Relationship of the SAMe-TT₂R₂ score to poor-quality anticoagulation, stroke, clinically relevant bleeding, and mortality in patients with atrial fibrillation

Chest. 2014 Sep;146(3):719-726. doi: 10.1378/chest.13-2976.

Abstract

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.

MeSH terms

  • Adult
  • Age Factors
  • Aged
  • Aged, 80 and over
  • Anticoagulants / adverse effects
  • Anticoagulants / therapeutic use*
  • Atrial Fibrillation / drug therapy*
  • Cerebral Hemorrhage / epidemiology*
  • Cerebral Hemorrhage / mortality
  • Cohort Studies
  • Comorbidity
  • Drug Interactions
  • Female
  • Follow-Up Studies
  • Humans
  • International Normalized Ratio / methods*
  • Male
  • Middle Aged
  • Predictive Value of Tests
  • Racial Groups
  • Risk Assessment / methods*
  • Sex Factors
  • Stroke / epidemiology*
  • Stroke / mortality
  • Survival Rate
  • Tobacco Use
  • Treatment Outcome
  • Vitamin K / adverse effects
  • Vitamin K / antagonists & inhibitors*

Substances

  • Anticoagulants
  • Vitamin K