Circadian rhythm and clinical characteristics in patients with acute myocardial infarction combined with obstructive sleep apnea

OBJECTIVE: The present study aimed to investigate the circadian rhythm and clinical characteristics of patients with acute myocardial infarction (AMI) combined with obstructive sleep apnea (OSA). METHODS: Patients with AMI combined with OSA were enrolled in the study, and those that met the inclusion criteria were divided into three time‐period groups based on their sleep–wake rhythm (22:00–5:59, 6:00–13:59, and 14:00–21:59). The differences between the three groups of patients in sleep‐monitoring data, blood routine, biochemical indicators, and coronary angiographic parameters were analyzed and compared. Count data were expressed as the number of cases, and the chi‐square test was used for statistical analysis. Continuous data were expressed as mean ± standard deviation, and analysis of variance was used for the statistical analysis of these data. The characteristics of circadian rhythm and clinical features in patients with AMI combined with OSA were analyzed. RESULTS: Of the 148 patients, 90/148 (61%) had chest pain and 58/148 (39%) had non‐chest pain symptoms. In the 22:00–05:59 group, there were 70/148 (47%) patients with AMI (of these, 46/70 [66%] had chest pain). In the 06:00–13:59 period group, there were 44/148 (30%) patients with AMI (of these, 26/44 [60%] had chest pain). In the 14:00–21:59 period group, there were 34/148 (23%) patients with AMI (of these, 17/34 [50%] had chest pain). There was no statistically significant difference in the apnea–hypopnea index (AHI) and SYNTAX score between patients in the 22:00–5:59 and 6:00–13:59 groups. However, the AHI and SYNTAX scores in the 22:00–5:59 and 6:00–13:59 groups were higher than those in the 14:00–21:59 group, and the differences were statistically significant. In patients in the 22:00–5:59 group, the levels of serum D‐dimer (DD), hemoglobin (Hb), and oxygen desaturation index (ODI3) were higher, the sleep mean oxygen saturation (MeanSaO(2)) was lower and the percentage of nighttime spent with oxygen saturation of less than 90% (Tsat(90)) and less than 85% (Tsat(85)) was longer. CONCLUSION: The peak period for the onset of AMI in patients with OSA was 22:00–5:59, and the incidence of chest pain was high. During this period, patients had higher DD and Hb, higher ODI3, lower MeanSaO(2) during sleep, and longer TSat(90) and TSat(85). During the 22:00–5:59 and 6:00–13:59 periods, patients had higher AHI and a higher SYNTAX score.