title: Arterial cardiovascular events, statins, low-dose aspirin and subsequent risk of venous thromboembolism: a population-based case-control study.
abstract: BACKGROUND
  Atherosclerotic disease has been associated with the risk of venous thromboembolism, but the available data are conflicting. There are similar confusions regarding the association of the use of aspirin and statins with venous thromboembolism.
  
  
  OBJECTIVE
  To determine whether arterial cardiovascular events, use of statins and low-dose aspirin were associated with the risk of venous thromboembolism.
  
  
  METHODS
  In this population-based case-control study, we identified 5824 patients with venous thromboembolism and 58 240 population controls with a complete hospital and prescription history. We used logistic regression to estimate the relative risk of venous thromboembolism, adjusted for potentially confounding factors.
  
  
  RESULTS
  Patients with a history of arterial cardiovascular events had a clearly increased relative risk. An event within 3 months before the index date conferred large increases in risk [relative risk 4.22 (95% confidence interval (CI), 2.33-7.64) after myocardial infarction, 4.41 (95% CI, 2.92-6.65) after stroke]. Myocardial infarction more than 3 months before the index date was not significantly associated with risk, although there was a relative risk of 1.29 (95% CI, 1.05-1.57) for myocardial infarction more than 60 months previously. A history of stroke was associated with small increases in risk after 3 months. Current use of statins was associated with a reduced risk of venous thromboembolism [relative risk=0.74 (95% CI, 0.63-0.85)]. Aspirin use was not associated with risk.
  
  
  CONCLUSIONS
  Patients with cardiovascular events are at a short-term increased risk of venous thromboembolism. Statins might prevent venous thromboembolism but aspirin does not. However, as the study is non-randomized residual confounding cannot be excluded.
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus C, Denmark. hts@dce.au.dk
authors.forename: H T
authors.initials: HT
authors.lastname: Sørensen
authors.forename: E
authors.initials: E
authors.lastname: Horvath-Puho
authors.forename: K K
authors.initials: KK
authors.lastname: Søgaard
authors.forename: S
authors.initials: S
authors.lastname: Christensen
authors.forename: S P
authors.initials: SP
authors.lastname: Johnsen
authors.forename: R W
authors.initials: RW
authors.lastname: Thomsen
authors.forename: P
authors.initials: P
authors.lastname: Prandoni
authors.forename: J A
authors.initials: JA
authors.lastname: Baron
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001157:Arterial Occlusive Diseases / Q000150:complications* / Q000453:epidemiology; D001241:Aspirin / Q000627:therapeutic use*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000453:epidemiology; D012306:Risk; D012307:Risk Factors; D020521:Stroke / Q000150:complications / Q000453:epidemiology; D013997:Time Factors; D054556:Venous Thromboembolism / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*
chemical_list: D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D001241:Aspirin