title: Potential Causes and Implications of Low Target Therapeutic Ratio in Warfarin-Treated Patients for Thrombosis Prophylaxis: A Single-Center Experience.
abstract: Time in therapeutic range (TTR) of international normalized ratio is crucial for the safety and efficacy of anticoagulation with warfarin and it is influenced by many factors. There are limited data about the quality of warfarin therapy and its effects on clinical outcomes in Turkey. The aim of this study is to demonstrate the quality of anticoagulant therapy with warfarin and evaluate the parameters that affect the quality of warfarin therapy. A total of 170 patients with atrial fibrillation (AF; mean age: 62.2 ± 13.3; 69.2% female) treated with warfarin were included in this study. The mean follow-up period was 20 ± 8.4 months. The mean TTR levels of all patients were found to be 54.2% ± 21.4%. The TTR levels were similar in patients with valvular AF (VAF) and nonvalvular AF (NVAF). Logistic regression analysis revealed that elderly, heart failure (HF), and renal dysfunction were independent predictors of lower TTR. There were no significant differences between the VAF and NVAF subgroups regarding the incidence of mortality, stroke, and myocardial infarction. Cox regression analysis revealed that HF, coronary artery disease, and renal dysfunction were independent predictors of clinical outcomes in addition to lower TTR. Our results provide data regarding the quality of anticoagulation with warfarin from a single tertiary center in Istanbul, Turkey. The questions remain in seeking quality improvement in anticoagulation.
authors.affiliation: 1 Department of Cardiology, Marmara University Faculty of Medicine, Istanbul, Turkey.
authors.forename: Halil
authors.initials: H
authors.lastname: Atas
authors.affiliation: 1 Department of Cardiology, Marmara University Faculty of Medicine, Istanbul, Turkey.
authors.forename: Ahmet Anıl
authors.initials: AA
authors.lastname: Sahin
authors.affiliation: 2 Division of Nephrology, Department of Internal Medicine, Marmara University Faculty of Medicine, Istanbul, Turkey.
authors.forename: Dilek
authors.initials: D
authors.lastname: Barutçu Atas
authors.affiliation: 1 Department of Cardiology, Marmara University Faculty of Medicine, Istanbul, Turkey.
authors.forename: Murat
authors.initials: M
authors.lastname: Sunbul
authors.affiliation: 1 Department of Cardiology, Marmara University Faculty of Medicine, Istanbul, Turkey.
authors.forename: Alper
authors.initials: A
authors.lastname: Kepez
authors.affiliation: 3 Department of Cardiology, Istanbul Medeniyet University Faculty of Medicine, Istanbul, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Agirbasli
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000188:drug therapy; D005260:Female; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D000076162:Therapeutic Index; D013927:Thrombosis / Q000188:drug therapy / Q000517:prevention & control*; D016896:Treatment Outcome; D014421:Turkey; D014859:Warfarin / Q000627:therapeutic use*
chemical_list: D014859:Warfarin
keywords: heart failure; time in therapeutic range; warfarin