Extended Anticoagulation for VTE: A Systematic Review and Meta-Analysis

Abstract

Background: The efficacy and safety of direct oral anticoagulants (DOACs) and vitamin K antagonists (VKAs) during extended anticoagulation for a VTE remains largely unknown, especially in terms of potential survival benefit. The goal of this study was to assess the effects of VKAs and DOACs on overall mortality and VTE-related mortality, as well as VTE recurrence and safety.

Methods: PubMed, EMBASE, and the Cochrane Library were searched from January 1990 through September 2018 for randomized controlled trials evaluating the effect of extended anticoagulants as secondary prevention for VTE compared with placebo. The primary outcome was the specific effects of standard-intensity VKAs and DOACs on overall mortality.

Results: Sixteen studies (12,458 patients) were included. DOACs were associated with a reduction in overall (risk ratio [RR], 0.48; 95% CI, 0.27-0.86; P = .01) and VTE-related (RR, 0.36; 95% CI, 0.15-0.89; P = .03) mortality, whereas VKAs were not (P > .50). Although VKAs and DOACs similarly prevented recurrent VTE, only VKAs were associated with an increased risk of major bleeding (RR, 2.67; 95% CI, 1.28-5.60; P < .01), resulting in an improved net clinical benefit for DOACs (RR, 0.25 [95% CI, 0.16-0.39; P < .01] vs 0.46 [95% CI, 0.30-0.72; P < .01]; P_interaction = .05).

Conclusions: DOACs for extended anticoagulation were associated with a significant reduction in overall mortality compared with observation alone.

Trial registry: PROSPERO; No.: CRD42018088739; URL: https://www.crd.york.ac.uk/prospero/.

Keywords: VTE; direct oral anticoagulant; extended anticoagulation; mortality; vitamin K antagonist.