The Effect of Onset Time on In-Hospital Mortality in Patients with Acute Type A Aortic Dissection of Different Gender: A Retrospective Cohort Study.

Background: Although the research on gender in acute type A aortic dissection (AAAD) patients has increased in recent years, the results are still controversial. The effect of time of onset on in-hospital mortality in patients with AAAD of different gender is unclear. The purpose of this study was to investigate the effect of onset time on in-hospital mortality of patients with AAAD of different gender.

Methods: In this retrospective observational study, patients with AAAD were selected from June 2013 to March 2020. Patients' information was extracted from electronic medical records. Based on the onset time, the patients were categorized into four groups: group one (00:00-05:59), group two (6:00-11:59), group three (12:00-17:59), and group four (18:00-23:59).

Results: A total of 760 subjects were included in our study. There were 591 (77.8%) males and 169 (22.2%) females. In male patients, 79 cases died, in female patients, 19 cases died (p < 0.05). We conducted subgroup analysis according to gender, univariate Cox regression analysis of male patients showed that compared with the patients at onset time of 0:00-5:59, patients at onset time of 12:00-17:59 and 18:00-23:59 were associated with an increased risk of in-hospital mortality. Multivariate Cox regression analysis of male patients showed that the onset time of 18:00-23:59 remained as the significant risk factor of in-hospital mortality of male patients hazard ratio (HR) = 4.396 (p < 0.05).

Conclusions: This analysis demonstrated that in-hospital mortality of AAAD patients was similar in different genders. In male patients, the onset time of 18:00-23:59 was significantly associated with an increased risk of in-hospital mortality.