Introduction: Randomized controlled trials have not shown a role for continuous positive airway pressure (CPAP) on the prevention of major cardiovascular (CV) events in obstructive sleep apnoea (OSA) patients. However, ethical constrains prevent the randomization of sleepy patients and therefore the studied populations are substantially different from real-world patients.

Aims and objectives: To assess the impact of CPAP treatment on major CV events in real-world OSA patients.

Methods: Population-based longitudinal observational study including all OSA patients terminating CPAP treatment in 2011 in Catalonia, Spain, with no further CPAP prescriptions in 2012-2015, and propensity-score-matched OSA patients continuing CPAP treatment.

Results: 3638 CPAP terminators and 3638 propensity-score-matched continuators were included (median age 66.5 (57–72) years, 71.5% male). During a median follow-up of 4.5 years CPAP continuators had a lower risk of CV death than terminators after adjusting by age, sex and key comorbidities (Hazard Ratio (HR); 95% CI: 0.66; 0.51–0.86). Similar results were found for CV hospitalizations (HR; 95% CI: 0.82; 0.70–0.96) and a composite of CV deaths and hospitalizations (HR; 95% CI: 0.80; 0.69–0.93).

Conclusions: The current results based on all CPAP-terminators OSA patients in Catalonia in 2011 and matched continuators showed a moderate but significant protective effect of CPAP on major CV events. This relationship contrasts with the results of randomized controlled trials tackling this issue and highlights the importance of including real-world patients in the studies.

Supported by ISCIII (PI18/00502, CP19/00108), SEPAR, SES, SOCAP, ResMed, ALLER.