A new bleeding risk score specifically developed for direct oral anticoagulants in a geriatric population

Although the use of direct oral anticoagulants increases in parallel with the increase in atrial fibrillation (AF) with age, none of the bleeding risk scores (HAS-BLED, HEMORR2HAGES, ATRIA nor RE-LY) have been developed in a geriatric population. Our study aimed to develop a bleeding risk score adapted to this specific population and this therapeutic class. Multicentre, longitudinal, prospective, observational, pharmacoepidemiologic study conducted in 60 French cardiologic and geriatric centres included consecutive patients aged ≥80 years with AF, treated with rivaroxaban and followed for at least 1 year. All thromboembolic, bleeding and clinical events, including falls, hospitalisations or deaths, were recorded every 3 months for 1 year. A predictive risk score based on the clinical variables most associated with bleeding events was developed from the total sample, randomly divided into a training sample and a validation sample. Among the 839 patients included (mean age = 86 year old, 62% women), there were 78 (9.3%) major haemorrhagic events. Variables associated with bleeding were age, anaemia, low albuminemia, amiodarone use and low creatinine clearance estimated with Cockcroft formula, grouped together as the A4C score. The A4C score better identifies bleeding risk in subjects ≥80 years than the scores already validated in younger populations, as its area under the curve in the training sample and in the validation sample was 0.73 and 0.66, respectively, whereas it was 0.49/0.55 for the HAS-BLED score, 0.53/0.50 for the HEMORR2HAGES score, 0.58/0.61 for the ATRIA score and 0.57/0.54 for the RE-LY score. A threshold of the A4C score ≥ 2 identifies subjects ≥80 years at high risk of bleeding.