Prognostic impact of heart rate during atrial fibrillation on clinical outcomes in elderly non-valvular atrial fibrillation patients: ANAFIE Registry sub-cohort study

BACKGROUND: Elderly patients with atrial fibrillation (AF) are at a higher risk for all-cause mortality and heart failure. Rate control is an essential component in AF management. This exploratory study assessed the relationship between resting heart rate during AF at baseline and clinical outcomes in Japanese elderly non-valvular AF (NVAF) patients, using the All Nippon AF In the Elderly Registry (ANAFIE) dataset. METHODS: This sub-cohort included patients who agreed to participate and presented with AF at enrollment in the ANAFIE study. They were categorized into six groups according to the resting heart rate during AF. Outcomes included 2-year cumulative incidences of stroke/systemic embolic events (SEE), ischemic stroke, major bleeding, cardiovascular (CV) events, CV death, all-cause death, and net clinical outcome, a composite of stroke/SEE, major bleeding, and all-cause death. RESULTS: Of the 8292 patients included in this sub-cohort (paroxysmal, 1496; non-paroxysmal, 6796), 90 % of patients were using anticoagulants. Higher heart rate was more frequently reported in women and in patients with paroxysmal AF and was associated with increased use of direct oral anticoagulants (DOACs) and antiarrhythmic drugs. Heart rate ≥110 beats per minute (bpm) was associated with a significantly higher incidence of cardiac events and numerically higher incidences of CV death and all-cause death compared with a heart rate of 60 to <80 bpm, all of which were driven by an increased risk in patients with non-paroxysmal AF. Hazard ratios by the type of anticoagulant for each clinical outcome were comparable across all heart rate categories, indicating no significant interactions. CONCLUSIONS: Elderly Japanese patients with non-paroxysmal NVAF and a heart rate ≥110 bpm have an increased risk of cardiac events. There was no interaction between heart rate category and the relative risk of adverse clinical events in patients taking DOACs compared with those taking warfarin.