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

Abstract 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.

摘要
背景：SAMe-TT2R2评分（SAMe-TT2R2 score）最初研发，用于识别维生素K拮抗剂（vitamin K antagonists, VKA）治疗期间无法达到良好治疗范围内时间（time in therapeutic range, TTR）的高风险心房颤动（atrial fibrillation）患者。
目的：本研究旨在评估该评分在静脉血栓栓塞症（venous thromboembolism, VTE）患者中的应用价值。
患者与方法：本研究为一项回顾性队列研究，纳入某三级教学医院门诊抗凝诊所接受诊疗的患者。根据SAMe-TT2R2评分将患者分为低风险（0~1分）与高风险（≥2分）两组，以评估其无法达到良好TTR的风险。计算ROC曲线下面积（area under the ROC curve）以评估该评分预测TTR≥65%的能力。采用Kaplan-Meier法（Kaplan-Meier method）绘制基于SAMe-TT2R2评分的无不良事件生存曲线，并通过log-rank检验（log-rank test）进行组间比较。以p值<0.05作为具有统计学显著性（statistically significant）的判定标准。
结果：本研究共纳入111例患者，中位随访时间为2.3（0.7~6.4）年。患者平均年龄为54.1±15.7岁，其中女性71例（占比64.0%）。低、高风险两组的平均TTR水平无显著差异（51.9% vs. 49.6%；p=0.593）。两组中TTR≥65%的患者占比亦无显著差异（35.6% vs. 25.8%；p=0.370）。针对TTR≥65%的预测，c统计量（c-statistic）为0.595（p=0.113）。抗凝治疗期间的无不良事件生存率在两组间同样无显著差异（p=0.136）。
结论：SAMe-TT2R2评分似乎并非VTE患者口服抗凝治疗决策制定中的有效工具，不应在该类患者群体中应用该评分。