Increased Mortality Seen with Episodic Amiodarone Therapy
Episodic treatment also increased both atrial fibrillation recurrences and hospitalizations
WEDNESDAY, Oct. 15 (HealthDay News) -- While there was no difference in composite cardiovascular endpoints in atrial fibrillation patients treated with episodic compared to continuous amiodarone therapy, episodic treatment was associated with higher rates of atrial fibrillation recurrence, all-cause mortality and cardiovascular hospitalizations, according to a report in the Oct. 15 issue of the Journal of the American Medical Association.
Sheba Ahmed, M.D., of the University of Groningen in the Netherlands, and colleagues randomized 209 ambulatory patients with recurrent symptomatic atrial fibrillation to receive either episodic or continuous amiodarone treatment following electrical cardioversion to determine if there was a difference in a composite of both amiodarone (e.g., pulmonary or liver toxicity) and underlying heart disease-related major events (e.g., bradycardia).
The investigators found that with a median follow-up of 2.1 years, 51 patients (48 percent) receiving episodic treatment compared to 64 patients (62 percent) receiving continuous amiodarone therapy were in sinus rhythm. Recurrence of atrial fibrillation was significantly more common with the episodic treatment than with the continuous treatment (80 percent versus 54 percent), but no significant differences in the composite end point were noted, the researchers report. However, patients receiving episodic therapy had an increased all-cause mortality and were more likely to undergo a cardiovascular hospitalization.
"The lack of usefulness of episodic compared with continuous amiodarone treatment may be explained, in part, by the fact that the majority of events were thyroid dysfunction occurring at comparable rates in both groups," the authors comment. "This study shows that episodic amiodarone treatment -- in contrast to our expectations-- has no clinical advantage over continuous treatment because it did not lower morbidity in patients with persistent atrial fibrillation over two years of follow-up."
The study received support from Medtronic, and one of the study authors reports financial relationships with the pharmaceutical industry.