The SAMe-TT2R2 scoreProietti M, Lip G. "Simple decision making between a Vitamin K Antagonist and Non-Vitamin K Antagonist Oral Anticoagulant (NOACs): Using the SAMe-TT2R2 Score. European Heart Journal - Cardiovascular Pharmac. http://ehjcvp.oxfordjournals.org/content/early/2015/03/03/ehjcvp.pvv012 is a clinical prediction rule to predict the quality of vitamin K antagonist anticoagulation therapy as measured by time in therapeutic INR range (TTR) (VKA e.g. warfarin).Apostolakis S, Sullivan RM, Olshansky B, Lip GY. Factors affecting quality of anticoagulation control among patients with atrial fibrillation on warfarin: the SAMe-TT₂R₂ score" Chest 2013 Nov;144(5):1555-63 It has been suggested that it can aid in the medical decision making between VKAs and new oral anticoagulant/non-VKA oral anticoagulant (NOAC e.g. dabigatran, rivaroxaban, apixaban or edoxaban) in patients with atrial fibrillation (AF).Proietti M, Lip G. Simple decision making between a Vitamin K Antagonist and Non-Vitamin K Antagonist Oral Anticoagulant (NOACs): Using the SAMe-TT2R2 Score. European Heart Journal - Cardiovascular Pharmac. http://ehjcvp.oxfordjournals.org/content/early/2015/03/03/ehjcvp.pvv012 This score can be used with patients with ≥1 additional stroke risk factors using the CHA2DS2-VASc score, where oral anticoagulation is recommended or should be considered.

This score reflects the need to offer an improved patient care pathway when using oral anticoagulants. While NOACs avoid the need for drug monitoring (e.g. INR monitoring), they have an unstable bioavailability and are not indicated for patients with chronic kidney failureRuff, Christian T., et al. "Evaluation of the novel factor Xa inhibitor edoxaban compared with warfarin in patients with atrial fibrillation: Design and rationale for the Effective aNticoaGulation with factor xA next GEneration in Atrial Fibrillation–Thrombolysis In Myocardial Infarction study 48 (ENGAGE AF–TIMI 48)." American Heart Journal 160.4 (2010): 635-641 or in patients with valvular replacement surgery.2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease (Journal of the American College of Cardiology). Published on March 3, 2014

In a newly diagnosed non-anticoagulated AF patient, the physician may avoid a ‘trial of warfarin’ (which may expose patients to increased stroke risk during the initial inception phase, with suboptimal anticoagulation controlAzoulay L, Dell'Aniello S, Simon TA, Renoux C, Suissa S. Initiation of warfarin in patients with atrial fibrillation: early effects on ischaemic strokes. Eur Heart J. 2014 Jul 21;35(28):1881-7.) and make an informed decision between patients likely to do well on a VKA (SAMe-TT2R2 score 0–2) or where a VKA is perhaps likely to be associated with poor quality anticoagulation control.

Calculate the SAMe-TT2R2 score

Condition/influencing factor Points Sex (female) 1 Age (<60 years) 1 Medical history (history of more than two of the following: hypertension, diabetes, CAD, PAD, heart failure, stroke; pulmonary, hepatic, or renal disease) 1 Treatment (interacting medications e.g. amiodarone) 1 Tobacco use (within 2 years) 2 Race (non-Caucasian) 2

Using the above table add together points assigned for different factors to a maximum score of 8.

Results Score result Action (Untested)Proietti M, Lip G. Simple decision making between a Vitamin K Antagonist and Non-Vitamin K Antagonist Oral Anticoagulant (NOACs): Using the SAMe-TT2R2 Score. European Heart Journal - Cardiovascular Pharmac. http://ehjcvp.oxfordjournals.org/content/early/2015/03/03/ehjcvp.pvv012 0-2 Patients are likely to achieve a high TTR (e.g. >65%) so initiating with a VKA is likely beneficial. >2 Improve education regarding anticoagulation control (e.g. a structured educational programmeClarkesmith DE, Pattison HM, Lip GY, Lane DA. "Educational intervention improves anticoagulation control in atrial fibrillation patients: the TREAT randomised trial. PLoS One. 2013 Sep 9;8(9):e74037. ) or select a NOAC would be better initial options.

See also CHA2DS2-VASc score

References

External links SAMe-TT2R2 score calculator Royal College of Physicians of Edinburgh