Omega-3 Fatty Acids Can Aid Cardiac Remodeling After Acute MI

Patients randomly assigned to take daily high-dose omega-3 fatty acids after acute myocardial infarction have significant reductions in adverse left ventricular remodeling and noninfarct myocardial fibrosis as assessed by cardiac MRI, according to the results of the OMEGA-REMODEL trial.

The study, published online today in Circulation, “highlights the benefits of high-dose omega-3 fatty acids taken during the initial 6 months in heart attack patients, based on evidence from our study that directly visualized heart structures and functions,” senior author Raymond Y. Kwong, MD, MPH (Brigham and Women’s Hospital, Boston, MA), wrote in an email to TCTMD.

“While not directly the focus of our current study,” he said, “we believe it is logical to infer that omega-3 fatty acids may be a beneficial treatment that reduces incidence of patients’ heart failure or even mortality after a heart attack.”

Along with Kwong, lead author Bobak Heydari, MD (Brigham and Women’s Hospital), and colleagues conducted a double-blind trial that enrolled revascularized acute MI patients at 3 tertiary centers, randomizing them to 6 months of 4 g per day omega-3 fatty acids (n = 180) or placebo (n = 178). All patients received standard medical therapy. Cardiac MRI was used to assess cardiac structure and tissue characteristics at baseline and at 6 months.

Improved Function, Reduced Scarring

With a 96% compliance based on pills counts, an intention-to-treat analysis showed that patients assigned to fatty acids had significant reductions in left ventricular systolic volume index (mean -5.8%; P = 0.017) and noninfarct myocardial fibrosis (mean -5.6%; P = 0.026) compared with patients given placebo.

In addition to imaging, the researchers also examined patients’ ability to absorb the omega-3 fatty acids. Patients assigned to fatty acids had increases in red blood cell levels of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and omega-3 index as well as and decreases in arachidonic acid compared with patients assigned placebo (P < 0.0001 for all).

Results of a per-protocol analysis suggested a dose-response relationship, with patients in the highest omega-3 index quartile experiencing a 13% reduction in left ventricular systolic volume index versus those in the lowest quartile.

Finally, patients assigned to fatty acids also had a significant reduction in several serum biomarkers of systemic and vascular inflammation and myocardial fibrosis, including myeloperoxidase, lipoprotein-associated phospholipase A2, and ST2.

Promising Treatment Option

Current US recommendations do not call for cardiologists to recommend or prescribe the use of omega-3 fatty acids from fish oil after acute MI, Kwong told TCTMD in a telephone interview.

Two large clinical trials examining omega-3 fatty acids in the last decade and a half produced conflicting results about the effects of omega-3 fatty acids on mortality in patients after MI. According to Kwang, there are many possible reasons why these trials offered inconsistent evidence, including the fact that standard therapies have changed over time, the use of a lower dose of fish oil, or the possibility that mortality may not be the best way to assess new treatments for these patients.

In fact, even if patients decided to take over-the-counter fish oil on their own, it will not be the same formulation used in this analysis. This study used Lovaza, an FDA-regulated, purified form of omega-3 fatty acids that is only available with a prescription and frequently not covered by insurance, Kwong said.

However, based on the results of this study, the researchers believe that advantages of taking omega-3 fatty acids could be clinically significant for patients after acute MI.

“Therapies that can improve healing of the heart or prevent adverse remodeling by suppressing inflammation, remain very limited,” Kwong wrote to TCTMD. “There had been other drugs in the past that attempted to suppress inflammation after a heart attacked and turned out to be harmful. So omega-3 fatty acids, if it continues to work as promising as our study shows, may offer a hopeful treatment option.”

While the number of patients in this study may seem small, Kwong acknowledged, the “majority of them received and could tolerate all the standard treatments we usually give heart attack patients.” Across the spectrum of MI patients, he said, “they were not considered very sick, most with only a mildly weakened heart after the heart attack.”

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