The incidence of bleeding in patients with nonvalvular atrial fibrillation using anticoagulants: a real-world report with the biggest Vietnamese data

This is a retrospective descriptive study carried out on 1036 patients with nonvalvular atrial fibrillation who took oral anticoagulants and visited the cardiology clinic of the University of Medicine and Pharmacy Hospital, Ho Chi Minh City, from 01/01/2021 to 30/06/2021. The objective was to investigate the incidence of bleeding in these patients. The average age of the study population was 72±12 years, with an average CHA₂DS₂VASc score of 4.2±1.8 and an average HAS-BLED score of 1.26±0.03. Rivaroxaban was the most prescribed anticoagulant, with a total of 463 cases, accounting for 44.7%. There were 99 bleeding events recorded; of these, 37 (37.4%) cases were severe bleeding, and 62 (62.6%) were minor bleeding. Gastrointestinal bleeding was the most common site in both severe and minor bleeding groups. The group who had an overdose of anticoagulants had a severe bleeding rate of 52.4%, similar to the group whose anticoagulant dose could not be assessed (55.6%), nearly twice as high as the group who took the standard dose (30.6%) and the group who took a lower dose than recommended (30.0%). Of the 37 cases of severe bleeding, 14 (37.8%) were using rivaroxaban, 12 (32.4%) were using vitamin K antagonists, 5 (13.5%) were using dabigatran, and 6 (16.2%) were using a combination of anticoagulants and antiplatelets. To conclude, gastrointestinal bleeding was a very common event in patients using anticoagulants for nonvalvular atrial fibrillation. Non-vitamin K antagonist oral anticoagulants should be preferred in patients with a high risk of bleeding (dabigatran may have advantages over rivaroxaban). It is important to assess the patient’s weight and renal function to determine the appropriate anticoagulant dose according to recommendations to reduce the risk of severe bleeding.