Atrial tachyarrhythmia (AT) is the most frequent complication following cardiac surgery. Previous studies examining the effect of prophylactic amiodarone therapy on the development of atrial tachyarrhythmia were small and underpowered; further investigation is, therefore, needed.OBJECTIVE
To find out whether prophylactic amiodarone therapy can safely and effectively preclude the occurrence of AT in patients after cardiac surgery.DESIGN
The Prophylactic Oral Amiodarone for the Prevention of Arrhythmias that Begin Early After Revascularization, Valve Replacement, or Repair (PAPABEAR) trial was a double-blind, placebo-controlled, single-center study. Patients scheduled for nonimmediate valve replacement or repair, CABG surgery, or both, were enrolled. Exclusion criteria included previous sustained AT, amiodarone therapy in the previous 3 months, and myocardial infarction within the previous 2 weeks.INTERVENTION
Eligible patients were randomly assigned 10 mg/kg amiodarone daily or placebo. Treatment with the drug or placebo regimen was initiated 6 days before and continued for 6 days after surgery. Patients were also monitored continuously by telemetric electrocardiography for 6 days following surgery. Notably, randomization was stratified according to age, use of β-blockers before surgery and type of surgery. All analyses were done on the basis of intention to treat.OUTCOME MEASURES
The main outcome was an episode of AT lasting 5 min or more that resulted in treatment and occurred in the 6 days following surgery.RESULTS
In total, 299 patients received amiodarone therapy and 302 received placebo. Fewer patients in the amiodarone-therapy group developed AT than in the placebo group (48 [16.1%] versus 89 [29.5%]; hazard ratio [HR] 0.52, 95% CI 0.34-0.69; P<0.001). To prevent 1 patient from developing AT, the number needed to treat was 7.5 (95% CI 4.8-14.7). The reduced incidence of AT with amiodarone therapy was seen in each of the patient subgroups analyzed: age less than 65 years (19 [11.2%] versus 36 [21.1%]; HR 0.51, 95% CI 0.28-0.94; P = 0.02); age 65 years or more (28 [21.7%] versus 54 [41.2%]; HR 0.45, 95% CI 0.27-0.75; P<0.001); CABG surgery only (22 [11.3%] versus 46 [23.6%]; HR 0.45, 95% CI 0.26-0.79; P = 0.002); either valve replacement or repair, with or without CAGB surgery (25 [23.8%] versus 44 [44.1%]; HR 0.51, 95% CI 0.31-0.84; P = 0.008); β-blocker therapy before surgery (27 [15.3%] versus 42 [25%]; HR 0.58, 95% CI 0.34-0.99; P = 0.03); and absence of β-blocker therapy before surgery (20 [16.3%] versus 48 [35.8%]; HR 0.40, 95% CI 0.22-0.71; P<0.001). There were no differences in rehospitalization, in-hospital mortality, 1-year mortality or serious complications between the two treatment groups.CONCLUSION
The authors conclude that prophylactic amiodarone therapy is a safe and effective treatment for reducing the incidence of AT in patients after cardiac surgery, regardless of age, previous β-blocker therapy or surgical intervention.