Heart rate in early rhythm control therapy in patients with atrial fibrillation

Preventing high heart rates in atrial fibrillation (AF) is recommended to reduce AF-related symptoms and morbidity. Evidence on a strong relationship between lower heart rate during AF and a reduction in symptoms or cardiovascular complications is, however, lacking.

This Early Treatment of Atrial Fibrillation for Stroke Prevention Trial analysis compared symptoms, treatment strategy and the composite of death from cardiovascular causes, stroke or hospitalisation with worsening of heart failure or acute coronary syndrome between patients with a heart rate <110 beats per minute and ≥110 beats per minute at baseline.

At baseline, 772 patients were in AF and had information on heart rate available. Mean age was 70.8±7.8 years, 305 (40%) were women, 385 (50%) were randomised to early rhythm control and 506 (66%) patients had a heart rate <110 beats per minute. Patients with a heart rate ≥110 beats per minute at baseline were more likely to have symptomatic AF (78% vs 62%, p<0.001) and more likely to have severe symptomatic AF with a European Heart Rhythm Association score ≥3 (19% vs 12%, p=0.032). The primary outcome, a composite of death from cardiovascular causes, stroke or hospitalisation with worsening of heart failure or acute coronary syndrome, occurred in 116 patients with a heart rate <110 beats per minute (5.1 per 100 person-years) and 62 patients with a heart rate ≥110 beats per minute (5.1 per 100 person years). The HR of the primary outcome for patients with a heart rate ≥110 beats per minute compared with patients with a heart rate <110 beats per minute was 1.08 (95% CI 0.79 to 1.48).

A high heart rate (≥110 beats per minute) during AF is associated with more and more severe AF-related symptoms. Cardiovascular event rates are not different between heart rates. Early rhythm control reduces outcomes in patients with high and low heart rates during AF.

NCT01288352.