IJCS | Volume 31, Nº5, September / October 2018

484 Pivatto Júnior et al. SAMe-TT 2 R 2 score forVTE patients? Int J Cardiovasc Sci. 2018;31(5)483-491 Original Article determined mainly by the time in therapeutic range (TTR), i.e., the percentage of days that prothrombin time/international normalized ratio (PT/INR) remains in the interval 2.0-3.0. Thus, the ability to identify patients treated with VKAwho will present poor anticoagulation control may be useful in establishing the indication for NOAC rather than VKA. 5 The SAMe-TT 2 R 2 score uses clinical risk factors to identify patients with atrial fibrillation (AF) at high risk of not achieving a good TTR (≥ 65%) during VKA therapy, who are, consequently, suitable candidates for the use of NOAC. It takes into account sex (S, 1 point), age (A, 1 point), medical history (Me, 1 point), treatment - especially interacting drugs, such as amiodarone - (T, 1 point), tobacco use in the previous 2 years (T, 2 points) and race (R, 2 points). The maximum score is 8, and patients scoring 0-1 are most likely to benefit from warfarin because they are also most likely to have a TTR ≥ 70%, indicating good anticoagulation control. Patients with scores ≥ 2 are at risk of suboptimal anticoagulation control. In the original study that developed the score, the score showed good discrimination performance in both the internal (c-statistic of 0.72 for TTR ≥ 64%; 95%CI: 0.64-0.79) and external (c-statistic of 0.7 for TTR ≥ 67%; 95%CI: 0.57-0.82) validation cohorts. 6 In a previous study conducted at our anticoagulation outpatient clinic, including only patients with AF, the low-risk group (score 0-1) had a better median TTR than the high-risk group (score ≥ 2): 69.2 vs. 56.3% p = 0.002. Similarly, the percentage of patients with a TTR ≥ 65% was higher in the low-risk group (58.7 vs. 36.8%; p = 0.001). 7 Use of the SAMe-TT 2 R 2 score in patients with VTE to predict a good TTR during anticoagulant therapy was only recently assessed, with conflicting results. Two studies showed that patients classified as at high risk (score ≥ 2) had a lower TTR than those at low risk, 8,9 whereas one study found no association between the SAMe-TT 2 R 2 score and TTR. 5 Moreover, the results regarding the association of the score with bleeding or thrombotic events were also contradictory. These studies differ in terms of their selection criteria, cutoff points, and study design, which may be a possible explanation for the conflicting results but precludes the widespread applicability of the SAMe-TT 2 R 2 score in patients with VTE. The present study was therefore designed to evaluate the SAMe-TT 2 R 2 score in patients with VTE and determine its usefulness in predicting TTR and adverse events. Material and methods This was a retrospective cohort study of patients on oral anticoagulant therapy with VKA at the outpatient anticoagulation clinic of a tertiary care teaching hospital in southern Brazil. All patients receiving care at the clinic from January to March 2014 were screened for inclusion in the study (screening period). Patients anticoagulated for lower-limb DVT and/or PE were included. Patients with upper-limb, abdominal or cerebral DVT and those using VKA for other indications (e.g., AF) were excluded. The study was approved by the Research Ethics Committee of the institution. Informed consent was waived due to the retrospective nature of data collection. The patients’ medical records were retrospectively reviewed for outpatient visits, emergency visits, and hospitalizations since the first PT/INR measurement after the start of VKA treatment until the end of treatment or the end of the study. Patients who were lost to follow-up, who died or whose anticoagulant therapy was discontinued were included in the analysis, and, in these cases, TTR was calculated until the last PT/INR measurement available. For the SAMe-TT 2 R 2 score (0-8 points), the following variables were assessed: female sex (1 point), age < 60 years (1 point), presence of > 2 comorbidities (1 point), use of amiodarone to control heart rhythm (1 point), tobacco use within the past 2 years (2 points), and non-white race (2 points). The following conditions were considered comorbidities: previous stroke, diabetes, peripheral artery disease, coronary artery disease, liver disease, pulmonary disease, renal disease, hypertension and heart failure. Based on the SAMe-TT 2 R 2 score, patients were divided into two groups: low risk (score 0-1) or high risk (score ≥ 2) of not achieving a good TTR during VKA therapy. Coronary artery disease was defined as prior myocardial infarction, angina pectoris, percutaneous coronary intervention or coronary artery bypass surgery. 10 Patients with left ventricular ejection fraction (LVEF) < 40% or with recently decompensated heart failure requiring hospitalization, regardless of LVEF, were classified as having heart failure. 11 LVEF was obtained preferably from the transthoracic echocardiogram and calculated by the Simpson’s method in the presence of segmental changes or by the Teichholz method in the absence of segmental changes (if more than one test was available, the lowest value was used for the analysis).