title: Onset seasons and clinical outcomes in patients with Stanford type A acute aortic dissection: an observational retrospective study.
abstract: To evaluate the association of onset season with clinical outcome in type A acute aortic dissection (AAD).
  
  
  
  A single-centre, observational retrospective study.
  
  
  
  The study was conducted in Fuwai Hospital, the National Centre for Cardiovascular Disease, Beijing, China.
  
  
  
  From 2008 to 2010, a set of consecutive patients with type A AAD, confirmed by CT scanning, were enrolled and divided into four groups according to onset season: winter (December, January and February), spring (March, April and May), summer (June, July and August) and autumn (September, October and November). The primary end points were in-hospital death and all-cause mortality during follow-up.
  
  
  
  Of the 492 cases in this study, 129 occurred in winter (26.2%), 147 in spring (29.9%), 92 in summer (18.7%), and 124 in autumn (25.2%). After a median follow-up of 20.4 months (IQR 9.7-38.9), the in-hospital mortality in cases occurring in autumn was higher than in the other three seasons (23.4% vs 8.4%, p<0.01). Long-term mortality was comparable among the four seasonal groups (p=0.63). After adjustment for age, gender and other risk factors, onset in autumn was still an independent factor associated with increased risk of in-hospital mortality (HR 2.05; 95% CI 1.15 to 3.64, p=0.02) in addition to surgical treatment. Further analysis showed that the seasonal effect on in-hospital mortality (autumn vs other seasons: 57.4% vs 27.3%, p<0.01) was only significant in patients who did not receive surgical treatment. No seasonal effect on long-term clinical outcomes was found in this cohort.
  
  
  
  Onset in autumn may be a factor that increases the risk of in-hospital death from type A AAD, especially in patients who receive conservative treatment. Immediate surgery improves the short-term and long-term outcomes regardless of onset season.
authors.affiliation: State Key Laboratory of Cardiovascular Disease, Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Diseases, Peking Union Medical College, Beijing, China.
authors.forename: Zhaoran
authors.initials: Z
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Cardiovascular Disease, Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Diseases, Peking Union Medical College, Beijing, China.
authors.forename: Bi
authors.initials: B
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Cardiovascular Disease, Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Diseases, Peking Union Medical College, Beijing, China.
authors.forename: Yanmin
authors.initials: Y
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Cardiovascular Disease, Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Diseases, Peking Union Medical College, Beijing, China.
authors.forename: Rutai
authors.initials: R
authors.lastname: Hui
authors.affiliation: State Key Laboratory of Cardiovascular Disease, Department of Cardiovascular Surgery, Fuwai Hospital, National Center for Cardiovascular Diseases, Peking Union Medical College, Beijing, China.
authors.forename: Haisong
authors.initials: H
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Cardiovascular Disease, Department of Cardiovascular Surgery, Fuwai Hospital, National Center for Cardiovascular Diseases, Peking Union Medical College, Beijing, China.
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Cardiovascular Disease, Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Diseases, Peking Union Medical College, Beijing, China.
authors.forename: Zhinan
authors.initials: Z
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Cardiovascular Disease, Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Diseases, Peking Union Medical College, Beijing, China.
authors.forename: Shu
authors.initials: S
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Cardiovascular Disease, Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Diseases, Peking Union Medical College, Beijing, China.
authors.forename: Xiaohan
authors.initials: X
authors.lastname: Fan
mesh_terms: D000328:Adult; D000784:Aortic Dissection / Q000401:mortality* / Q000628:therapy; D001014:Aortic Aneurysm / Q000401:mortality* / Q000628:therapy; D000068476:Beijing; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D012621:Seasons; D016019:Survival Analysis; D016896:Treatment Outcome
keywords: Stanford type A; acute aortic dissection; autumn; in-hospital death; onset seasons