Intravenous Administration of Metoprolol Is More Effective Than Oral Administration in the Prevention of Atrial Fibrillation After Cardiac Surgery

Abstract

Background-Atrial fibrillation (AF) is the most common arrhythmia to occur after cardiac surgery, with an incidence of 20% to 40%. AF is associated with postoperative complications, including increased risk of stroke and need of additional treatment, as well as prolonged hospital stay and increased costs. It has been shown that prophylactic oral administration of ␤-blocker therapy reduces the incidence of postoperative AF after cardiac surgery. However, it is possible that absorption of drugs is impaired after cardiopulmonary perfusion associated with cardiac surgery. The purpose of this prospective, controlled, randomized trial was to study compare intravenous and per oral metoprolol administration in the prevention of AF after cardiac surgery. Methods and Results-240 consecutive patients who were scheduled to undergo their first on-pump coronary artery bypass graft (CABG), aortic valve replacement, or combined aortic valve replacement and CABG were randomized to receive 48-hour infusion of metoprolol or oral metoprolol starting on the first postoperative morning. Patients were excluded if they had contraindications for ␤-blocker or had to stay Ͼ1 day in the intensive care unit. Dosage of metoprolol was adjusted according to heart rate. The dosage was 1 to 3 mg/h in the intravenous group and from 25 mg twice per day to 50 mg 3 times per day in the oral group. The incidence of postoperative AF was significantly lower in the intravenous group than in the oral group (16.8% versus 28.1%, Pϭ0.036). No serious adverse effects were associated with intravenous metoprolol therapy. Conclusions-Our study suggests that intravenous metoprolol is well-tolerated and more effective than oral metoprolol in the prevention of AF after cardiac surgery.

Delirium following vascular surgery: increased incidence with preoperative β-blocker administration

“…This finding is likely related to the fact that betablocker absorption is considerably reduced in the early postoperative period resulting in decreased bioavailability of orally administered preparations. 30 It has been previously shown that perioperative administration of beta-blockers is associated with higher stroke rates in both surgical and non-surgical patient populations. 18,31,32 Postoperative neurological complications can be related to both the cardiovascular and the central nervous system effects of beta-blockers.…”

The influence of preoperative pharmacotherapy on the appearance of postoperative atrial fibrillation in patients undergoing isolated coronary artery bypass grafting

“…Halonen et al, in an attempt to compare the intravenous with the oral use of metoprolol, randomized 240 patients who underwent first on pump CABG, aortic valve replacement or combined aortic valve replacement and CABG. 36 In both groups, the metoprolol administration was based on heart rate for a 48 hour period. POAF presented a significant decrease (p = 0.036) in intravenous group (16.8%) compared to oral group (28.1%).…”

The Role of β-Blockers in Cardiac Perioperative Management

“…Halonen, et al reported that intravenous administration of metoprolol was more effective than oral administration for the prevention of atrial fibrillation, with the incidence being 28.1% in the oral group versus 16.8% in the intravenous group. 10) In contrast, Maniar, et al compared the prophylactic effect of intravenous esmolol with oral β-blockers and found no difference in the occurrence of POAF between the 2 groups, although hypotension was significantly more frequent in the intravenous esmolol group and this was a safety problem. 11) In a large-scale study comparing early intravenous administration with oral administration of metoprolol in 45852 patients after acute myocardial infarction, the incidence of non-fatal myocardial infarction and ventricular fibrillation was lower in the intravenous group than the oral group.…”