Reduced-dose direct oral anticoagulants in the extended treatment of venous thromboembolism: a systematic review and meta-analysis

J Thromb Haemost. 2018 Jul;16(7):1288-1295. doi: 10.1111/jth.14156. Epub 2018 Jun 17.


Essentials In venous thromboembolism (VTE), benefits of extended treatment are balanced by bleeding risks. This is a meta-analysis of reduced-dose direct oral anticoagulants (DOACs) in extended treatment. Reduced-dose DOACs are as effective as full anticoagulation with bleeding risks similar to placebo. Reduced-dose DOACs are an attractive option for patients in the extended phase of VTE treatment.

Summary: Background Extended-duration anticoagulation is beneficial for preventing recurrent venous thromboembolism (VTE). Reduced-dose direct oral anticoagulants (DOACs) may be preferable if they preserve efficacy and cause less bleeding. We conducted a systematic review and meta-analysis of trials comparing reduced-dose DOACs with full-dose DOACs and aspirin or placebo in the extended phase of VTE treatment. Methods A literature search was conducted by use of the MEDLINE, EMBASE and CINAHL databases, supplemented by hand-searching. One thousand three hundred and ninety-nine titles were screened, with data from accepted studies being extracted by two independent reviewers. Major outcomes analyzed included recurrent VTE and major and clinically relevant non-major bleeding events, presented as risk ratios (RRs) and 95% confidence intervals (CI). Results Two trials met the prespecified inclusion criteria. Data from 5847 patients were analyzed for efficacy outcomes, and from 5842 patients for safety outcomes. Reduced-dose DOACs were as effective as full-dose treatment in preventing recurrent VTE at 1 year (RR 1.12 [95% CI 0.67-1.87]), and more effective than aspirin or placebo (RR 0.26 [95% CI 0.14-0.46]). Rates of major or clinically relevant non-major bleeding events were similar between patients receiving reduced-dose DOACs and and those receiving aspirin or placebo (RR 1.19 [95% CI 0.81-1.77]). There was a trend towards less bleeding when reduced-dose and full-dose DOACs were compared (RR 0.74 [95% CI 0.52-1.05]). Conclusions Extended-duration treatment of VTE with reduced-dose DOACs may be as efficacious as full-dose treatment, with rates of major bleeding being similar to those in patients receiving treatment with aspirin or placebo, but further long-term studies are needed.

Keywords: anticoagulants; apixaban; aspirin; hemorrhage; rivaroxaban; venous thromboembolism.

Publication types

  • Meta-Analysis
  • Systematic Review

MeSH terms

  • Administration, Oral
  • Aged
  • Aged, 80 and over
  • Anticoagulants / administration & dosage*
  • Anticoagulants / adverse effects
  • Blood Coagulation / drug effects*
  • Drug Administration Schedule
  • Female
  • Hemorrhage / chemically induced
  • Humans
  • Male
  • Middle Aged
  • Risk Assessment
  • Risk Factors
  • Time Factors
  • Treatment Outcome
  • Venous Thrombosis / blood
  • Venous Thrombosis / diagnosis
  • Venous Thrombosis / drug therapy*


  • Anticoagulants