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CC BY 4.0 · TH Open 2020; 04(03): e145-e152
DOI: 10.1055/s-0040-1714918
Original Article
Georg Thieme Verlag KG Stuttgart · New York

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   Division of Hematology, Department of Medicine, Western University, London, Ontario, Canada
,
Rohan Kehar   *
1   Division of Hematology, Department of Medicine, Western University, London, Ontario, Canada
,
Alla Iansavitchene
2   Library Services, London Health Sciences Centre, London, Ontario, Canada
,
Alejandro Lazo-Langner 
1   Division of Hematology, Department of Medicine, Western University, London, Ontario, Canada
3   Department of Epidemiology and Biostatistics, Western University, London, Ontario, Canada
› Author Affiliations Funding A.L.-L. is an investigator of the Canadian Venous Thromboembolism Clinical Trials and Outcomes Research (CanVECTOR) Network. This CanVECTOR Network receives grant funding from the Canadian Institutes of Health Research (Funding Reference: CDT-142654).
Further Information

Publication History

06 March 2020

26 May 2020

Publication Date:
13 July 2020 (online)

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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 - direct oral anticoagulants - bleeding - observational studies - meta-analysis

* These authors contributed equally to this work.


Supplementary Material

 

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