Impact of obstructive sleep apnea on arrhythmic risk in ischemic heart disease and hypertrophic cardiomyopathy: insights from a large national cohort.

BACKGROUND: Obstructive sleep apnea (OSA) is a prevalent sleep-disordered breathing condition associated with atrial fibrillation (AF) and cardiovascular morbidity. Its impact on life-threatening arrhythmic events, including cardiac arrest (CA) and ventricular fibrillation (VF), in patients with ischemic heart disease (IHD) and hypertrophic cardiomyopathy (HCM) remains incompletely understood. OBJECTIVES: We aimed to evaluate the association between OSA and arrhythmic outcomes in patients with IHD or HCM and to explore the potential role of AF as an intermediate pathway. METHODS: Using the National Inpatient Sample (2016-2020), we identified adults with IHD or HCM. OSA and arrhythmic events were defined by ICD-10 codes. Baseline characteristics were compared, and 1:1 propensity score matching (PSM) was performed. Multivariate logistic regression assessed the relationship between OSA and AF, AF and the composite endpoint of CA/VF, and the combined effect of OSA and AF in hierarchical models. Odds ratios (ORs) with 95% confidence intervals (CIs) were reported. RESULTS: Among 20,590 patients, 3,974 (19.3%) had OSA. OSA was independently associated with AF (OR 1.37, 95% CI 1.15-1.62, p < 0.001). AF was a strong predictor of CA/VF (OR 13.88, 95% CI 10.70-18.01, p < 0.001). In hierarchical models, the effect of OSA on CA/VF was attenuated and non-significant (OR 1.14, 95% CI 0.96-1.36, p = 0.13), whereas AF remained robustly associated. CONCLUSIONS: In patients with IHD or HCM, OSA was associated with a higher prevalence of AF, which may represent an important intermediate pathway associated with life-threatening arrhythmic events.