title: Association between smoking and recurrence of venous thromboembolism and bleeding in elderly patients with past acute venous thromboembolism.
abstract: BACKGROUND
  While the association between smoking and arterial cardiovascular events has been well established, the association between smoking and venous thromboembolism (VTE) remains controversial.
  
  
  OBJECTIVE
  To assess the association between smoking and the risk of recurrent VTE and bleeding in patients who have experienced acute VTE.
  
  
  METHODS
  This study is part of a prospective Swiss multicenter cohort that included patients aged ≥65years with acute VTE. Three groups were defined according to smoking status: never, former and current smokers. The primary outcome was the time to a first symptomatic, objectively confirmed VTE recurrence. Secondary outcomes were the time to a first major and clinically relevant non-major bleeding. Associations between smoking status and outcomes were analysed using proportional hazard models for the subdistribution of a competing risk of death.
  
  
  RESULTS
  Among 988 analysed patients, 509 (52%) had never smoked, 403 (41%) were former smokers, and 76 (8%) current smokers. After a median follow-up of 29.6months, we observed a VTE recurrence rate of 4.9 (95% confidence interval [CI] 3.7-6.4) per 100 patient-years for never smokers, 6.6 (95% CI 5.1-8.6) for former smokers, and 5.2 (95% CI 2.6-10.5) for current smokers. Compared to never smokers, we found no association between current smoking and VTE recurrence (adjusted sub-hazard ratio [SHR] 1.05, 95% CI 0.49-2.28), major bleeding (adjusted SHR 0.59, 95% CI 0.25-1.39), and clinically relevant non-major bleeding (adjusted SHR 1.21, 95% CI 0.73-2.02).
  
  
  CONCLUSIONS
  In this multicentre prospective cohort study, we found no association between smoking status and VTE recurrence or bleeding in elderly patients with VTE.
authors.affiliation: Department of Ambulatory Care and Community Medicine, University of Lausanne, Lausanne, Switzerland. Electronic address: philippe.carruzzo@unil.ch.
authors.forename: Philippe
authors.initials: P
authors.lastname: Carruzzo
authors.affiliation: Department of General Internal Medicine, Bern University Hospital, Bern, Switzerland; Department of Internal Medicine, University Hospital, Lausanne, Switzerland.
authors.forename: Marie
authors.initials: M
authors.lastname: Méan
authors.affiliation: Clinical Trials Unit Bern, Department of Clinical Research, Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland.
authors.forename: Andreas
authors.initials: A
authors.lastname: Limacher
authors.affiliation: Department of General Internal Medicine, Bern University Hospital, Bern, Switzerland.
authors.forename: Drahomir
authors.initials: D
authors.lastname: Aujesky
authors.affiliation: Department of Ambulatory Care and Community Medicine, University of Lausanne, Lausanne, Switzerland.
authors.forename: Jacques
authors.initials: J
authors.lastname: Cornuz
authors.affiliation: Department of Ambulatory Care and Community Medicine, University of Lausanne, Lausanne, Switzerland.
authors.forename: Carole
authors.initials: C
authors.lastname: Clair
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006470:Hemorrhage / Q000209:etiology* / Q000473:pathology; D006801:Humans; D008297:Male; D011446:Prospective Studies; D012008:Recurrence; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D054556:Venous Thromboembolism / Q000209:etiology* / Q000473:pathology
keywords: Aged; Hemorrhage; Recurrence; Smoking; Venous thromboembolism