Validation of HAS-BELD scoring system and risk factors of bleeding with warfarin among non-valvular atrial fibrillation patients

Type of funding sources: None.

This study aimed to validate different bleeding scoring systems including HAS-BELD score and other scores and risks of bleeding in Thai patients with non-valvular atrial fibrillation (AF).

AF is the most common sustained arrhythmia and associated with an increased risk of embolic stroke. Although warfarin can decrease the risk for thromboembolism, it increases the risk of major bleeding. The use of the bleeding scoring system can predict bleeding risks and guide physicians to decide the benefit and risk ratio before prescribing warfarin to prevent stroke in patients with AF. However, the validation of these scoring systems as well as studies evaluating risk factors associated with bleeding complications in Thai patients are still lacking.

A retrospective study was conducted in adult patients diagnosed with AF who received warfarin therapy and were followed at hospital during January 2015 to December 2019. Validation of HAS-BELD score, ATRIA score and ORBIT score were determined using the c-index. Individual factors for bleeding were assessed.

From medical record review, 200 patients met inclusion criteria, and 27 patients presented with major bleeding events. HAS-BELD score, ATRIA score and ORBIT score had c-index of 0.790 (95%CI0.651-0.865, p < 0.001), 0.708 (95%CI0.615-0.802, p < 0.001) and 0.752 (95%CI0.651-0.853, p < 0.001), respectively. There were no statistical differences among these scores in predicting the bleeding risk (P = 0.089). Notably, risk factors significantly associated with major bleeding in this population in multivariate analysis were anemia (OR3.28, 95%CI1.15-9.38, p = 0.027), bleeding history (OR5.34, 95%CI1.94-14.71, p = 0.001), concomitant NSAIDs (OR8.94, 95%CI1.48-53.83, p = 0.017) and time in therapeutic range < 60% (OR11.57, 95%CI2.51-53.41, p = 0.002) and were incorporated into the new scoring system, ABC-TTR.

HAS-BELD, ATRIA and ORBIT scores demonstrated diagnostic ability to predict major bleeding events in non-valvular atrial fibrillation patient receiving warfarin. Risk factors associated with bleeding in Thais with AF were identified.

Abstract Figure. C-index to predict major bleeding