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International Normalized Ratio Stability in Warfarin-Experienced Patients with Nonvalvular Atrial Fibrillation

BACKGROUND: Maintaining stable levels of anticoagulation using warfarin therapy is challenging. Few studies have examined the stability of the international normalized ratio (INR) in patients with nonvalvular atrial fibrillation (NVAF) who have had ≥6 months’ exposure to warfarin anticoagulation for...

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Autores principales: Nelson, Winnie W., Desai, Sunita, Damaraju, Chandrasekharrao V., Lu, Lang, Fields, Larry E., Wildgoose, Peter, Schein, Jeffery R.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Springer International Publishing 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4451756/
https://www.ncbi.nlm.nih.gov/pubmed/25944648
http://dx.doi.org/10.1007/s40256-015-0120-9
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author Nelson, Winnie W.
Desai, Sunita
Damaraju, Chandrasekharrao V.
Lu, Lang
Fields, Larry E.
Wildgoose, Peter
Schein, Jeffery R.
author_facet Nelson, Winnie W.
Desai, Sunita
Damaraju, Chandrasekharrao V.
Lu, Lang
Fields, Larry E.
Wildgoose, Peter
Schein, Jeffery R.
author_sort Nelson, Winnie W.
collection PubMed
description BACKGROUND: Maintaining stable levels of anticoagulation using warfarin therapy is challenging. Few studies have examined the stability of the international normalized ratio (INR) in patients with nonvalvular atrial fibrillation (NVAF) who have had ≥6 months’ exposure to warfarin anticoagulation for stroke prevention. OBJECTIVE: Our objective was to describe INR control in NVAF patients who had been receiving warfarin for at least 6 months. METHODS: Using retrospective patient data from the CoagClinic™ database, we analyzed data from NVAF patients treated with warfarin to assess the quality of INR control and possible predictors of poor INR control. Time within, above, and below the recommended INR range (2.0–3.0) was calculated for patients who had received warfarin for ≥6 months and had three or more INR values. The analysis also assessed INR patterns and resource utilization of patients with an INR >4.0. Logistic regression models were used to determine factors associated with poor INR control. RESULTS: Patients (n = 9433) had an average of 1.6 measurements per 30 days. Mean follow-up time was 544 days. Approximately 39 % of INR values were out of range, with 23 % of INR values being <2.0 and 16 % being >3.0. Mean percent time with INR in therapeutic range was 67 %; INR <2.0 was 19 % and INR >3.0 was 14 %. Patients with more than one reading of INR >4.0 (~39 %) required an average of one more visit and took 3 weeks to return to an in-range INR. Male sex and age >75 years were predictive of better INR control, whereas a history of heart failure or diabetes were predictive of out-of-range INR values. However, patient characteristics did not predict the likelihood of INR >4.0. CONCLUSIONS: Out-of-range INR values remain frequent in patients with NVAF treated with warfarin. Exposure to high INR values was common, resulting in increased resource utilization.
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spelling pubmed-44517562015-06-09 International Normalized Ratio Stability in Warfarin-Experienced Patients with Nonvalvular Atrial Fibrillation Nelson, Winnie W. Desai, Sunita Damaraju, Chandrasekharrao V. Lu, Lang Fields, Larry E. Wildgoose, Peter Schein, Jeffery R. Am J Cardiovasc Drugs Original Research Article BACKGROUND: Maintaining stable levels of anticoagulation using warfarin therapy is challenging. Few studies have examined the stability of the international normalized ratio (INR) in patients with nonvalvular atrial fibrillation (NVAF) who have had ≥6 months’ exposure to warfarin anticoagulation for stroke prevention. OBJECTIVE: Our objective was to describe INR control in NVAF patients who had been receiving warfarin for at least 6 months. METHODS: Using retrospective patient data from the CoagClinic™ database, we analyzed data from NVAF patients treated with warfarin to assess the quality of INR control and possible predictors of poor INR control. Time within, above, and below the recommended INR range (2.0–3.0) was calculated for patients who had received warfarin for ≥6 months and had three or more INR values. The analysis also assessed INR patterns and resource utilization of patients with an INR >4.0. Logistic regression models were used to determine factors associated with poor INR control. RESULTS: Patients (n = 9433) had an average of 1.6 measurements per 30 days. Mean follow-up time was 544 days. Approximately 39 % of INR values were out of range, with 23 % of INR values being <2.0 and 16 % being >3.0. Mean percent time with INR in therapeutic range was 67 %; INR <2.0 was 19 % and INR >3.0 was 14 %. Patients with more than one reading of INR >4.0 (~39 %) required an average of one more visit and took 3 weeks to return to an in-range INR. Male sex and age >75 years were predictive of better INR control, whereas a history of heart failure or diabetes were predictive of out-of-range INR values. However, patient characteristics did not predict the likelihood of INR >4.0. CONCLUSIONS: Out-of-range INR values remain frequent in patients with NVAF treated with warfarin. Exposure to high INR values was common, resulting in increased resource utilization. Springer International Publishing 2015-05-06 2015 /pmc/articles/PMC4451756/ /pubmed/25944648 http://dx.doi.org/10.1007/s40256-015-0120-9 Text en © The Author(s) 2015 Open AccessThis article is distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/), which permits any noncommercial use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
spellingShingle Original Research Article
Nelson, Winnie W.
Desai, Sunita
Damaraju, Chandrasekharrao V.
Lu, Lang
Fields, Larry E.
Wildgoose, Peter
Schein, Jeffery R.
International Normalized Ratio Stability in Warfarin-Experienced Patients with Nonvalvular Atrial Fibrillation
title International Normalized Ratio Stability in Warfarin-Experienced Patients with Nonvalvular Atrial Fibrillation
title_full International Normalized Ratio Stability in Warfarin-Experienced Patients with Nonvalvular Atrial Fibrillation
title_fullStr International Normalized Ratio Stability in Warfarin-Experienced Patients with Nonvalvular Atrial Fibrillation
title_full_unstemmed International Normalized Ratio Stability in Warfarin-Experienced Patients with Nonvalvular Atrial Fibrillation
title_short International Normalized Ratio Stability in Warfarin-Experienced Patients with Nonvalvular Atrial Fibrillation
title_sort international normalized ratio stability in warfarin-experienced patients with nonvalvular atrial fibrillation
topic Original Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4451756/
https://www.ncbi.nlm.nih.gov/pubmed/25944648
http://dx.doi.org/10.1007/s40256-015-0120-9
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