Assessment of the bleeding risk of anticoagulant treatment in non-severe frail octogenarians with atrial fibrillation.

Background: Physicians estimate the frailty in elderly patients with atrial fibrillation (AF) to aid in the decision making with respect to oral anticoagulant (OAC) therapy. There are limited data on the safety of OAC therapy in non-severe frail elderly patients. We evaluated the risk factors of bleeding among non-severe frail octogenarians with AF taking OACs.

Methods: Among 430 consecutive AF patients aged 80 years and over with non-severe frailty, we enrolled 346 patients [167 men, 83.7 (81.0-85.0) years] who were newly initiated on OACs: dabigatran, rivaroxaban, apixaban, edoxaban, or warfarin. To measure the frailty, the clinical frailty scale (CFS) was used. Non-severe frailty was defined as a CFS score of <7. The clinical factors were compared between the patients with and without bleeding during the OAC therapy.

Results: Out of the 346 patients enrolled, 266 (76.9%) received direct OACs (DOACs) and 80 (23.1%) warfarin. Of the 266 patients receiving DOACs, there were 204 (76.7%) prescribed appropriately adjusted-dose DOACs based on the approved Japanese recommendations. Of the 80 warfarin-treated patients, 52 (65.0%) were prescribed appropriately adjusted-dose warfarin. During a follow-up of 32.7 (14.0-51.0) months, bleeding events were detected in 59 patients (17.1%). Among the clinical factors, a multivariate analysis found that having a low body mass index (BMI) (<18.5kg/m) was associated with the development of bleeding [hazard ratio (HR): 3.26, 95% confidence interval (CI): 1.65-6.50, p<0.01)]. Moreover, having a low BMI remained an independent risk factor for bleeding in the patients treated with appropriately adjusted-dose OACs (HR: 2.17, 95% CI: 1.01-4.70, p=0.048).

Conclusions: In non-severe frail octogenarians with AF taking OACs, having a low BMI was the most significant factor associated with the development of bleeding.