Prescription omega-3 no better than placebo in treating atrial fibrillation

Prescription omega-3 no better than placebo in treating atrial fibrillation
Abstract 21811

Study Highlights:

•Prescription omega-3 fatty acids weren’t better than placebo in delaying the recurrence of the most common form of atrial fibrillation, a potential trigger for fatal heart attacks and strokes.
•The findings do not apply to dietary omega-3 fatty acids or to prescription omega-3 usage for heart ailments other than atrial fibrillation.


CHICAGO, Nov. 15, 2010 – Prescription omega-3 fatty acids didn’t prevent the recurrence of the most common type of erratic beats in the heart’s upper chambers, according to late-breaking clinical trial research presented at the American Heart Association’s Scientific Sessions 2010.

Efficacy and Safety of Prescription Omega-3 Acid Ethyl Esters (P-OM3) for the Prevention of Recurrent Symptomatic Atrial Fibrillation is a prospective, randomized, double-blind trial of 663 patients (average age 61, 56 percent male) enrolled at 96 sites.

In the study, researchers compared the use of the fish-oil-derived product (4grams/day) and a placebo in patients with paroxysmal atrial fibrillation (AF), an intermittent, abnormal heartbeat in which the upper chambers of the heart quiver instead of beating effectively to move blood into the lower chambers.

“This was an attempt to do a definitive study to find out if manufactured omega-3 is beneficial in patients with atrial fibrillation,” said Peter R. Kowey, M.D., study author and chief of cardiology at Main Line Health Hospital System near Philadelphia, Pa. “The major finding was that fish oil did not work.”

Eating fish rich in omega-3 fatty acids benefits patients with some types of heart problems, including heart failure and heart attack. As part of a heart healthy diet, it is associated with reduced risk of sudden death and death from coronary artery disease in adults. Previous evidence of prescription omega-3 benefits in AF came from small studies in which researchers reported conflicting findings.

The findings of this study don’t relate to omega-3 ingested from fish, Kowey said. “This was not a dietary study; this was a product manufactured from fish oil.”

Some 2.66 million Americans currently have one of three forms of atrial fibrillation — paroxysmal, persistent and permanent — that increase the risk of fatal coronary heart disease, heart failure and stroke.

Researchers randomly assigned 542 paroxysmal AF patients and 121 persistent AF patients to receive 4 grams of prescription omega-3 a day or a corresponding placebo. Treatment lasted 24 weeks. The trial’s primary endpoint was the time to the first recurrence of paroxysmal AF symptoms.

Researchers found:

•Paroxysmal AF patients who received omega-3 didn’t differ significantly from the placebo group in the time to first recurrence of symptoms.
•There was no significant difference between treated persistent AF and the placebo group.
•The same result emerged after researchers combined data from both types of treated AF patients.
•Prescription omega-3 proved safe and patients tolerated it well.
“The trial’s major implication is that using prescription omega-3 in the vast majority of paroxysmal atrial fibrillation patients who do not have significant heart disease is fruitless,” Kowey said. “In the absence of any data that it works, it is probably better not to take prescription omega-3, simply because you don’t have to and it costs money.”

The researchers’ findings applied only to paroxysmal AF. “We excluded AF patients with heart failure, so the possibility that the drug might work in those patients is not completely closed,” Kowey said. “However, we have never seen a drug that worked in a sicker group after it failed in a group less ill.”

He said he didn’t believe that taking other doses of omega-3 would benefit people. “As far as I know, everybody who gets omega-3 prescribed takes a lower dose than we used in this study. I think it’s unlikely that if you took more, you would do better.”

Co-authors are James A. Reiffel, M.D.; Kenneth A. Ellenbogen, M.D.; Craig M. Pratt, M.D.; and Gerald V. Naccarelli, M.D. Author disclosures are on the abstract.

GlaxoSmithKline funded the study.

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NR10-1172 (SS10/LBCT II-Kowey)

(Note: Actual presentation time: 11:29 a.m. CT, Monday, Nov. 15, 2010)

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Prescription omega-3 no better than placebo in treating atrial fibrillation