Carvedilol versus Metoprolol for the prevention of atrial fibrillation after off-pump coronary bypass surgery: rationale and design of the Carvedilol or Metoprolol Post-Revascularization Atrial Fibrillation Controlled Trial (COMPACT).
BACKGROUND
Postoperative new-onset atrial fibrillation (AF) remains the most common complication of coronary artery bypass graft surgery. Postoperative AF carries the risk of hemodynamic instability, increases the risk of thromboembolic events, and has a significant economic impact. Current guidelines recommend treatment with beta-blockers to prevent AF; information, however, is limited regarding the relative efficacy of beta-blocking agents. Carvedilol is a non-selective adrenergic blocker with anti-inflammatory, antioxidant, and multiple cationic channel blocking properties. These unique properties of carvedilol have generated interest in its use as a prophylaxis for postoperative AF.


METHODS
We hypothesize that carvedilol will be more effective than metoprolol, a conventional beta(1)-selective antagonist, in suppressing newly developed AF following off-pump coronary artery bypass (OPCAB) surgery. We have designed the Carvedilol or Metoprolol Post-Revascularization Atrial Fibrillation Controlled Trial (COMPACT) to test our hypothesis in a multi-center, open-label, randomized, and controlled trial. A total of at least 650 patients will be randomized to receive an initial oral dose of either 5 mg of carvedilol twice per day or 20 mg of metoprolol tartrate three times per day following surgery. The dose of each beta-blocker will be increased to the maximum tolerated dose. The primary endpoint is the incidence of new-onset AF during the first 7 days after surgery.


CONCLUSIONS
The COMPACT is the first multi-center, randomized, controlled trial to directly compare two different beta-blockers in patients following surgical coronary revascularization. Results of this trial will help to guide physicians in choosing appropriate medications following OPCAB surgery.
Kamei
Masataka
M
Department of Anesthesiology, National Cardiovascular Center, Osaka, Japan. mkamei@hsp.ncvc.go.jp
Morita
Satoshi
S
Hayashi
Yukio
Y
Kanmura
Yuichi
Y
Kuro
Masakazu
M
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000517:prevention & control*; D002227:Carbazoles / Q000627:therapeutic use*; D000077261:Carvedilol; D047549:Coronary Artery Bypass, Off-Pump / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008790:Metoprolol / Q000627:therapeutic use*; D008875:Middle Aged; D011412:Propanolamines / Q000627:therapeutic use*
D000319:Adrenergic beta-Antagonists; D002227:Carbazoles; D011412:Propanolamines; D000077261:Carvedilol; D008790:Metoprolol