The treatment indication affects the time in therapeutic range

Objectives: This study aimed to compare the efficacy and safety of the treatment in patients with deep vein thrombosis (DVT) and mechanical mitral valve replacement (MVR) who were treated with warfarin for different indications. Patients and methods: A total of 536 patients (314 males, 222 females; mean age: 55.6±10.8 years; range, 18 to 89 years) were retrospectively reviewed between January 2016 and January 2020. The patients were evaluated in two groups: 273 DVT patients (149 males, 124 females; mean age: 56.7±11.3 years) who received long-term therapy (six months) and 263 mechanical MVR patients (165 males, 98 females; mean age: 56.2±9.4 years). Both groups were compared in terms of the percentage of time in the therapeutic range (TTR), the time to reach the target international normalized ratio (INR), and warfarin related complications. Results: The number of total hospital visits and total INR measurements for six months in the MVR group was statistically significantly higher than in the DVT group (p<0.001). The duration and percentage of TTR in the first three and six months of the MVR group were statistically significantly higher than the DVT group (p<0.05). Conclusion: More MVR patients remained in the therapeutic range than DVT patients due to the frequent hospital visits of these patients for various reasons; thus, it may be beneficial to increase the frequency of follow-up examinations or measurements of INR in patients who have started warfarin treatment for an indication other than valve replacement.