Rhythm Control Demonstrated as Equally Effective as Rate Control in Preventing CV Mortality

November 6, 2007 By Scott Williams [mailto:swilliams@perfuse.org]

Orlando, FL: The AF-CHF trial demonstrated no differences in cardiovascular mortality among patients with atrial fibrillation (AF) and heart failure (HF) in either the rhythm control or rate control study groups through a mean follow up of 3 years. The results were presented by Dr. Denis Roy at the AHA’s Scientific Sessions.

The AF-CHF study enrolled 1376 patients with heart failure and atrial fibrillation to study the effects of rate control versus rhythm control among these patients. To be considered as having HF, patients had to be classified as having New York Heart Association (NYHA) class II to class IV congestive heart failure and a left ventricular (LVEF) ejection fraction of equal to or less than 35%, or NYHA class I classification with prior hospitalization for heart failure or an LVEF equal to or less than 25%. A document clinically significant episode of AF within the past 6 months was also required for inclusion in the study. The trial’s population had a mean age of 67 years and 18% were females.

682 patients were randomized to receive rhythm control treatments consisting of electrical cardioversion with amiodarone as the first choice as an antiarrythmic drug (82% of patients in the rhythm control group). Sotalol (1.8% of patients) and dofetilide (0.4% of patients) were administered as necessary. The trial’s other 694 patients received beta-blockers (88% of patients), digoxin (75% of patients), or pacemaker and AV node ablation as necessary. There was a crossover rate of 10% from the rhythm control group to the rate control group, and 21% from the rate control group to the rhythm control group.

Through the mean follow up period of 3 years there was no significant difference displayed between the two groups for the study’s primary endpoint of cardiovascular death (26.7% in the rhythm population vs. 25.2% in the rate population, p=0.59). Differences between the secondary endpoints of all cause mortality, stroke and worsening HF were also non significant. Two areas where rhythm control and rate controlled differed were in the rate of cardioversion (39% vs. 8%, p=0.0001) and the frequency of bradyarrhythmias (8.5% vs. 4.9%, p=0.007).

Although prior studies have attributed negative hemodynamic effects to atrial fibrillation, rhythm control appeared to be equally as safe and effective as rate control in preventing cardiovascular mortality and worsening heart failure.

References 1. Originally presented at AHA Scientific Sessions 2007 by Dr. Denis Roy.