J Clin Neurol.  2017 Jul;13(3):273-280. 10.3988/jcn.2017.13.3.273.

Quality of Anticoagulation with Warfarin in Korean Patients with Atrial Fibrillation and Prior Stroke: A Multicenter Retrospective Observational Study

• Hong KS
• Kim YK
• Bae HJ
• Nam HS
• Kwon SU
• Bang OY
• Cha JK
• Yoon BW
• Rha JH
• Lee BC
• Park JM
• Park MS
• Lee J
• Choi JC
• Kim DE
• Lee KB
• Park TH
• Lee JS
• Kim SE
• Lee J

• KMID: 2391671
• DOI: http://doi.org/10.3988/jcn.2017.13.3.273

Abstract

BACKGROUND AND PURPOSE
The quality of anticoagulation is critical for ensuring the benefit of warfarin, but this has been less well studied in Korean ischemic stroke patients with atrial fibrillation (AF).
METHODS
This study retrospectively analyzed the data of patients who had an AF-related ischemic stroke and were treated with long-term warfarin therapy in 16 Korean centers. The quality of warfarin therapy was primarily assessed by the time in therapeutic range [TTR; international normalized ratio (INR), 2.0-3.0] and additionally by the proportion of INR values within the therapeutic range.
RESULTS
The long-term warfarin-treated cohort comprised 1,230 patients. They were aged 70.1±9.7 years (mean±SD), 42.5% were female, and their CHAâ‚‚DSâ‚‚-VASc score was 4.75±1.41. The TTR analysis included 33,941 INR measurements for 27,487 months: per patients, 27.6 (SD, 22.4) INR measurements for 22.4 (SD, 12.9) months. The mean TTR of individual patients was 49.1% (95% confidence interval, 47.9-50.3%), and the TTR quartiles were <34.5, 34.5-49.1, 49.1-64.5%, and >64.5%. None of the 16 centers achieved a mean TTR of >60%. Of all INR measurements, 44.6% were within the therapeutic range, 41.7% were <2.0, and 13.7% were >3.0.
CONCLUSIONS
In Korean ischemic stroke patients who had AF, the quality of warfarin therapy was low and might be inadequate to effectively prevent recurrent stroke or systemic embolism.

Keyword

warfarin; quality; time in therapeutic range; atrial fibrillation; seconadry stroke prevention

MeSH Terms

Atrial Fibrillation*
Cohort Studies
Embolism
Female
Humans
International Normalized Ratio
Observational Study*
Retrospective Studies*
Stroke*
Warfarin*
Warfarin

Figure

• 

  Fig. 1 Selection of patients. AF: atrial fibrillation, INR: international normalized ratio, TTR: time in therapeutic range.

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  Fig. 2 Proportion of patients according to TTRs in the long-term warfarin-treated cohort. TTR: time in therapeutic range.

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