Every year, some 720,000 Americans suffer a heart attack.
After a heart attack, the heart can “remodel” or reorganize itself to maintain or improve function.
In some cases, the heart suffers scarring, enlargement, weakened pumping power, and cardiac strain that can promote heart failure and arrhythmias.
Medical bodies worldwide agree that fish and omega-3 fish oil help prevent heart disease, sudden cardiac death, repeat heart attacks, and stroke.
And new clinical findings suggest that taking high-dose omega-3s after a heart attack can blunt its damaging effects and promote better recovery.
We hope that cardiologists will get appropriately excited about – and act on – the results of this landmark clinical trial.
Trial finds omega-3s helpful after a heart attack
The U.S.-Canadian trial found that taking omega-3s after a heart attack cut inflammation and deterred heart scarring, enlargement, and functional declines.
Remarkably, omega-3 supplements produced these benefits among recent heart attack survivors who were already receiving optimal medical care.
This novel, NIH-funded trial is the first to use cardiac MRI scans to gauge the effects of taking high-dose omega-3 fish oil after a major heart attack.
The results will be formally presented at the American College of Cardiology's 64th Annual Scientific Session, held from March 14 to 16.
Details of the post-heart-attack omega-3 trial
The randomized, placebo-controlled clinical trial involved 358 heart-attack patients: 69 women and 289 men.
The participants were randomly assigned to one of two daily regimens for six months after their heart attack:
- Placebo capsules (178 patients)
- Omega-3 fish oil capsules (180 patients)
Compared to previous research, this study used a much higher dose of omega-3 fatty acids: 4 grams versus only 1 gram daily. (The placebo capsules contained corn oil, which has no omega-3s.)
The omega-3 group received a (very costly) prescription-only omega-3 fish oil supplement called Lovaza, provided by the pharmaceutical giant GlaxoSmithKline.
Each 1000mg capsule of Lovaza brand fish oil provides 465mg of EPA and 375mg of DHA (840 mg total EPA+DHA).
By comparison, each 850mg capsule of Vital Choice brand High Potency Omega-3 Therapy
fish oil provides 670mg of EPA and 340mg of DHA (1,010mg total EPA+DHA).
Both groups were balanced in terms of their ages and the location of the necrotic (dead) heart tissue caused by impaired blood supply.
The patients' blood samples and cardiac MRI scans were analyzed at points two to four weeks after the heart attack and again at six months.
By using cardiac MRI scans, the researchers were able to see changes in patients' hearts and see the disease process before and after treatment.
They used two measures as surrogate markers for poor outcomes after heart attack:
- Adverse changes in left ventricular remodeling and function.
- Worsening of fibrosis, which can develop when the surviving heart muscle works harder and under high pressure to compensate for damage to the heart.
Omega-3s reduced heart-attack damage and improved recovery
Six months after their heart attacks, patients in the omega-3 fish oil group were significantly more likely to show improvements in heart function.
Patients in the omega-3 group were 39 percent less likely to suffer reduced heart function, while markers of heart-tissue damage and systemic inflammation were also reduced.
In particular, the severity of “adverse cardiac remodeling” was substantially reduced in the omega-3 group.
And patients in the omega-3 group showed significantly less fibrosis—a thickening or scarring of the areas of the heart remote from the heart attack.
“Giving a high dose of omega-3 fatty acids soon after a heart attack appears to improve cardiac structure and heart functioning above and beyond the standard of care,” said senior author Raymond W. Kwong, M.D., M.P.H. (ACC 2015)
“Omega-3 fatty acids may have anti-inflammatory effects and also promote better cardiac healing,” he said.
“This is important because other anti-inflammatory agents, including steroids and NSAIDS, have failed to make a difference after myocardial infarction.”
Dr. Kwong believes their findings prove that omega-3s add benefits to standard medical treatments:
“Because this is a unique group of patients with remarkably high adherence to [current medical] treatments for acute myocardial infarction [heart attack] already, we feel fairly confident that the benefits from this [omega-3] therapy are additive. The implications of this study could be fairly large.” (ACC 2015)
Higher omega-3 levels linked to better outcomes
The patients who showed the biggest increases in their omega-3 blood levels derived the most benefit.
The 92 percent of patients in the fish oil group whose omega-3 blood levels rose by at least five percent enjoyed the best outcomes.
As Dr. Kwong noted, “… a 5 percent increase in the serum [blood] level of omega-3 fatty acids correlates with a 10 percent improvement in left ventricular remodeling.” (ACC 2015)
Eat like the Japanese
The American College of Cardiology and the American Heart Association have long recommended that people eat fatty fish rich in omega-3s at least twice a week … but few Americans follow this advice.
In contrast, as Dr. Kwong noted, the Japanese have higher average blood levels of omega-3 and lower risks of heart disease and sudden cardiac death … despite having an average heart-risk profile that's otherwise similar to North Americans'.
Interestingly, the five percent rise in the omega-3 blood level of most patients in the fish oil group brought their blood levels close to the average levels found in Japanese people.
Fatty fish such as salmon, tuna, and sardines contain the most omega-3s.
However, as Dr. Kwong said, few patients will eat enough seafood daily for six months to get 4 grams—the amount in about 8 ounces of salmon—per day.
So this is one—among many—cases where omega-3 supplements make good sense.
- American College of Cardiology (ACC). Omega-3 Fatty Acids Appear to Protect Damaged Heart After Heart Attack. March 4, 2015. Accessed at https://www.acc.org/about-acc/press-releases/2015/03/04/16/36/omega-3-fatty-acids-appear-to-protect-damaged-heart-after-heart-attack?w_nav=S
- Belevych AE, Ho HT, Terentyeva R, Bonilla IM, Terentyev D, Carnes CA, Gyorke S, Billman GE. Dietary omega-3 fatty acids promote arrhythmogenic remodeling of cellular Ca2+ handling in a postinfarction model of sudden cardiac death. PLoS One. 2013 Oct 18;8(10):e78414. doi: 10.1371/journal.pone.0078414. eCollection 2013.
- Billman GE. The effects of omega-3 polyunsaturated fatty acids on cardiac rhythm: a critical reassessment. Pharmacol Ther. 2013 Oct;140(1):53-80. doi: 10.1016/j.pharmthera.2013.05.011. Epub 2013 Jun 2. Review.
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- Heydari B et al. Effect of Purified Omega-3 Fatty Acids on Reducing Left Ventricular Remodeling after Acute Myocardial Infarction (OMEGA-REMODEL Study: A Double-Blind Randomized Clinical Trial). Journal of Cardiovascular Magnetic Resonance 2015, 17(Suppl 1):O7. doi:10.1186/1532-429X-17-S1-O7, Published February 3, 2015. Accessed at http://www.jcmr-online.com/content/17/S1/O7
- Nagai T, Anzai T, Mano Y, Kaneko H, Anzai A, Sugano Y, Maekawa Y, Takahashi T, Yoshikawa T, Fukuda K. Eicosapentaenoic acid suppresses adverse effects of C-reactive protein overexpression on pressure overload-induced cardiac remodeling. Heart Vessels. 2013 May;28(3):404-11. doi: 10.1007/s00380-012-0270-5. Epub 2012 Aug 9.
- Radosinska J, Bacova B, Knezl V, Benova T, Zurmanova J, Soukup T, Arnostova P, Slezak J, Gonçalvesova E, Tribulova N. Dietary omega-3 fatty acids attenuate myocardial arrhythmogenic factors and propensity of the heart to lethal arrhythmias in a rodent model of human essential hypertension. J Hypertens. 2013 Sep;31(9):1876-85. doi: 10.1097/HJH.0b013e328362215d.
- Shah KB, Duda MK, O'Shea KM, Sparagna GC, Chess DJ, Khairallah RJ, Robillard-Frayne I, Xu W, Murphy RC, Des Rosiers C, Stanley WC. The cardioprotective effects of fish oil during pressure overload are blocked by high fat intake: role of cardiac phospholipid remodeling. Hypertension. 2009 Sep;54(3):605-11. doi: 10.1161/HYPERTENSIONAHA.109.135806. Epub 2009 Jul 13.