Evaluation of the SAMe-TT2R2 score to predict the quality of anticoagulation control in a cohort of patients with venous thromboembolism treated with vitamin K antagonists.

Objective: The SAMe-TT2R2 score has been recently proposed to predict the quality of anticoagulation control in patients with atrial fibrillation treated with vitamin K antagonists (VKA). We aimed at calculating this score in a cohort of patients with Venous Thromboembolism (VTE) and determine its usefulness.

Methods: We included all consecutive patients with VTE treated with VKA for >90days. We collected all variables included in the score (female sex, age<60years, medical history [>2 comorbidities], treatment [interacting drugs: e.g. amiodarone], tobacco [doubled], race [doubled]) and analyzed the relationship between the SAMe-TT2R2 score and time in therapeutic range (TTR), determined by the Rosendaal method and by the percentage of INR determinations (after excluding the first month).

Results: 135 patients were treated with VKA for >90days, with a median TTR 65%. No differences in INR controls within range were found between patients with score 0-1 vs ≥2 (64.7±19.5% vs 66.0±20.5%, p=0.728). No differences were found in INR controls above (21.5±18.1% vs 21.2±21.3%, p=0.605) or below (3.9±14% vs 2.9±15.9%, p=0.517) the therapeutic range.

Conclusions: The SAMe-TT2R2 score is not useful to predict quality of anticoagulation control in patients with VTE treated with VKA.