Obstructive sleep apnea is associated with nonsustained ventricular tachycardia in patients with hypertrophic obstructive cardiomyopathy

BACKGROUND Hypertrophic cardiomyopathy (HCM) is associated with arrhythmias and cardiovascular death. Obstructive sleep apnea (OSA) is highly prevalent and independently associated with atrial fibrillation in patients with HCM. OBJECTIVE The purpose of this study was to determine the relationship between nonsustained ventricular tachycardia (NSVT) and OSA in hypertrophic obstructive cardiomyopathy (HOCM). METHODS One hundred thirty consecutive patients with a confirmed diagnosis of HOCM in Fuwai Hospital between September 2017 and May 2018 were included. Polysomnography and Holter electrocardiography were performed in all patients. RESULTS Of 130 patients, 72 (55%) were diagnosed with OSA, including 38 with mild, 21 with moderate, and 13 with severe OSA, and 27 patients (21%) had NSVT. The prevalence of NSVT increased with the severity of OSA (none, mild, moderate, and severe: 12%, 16%, 33%, and 54%, respectively; P < .001 for trend). Compared to patients without NSVT, the apnea-hypopnea index was significantly higher in patients with NSVT among the different OSA groups (mild, moderate, and severe: 12 [11-13] vs 7 [6-8], P = .001; 24 [22-28] vs 19 [17-22], P = .01; and 54 [41-62] vs 34 [31-39], P = .008). In multivariate logistic regression analysis, family history of HCM or sudden cardiac death (odds ratio 6; 95% confidence interval 2-22; P = .005) and apnea-hypopnea index (odds ratio 1.07; 95% confidence interval 1.02-1.12; P = .001) were the only factors associated with NSVT after adjustment for age, sex, and body mass index. CONCLUSION The presence and severity of OSA in patients with HOCM is independently associated with NSVT, which is a risk factor for sudden cardiac death and cardiovascular death in this population.