Abnormal Heart Rhythm Drug Increases Risk of Dying

Dronedarone study halted early after medication is shown to increase risk of death in permanent AF patients

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) A drug that aids patients with intermittent atrial fibrillation, a common heart arrhythmia, increased the risk of death among patients with permanent atrial fibrillation. As a result the study was halted early.

Dronedarone, an anti-arrhythmic drug, is approved to treat non-permanent atrial fibrillation. It reduces the occurrence of irregular heartbeat and reduces patients' chances of being hospitalized for heart problems. It is not currently approved to treat patients with permanent atrial fibrillation, who usually take medication to control their heart rate.

"Ask your cardiologist about permanent atrial fibrillation treatments."

Dr. Stuart J. Connolly,  lead author of the study and professor of cardiology at McMaster University in Canada, said that there have been no previous trials aimed at reducing death rates among high risk patients with permanent atrial fibrillation.

Researchers stopped enrolling patients in the PALLAS (Permanent Atrial fibriLLAtion outcome Study using Dronedarone on top of standard therapy) study in July when the data and a safety monitoring board noticed excessive serious vascular events such as heart attacks, and deaths in patients taking dronedarone.

The randomized clinical trial of dronedarone in patients with permanent atrial fibrillation included only 3,236 of the planned 10,800 patients before researchers stopped recruiting and halted treatment. All of the patients were over the age of 65, had other risk factors for vascular events and randomly took either dronedarone or a placebo.

Dr. Connolly said the message is that the drug should not be used to treat patients with permanent atrial fibrillation. Patients taking dronedarone were 2.2 times more likely to suffer a heart attack, stroke or other cardiovascular event as compared to the placebo group.

During the study 43 patients taking the drug suffered a stroke, heart attack, systemic blood clot or cardiovascular-related death as compared to 19 patients taking a placebo. Of those, 21 cardiovascular deaths occurred among dronedarone patients as compared to 10 patients taking the placebo, while 13 arrhythmia deaths were reported among the group taking the medication versus four in the control group.

In addition, 22 patients taking the drug had strokes, while nine were reported among the placebo group. Taking dronedarone also increased the risk of hospitalization for heart failure

The research was presented at the American Heart Association’s conference in Orlando, Fla., and simultaneously published in the New England Journal of Medicine.

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Review Date: 
November 14, 2011
Last Updated:
November 14, 2011