Objective. To analyze the clinical characteristics of patients taking Factor Xa inhibitors (FXai), either direct FXai or enoxaparin (only in active cancer patients), and to estimate the incidence of and risk factors for major bleeding during FXai use. Methods. A retrospective cohort study, which included secondary data from computerized health records of primary care centers and hospitals in seven Spanish Autonomous Communities. Results. 9374 patients were analyzed, with 8972 taking direct FXai and 402 enoxaparin. At baseline, the mean age (SD) was 71.8 (9.4) years, 56.0% were women, 76.3% had hypertension, 33.6% had type 2 diabetes, and 25.5% had heart failure. The most common indication for FXai use was atrial fibrillation (72.3%), followed by venous thromboembolism (22.2%) and non-mechanical cardiac-valve replacement (5.6%). At the end of the follow-up period, the incidence rates of major bleeding overall, gastrointestinal, and intracranial were 10.2, 9.0, and 0.8 per 100 person-years, respectively. The total incidence of fatal major bleeding was 0.5 per 100 person-years. Incidence rates of all bleedings progressively decreased over time, with 62.5% of the first events occurring in the initial three months and reaching 76.8% within six months following initiation of treatment. Only 4.8% of the 1st major bleedings led to death, 2.3% in the case of major gastrointestinal bleeding, and 30.8% after an intracranial bleeding. 65.9% of patients discontinued anticoagulation after experiencing major bleeding. Conclusions. In Spain, patients taking FXai were old and had many comorbidities. Despite incidence rates of major bleeding were high, incidence rates of intracranial and fatal bleedings were low, but more efforts are required due to their relevant clinical impact.
Keywords: Factor Xa inhibitors; apixaban; bleeding; edoxaban; enoxaparin; rivaroxaban.