Direct oral anticoagulants for patients aged over 80 years in nonvalvular atrial fibrillation: the impact of frailty.

Abstract

In patients aged at least 80 years, atrial fibrillation is responsible for significant morbidity and mortality, with a high incidence of stroke. Four new direct oral anticoagulants (DOACs) have been introduced in Italy for the prevention of thromboembolism. Their safety and efficacy in the elderly have already been confirmed. Frailty is frequently associated with aging, but only a few studies have paid attention to interactions between frailty and anticoagulation therapy. We retrospectively evaluated the effectiveness and safety of DOACs in a population aged at least 80 years. Frailty was appraised using an adaptation of the Reported Edmonton Frail Scale, considering a value at least 8 (on a scale from 0 to 18). The majority (644/731) of patients remained on DOACs for more than 1 year. A total of 19 patients experienced a thrombotic event while on anticoagulation (1.11 events per 100 person-years) and 26 patients a major bleeding episode (1.52 events per 100 person-years). The probability of interrupting therapy increased significantly with frailty [hazard ratio 2.91 with confidence interval (CI) 2.15-3.92 at univariate analysis, hazard ratio 2.80 with CI 2.03-3.86 at multivariate]; frailty showed a significant impact also on major bleeding (hazard ratio 3.28 with CI 1.45-7.37 at univariate analysis, hazard ratio 3.56 with CI 1.58-8.01 at multivariate). Our study highlights how DOACs are a safe and effective option for anticoagulation, even in frail elderly people; the introduction of these drugs is leading to an increased use of anticoagulation therapy in this population. Prospective trials will be needed to reinforce these results and to consider new variables in the thrombotic and hemorrhagic risk scores underlying the prescription of DOACs.