Abstract:

Aim: Time in therapeutic range (TTR) is a method used to assess the efficacy of anticoagulant treatment in patients using warfarin. Aim of this study was to determine the rate of patients in TTR who are under warfarin treatment and to determine whether there is a difference in TTR according to age, gender and the indications of warfarin use. Methods: A total of 155 patients (63 male, 92 female, mean age: 68±12) under warfarin treatment for any reason and with at least 4 INR measurements were recruited retrospectively from Istanbul Medeniyet University Goztepe Training and Research Hospital both Cardiology and Internal Medicine Clinics. TTR levels of each patient were calculated with Rosendaal method. A TTR level above 60% was considered as warfarin being in therapeutic range. TTR levels were compared to age groups (≥60 and <60), gender and indications of warfarin use. Results: Indications of warfarin use were as follows: 77.4% atrial fibrillation, 13.5% cerebrovascular disease, 5.8% valve replacement, 3.3% deep vein thrombosis. In all patients mean TTR level was 57.2±22.5% (58.86±22.10% female and 56.06±22.78% male, p=0.44). The rate of patients with a TTR value higher than 60% was 45.8% and rate of patients with INR value within range was 51.7%. There was no significant difference in TTR values according to gender, age groups and warfarin indications. Conclusion: More than half of the patients using warfarin were not in therapeutic range. Drug interactions, socioeconomial and sociocultural characteristics and inadequate informing of patients may have a role in these results.

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