title: Self-managed long-term low-molecular-weight heparin therapy: the balance of benefits and harms.
abstract: OBJECTIVE
  A substantial clinical need exists for an alternate to vitamin K antagonists for treating deep vein thrombosis in many patients. Long-term low-molecular-weight heparin (LMWH), body-weight adjusted, avoids anticoagulant monitoring and may be associated with less bleeding. We evaluated the effectiveness and safety of long-term LMWH compared with vitamin K antagonist therapy in a broad spectrum of patients with proximal vein thrombosis.
  
  
  METHODS
  We performed a multicenter, randomized, open-label clinical trial using objective outcome measures comparing therapy for 3 months. Outcomes were assessed at 3 and 12 months.
  
  
  RESULTS
  Of 737 patients, 18 of 369 receiving tinzaparin (4.9%) had recurrent venous thromboembolism at 3 months compared with 21 of 368 (5.7%) receiving usual care (absolute difference, -0.8%, 95% confidence interval -4.1-2.4). Hemorrhagic complications occurred less frequently in the LMWH group largely because of less minor bleeding: 48 of 369 patients (13.0%) versus 73 of 368 patients (19.8%) receiving usual-care anticoagulation (absolute difference -6.8%; P = .011; risk ratio = 0.66). New major bleeding events ceased early (by day 23, P = .034) for patients receiving LMWH but persisted throughout the study treatment interval for patients receiving vitamin K antagonist therapy. No mortality advantage was shown for LMWH.
  
  
  CONCLUSIONS
  Our study shows that LMWH is similar in effectiveness to the usual-care vitamin K antagonist treatment for preventing recurrent venous thromboembolism in a broad spectrum of patients. It causes less harm and enhances the clinicians' therapeutic options for patients with proximal deep vein thrombosis. Our findings reported here suggest the possibility of a broader role for long-term LMWH in selected patients.
authors.affiliation: University of Calgary, Calgary, AB, Canada. Jeanne.Sheldon@calgaryhealthregion.ca
authors.forename: Russell D
authors.initials: RD
authors.lastname: Hull
authors.forename: Graham F
authors.initials: GF
authors.lastname: Pineo
authors.forename: Rollin F
authors.initials: RF
authors.lastname: Brant
authors.forename: Andrew F
authors.initials: AF
authors.lastname: Mah
authors.forename: Natasha
authors.initials: N
authors.lastname: Burke
authors.forename: Richard
authors.initials: R
authors.lastname: Dear
authors.forename: Turnly
authors.initials: T
authors.lastname: Wong
authors.forename: Roy
authors.initials: R
authors.lastname: Cook
authors.forename: Susan
authors.initials: S
authors.lastname: Solymoss
authors.forename: Man-Chiu
authors.initials: MC
authors.lastname: Poon
authors.forename: Gary
authors.initials: G
authors.lastname: Raskob
mesh_terms: D000925:Anticoagulants / Q000008:administration & dosage / Q000627:therapeutic use; D002423:Cause of Death; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D006470:Hemorrhage / Q000453:epidemiology; D006495:Heparin, Low-Molecular-Weight / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012646:Self Administration; D000078222:Tinzaparin; D016896:Treatment Outcome; D020246:Venous Thrombosis / Q000188:drug therapy*; D014812:Vitamin K / Q000037:antagonists & inhibitors*; D014859:Warfarin / Q000008:administration & dosage / Q000627:therapeutic use
chemical_list: D000925:Anticoagulants; D005343:Fibrinolytic Agents; D006495:Heparin, Low-Molecular-Weight; D014812:Vitamin K; D014859:Warfarin; D000078222:Tinzaparin