No Advances Made in Two Studies of Heart Failure Patients
Rhythm control approach not linked to lower deaths than rate control in patients with atrial fibrillation; dronedarone trial halted early
WEDNESDAY, June 18 (HealthDay News) -- A rhythm-control strategy didn't reduce the death rate from cardiovascular causes compared to a rate-control strategy in patients with atrial fibrillation and congestive heart failure, and the antiarrhythmic drug dronedarone was associated with worsening heart failure, according to two studies published in the June 19 issue of the New England Journal of Medicine.
In the first study, Denis Roy, M.D., of the Universite de Montreal in Quebec, Canada, and colleagues analyzed data from 1,376 patients with congestive heart failure, history of atrial fibrillation and left ventricular ejection fraction of 35 percent or less. Patients were randomized to either maintenance of sinus rhythm with therapies such as medications, electrical cardioversion and pacemaker; or rate control with therapies such as beta-blockers, digitalis, and atrioventricular nodal ablation and pacemaker. Patients were followed for a mean 37 months, and the death rate from cardiovascular causes wasn't significantly different between the groups.
In the second study, Lars Kober, M.D., of the University of Copenhagen in Denmark, and colleagues analyzed data from 627 patients with symptomatic heart failure and severe left ventricular systolic dysfunction, who were randomized to receive 400 mg of dronedarone twice daily or placebo. The trial was terminated early; during a median two months of follow-up, more patients in the treatment group died (hazard ratio, 2.13). The increased deaths were largely related to worsening of heart failure.
"Investigators should next focus on a rhythm-control strategy that eliminates the confounding contributions of low efficacy and high toxicity associated with antiarrhythmic drug therapy to better determine the desirability of maintaining sinus rhythm in patients with atrial fibrillation. Ablation therapy serves this purpose. There are clinical trials in progress and being planned to test catheter ablation of atrial fibrillation, as compared with conventional antiarrhythmic drug therapy," write Michael E. Cain, M.D., and Anne B. Curtis, M.D., in an accompanying editorial.
Roy and a number of his co-authors disclosed financial relationships with a variety of pharmaceutical companies, as did several co-authors on the Kober study, which was supported by Sanofi-Aventis. The editorial authors disclosed financial relationships with Sanofi-Aventis, among other companies.