Abstract

The annual risk of major bleeding due to anticoagulant use ranges from 2% to 5%, with 0.5% to 1% of these bleedings being fatal. The global usage of oral anticoagulants is 0.65%, with warfarin being the most commonly used oral anticoagulant agent. In our study, we aimed to determine the long-term bleeding risks of patients using warfarin in our clinic and to make treatment and risk factor adjustments according to this risk situation. We investigated the effectiveness of the most commonly used bleeding risk scores and their superiority over one another in this study.

This study included patients taking warfarin from January 2010 to January 1, 2022. Demographic data, laboratory parameters, known, and potential bleeding risk factors were recorded for all patients. Pre-treatment CHA₂DS₂-VASc, ATRIA, HAS-BLED, and ORBIT scores were calculated for all patients included in the study, along with their time in therapeutic range (TTR) values during follow-up. Patients were retrospectively monitored for bleeding events.

In our study, we observed that anemia, chronic kidney failure, cancer, and mechanical valves were associated with an increased risk of bleeding compared with other risk factors. We found that among the risk scores assessed in patients, the HAS-BLED risk score more strongly predicted the risk of bleeding than the other risk scores. Additionally, we found that low TTR values were directly associated with bleeding.

Modifying identified risk factors in patients during the warfarin treatment process (such as anemia, chronic kidney failure, etc.) may reduce the risk of bleeding. Similarly, close monitoring of TTR, particularly in patients with high HAS-BLED and ORBIT risk scores assessed before treatment initiation, is considered a safe treatment approach to reduce the risk of bleeding.