Day-night pattern of acute ST-segment elevation myocardial infarction onset in patients with obstructive sleep apnea

Study Objectives: Obstructive sleep apnea (OSA) is associated with acute nocturnal hemodynamic and neurohormonal abnormalities that may increase the risk of coronary events, especially during the nighttime. This study sought to investigate the day -night pattern of acute ST -segment elevation myocardial infarction (STEMI) onset in patients with OSA and its impact on cardiovascular adverse events. Methods: We prospectively enrolled 397 patients with STEMI, for which the time of onset of chest pain was clearly identified. All participants were categorized into non-OSA (n = 280) and OSA (n = 117) groups. The association between STEMI onset time and major adverse cardiovascular and cerebrovascular events was estimated by Cox proportional hazards regression. Results: STEMI onset occurred from midnight to 5:59 AM in 33% of patients with OSA, as compared with 15% in non-OSA patients ( P < .01). For individuals with OSA, the relative risk of STEMI from midnight to 5:59 AM was 2.717 [95% confidence interval (CI) 1.616 - 4.568] compared with non-OSA patients. After a median of 2.89 +/- 0.78 years follow-up, symptom onset time was found to be significantly associated with risk of major adverse cardiovascular and cerebrovascular events in patients with OSA, while there was no significant association observed in non-OSA patients. Compared with STEMI presenting during noon to 5:59 PM , the hazard ratios for major adverse cardiovascular and cerebrovascular events in patients with OSA were 4.683 (95% CI 2.024 - 21.409, P = .027) for midnight to 5:59 AM and 6.964 (95% CI 1.379 - 35.169, P = .019) for 6 PM to midnight, whereas the hazard ratios for non-OSA patients were 1.053 (95% CI 0.394 - 2.813, P = .917) for midnight to 5:59 AM and 0.745 (95% CI 0.278 -1.995, P = .558) for 6 PM to midnight. Conclusions: Patients with OSA exhibited a peak incidence of STEMI between midnight and 5:59 AM , which showed an independent association with cardiovascular adverse events.