SAMe-TT2R2 Score: A Useful Tool in Oral Anticoagulation Decision-Making for Venous Thromboembolism Patients?

Background: The SAMe-TT2R2 score was introduced to identify atrial fibrillation patients with a high risk of not achieving a good time in therapeutic range (TTR) during vitamin K antagonists (VKA) therapy. Objective: The aim of this study was to evaluate this score in venous thromboembolism (VTE) patients. Patients and methods: A retrospective cohort study of patients receiving care at the outpatient anticoagulation clinic of a tertiary care teaching hospital. Patients were classified as having low (score 0-1) or high risk (score ≥ 2) of not achieving a good TTR. The area under the ROC curve was calculated to assess the ability of the score to predict a TTR ≥ 65%. Adverse event-free survival curves according to the SAMe-TT2R2 score were calculated by the Kaplan-Meier method and compared by the log-rank test. A p-value < 0.05 was considered statistically significant. Results: We investigated 111 patients during a median follow-up of 2.3 (0.7-6.4) years. Mean age was 54.1 ± 15.7 years and 71 (64.0%) were women. Low- and high-risk groups had similar mean TTR (51.9 vs. 49.6%; p = 0.593). The two groups did not differ significantly in the percentage of patients achieving a TTR ≥ 65% (35.6 vs. 25.8%; p = 0.370). The c-statistic was 0.595 (p = 0.113) for TTR ≥ 65%. Adverse event-free survival during anticoagulation was also similar in both groups (p = 0.136). Conclusions: The SAMe-TT2R2 score does not seem to be a useful tool in oral anticoagulation decision-making for patients with VTE and should not be used in this setting.