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INTRODUCTION@#International normalised ratio (INR) control is an important factor in patients with non-valvular atrial fibrillation (NVAF) being treated with warfarin. INR control was previously reported to be poorer among Asians compared to Westerners. We aimed to validate the SAMe-TT2R2 score for prediction of suboptimal INR control (defined as time in therapeutic range [TTR] < 65% in the Thai population) and to investigate TTR among Thai NVAF patients being treated with warfarin.@*METHODS@#INR data from patients enrolled in a multicentre NVAF registry was analysed. Clinical and laboratory data was prospectively collected. TTR was calculated using the Rosendaal method. Baseline data was compared between patients with and without suboptimal INR control. Univariate and multivariate analyses were performed to identify variables independently associated with suboptimal INR control.@*RESULTS@#A total of 1,669 patients from 22 centres located across Thailand were included. The average age was 69.1 ± 10.7 years, and 921 (55.2%) were male. The mean TTR was 50.5% ± 27.5%; 1,125 (67.4%) had TTR < 65%. Univariate analysis showed hypertension, diabetes mellitus, heart failure, renal disease and SAMe-TT2R2 score to be significantly different between patients with and without optimal TTR. The SAMe-TT2R2 score was the only factor that remained statistically significant in multivariate analysis. The C-statistic for the SAMe-TT2R2 score in the prediction of suboptimal TTR was 0.54.@*CONCLUSION@#SAMe-TT2R2 score was the only independent predictor of suboptimal TTR in NVAF patients being treated with warfarin. However, due to the low C-statistic, the score may have limited discriminative power.
RESUMEN
Resumen Introducción: la fibrilación auricular (FA) es la arritmia cardiaca más frecuente y está relacionada con eventos embólicos. La eficacia y seguridad de la warfarina en prevención del ictus depende del tiempo en rango terapéutico (TTR). Se han diseñado escalas para predecir el comportamiento del TTR al inicio de la terapia. El objetivo de este trabajo fue evaluar la capacidad predictiva y discriminativa del SAMeTT2R2 score en una población no caucásica. Material y métodos: estudio analítico de cohorte retrospectiva en pacientes con FA no valvu lar tratados con warfarina entre 2013 y 2016 en una clínica de anticoagulación. Se caracterizó la muestra sociodemográfica y clínicamente. Se definió mal control de la anticoagulación como (TTR/ PINNR<65%). Se comparó el TTR/PINNR <65% y SAMeTT2R2 <=2 versus >2 con la prueba U de Mann-Whitney y chi cuadrado. Se construyeron curvas ROC para determinar discriminación de la escala. Se evaluó cada uno de sus elementos a través de regresión logística. Resultados: se incluyeron 646 pacientes (edad media 77 años ± 8,8 años, 51,4% hombres). El TTR promedio fue 67.7% y el PINNR 63.6%. Al comparar la frecuencia de pobre control entre SAMeTT2R2 score ≤2 versus >2 con una prueba chi cuadrado, el PINNR fue significativo (p=0.004). La capacidad discriminativa de la escala para el TTR/PINNR fue baja (AUC: 0.52 y 0.54 respectivamente). No se encontró relación entre cada una de las variables que integran el SAMeTT2R2 score y el TTR/PINNR. Conclusiones: la puntuación SAMeTT2R2 no mostró buena capacidad predictiva y discriminativa en la población estudiada. La calidad de la anticoagulación es el resultado de un proceso dinámico en relación con el cumplimiento, estado de salud o enfermedad intercurrente. (Acta Med Colomb 2019; 44: 75-81).
Abstract Introduction: atrial fibrillation (AF) is the most common cardiac arrhythmia and is related to embolic events. The efficacy and safety of warfarin in stroke prevention depends on the time in therapeutic range (TTR). Scales have been designed to predict the behavior of TTR at the start of therapy. The objective of this work was to evaluate the predictive and discriminative capacity of the SAMeTT2R2 score in a non-Caucasian population. Material and methods: retrospective cohort analytical study in patients with non-valvular AF treated with warfarin between 2013 and 2016 in an anticoagulation clinic. The sample was demodemographically and clinically characterized. Poor control of anticoagulation was defined as (TTR / PINNR <65%). The TTR / PINNR <65% and SAMeTT2R2 <= 2 versus> 2 were compared with the Mann-Whitney U test and chi square. ROC curves were constructed to determine scale discrimination. Each of its elements was evaluated through logistic regression. Results: 646 patients were included (mean age 77 years ± 8.8 years, 51.4% men). The average TTR was 67.7% and the PINNR 63.6%. When comparing the frequency of poor control between C. L. Sandoval-Riveros y cols. SAMeTT2R2 score ≤2 versus> 2 with a chi square test, the PINNR was significant (p = 0.004). The discriminative capacity of the scale for the TTR / PINNR was low (AUC: 0.52 and 0.54 respec tively). No relationship was found between each of the variables that constitute the SAMeTT2R2 score and the TTR / PINNR. Conclusions: the SAMeTT2R2 score did not show good predictive and discriminative capac ity in the studied population. The quality of anticoagulation is the result of a dynamic process in relation to compliance, health status or intercurrent disease. Acta Med Colomb 2019; 44: 75-81).