Clinical Pearls & Morning Reports
Published September 30, 2020
Kirchhof et al. conducted a trial that tested whether a strategy of early rhythm-control therapy that included atrial fibrillation ablation was associated with better outcomes in patients with early atrial fibrillation than contemporary, evidence-based usual care. Read the NEJM Original Article here.
Q: How common are adverse outcomes among patients diagnosed with atrial fibrillation?
A: Even with current guideline-based management, patients with atrial fibrillation have stroke, acute coronary syndrome, heart failure, and cardiovascular death at a rate of approximately 5% of patients per year, and 35 to 50% of patients with atrial fibrillation who receive adequate anticoagulation either receive inpatient therapy or die within 5 years.
Q: What was meant by “early atrial fibrillation” in the trial by Kirchhof et al.?
A: The risk of cardiovascular complications is increased during the first year after atrial fibrillation is diagnosed (a period referred to in the trial as “early atrial fibrillation”). Rhythm-control therapy may be more effective when delivered early.
A: Early rhythm control required antiarrhythmic drugs or atrial fibrillation ablation, as well as cardioversion of persistent atrial fibrillation, to be initiated early after randomization. Patients who were randomly assigned to usual care were initially treated with rate-control therapy without rhythm-control therapy. Rhythm-control therapy was used only to mitigate uncontrolled atrial fibrillation–related symptoms during adequate rate-control therapy. The first primary outcome was a composite of death from cardiovascular causes, stroke (either ischemic or hemorrhagic), or hospitalization with worsening of heart failure or acute coronary syndrome, analyzed in a time-to-event analysis. The trial was stopped for efficacy at the third interim analysis after a median follow-up of 5.1 years per patient. A first-primary-outcome event occurred in 249 patients assigned to receive early rhythm control (3.9 per 100 person-years) and in 316 patients assigned to receive usual care (5.0 per 100 person-years). When the results were adjusted for the group-sequential design of the trial, a first-primary-outcome event was found to have occurred less often in patients assigned to early rhythm control than in patients assigned to usual care (hazard ratio, 0.79; 96% confidence interval, 0.66 to 0.94; P=0.005).
A: There was no significant difference in the mean (±SD) number of nights spent in the hospital between the treatment groups (early rhythm control, 5.8±21.9 days per year; usual care, 5.1±15.5 days per year; P=0.23). Mortality was similar in the two treatment groups, and stroke occurred less frequently among patients assigned to early rhythm control than among those assigned to usual care. Serious adverse events related to rhythm-control therapy were more common in the group assigned to early rhythm control but were infrequent.