When should we discontinue antiarrhythmic therapy for atrial fibrillation after coronary artery bypass grafting? A prospective randomized study.

BACKGROUND

New-onset atrial fibrillation after coronary artery bypass grafting is common. Medical therapy includes various antiarrhythmic drugs to control heart rate and restore sinus rhythm. The purpose of this study was to determine the duration of antiarrhythmic therapy after discharge from the hospital.

METHODS

One hundred twenty-nine patients in whom new atrial fibrillation after coronary artery bypass grafting developed and successfully reverted to sinus rhythm were prospectively randomized at dismissal to receive antiarrhythmic therapy for 1 week (group A; n = 44), 3 weeks (group B; n = 42), or 6 weeks (group C; n = 43). Patients were followed up for an additional 4 weeks after discontinuation of antiarrhythmic therapy for detection of recurrent atrial fibrillation.

RESULTS

The incidence of new atrial fibrillation during the study period was 21.2% (256/1206). Among the 129 patients who consented to the study, conversion to sinus rhythm was accomplished with the following medications: amiodarone (group A, 82%; group B, 93%; group C, 88%; P = .29), digoxin (group A, 16%; group B, 7%; group C, 7%; P = .29), beta-blockers (group A, 27%; group B, 19%; group C, 14%; P = .30), calcium channel blockers (group A, 2%; group B, 2%; group C, 0%; P = .60), quinidine (group A, 2%; group B, 2%; group C, 7%; P = .44), and procainamide (group A, 4.5%; group B, 2%; group C, 0%; P = .37). Follow-up was completed in 128 patients (99.2%). There was no significant difference in the recurrence of atrial fibrillation among groups (0%, 2%, and 0% for groups A, B, and C, respectively).

CONCLUSIONS

Patients with new atrial fibrillation after coronary artery bypass grafting, converted to normal sinus rhythm before hospital discharge, have a benign course. Antiarrhythmic therapy as short as 1 week may be appropriate in these patients.