Obstructive sleep apnea and cardiac arrest in hypertrophic cardiomyopathy: An analysis of the nationwide inpatient sample database

BACKGROUND: The association between OSA and sudden cardiac death (SCD) risk in patients with hypertrophic cardiomyopathy (HCM) is poorly defined. We hypothesized that OSA may be associated with the risk of cardiac arrest and ventricular fibrillation (CA-VF) in HCM patients. METHODS: We conducted a retrospective analysis of the National Inpatient Sample (2016-2020), including adults with HCM without prior history of SCD. Patients were stratified by the presence of OSA. The primary outcome was a composite of CA-VF. Multivariate logistic regression and propensity score matching (PSM) assessed the association between OSA and outcomes, adjusting for age, gender, family history of SCD, CIHD, AF, use of ICD, syncope, and LVEF<50%. Mediation analysis was performed to assess whether AF, a known outcome of OSA and predictor of SCD in HCM, mediates the association between OSA and the composite endpoint. RESULTS: Of 52,106 HCM admissions, 8848 (16.98%) had OSA. In a multivariate model excluding AF, OSA was associated with CA-VF (OR 1.16, 95% CI 1.10-1.27, p = 0.002). However, after adjusting for AF, this association was no longer significant (OR 1.001, 95% CI 0.91-1.10, p = 0.97). Mediation analysis showed a significant average causal mediation effect (ACME, p < 0.001), with AF accounting for approximately 98.5% of the total effect of OSA on CA-VF. CONCLUSION: In this large cohort of HCM patients, the association between OSA and CA-VF appeared to be predominantly mediated by AF, with no significant independent direct effect observed. These findings suggest that OSA may contribute to arrhythmic risk in HCM primarily through its relationship with AF and should be considered hypothesis-generating.