Vitamin K Antagonists or Low-Molecular Weight Heparin for Venous Thromboembolism

A Cochrane review [Abstract] 1 included 16 studies with a total of 3 299 subjects. A statistically non-significant reduction of the risk of recurrent symptomatic venous thromboembolism in favour or LMWH was found (OR 0.83, 95% CI 0.60 to 1.15). The difference in bleeding significantly favoured treatment with LMWH (OR 0.51, 95% CI 0.32 to 0.80). However, when comparing only high-quality studies for bleeding, no clear differences between LMWH and VKA (Peto OR 0.62, 95% CI 0.36 to 1.07; 7 studies, n=1 872) were observed. No difference was observed in mortality (OR 1.08, 95% CI 0.75 to 1.56).

Comment: The quality of evidence is downgraded by study limitations (unclear allocation concealment and lack of blinding).

References

• Andras A, Sala Tenna A, Stewart M. Vitamin K antagonists versus low-molecular-weight heparin for the long term treatment of symptomatic venous thromboembolism. Cochrane Database Syst Rev 2017;(7):CD002001. [PubMed].