, I2  = 0%), stroke (RR 1.01, 95% CI 0.73 to 1.38, p <0.0.86, I2  = 0%), and transient ischemic attack (RR 1.36, 95% CI 00.69 to 2.68, p <0.24, I2  = 30%) was observed. Subgroup analysis of CPAP adherence in regards to cardiac outcomes showed that CPAP use is not associated with decreased risk of heart failure (RR 0.91, 95% CI 0.50 to 1.66, p <0.55, I2  = 0%). In conclusion, compared with medical therapy alone, utilization of CPAP in patients with OSA is not associated with improved cardiac outcomes except in patients who wore it for >4 hours.