Abstract 14204: Efficacy and Safety of Low-Dose Edoxaban According to Body Weight in Very Elderly Patients With Atrial Fibrillation: A Sub-Analysis of the ELDERCARE-AF Trial

Background: The ELDERCARE-AF trial showed that low-dose edoxaban is beneficial in elderly patients with non-valvular atrial fibrillation (AF) who are considered ineligible candidates for standard oral anticoagulants (OACs) due to high bleeding risk, but it was not known whether this is the case in low-body-weight patients.

Methods: This was a prespecified sub-analysis, by body weight (≤45 and >45 kg), of the ELDERCARE-AF trial, a randomized, placebo-controlled trial comparing low-dose edoxaban (15 mg once daily) with placebo. All patients were of Japanese ethnicity and considered ineligible for standard doses of OACs. The primary efficacy endpoint was stroke or systemic embolism (SSE). The key secondary endpoints were all-cause mortality and net clinical outcome. The primary safety endpoint was major bleeding according to the definition of the International Society on Thrombosis and Hemostasis.

Results: Of the 984 patients, 374 patients (38.0%) were in the ≤45 kg group and 610 (62.0%) patients were in the >45 kg group. The SSE was lower with edoxaban than with placebo in both weight groups (≤45 kg group: hazard ratio [HR] 0.36, 95% confidence interval [CI] 0.16-0.80; >45 kg group: HR 0.31, 95% CI 0.13-0.73; interaction P 0.82). Both all-cause mortality and net clinical outcome were higher in the ≤45 kg group, with no significant difference between treatment groups. Major bleeding was numerically higher with edoxaban than with placebo (≤45 kg group: HR 3.05, 95% CI 0.84-11.11; >45 kg group: HR 1.40, 95% CI 0.56-3.48), with no interaction with body weight (interaction P 0.33). Similar results were obtained in the exploratory analysis of patients divided into four quartiles of body weight (>57.9, >49.0 to ≤57.9, >42.0 to ≤49.0, and ≤42.0 kg).

Conclusions: The benefit of edoxaban 15 mg was consistent in elderly AF patients with low body weight, provided clinicians remain vigilant about the risk of major bleeding.