Open AccessComparative efficacy and safety of low‐intensity warfarin therapy in preventing unprovoked recurrent venous thromboembolism: A systematic review and meta‐analysis
Author(s) -
Jiang Rong,
Shi Yu,
Zhang Rui,
Pudasain Bigyan,
Wang Lan,
Zhao QinHua,
Yuan Ping,
Guo Jian,
Zhu ChangTai,
Liu JinMing
Publication year - 2018
Publication title -
the clinical respiratory journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.789
H-Index - 33
eISSN - 1752-699X
pISSN - 1752-6981
DOI - 10.1111/crj.12795
Subject(s) - medicine , warfarin , placebo , antithrombotic , randomized controlled trial , relative risk , meta analysis , intensity (physics) , venous thromboembolism , surgery , confidence interval , atrial fibrillation , thrombosis , physics , alternative medicine , pathology , quantum mechanics
Background Although there exists potential risk of bleeding, extended ‘lifelong’ conventional‐intensity [international normalized ratio (INR): 2.0‐3.0] warfarin anticoagulation is recommended for unprovoked venous thromboembolism (VTE) patients because of risk of recurrent VTE. Whether long‐term low‐intensity (INR: 1.5‐2.0) warfarin therapy reduced the risk of major bleeding without substantially lowered antithrombotic efficacy is not well understood. The aim of this study was to perform a systematic review and meta‐analysis to evaluate the risk‐benefits of low‐intensity warfarin therapy. Methods We conducted a comprehensive search of electronic databases and included randomized control trials (RCTs) that reported efficacy (recurrent VTE) and safety (bleeding episodes) of low‐intensity warfarin therapy compared with conventional‐intensity warfarin or placebo from inception through Jun 2016. Results Four RCTs reporting high GRADE quality evidence were included. Although the relative risk of recurrent VTE with low‐intensity therapy was significantly increased [2.96 (95% CI: 1.40 to 6.24), P < .004] compared to conventional‐intensity warfarin, there was significant decrease of relative risk when compared with placebo [0.37 (95% CI: 0.24 to 0.56), P < .00001]. As per included publications, no significant major bleeding episodes were observed in low‐intensity warfarin group. Conclusions Although less effective than conventional‐intensity warfarin therapy this meta‐analysis indicates that long‐term low‐intensity warfarin therapy is highly effective for preventing recurrent VTE than placebo, along with reduced risks of major bleeding and minimizing potential complications.