Heart rate control in atrial fibrillation (AF) is recommended to reduce symptoms, though its relationship with cardiovascular outcomes remains uncertain. This prespecified analysis of the Early Treatment of Atrial Fibrillation for Stroke Prevention Trial (EAST-AFNET 4) published in the Heart included 772 patients who were in AF at baseline and had heart rate data available..

Participants were categorized by baseline heart rate as <110 beats per minute (bpm) or ≥110 bpm. The primary endpoint was a composite of cardiovascular death, stroke, or hospitalization for worsening heart failure or acute coronary syndrome. The cohort had a mean age of 70.8 ± 7.8 years, 40% were women, and 50% were assigned to early rhythm control therapy.

Patients with heart rate ≥110 bpm more frequently reported symptomatic AF (78% vs 62%; p<0.001) and severe symptoms (EHRA score ≥3: 19% vs 12%; p=0.032). However, the primary outcome occurred at similar rates in both groups (5.1 per 100 person-years), with no significant association between higher heart rate and events (HR 1.08; 95% CI 0.79–1.48).

As a subgroup analysis within a randomized trial, the findings are observational and not designed to establish optimal heart rate thresholds.