Intravenous amiodarone is widely used for the treatment of acute onset atrial fibrillation despite the lack of prospective, randomized, controlled trials supporting its efficacy. The use of intravenous amiodarone at our hospital has almost doubled in the last three years and has been associated with a concurrent increase in drug costs. Intravenous procainamide, which has been shown to be effective in the treatment of acute onset atrial fibrillation in uncontrolled trials, is the only other intravenous antiarrhythmic readily available in Canada for this patient population.
The objective of this study was to compare the efficacy, safety, and cost of intravenous amiodarone and intravenous procainamide in the treatment of acute onset atrial fibrillation.
A Canadian community-based hospital.
Medical records of patients who were diagnosed with acute onset atrial fibrillation at our hospital over a 2-year period were reviewed. Patients were included if intravenous amiodarone or intravenous procainamide was used for cardioversion.
Main Outcome Measures
Primary endpoints included conversion to and maintenance of normal sinus rhythm (NSR) and time to conversion. Secondary endpoints included duration and cost of treatment, and incidence of side effects.
Sixteen patients met inclusion criteria: 9 received procainamide and 7 received amiodarone. Fifteen of the sixteen patients converted to and maintained NSR during their hospital stay. Conversion to NSR occurred in 33% and 0% of patients by 8 hours and in 56% and 29% of patients by 24 hours of treatment in the procainamide and amiodarone groups, respectively. The majority of patients (67%) in the amiodarone group converted to NSR after receiving greater than 24 hours of treatment. Conversion with amiodarone took 8 times longer than with procainamide. The median time to conversion was 5 hours for procainamide and 44 hours for amiodarone. The average cost of treatment was 20 times higher with amiodarone than procainamide. For patients in the amiodarone group, the average treatment cost was $916.07 CAN, whereas with procainamide the average treatment cost was $42.64 CAN. Hypotension was observed in 22% of patients, all in the procainamide group.
The results of this study suggest that both intravenous amiodarone and intravenous procainamide seem to be effective at converting acute onset atrial fibrillation. Intravenous procainamide appears to convert patients to NSR faster with few side effects and at a lower cost.