Modified application of SAMe-TT ₂R ₂ scoring system in Asian patients with atrial fibrillation for the selection of oral anticoagulants

Abstract

Background/Aims

The SAMe-TT ₂R ₂ score is used for assessing anticoagulation control (AC) quality with warfarin. However, it is hard to apply SAMe-TT ₂R ₂ score in Asian patients with atrial fibrillation (AF), because it has not been proven in those populations. This study aimed to validate the SAMe-TT ₂R ₂ score in Asian patients with AF and suggest a modified SAMe-TT ₂R ₂ score for this population.

Methods

We analyzed 710 Korean patients with AF who were using warfarin. The AC quality was assessed as the mean time in therapeutic range (TTR). Each component of SAMe-TT ₂R ₂ score was evaluated for the relationship with AC. Further clinical factors that predict AC were analyzed. Identified factors were re-assorted and constructed as SA ₂Me-TTR scoring system.

Results

Of the components of the SAMe-TT ₂R ₂ score, female, age, and rhythm control were associated with AC. Heart failure and renal insufficiency were newly identified factors associated with AC. The modified SA ₂Me-TTR score was reconstructed with the relevant risk factors (S, female gender, 1 point; A, age < 60 yr, 2 points; Me, medical history of heart failure, 1 point; T, treatment for rhythm control, 1 point; T, history of stroke or transient ischemic attack, 1 point; R, renal insufficiency, 1 point). The modified SA ₂Me-TTR score demonstrated an excellent relationship with the grading of AC. The modified SA ₂Me-TTR score ≤ 1 identified patients with good AC (hazard ratio 2.46, 95% CI 1.75–3.47).

Conclusions

The modified SA ₂Me-TTR score was useful for guiding oral anticoagulants selection in Asian patients with AF.