Reduced postoperative atrial fibrillation using multidrug prophylaxis

Background: Atrial fibrillation (AFIB) is the most common complication foll owing coronary artery bypass grafting (CABG). Despite three decades of reco gnition, efforts to reduce the high incidence reported (15%-30%) have been largely unsuccessful. Reasons for postoperative AFIB are likely multifactor ial. As a result, we defined a multidrug prophylaxis based on agents known to be individually effective. This method was applied prospectively to a se ries of consecutive CABG patients with the goal of reducing the incidence o f new-onset postoperative AFIB. Methods: Isolated CABG with cardiopulmonary bypass was performed on 517 consecutive patients. A rapid recovery protoco l emphasizing AFIB multidrug prophylaxis was applied to all patients. All p atients received 10 mug of triiodothyronine intraoperatively when the clamp on the aorta was released. Immediately following CABG, parenteral magnesiu m was administered to assure a serum magnesium > 2.2 mEq/dL. Thyroxine 200 mug was administered parenterally to all patients on postoperative days 1 a nd 2. Metoprolol (25 mg to 100 mg/day) was begun on all patients after extu bation provided: heart rate > 85 beats/min and systolic blood pressure > 13 0 mmHg. Parenteral procainamide (12 mg/kg) loading dose, followed by a main tenance dose (2 mg/min), was used for patients who developed premature atri al contractions (> 1/min), nonsustained supraventricular tachycardia, or an y episodes of atrial fibrillation. All patients also received postoperative digitalization, steroids, and aggressive diuresis. Results: The 30-day ope rative mortality was 3.7%. The overall incidence of new-onset postoperative AFIB was 10.3% (53 patients). There was no major difference in operative m ortality (7.5% vs 3.2%, p = 0.23), Parsonnet risk score, or intraoperative variables between AFIB patients and the non-AFIB patients. Patients present ing with a preoperative acute myocardial infarction (p < 0.05), left main s tenosis <greater than or equal to> 70% (p < 0.01), and advanced age <greate r than or equal to> 70 years (p < 0.05) were at increased risk of developin g AFIB. The length of stay for patients with AFIB was 9.9 +/- 9.6 days vers us 5.9 +/- 5.2 days (p < 0.001). Conclusion: Application of a multidrug pro phylaxis can reduce postoperative AFIB to a low incidence. Identification o f associated clinical features can help predict patients at risk for postop erative AFIB. Additional strategies to target postoperative AFIB may includ e treatment at the earliest recognition of atrial rhythm instability.