Time in Therapeutic Range in Patients with Venous Thromboembolism on Vitamin K Antagonist in a Moroccan Thrombosis Unit : An Observational Study

Background: Patients with venous thromboembolism (VTE) frequently require vitamin K antagonists (VKAs) to treat and prevent recurrent events. Aims: We performed a study to assess the quality of anticoagulation in patients with VTE treated with VKAs using time in therapeutic range (TTR), to identify associated factors with predictors of poor control and outcomes in VTE patients. Methods: We performed an observational, retrospective study that included VTE patients treated with VKA. The primary outcome was the TTR calculated according to the Rosendaal algorithm. Results: 171 VKA-treated patients were evaluated (53.2% men). The average age of our patients at diagnosis was 49.8 + 16.6 years [17-92]. VTE's most common location was the lower limbs, with 91.8 % cases, proximal in 83.6%. Patients were followed for a mean period of 178 days. The mean TTR was 41.2% (SD 32.9%), and 74.3% of the patients had a mean TTR < 65%. The rates of major bleeds and thromboembolic events were 0.5% and 2.2%, respectively. After multivariate statistical analysis, age older than 65 and surgery provoked VTE were associated with better TTR. Conclusions: These results are informative and may help identify patients who require closer monitoring or innovative strategies to optimize oral anticoagulant therapy outcomes.