Relationship of the SAMe-TT₂R₂ score to poor-quality anticoagulation, stroke, clinically relevant bleeding, and mortality in patients with atrial fibrillation.
BACKGROUND
The efficacy and safety of anticoagulation with use of vitamin K antagonists (VKAs) is highly dependent on the quality of anticoagulation control as reflected by the average time in a therapeutic range of 2.0 to 3.0. A clinical dilemma is trying to predict which anticoagulation-naive patients with atrial fibrillation (AF) would do well on a VKA (with a time in therapeutic range > 70%) and which are less likely to do well on a VKA but could be managed with novel oral anticoagulants.


METHODS
The cohort comprised 8,120 patients, among whom 4,637 patients were receiving VKA. We investigated whether the SAMe-TT₂R₂ (sex female, age < 60 years, medical history [more than two comorbidities], treatment [interacting drugs, eg, amiodarone for rhythm control], tobacco use [doubled], race [doubled]) score could discriminate among patients with AF who were likely to have a labile international normalized ratio (INR) during follow-up as well as stroke/thromboembolism (TE), clinically relevant bleeding (defined as severe bleeding and as Bleeding Academic Research Consortium [BARC]-defined major bleeding), and death while being treated with a VKA.


RESULTS
During a mean follow-up of 1,016 ± 1,108 days, there was a significant increase in risk of severe bleeding events (risk ratio [RR], 1.38; 95% CI, 1.12-2.68; P = .002) and a significant increase in risk of major BARC bleeding (RR, 1.77; 95% CI, 1.29-2.44; P = .0005) in patients with AF with a high SAMe-TT₂R₂ score (> 2). Increasing SAMe-TT₂R₂ score was associated with an increasing risk of labile INR (P = .004), stroke/TE (P = .007), severe bleeding (P < .0001), major BARC bleeding (P < .0001), and death (P = .002) at follow-up. Among the patients taking VKAs, the SAMe-TT₂R₂ score was predictive of labile INR (C statistic approximately 0.58) as well as of stroke/TE, severe bleeding, major BARC bleeding, and death (C statistic, 0.54-0.57 for events), reflecting the suboptimal time in therapeutic range in such patients. This was not the case for patients who were not taking VKAs.


CONCLUSIONS
We demonstrate that the SAMe-TT₂R₂ score was predictive for an increasing risk of stroke/TE, severe bleeding, major BARC bleeding, and death, reflecting poor anticoagulation control (and labile INRs) among patients with AF given VKAs.
University of Birmingham Centre for Cardiovascular Sciences, City Hospital, Birmingham, England. Electronic address: g.y.h.lip@bham.ac.uk.
Gregory Y H
GYH
Lip
Service de Cardiologie, Pôle Coeur Thorax Vasculaire, Centre Hospitalier, Universitaire Trousseau et Faculté de Médecine, Université François Rabelais, Tours, France.
Ken
K
Haguenoer
Service de Cardiologie, Pôle Coeur Thorax Vasculaire, Centre Hospitalier, Universitaire Trousseau et Faculté de Médecine, Université François Rabelais, Tours, France.
Christophe
C
Saint-Etienne
Service de Cardiologie, Pôle Coeur Thorax Vasculaire, Centre Hospitalier, Universitaire Trousseau et Faculté de Médecine, Université François Rabelais, Tours, France.
Laurent
L
Fauchier
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000188:drug therapy*; D002543:Cerebral Hemorrhage / Q000453:epidemiology* / Q000401:mortality; D015331:Cohort Studies; D015897:Comorbidity; D004347:Drug Interactions; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D019934:International Normalized Ratio / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D044469:Racial Groups; D018570:Risk Assessment / Q000379:methods*; D012737:Sex Factors; D020521:Stroke / Q000453:epidemiology* / Q000401:mortality; D015996:Survival Rate; D064424:Tobacco Use; D016896:Treatment Outcome; D014812:Vitamin K / Q000009:adverse effects / Q000037:antagonists & inhibitors*
D000925:Anticoagulants; D014812:Vitamin K