CPAP Adherence and Risk of Recurrent CV Events

Quick Takes

  • Among 4,168 patients with established CVD and obstructive sleep apnea who were enrolled in randomized controlled trials evaluating the effects of continuous positive airway pressure (CPAP), an intention-to-treat analysis showed no CV benefit of CPAP.
  • However, among patients with good CPAP adherence (≥4 hours per day), risk of major adverse cardiovascular and cerebrovascular events was reduced (HR, 0.69; 95% CI, 0.52-0.92; p = 0.01).

Study Questions:

In a population with obstructive sleep apnea (OSA) and established cardiovascular disease (CVD), what are the effects of continuous positive airway pressure (CPAP) therapy on cardiovascular (CV) events?


This was an individual participant data meta-analysis, based on a hypothetical scenario in which patients who adhered to CPAP were compared with those who did not adhere. Randomized controlled trials focused on adult patients with moderate to severe OSA were included. The primary outcome was a composite of the first major adverse cardiovascular or cerebrovascular event (MACCE), including death from cardiovascular causes.


Data from three trials and 4,186 patients were included in the analysis. The mean age of patients ranged from 60 to 66 years, and patients were mostly male (range, 81-84%). Mean follow-up period ranged from 34 to 52 months. A total of 691 MACCEs (16.5%) occurred. An intention-to-treat analysis did not demonstrate statistically significant differences in MACCEs between the CPAP and non-CPAP groups (hazard ratio [HR] of CPAP, 1.01; 95% confidence interval [CI], 0.87-1.17; p = 0.94).

In the CPAP group, overall median adherence was 3.03 hours per day (interquartile range, 0.75-5.10), and 38.5% of patients had good adherence (≥4 hours per day). CPAP adherence significantly decreased over the first 12 months and then remained stable. On-treatment analysis adjusted by time-varying and baseline confounding factors, using a marginal structured Cox model, showed a decreased event risk among patients with good CPAP adherence (HR, 0.69; 95% CI, 0.52-0.92; p = 0.01).


Among patients with established CVD and OSA, good CPAP adherence (≥4 hours per day) is associated with a lower risk of MACCE.


OSA is an independent risk factor for CVD and mortality. Patient acceptance of CPAP therapy remains limited in clinical practice, especially among patients who do not derive overt symptomatic benefit from treatment, such as reduced daytime somnolence. While this study did not address the effects of CPAP alternatives such as oral appliances and hypoglossal nerve stimulators, referral to a comprehensive sleep clinic is an important next step for patients who cannot tolerate positive airway pressure therapy. Limitations of this study include the low percentage of female patients and possibility of residual confounding (i.e., potential association of CPAP adherence with other positive health behaviors).

Clinical Topics: Prevention, Sleep Apnea

Keywords: Continuous Positive Airway Pressure, Heart Disease Risk Factors, Secondary Prevention, Sleep Apnea, Obstructive

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