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Thromb Haemost 2015; 113(06): 1370-1377
DOI: 10.1160/TH14-10-0859
Atherosclerosis and Ischaemic Disease
Schattauer GmbH

Safety and efficacy of well managed warfarin

A report from the Swedish quality register Auricula
Vilhelm Sjögren
1   Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden
,
Bartosz Grzymala-Lubanski
1   Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden
,
Henrik Renlund
2   Uppsala Clinical Research Center, Uppsala University, Uppsala, Sweden
,
Leif Friberg
3   Karolinska Institute and Department of Cardiology, Danderyd University Hospital, Stockholm, Sweden
,
Gregory Y. H. Lip
4   University of Birmingham, Centre for Cardiovascular Sciences, City Hospital, Birmingham, UK
5   Aalborg Thrombosis Research Unit, department of Clinical Medicine, Faculty of Health, Aalborg University, Aalborg, Denmark
,
Peter J. Svensson
6   Department for Coagulation Disorders, University of Lund, Malmö, Sweden
,
Anders Själander
1   Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden
› Author Affiliations Financial support: This study was supported by the Department of Public Health and Clinical Medicine, Umeå University and the Department of Research and Development, County Council of Vasternorrland [LVNFOU216571, 310871, 385111].
Further Information

Publication History

Received: 15 October 2014

Accepted after major revision: 10 January 2015

Publication Date:
29 November 2017 (online)

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Summary

The safety and efficacy of warfarin in a large, unselected cohort of warfarin-treated patients with high quality of care is comparable to that reported for non-vitamin K antagonists. Warfarin is commonly used for stroke prevention in atrial fibrillation, as well as for treatment and prevention of venous thromboembolism. While reducing risk of thrombotic/embolic incidents, warfarin increases the risk of bleeding. The aim of this study was to elucidate risks of bleeding and thromboembolism for patients on warfarin treatment in a large, unselected cohort with rigorously controlled treatment. This was a retrospective, registry-based study, covering all patients treated with warfarin in the Swedish national anticoagulation register Auricula, which records both primary and specialised care. The study included 77,423 unselected patients with 100,952 treatment periods of warfarin, constituting 217,804 treatment years. Study period was January 1, 2006 to December 31, 2011. Atrial fibrillation was the most common indication (68%). The mean time in therapeutic range of the international normalised ratio (INR) 2.0-3.0 was 76.5%. The annual incidence of severe bleeding was 2.24% and of thromboembolism 2.65%. The incidence of intracranial bleeding was 0.37% per treatment year in the whole population, and 0.38% among patients with atrial fibrillation. In conclusion, warfarin treatment where patients spend a high proportion of time in the therapeutic range is safe and effective, and will continue to be a valid treatment option in the era of newer oral anticoagulants.

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

 

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