Older patients with central sleep apnea (CSA) have a higher risk of mortality compared to those with obstructive sleep apnea (OSA), according to results of a study published in the Annals of the American Thoracic Society. ¹ Patients with CSA were also likely to die earlier. Underlying heart failure was associated with increased mortality in both groups of patients.

In this study, researchers retrospectively analysed data of 2961 patients with CSA and 1,487,353 patients with OSA to compare mortality and time to death between the two groups. The electronic medical records of the patients, from October 1999 to September 2020, were sourced from the Veterans Health Administration database. Majority (95.7%) of them were male and their median age was 61.8 years. Patients with OSA were younger (56.7 years) in comparison to those with CSA (61.8 years).

During the follow-up period of 5.9 years (mean), more deaths occurred among patients with CSA compared to those with OSA; 25.1% vs 14.9%, respectively with adjusted hazard ratio (aHR) of 1.53 for mortality. Death occurred much earlier in patients with CSA vs OSA; 18.7% died within ~ 5 years of their diagnosis. The median time to death among patients with central sleep apnea was 2.7 years; it was 5.1 years in patients with OSA.

Among CSA patients, four major predictors of mortality were heart failure, history of cerebrovascular disease, hemiplegia and being underweight (BMI <18.5 kg/m2). Comorbid heart failure increased mortality risk 7-folds in CSA patients with HR of 7.4 and 4-folds in OSA patients with HR of 4.3. The aHRs were 3.66 in CSA patients and 2.2 in OSA patients illustrating the persistence of higher hazard for mortality. Among the participants with opiate prescriptions, the mortality was higher in patients with CSA compared to patients with OSA with HR of 1.91.

These findings demonstrate the higher mortality as well as shorter time to death (from the day of diagnosis) in patients with CSA compared to those with OSA. Comorbid conditions were present more commonly in the CSA group; but the mortality risk remained significant even after adjusting for comorbid conditions. Older patients with CSA including those with a greater number of comorbidities and more males, were more at risk of adverse outcomes and hence need to be watched more closely.

Reference

1. Agrawal R, et al. Mortality patterns associated with central sleep apnea among veterans: a large, retrospective, longitudinal report. Ann Am Thorac Soc. 2023 Mar;20(3):450-455. doi: 10.1513/AnnalsATS.202207-648OC.