NEW YORK — Intraoperative and postoperative treatment with amiodarone was associated with a significantly lower incidence of atrial fibrillation in patients undergoing cardiac surgery, in a comparison of case series with a total of more than 1,000 patients.
And among patients who developed atrial fibrillation despite amiodarone treatment, their length of hospital stay for atrial fibrillation was significantly reduced, Keith B. Allen, M.D., and his associates reported in a poster at the annual meeting of the International Society for Minimally Invasive Cardiothoracic Surgery.
The study compared the atrial fibrillation outcomes of 476 consecutive patients who underwent cardiac surgery in Indianapolis from July to December 2002 without amiodarone treatment, and 592 consecutive patients who underwent cardiac surgery with amiodarone treatment from January to June 2003. Aside from amiodarone treatment, all other facets of their medical and surgical care were the same, said the report's authors, who were led by Dr. Allen, a cardiothoracic surgeon at St. Vincent's Medical Center in Indianapolis.
The amiodarone regimen began with an intraoperative dose of 150 mg administered intravenously. Treatment continued postoperatively until hospital discharge with a 200 mg oral dose administered t.i.d. All patients also received metoprolol postoperatively, and magnesium sulfate during and after their surgery.
During the postoperative period, 29% of patients who had surgery without amiodarone developed atrial fibrillation, compared with 16% of patients who received amiodarone, a 45% relative cut in the atrial fibrillation rate that was statistically significant.
A second analysis looked at the average duration of hospitalization for atrial fibrillation in those patients who had this complication. The mean length of stay was 13.1 days among those who did not receive prophylactic amiodarone, and 9.4 days among patients who received the drug, a difference that was just short of statistical significance.
In a multivariate analysis that adjusted for baseline clinical and demographic differences between the two groups of patients, routine use of prophylactic amiodarone was associated with a statistically significant, 35% cut in the incidence of atrial fibrillation, Dr. Allen and his associates said.