Chronologic and Climatic Factors of Acute Aortic Dissection: Study of 1642 Patients in Two Continents

The purpose of this study was to examine whether chronologic and climatic factors and lunar phases affect the onset of acute aortic dissection (AAD).The frequencies of AAD were analyzed with regard to the chronologic and climatic factors and lunar phases on the day when AAD occurred for 1642 patients with AAD from two aortic referral centers in the United States and China.Mean age of patients was 51.6 ± 13.1 years, and 1260 (76.7%) were men. Dissection was type A in 1125 patients (68.5%) and type B in 517 (31.5%). Early mortality rate was 11.6% (190 of 1642), including 89 aortic ruptures before operation and 101 operative deaths. There was a winter peak in occurrence (33.6%, P.01) with a relative risk of 1.519. In a week, the frequency was highest on Wednesday (15.5%) and Monday (15.2%), and lowest on Sunday (12.8%). Month-specific incidence was significantly inversely correlated to the mean temperature (rho = -0.650, P = .022) and directly correlated to the atmospheric pressure (rho = 0.706, P = .001). The proportion of type A dissection was significantly higher in the full moon phase compared with type B dissection (73.7% vs 66.9%, P = .012).Acute aortic dissection exhibits significant chronologic variation in the frequency of occurrence, with a peak in winter and on Wednesdays, and nadir in summer and on Sundays. The incidence is significantly correlated to the mean temperature and atmospheric pressure. The proportion of type A dissection is higher in the full moon phase. These results are important for understanding the mechanisms involved in triggering AAD events and helpful for improving disease prevention and patient care.