Physicians' Academy for Cardiovascular Education

Rate vs Rhythm control in post-operative atrial fibrillation

News - Apr. 4, 2016

A Randomized Trial of Rate Control Versus Rhythm Control for Atrial Fibrillation after Cardiac Surgery

Marc Gillinov (Cleveland Clinic, Cleveland, Ohio, USA)
               
Presented at ACC 2016
 

Background

Postoperative atrial fibrillation (POAF) is the most common complication after cardiac surgery and is associated with increased morbidity, mortality, length of stay (LOS) and resource utilization. Recommendations for optimal management of POAF in stable patients (i.e., rate control or rhythm control) lack a rigorous evidence base, resulting in large practice pattern variations.
The objective of this trial was to compare the strategies of rate versus rhythm control in patients with POAF after cardiac surgery. The study was conducted at 23 academic medical centers in the United States and Canada. It enrolled 2,109 patients who were about to undergo either bypass or valve replacement/valve repair surgery.
Patients who had either one episode of POAF lasting more than 60 minutes or more than one POAF episode during the first seven days after surgery were eligible to be randomly assigned to one of the two study treatments. The 523 patients who developed postoperative AF were randomly assigned to either heart rate control treatment with beta blockers or rhythm control (amiodarone, ± direct current (DC) cardioversion). Warfarin anticoagulation, when not otherwise needed for treatment of a non-rhythm indication, was provided to all patients with AF >48 hours duration and to all patients whose AF spontaneously terminated but recurred during hospitalization. The mean age was 68.8±9.1 years and 24% were female. The follow-up period was 60 days after surgery.
The primary endpoint was the total number of hospital days including the primary admission and any subsequent admissions occurring within 60 days of randomization. Secondary endpoints were heart rhythm at 60 days, mortality, adverse events (including bleeding, cerebrovascular and non-cerebral thromboembolism), and permanent pacemaker implantation.
 

Main results  

  • The total numbers of hospital days in the rate-control group and the rhythm-control group were similar (median, 5.1 days and 5.0 days, respectively; P=0.76).
  • There were no significant between-group differences in the rates of death (P=0.64) or overall serious adverse events (24.8 per 100 patient-months in the rate-control group and 26.4 per 100 patient-months in the rhythm-control group, P=0.61), including thromboembolic and bleeding events.
  • About 25% of the patients in each group deviated from the assigned therapy, mainly because of drug ineffectiveness (in the rate-control group) or amiodarone side effects or adverse drug reactions (in the rhythm-control group).
  • At 60 days, 93.8% of the patients in the rate-control group and 97.9% of those in the rhythm-control group had had a stable heart rhythm without atrial fibrillation for the previous 30 days (P=0.02), and 84.2% and 86.9%, respectively, had been free from atrial fibrillation from discharge to 60 days (P=0.41).
 

Conclusion  

In this study, strategies for rate control and rhythm control to treat postoperative atrial fibrillation were associated with equal numbers of days of hospitalization, similar complication rates, and similarly low rates of persistent atrial fibrillation 60 days after onset. Neither treatment strategy showed a net clinical advantage over the other.
Treatment choice should be determined by patient and physician preferences.
An initial strategy of rate control in hemodynamically stable patients with postoperative AF is reasonable, to avoids toxicity associated with amiodarone and as the need to institute rhythm control is usually evident during index hospitalization.
 
This study was published simultaneously in NEJM
 

Source

Press release ACC 2016, 4 April 2016