Atrial Fibrilation Treatment Reduction Worsens Outcomes While Maintaining Side Effects

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Main Category: Heart Disease
Also Included In: Cardiovascular / Cardiology;  Clinical Trials / Drug Trials
Article Date: 15 Oct 2008 - 0:00 PDT

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Reducing amiodarone treatment frequency is not associated with a corresponding decrease in medication related side effects, and is linked to increased atrial fibrilation recurrence and risk of death, including from cardiovascular events, according to an article released on October 14, 2008 in JAMA.

Atrial fibrillation (AF) is an abnormal heart rhythm, or arrhythmia, caused by irregular electrical impulses created in the atrial region, causing irregular contraction of the ventricles. It is associated with an increased risk of death in addition to a number of symptoms and other diseases such as heart attack and stroke. Amiodarone is a standard, effective antiarrhythmic, but has a number of non-cardiac related side effects that might be associated with higher regular doses and long-term therapy, according to the article.

To investigate the comparative effects of an episodic treatment in comparison a continuous one, Sheba Ahmed, M.D., of the University of Groningen, Netherlands, and colleagues enrolled 209 patients with recurrent atrial fibrillation. The patients were all treated for one month with amiodarone, then treated according to a randomly assigned treatment. In the episodic treatment, amiodarone was discontinued after one month of regular sinus rhythm, then reinitiated if the patient suffered relapse. In the continuous treatment group, treatment with amiodarone was maintained through the course of the study. The patients were followed up for a median 2.1 years and evaluated for recurrence of atrial fibrillation, heart disease events, and death.

Over the course of the study:

• 48% of patients in the episodic group and 62% in the continuous treatment group regained sinus rhythm. 
• 80% of patients in the episodic group and 54% in the continuous treatment group suffered recurrence of atrial fibrillation.
• 35% of patients in the episodic group and 33% in the continuous treatment group experienced some kind of amiodarone or heart disease-related major event. 
• There was not a statistically significant difference in the incidence of amiodarone major events or underlying heart disease-related events.
• 53% of patients in the episodic group and 34% in the continuous treatment group experienced death or cardiovascular hospitalization. 

The authors conclude, not recommending episodic treatment for most patients: "Considering the above, episodic amiodarone treatment cannot be advocated for most patients with persistent atrial fibrillation," they say. "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 2 years of follow-up."

Continuous vs Episodic Prophylactic Treatment With Amiodarone for the Prevention of Atrial Fibrillation: A Randomized Trial
Sheba Ahmed; Michiel Rienstra; Harry J. G. M. Crijns; Thera P. Links; Ans C. P. Wiesfeld; Hans L. Hillege; Hans A. Bosker; Dirk J. A. Lok; Dirk J. Van Veldhuisen; Isabelle C. Van Gelder; for the CONVERT Investigators
JAMA. 2008;300(15):1784-1792.
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Written by Anna Sophia McKenney
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