title: Comparison between idiopathic deep vein thrombosis of the upper and lower extremity regarding risk factors and recurrence.
abstract: BACKGROUND
  The pathogenesis and natural course of idiopathic upper extremity deep vein thrombosis (UEDVT) are unclear.
  
  
  OBJECTIVE
  To compare patients with UEDVT and with idiopathic lower extremity deep vein thrombosis (LEDVT) regarding risk factors and recurrence.
  
  
  METHODS
  We followed 50 patients with first idiopathic UEDVT and 841 patients with first idiopathic LEDVT for an average of 59 and 46 months, respectively. We excluded patients with natural inhibitor deficiency, lupus anticoagulant, cancer, pregnancy, isolated pulmonary embolism (PE), or long-term antithrombotic treatment. The endpoint was recurrent venous thromboembolism (VTE).
  
  
  RESULTS
  In comparison to LEDVT patients, UEDVT patients were younger (38 +/- 13 years vs. 49 +/- 16 years, P < 0.001), slimmer (body mass index: 24 +/- 4 vs. 27 +/- 5, P < 0.001), less frequently had a family history of VTE (18% vs. 31%, P = 0.06) or concomitant PE (8% vs. 31%, P =0.001), were less frequently carriers of factor V Leiden (12% vs. 30%, P = 0.009), and had lower thrombin generation marker levels (D-dimer, 283 +/- 361 ng mL(-1) vs. 456 +/- 446 ng mL(-1), P < 0.001; peak thrombin, 298 +/- 101 nm vs. 363 +/- 111 nm, P = 0.001). Recurrence occurred in two of 50 patients with UEDVT (4%) and in 129 of 841 patients with LEDVT (15%). After 5 years, the likelihood of recurrence was 2% [95% confidence interval (CI) 0-6] among UEDVT patients and 19% (95% CI 16-22; P = 0.02) among LEDVT patients. As compared to LEDVT patients, the adjusted risk of recurrence was 0.26 (95% CI 0.06-1.05; P = 0.059) in UEDVT patients.
  
  
  CONCLUSIONS
  The pathogenesis and natural course of the disease differ between patients with idiopathic UEDVT and LEDVT.
authors.affiliation: Department of Medicine I, Medical University of Vienna, Vienna, Austria.
authors.forename: D
authors.initials: D
authors.lastname: Lechner
authors.forename: C
authors.initials: C
authors.lastname: Wiener
authors.forename: A
authors.initials: A
authors.lastname: Weltermann
authors.forename: L
authors.initials: L
authors.lastname: Eischer
authors.forename: S
authors.initials: S
authors.lastname: Eichinger
authors.forename: P A
authors.initials: PA
authors.lastname: Kyrle
mesh_terms: D000328:Adult; D000368:Aged; D001132:Arm; D015415:Biomarkers / Q000097:blood; D001779:Blood Coagulation Factors / Q000378:metabolism; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007866:Leg; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012008:Recurrence; D012307:Risk Factors; D020246:Venous Thrombosis / Q000097:blood / Q000209:etiology* / Q000517:prevention & control
chemical_list: D015415:Biomarkers; D001779:Blood Coagulation Factors