Major cardiovascular event or death risk in obstructive sleep apnoea and the effect of positive airway pressure

Evidence regarding the efficacy of positive airway pressure (PAP) therapy in reducing the risk of non-fatal major cardiovascular events (NF-MACE) and mortality in patients with obstructive sleep apnoea (OSA) remains controversial. This study aims to quantify the impact of PAP therapy on these risks and develop a predictive risk estimator.

We conducted a multicentre, observational, prospective study involving 5358 individuals diagnosed with OSA, with a median (interquartile range (IQR)) follow-up of 14 (10-15) years. We derived and validated a risk estimator of NF-MACE (including myocardial infarction, stroke, revascularisation procedures and congestive heart failure) and all-cause mortality, incorporating PAP adherence alongside clinical and sleep-related data.

The cohort had mean±sd age 55±11 years, body mass index 32.0±5.4 kg·m^-2 and apnoea-hypopnoea index (AHI) 35±22 events·h^-1; 26% were females and 1467 (37%) were PAP adherent. Over the follow-up period, 754 participants experienced NF-MACE, while 858 deaths were recorded. Significant predictors included prior cardiovascular events, non-high-density lipoprotein cholesterol ≥200 mg·dL^-1, COPD diagnosis, AHI >30 events·h^-1 and age >60 years. PAP adherence was protective (OR 0.46, 95% CI 0.38-0.56) and the absolute risk reduction varied depending on the baseline risk (median (IQR) 16% (12-18%)). The risk estimator yielded an area under the receiver operating characteristic curve of 0.75 and a Brier score of 0.17, with 64% sensitivity and 75% specificity.

PAP therapy is associated with long-term risk reduction of NF-MACE and mortality in OSA patients, while the developed risk estimator enhances clinical decision making regarding therapy initiation.