umu.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Warfarin persistence among stroke patients with atrial fibrillation
Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine. (Sundsvall Research Unit)
Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine. (Sundsvall Research Unit)
2015 (English)In: Thrombosis Research, ISSN 0049-3848, E-ISSN 1879-2472, Vol. 136, no 4, 744-748 p.Article in journal (Refereed) Published
Abstract [en]

INTRODUCTION: Warfarin treatment discontinuation is significant among patients with atrial fibrillation (AF). For AF patients with stroke a warfarin persistence rate of 0.45 after 2years has previously been reported. No consistent predictors for discontinuation have been established.

AIMS: Evaluation of warfarin persistence and variables associated with discontinuation, in a large Swedish cohort with unselected stroke/TIA patients with AF treated with warfarin.

MATERIALS AND METHODS: 4 583 patients with stroke/TIA and AF in the Swedish National Patient Register (NPR), from 1. Jan 2006 to 31. Dec 2011, were matched with the Swedish national quality register AuriculA. They were followed until treatment cessation, death or end of study. Baseline characteristics and CHA2DS2VASc score were retrieved from NPR. Treatment-time was retrieved from AuriculA.

RESULTS: Overall proportion of warfarin persistence was 0.78 (95% confidence interval (CI) 0.76 to 0.80) after one year, 0.69 (95% CI 0.67 to 0.71) after 2years and 0.47 (95% CI 0.43 to 0.51) after 5years. Variables clearly associated with higher discontinuation were dementia (hazard ratio (HR) 2.22, CI 1.51-3.27) and alcohol abuse (HR 1.66, CI 1.19-2.33). Chronic obstructive pulmonary disease (COPD), cancer and chronic heart failure (CHF) were each associated with over 20% increased risk of treatment discontinuation. Higher CHA2DS2VASc score and start-age lead to lower persistence (p<0.001).

CONCLUSIONS: Persistence to warfarin in unselected stroke/TIA patients with AF is in Sweden greater than previously reported. Lower persistence is found among patients with high treatment start-age, incidence of dementia, alcohol abuse, cancer, CHF, COPD and/or high CHA2DS2VASc score.

Place, publisher, year, edition, pages
Elsevier, 2015. Vol. 136, no 4, 744-748 p.
Keyword [en]
Atrial fibrillation, Discontinuation, Persistence, Stroke, Treatment, Warfarin
National Category
Cardiac and Cardiovascular Systems Hematology
Identifiers
URN: urn:nbn:se:umu:diva-110298DOI: 10.1016/j.thromres.2015.07.028ISI: 000365800600009PubMedID: 26254195OAI: oai:DiVA.org:umu-110298DiVA: diva2:862005
Available from: 2015-10-20 Created: 2015-10-20 Last updated: 2016-09-28Bibliographically approved
In thesis
1. Warfarin treatment quality in stroke prevention
Open this publication in new window or tab >>Warfarin treatment quality in stroke prevention
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Background

Ischemic stroke is a serious condition often associated to presence of atrial fibrillation (AF). Use of anticoagulants for AF patients greatly reduces the risk of stroke. Warfarin is the most commonly used anticoagulant in Sweden. The aim of this thesis was to study the impact of warfarin treatment quality in Swedish stroke prevention.

Methods

Study I, II and IV were relatively large multicentre, retrospective, cohort studies based on Swedish registries, especially AuriculA, a quality register for AF and anticoagulation. Background data as well as bleeding and thromboembolic complications were retrieved from the National Patient Register. The Cause of Death Register was used in study II and IV. The Swedish Prescribed Drug Register was used in study IV, for data on concomitant acetylsalicylic acid (ASA) use. Study period was January 1, 2006, to December 31, 2011. Study III enrolled all warfarin treated AF patients in Sundsvall, registered in AuriculA on January 1, 2010. This smaller cohort was followed until discontinuation or study-stop December 31, 2013. All used data were collected from each patient’s medical record.

Results

The annual risk of major bleedings and thromboembolic events for warfarin treated patients, including all different indications for warfarin, was relatively low (2.24% and 2.66%), with incidence of intracranial bleeding of 0.37% per treatment year. The overall mean time in therapeutic range (TTR) was 76.5%. Patients started on warfarin due to AF had a mean TTR of 68.6%, with an annual risk of major bleeding and thromboembolic events of 2.23% and 2.95%, and with 0.44% annual risk of intracranial bleeding. No significant differences in overall complications were found when comparing treatment monitored in anticoagulation clinics (ACC) with treatment monitored in primary health care centers (PHCC). There were significantly increased risk of both overall major bleedings and thromboembolic events for those warfarin treated AF patients receiving additional ASA treatment, having individual TTR (iTTR) below 70%, or having high international normalized ratio (INR) variability. AF patients with low INR variability had generally lower complication rates, compared with patients with high INR variability. There were however no alteration on cumulative incidence of complications due to INR variability, for AF patients with iTTR ≥70%. The overall proportion of persistence to warfarin treatment for stroke patients with AF was found to be 0.69 after 2 years treatment and 0.47 after 5 years. Stroke patients with diagnosed dementia at baseline were more than two-times likely of discontinuing warfarin than others. Excessive alcohol use, chronic obstructive pulmonary disease, cancer and chronic heart failure were baseline diagnoses each associated with over 20% increased risk of treatment discontinuation. Lower persistence to treatment was linked to increasing start-age and CHA2DS2-VASc scores. As documented reasons for warfarin treatment discontinuation in AF patients, we found regained sinus rhythm as the most common addressed cause (31.2%), followed by problematic monitoring and bleedings. We estimated that only half (49.5%) of the treatment discontinuations were clinically well motivated.

Conclusions

Quality of Swedish warfarin treatment in initiated stroke prevention is high, with generally low rates of complications and high TTRs, no matter treatment in ACC or PHCC, including high long time persistence to warfarin in secondary stroke prevention. For better outcome in future warfarin stroke prophylactic treatment clinicians should aim for iTTRs above 70%, avoid additional ASA therapy, support fragile patients like those with excessive alcohol use and dementia, and base decisions on treatment discontinuations on solid medical arguments.

Place, publisher, year, edition, pages
Umeå: Umeå University, 2016. 50 p.
Series
Umeå University medical dissertations, ISSN 0346-6612 ; 1827
Keyword
Anticoagulation, atrial fibrillation, complications, international normalized ratio (INR) variability, persistence, stroke, time in therapeutic range (TTR), treatment quality, warfarin
National Category
Cardiac and Cardiovascular Systems Hematology
Research subject
Medicine, cardiovascular disease
Identifiers
urn:nbn:se:umu:diva-125998 (URN)978-91-7601-513-1 (ISBN)
Public defence
2016-10-21, Aulan, Utbildningslokalerna 1 trp, Sundsvalls sjukhus, Sundsvall, 13:00 (Swedish)
Opponent
Supervisors
Available from: 2016-09-30 Created: 2016-09-26 Last updated: 2016-09-29Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textPubMed

Search in DiVA

By author/editor
Björck, FredrikSjälander, Anders
By organisation
Medicine
In the same journal
Thrombosis Research
Cardiac and Cardiovascular SystemsHematology

Search outside of DiVA

GoogleGoogle Scholar

Altmetric score

Total: 108 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf