Determination of the Risk Factors in Patients Admitted with Bleeding Due to Warfarin use and Evaluation of the Current Bleeding Risk Scores

Abstract

Warfarin is the most common drug used in oral anticoagulation. The most serious side effect is bleeding. The aim of this study is to determine the risk factors that increase bleeding. In this retrospective study, we evaluated 283 patients with the diagnosis of bleeding due to warfarin use. The patients were divided into two groups as major and minor bleeding according to the need for blood transfusion. Age, gender, international normalized ratio (INR) level, drug use history, presence of additional disease, duration of treatment, warfarin dosage and laboratory data were obtained from patient files. Bleeding risk scores of 197 patients for whom laboratory data could be obtained before the bleeding event were calculated. The mean age of the patients was 69.16 ± 12.90 years. 51.9% were female and 48.1% were male. The major bleeding group was older (p=0,007). The rate of drug use that interacts with warfarin was 53.3%. Acetylsalicylic acid (ASA) usage rate was 31.4%. ASA use was more common in the major bleeding group (p=0,000). Concomitant disease was detected in 86.9% of the patients. The most common concomitant diseases were heart disease 59%, hypertension 56.5% and diabetes 21.2%, respectively. Heart disease was more common in the major bleeding group (p=0,001). The hemoglobin value measured at least one month before the bleeding was found to be significantly lower in the major bleeding group (p=0,001). Only the ATRIA (Anticoagulation and Risk Factors in Atrial Fibrillation) median score was significantly higher in patients experiencing major bleeding than minor bleeding (p = 0.002). In our study, it was found that major bleeding due to warfarin was associated with advanced age, ASA use, concomitant heart disease and anemia development before bleeding. Therefore, close monitoring of the bleeding profile is very important. Patients and their care providers should be well informed about the side effects of the drug.