Cardiothoracic Surgical Trials Network: Rate vs. Rhythm Control for Atrial Fibrillation After Cardiac Surgery - CTSN: Rate vs. Rhythm Control for AF After Cardiac Surgery
The goal of the trial was to determine the efficacy and safety of a rate control strategy versus a rhythm control strategy using amiodarone and/or DC cardioversion (DCCV) for postoperative atrial fibrillation (AF) in patients undergoing cardiac surgery.
Contribution to the Literature: This study suggests that a rate control strategy is similar in efficacy to a rhythm control strategy using amiodarone and/or DCCV for postoperative AF in patients undergoing cardiac surgery.
Patients with postoperative AF were randomized to either rhythm control (n = 261) or rate control (n = 262) strategies. Rhythm control was with amiodarone and/or DCCV if AF was >24 hours after initiation of amiodarone. Rate control was with beta-blocker, calcium channel blocker, or digoxin with a target heart rate of <100 bpm at rest. Persistent or recurrent AF patients received anticoagulation with Coumadin (target international normalized ratio [INR] 2-3) for at least 2 months.
- Onset during index hospitalization (within 7 days of surgery) and either:
- AF/atrial flutter (AFL) persisting for > 60 minutes
- Recurrent episodes of AF/AFL
- Total number of enrollees: 523
- Duration of follow-up: Hospital discharge
- Mean patient age: 69 years
- Percentage female: 24%
- Percentage diabetics: 31%
Other salient features/characteristics:
- History of stroke: 6%
- Valve disease: 55.1%
- Surgery performed: coronary artery bypass grafting (CABG) alone: 41%, valve alone: 40%, CABG + valve: 20%
Primary outcome, total number of days within 60 days of surgery in the hospital, for rate vs. rhythm control: 5.1% vs. 5.0%, p = 0.76
Secondary outcomes (for rate vs. rhythm control):
- Index length of stay: 4.3 vs. 4.3 days, p = 0.88
- Cardiac arrhythmias: 4.3% vs. 4.6%, p = 0.8
- Cerebrovascular thromboembolic event: 0.8% vs. 0.4%, p = 0.4
- Death: 0.6% vs. 0.4%, p = 0.64
- All readmissions: 18.5% vs. 18.5%, p = 0.99
The results of this trial indicate that a rate control strategy is similar in efficacy to a rhythm control strategy (using amiodarone and DCCV) for postoperative AF in patients undergoing cardiac surgery. A rate control strategy could thus be considered first in these patients, similar to the management of patients with paroxysmal AF.
Postoperative AF is a common problem in patients undergoing cardiac surgery and is associated with high mortality and morbidity. A couple of points regarding the current trial are worth noting. There was a high rate of cross-over between the two arms (20-25%), which may have biased the result towards the null. Postoperative AF in valve patients may also be different than in CABG patients. Although inflammation is a common theme, valve patients may have left atrial (LA) enlargement and LA wall stress that may contribute to AF. More effective rhythm control strategies such as catheter-based ablation or other class III antiarrhythmic drugs need to be evaluated in future trials.
Gillinov AM, Bagiella E, Moskowitz AJ, et al., on behalf of the CTSN. Rate Control Versus Rhythm Control for Atrial Fibrillation After Cardiac Surgrey. N Engl J Med 2016;Apr 4:[Epub ahead of print].
Presented by Dr. A. Marc Gillinov at the American College of Cardiology Annual Scientific Session, Chicago, IL, April 4, 2016.
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