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. 2020 Jul 13;4(3):e145-e152.
doi: 10.1055/s-0040-1714918. eCollection 2020 Jul.

Bleeding Risk in Nonvalvular Atrial Fibrillation Patients Receiving Direct Oral Anticoagulants and Warfarin: A Systematic Review and Meta-Analysis of Observational Studies

Yimin Pearl Wang  1 , Rohan Kehar  1 , Alla Iansavitchene  2 , Alejandro Lazo-Langner  1   3
Affiliations

Bleeding Risk in Nonvalvular Atrial Fibrillation Patients Receiving Direct Oral Anticoagulants and Warfarin: A Systematic Review and Meta-Analysis of Observational Studies

Yimin Pearl Wang et al. TH Open. .

Abstract

Introduction In randomized trials in atrial fibrillation (AF) patients on direct oral anticoagulants (DOACs) have a lower risk of bleeding compared with warfarin. However, data from randomized trials may not extrapolate to general population. We aimed to determine the risk of bleeding in patients on DOACs in observational studies. Materials and Methods Observational studies from 1990 to January 2019 were included. A pooled effect hazard ratio (HR) was calculated with a random effects model using the generic inverse variance method. Subgroup analyses according to previous anticoagulants exposure, study type, funding source, and DOAC type (direct thrombin inhibitors vs. factor Xa inhibitors) were conducted. Results A total of 35 studies comprising 2,356,201 patients were included. The average pooled HR for observational data was 0.78 (95% confidence interval [CI] 0.71, 0.85). There were no statistically significant differences in pooled HR by previous exposure to anticoagulants, DOAC type (direct thrombin vs. factor Xa inhibitors), study type, and funding source. Among patients receiving factor Xa inhibitors, patients on apixaban had a lower risk of bleeding compared with warfarin (HR 0.60, 95% CI 0.50, 0.71, p < 0.001) in contrast to those on rivaroxaban (HR 0.98, 95% CI 0.91, 1.06, p = 0.60). Conclusion In observational studies, AF patients on DOACs experience less bleeding events compared with warfarin; however, apixaban and dabigatran, but not rivaroxaban, have a lower risk of bleeding than warfarin.

Keywords: atrial fibrillation; bleeding; direct oral anticoagulants; meta-analysis; observational studies.

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Conflict of interest statement

Conflict of Interest None declared.

Figures

Fig. 1
Fig. 1
PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) flow diagram summarizing the identification process of relevant studies.
Fig. 2
Fig. 2
Comparison of bleeding risk between direct oral anticoagulants and warfarin stratified by drug class.
Fig. 3
Fig. 3
Comparison of bleeding risk between direct factor Xa inhibitors and warfarin stratified by individual agent.
See this image and copyright information in PMC

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