Deep night: critical periods for the onset of acute myocardial infarction in obstructive sleep apnea patients

Abstract

Abstract Introduction Obstructive sleep apnea (OSA) is associated with acute nocturnal hemodynamic and neurohormonal abnormalities that may increase the risk of coronary events, especially during deep sleeping time. This study sought to investigate the circadian variation of onset of acute myocardial infarction (AMI) in OSA patients and its long-term prognosis. Purpose In this study, we tested the hypothesis that people with OSA are more likely to have AMI during deep sleeping time than the other six-hour intervals of the day. Additionally, we assess the impact of circadian symptom-onset patterns of AMI on prognosis in OSA patients. Methods We prospectively enrolled 397 patients with AMI, for which the time of onset of chest pain was clearly identified. All subjects were categorized into non-OSA (n = 280) and OSA (n = 117) groups. The association between AMI onset time and major adverse cardiovascular and cerebrovascular events (MACCEs) was estimated by Cox proportional hazards regression. Results AMI onset occurred from midnight to 6 a.m. in 33% of OSA patients, as compared with 15% in non-OSA patients (P < 0.01). For OSA people, the relative risk of AMI from midnight to 6 a.m. was 1.990 (95% CI 1.329-2.929) compared with non-OSA patients (Figure 1). After a median of 2.89 ± 0.78 years follow-up, symptom onset time was significantly associated with risks of MACCEs in OSA patients, but not in non-OSA patients. The hazard ratios (HRs) for OSA patients were 4.683 (95% CI 2.024 to 21.409) for midnight to 6 a.m., and 6.964 (95% CI 1.379 to 35.169) for 6 p.m. to midnight as compared with AMI presenting during noon to 6 p.m (Figure 2). Conclusion Patients with OSA showed a peak incidence of AMI during the deep night, which was independently associated with adverse events.Figure 1Figure 2