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Thromb Haemost 2016; 116(05): 975-986
DOI: 10.1160/TH16-05-0403
Stroke, Systemic or Venous Thromboembolism
Schattauer GmbH

Real-world comparison of major bleeding risk among non-valvular atrial fibrillation patients initiated on apixaban, dabigatran, rivaroxaban, or warfarin

A propensity score matched analysis
Gregory Y. H. Lip
1   University of Birmingham Institute of Cardiovascular Sciences, City Hospital, Birmingham, UK
2   Aalborg Thrombosis Research Unit, Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
,
Allison Keshishian
3   STATinMED Research, Ann Arbor, Michigan, USA
,
Shital Kamble
4   Bristol-Myers Squibb Company, Princeton, New Jersey, USA
,
Xianying Pan
4   Bristol-Myers Squibb Company, Princeton, New Jersey, USA
,
Jack Mardekian
5   Pfizer, Inc., New York, New York, USA
,
Ruslan Horblyuk
5   Pfizer, Inc., New York, New York, USA
,
Melissa Hamilton
4   Bristol-Myers Squibb Company, Princeton, New Jersey, USA
› Author Affiliations
Further Information

Publication History

Received: 25 May 2016

Accepted after major revision: 27 July 2016

Publication Date:
30 November 2017 (online)

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Summary

In addition to warfarin, there are four non-vitamin K antagonist oral anticoagulants (NOACs) available for stroke prevention in non valvular atrial fibrillation (NVAF). There are limited data on the comparative risks of major bleeding among newly anticoagulated NVAF patients who initiate warfarin, apixaban, dabigatran, or rivaroxaban, when used in ‘real world’ clinical practice. The study used the Truven MarketScan® Commercial & Medicare supplemental US claims database. NVAF patients aged ≥18 years newly prescribed an oral anticoagulant 01JAN2013–31DEC2014, with a ≥1-year baseline period, were included (study period: 01JAN2012–31DEC2014). Major bleeding was defined as bleeding requiring hospitalisation. Propensity score matching (PSM) was used to balance age, sex, region, baseline comorbidities, and comedications. Cox proportional hazards models were used to estimate the PSM hazard ratio (HR) of major bleeding. Among 45,361 newly anticoagulated NVAF patients, 15,461 (34.1 %) initiated warfarin, 7,438 (16.4 %) initiated apixaban, 17,801 (39.2 %) initiated rivaroxaban, and 4,661 (10.3 %) initiated dabigatran. Compared to matched warfarin initiators, apixaban (HR: 0.53; 95 % CI: 0.39–0.71) and dabigatran (HR: 0.69; 95 % CI: 0.50–0.96) initiators had a significantly lower risk of major bleeding. Patients initiating rivaroxaban (HR: 0.98; 95 % CI: 0.83–1.17) had a non-significant difference in major bleeding risk compared to matched warfarin patients. When comparisons were made between NOACs, matched rivaroxaban patients had a significantly higher risk of major bleeding (HR: 1.82; 95 % CI: 1.36–2.43) compared to apixaban patients. The differences for apixaban-dabigatran and dabigatran-rivaroxaban matched cohorts were not statistically significant. Among newly anticoagulated NVAF patients in the real-world setting, apixaban and dabigatran initiation was associated with significantly lower risk of major bleeding compared to warfarin initiation. When compared to apixaban, rivaroxaban initiation was associated with significantly higher risk of major bleeding.

Note: The review process for this paper was fully handled by Christian Weber, Editor in Chief.

Supplementary Material to this article is available online at www.thrombosis-online.com.

Keywords

Non-valvular atrial fibrillation - major bleeding - warfarin - apixaban - dabigatran - rivaroxaban

 

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