Sleep-Disordered Breathing Is an Independent Risk Factor of Aborted Sudden Cardiac Arrest in Patients With Coronary Artery Spasm

Background: Sleep-disordered breathing (SDB) is often associated with sudden cardiac arrest (SCA) during sleep. Coronary artery spasm (CS) also occurs during sleep and is rarely associated with SCA, but the role of SDB in the risk of SCA is unknown in CS patients. This study evaluated the breathing patterns during sleep in CS patients with a prior history of aborted SCA. Methods and Results: This study enrolled 24 patients (age 61.6 +/- 11.0 years, male/female 19/5) with CS proven by an acetylcholine provocation test. They were divided into 2 groups: prior history of aborted SCA due to fatal arrhythmia (SCA group; n=9) and no such history (no-SCA group; n=15). Patients underwent overnight polysomnography with ambulatory electrocardiography. The overall prevalence of SDB (apnea hypopnea index >= 15) was 45.8% in this cohort. SDB was more frequent in the SCA group than in the no-SCA group (88.9% vs. 20.0% P=0.001) and identified as a pivotal risk factor of aborted SCA (odds ratio: 38.9, 95% Cl: 2.80-1,498.2, P=0.01). Very-low-frequency was significantly correlated with the apnea hypopnea index in patients with SCA (P=0.01, r=0.78) during sleep. Conclusions: SDB is a significant risk factor for SCA in CS patients and autonomic instability during sleep might be involved in this association. (Circ J 2012; 76: 2204-2210)