Self-managed long-term low-molecular-weight heparin therapy: the balance of benefits and harms

Am J Med. 2007 Jan;120(1):72-82. doi: 10.1016/j.amjmed.2006.03.030.

Abstract

Purpose: 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.

Conclusion: 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.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anticoagulants / administration & dosage
  • Anticoagulants / therapeutic use
  • Cause of Death
  • Female
  • Fibrinolytic Agents / administration & dosage
  • Fibrinolytic Agents / adverse effects
  • Fibrinolytic Agents / therapeutic use*
  • Hemorrhage / epidemiology
  • Heparin, Low-Molecular-Weight / administration & dosage
  • Heparin, Low-Molecular-Weight / adverse effects
  • Heparin, Low-Molecular-Weight / therapeutic use*
  • Humans
  • Male
  • Middle Aged
  • Recurrence
  • Self Administration
  • Tinzaparin
  • Treatment Outcome
  • Venous Thrombosis / drug therapy*
  • Vitamin K / antagonists & inhibitors*
  • Warfarin / administration & dosage
  • Warfarin / therapeutic use

Substances

  • Anticoagulants
  • Fibrinolytic Agents
  • Heparin, Low-Molecular-Weight
  • Vitamin K
  • Warfarin
  • Tinzaparin