Cardiometabolic Factors Linked to CV Death in OSA

TOPLINECardiovascular mortality among adults referred for sleep testing for suspected obstructive sleep apnea (OSA) was linked to classic cardiometabolic factors, including older age, atrial fibrillation (AF), hypertension, and prior myocardial infarction, but not to time spent with low nocturnal oxygen saturation, a study showed. A good continuous positive airway pressure (CPAP) response was linked to lower cardiovascular mortality among patients with moderate-to-severe disease.METHODOLOGYResearchers conducted a retrospective cohort study including data from 4368 adults (median age, 58 years; 69.9% men) who underwent diagnostic polysomnography at a tertiary sleep center in Łódź, Poland.Cause-specific cardiovascular death, the primary outcome, was identified though linkage with national death registry using the International Classification of Diseases, 10th Revision coding; noncardiovascular deaths were assessed as competing events. CPAP response was classified as good (apnea-hypopnea index [AHI] reduction ≥ 50% and residual AHI < 10 events/h), poor, or no CPAP (reference), and was modeled as a fixed baseline exposure. A subgroup of 2304 patients with AHI ≥ 15 events/h was analyzed separately.Patients were grouped into six clusters based on random survival forest (RSF) model-predicted cumulative incidence over time to identify patient phenotypes and compared for cardiovascular mortality.Patients were followed for up to 20 years, and the median follow-up was 8.6 years.TAKEAWAYDuring follow-up, 335 cardiovascular deaths occurred. In the full cohort, independent predictors of cardiovascular death were age (hazard ratio [HR], 1.08 per year; P < .001), AF (HR, 2.16; P < .001), hypertension (HR, 1.73; P < .001), prior myocardial infarction (HR, 1.71; P < .001), male sex (HR, 1.68; P < .001), active smoking (HR, 1.68; P < .001), diabetes (HR, 1.37; P = .02), and AHI (HR, 1.01 per event/h; P < .001).Nocturnal desaturation and BMI showed no significant associations after adjustment. In a subgroup including patients with moderate-to-severe disease (AHI ≥ 15 events/h), a good CPAP response was linked to lower cardiovascular mortality (HR, 0.72; P = .02). In the RSF model, age was identified as the main predictor, followed by cumulative respiratory event burden and prior myocardial infarction.Cardiovascular mortality across the six phenotypes ranged from 2.9% to 14.4%. Between-cluster differences were significant (P < .001).IN PRACTICE"These findings support a shift in clinical thinking: cardiovascular mortality prevention in OSA should be anchored in guideline-directed management of hypertension, diabetes, dyslipidemia, smoking, and atrial fibrillation rather than in CPAP titration alone," the authors wrote.SOURCEThe study was led by Wojciech Kuczyński, MD, PhD, Medical University of Łódź, Łódź, Poland. It was published online on October 28 in SLEEP.LIMITATIONSThe study was limited by its retrospective design, reliance on death certificate coding data, and lack of data on objectively measured long-term CPAP use, echocardiographic parameters, and comorbidity changes. The study lacked the computation of heart-rate response, hypoxic burden, pulse-wave amplitude drop index, and burdens of ventilation and arousal. Additionally, the RSF model was validated only internally, and the data came from one tertiary center.DISCLOSURESThe study received no specific funding. Disclosure information for the study investigators is available in the original study publication.This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.