April 4, 2009 (Orlando, Florida) — In patients who have suffered an acute MI and are receiving optimal medical care, omega-3 fatty acids--the kind found in oily fish--offer no additional benefits, a new study has shown. Dr Jochen Senges (University of Heidelberg, Germany) presented the findings of the OMEGA study at a late-breaking clinical-trials session at the American College of Cardiology 2009 Scientific Sessions earlier this week.
Senges said that the results apply only to the particular patient population studied and illustrate that if patients are receiving very good care after a heart attack, their "cardiac event rates become very low, and omega-3 does not further improve them."
Asked during a press conference whether people should still follow AHA recommendations to eat several portions of fish a week or take fish oil, Senges replied: "In other patients without acute MI and without optimized current guideline treatment, omega-3 might be helpful. It would be incorrect to say that omega-3 fatty acids are not effective."
Senges explained that previous studies on the benefits of omega-3 fatty acid have been inconclusive. One in particular, however--the Italian GISSI-Prevenzione trial--found a 50% reduction in sudden cardiac death in those who took omega-3 in the first months after an acute MI. "We thought, if this is positive, should omega-3 fatty acids be part of a polypill or even in the drinking water?" he commented.
In OMEGA, 3827 patients from 104 German centers were randomized to one year of treatment with omega-3-acid ethylesters 90 (460 mg eicosapentaenoic acid [EPA] and 380 mg docosahexaenoic acid [DHA]) 1 g daily or to placebo (1 g of olive oil) within three to 14 days of their heart attack. In addition, they received the best possible medical care.
There was no difference in the rate of the primary end point--sudden cardiac death--which occurred in 1.5% of patients in both groups. Nor were there any differences in any secondary end points, which included total mortality, reinfarction, stroke, arrhythmic events and revascularization.
OMEGA: Secondary End Points at One Year
|End point||Total||Omega-3, n=1919 (%)||Placebo, n=1885 (%)||p|
|MACCE (total death, re-MI, stroke)||9.6||10.4||8.8||0.10|
|Resuscitation or DC shock||0.6||0.6||0.6||0.98|
The study was underpowered to show an effect, because of the low rate of sudden cardiac death, Senges explained. But he said there was no trend toward benefit with omega-3--the survival curves "were extremely superimposable"--so it was unlikely that even an adequately powered study would have demonstrated any advantage.
Late Benefits Unlikely in AMI
During a panel discussion after the presentation, Dr Christopher P Cannon (Brigham and Women's Hospital, Boston, MA) wondered whether longer follow-up might reveal a late effect of omega-3 fatty acids. Senges said this was unlikely: "The later effect is something you see in heart-failure patients, not acute-MI ones. In the GISSI-Prevenzione study [in acute MI], benefit of omega-3 was seen after just two to three months."
Senges said there were "very clear differences" in treatment following AMI between OMEGA and Gissi-Prevenzione, which likely explain the results. "80% of our patients received acute revascularization, 90% got clopidogrel, and half had GP IIb/IIIa inhibitors," he noted, adding that those in GISSI-Prevenzione "had none of these." In addition, over 90% of those in OMEGA were prescribed aspirin, beta blockers, and statins, and more than 80% received ACE inhibitors.
In response to another question about whether there could have been a placebo effect, Senges said he could not exclude that possibility.
Senges has acted as a speaker for Pronova Biopharma (Norway) and Trommsdorff Arzneimittel (Germany).
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Cite this: ACC 2009: Optimal MI Care Eliminates OMEGA-3 Benefits - Medscape - Apr 04, 2009.