People on icosapent ethyl experienced a slowdown in plague growth at nine months, including 42 percent less progression in total plaque. Photo by Steve Buissinne/Pixabay

Prescription-strength fish oil slows the development of artery-clogging plaques, according to early results from an ongoing clinical trial.

Icosapent ethyl -- a purified fish oil drug sold under the brand name Vascepa -- put the brakes on key aspects of plaque formation after nine months of use, said lead researcher Dr. Matthew Budoff, a professor at UCLA's David Geffen School of Medicine.


"We found significant slowing of progression among four different plaque markers, including total plaque," Budoff noted in a presentation on Monday at the American Heart Association's annual meeting, in Philadelphia.

These early results provide some tantalizing hints why icosapent ethyl was found to reduce risk of heart-related disease and death by 25 percent in another study released last year, said Dr. Donald Lloyd-Jones, chair of preventive medicine at Northwestern University Feinberg School of Medicine.

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The new clinical trial, called EVAPORATE, is ongoing and will report final results after 18 months.

Experts hope more data from the trial will show which aspect of the drug's effect on plaque is reducing heart risk.

"We really don't know necessarily yet which of those components of plaque is associated with the most important stabilization and reduction that will translate into reduced clinical events," Lloyd-Jones said.

Vascepa is approved for patients with extremely high levels of triglycerides, a type of fat in the blood associated with heart disease.

The drug's manufacturer, Amarin, is seeking approval from the U.S. Food and Drug Administration for the use of Vascepa in patients who have lower blood fat levels but still have a risk of heart problems, despite taking cholesterol-lowering statins. A month's supply of Vascepa costs roughly $300.

An FDA advisory panel unanimously voted in favor of expanded use of Vascepa last week, basing their decision on research showing that the drug can reduce rates of dangerous heart problems in high-risk patients.

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The EVAPORATE trial placed 40 people on high doses of icosapent ethyl and another 40 on a placebo. All participants were already taking statins and had developed at least one artery-clogging plaque. Amarin paid for the trial.

Participants underwent CT scans at the beginning of the study and at nine months to track progression of arterial plaque in their bodies. They'll undergo a final CT scan at 18 months.

Compared to the control group, people on icosapent ethyl experienced a slowdown in plague growth at nine months, including:

42 percent less progression in total plaque,

89 percent less new calcified plaque,

57 percent less new fibrous plaque,

19 percent less new non-calcified plaque.

Notably, the fish oil drug did not appear to actually melt away plaques, but only slowed down their growth, said Dr. Stephen Nicholls, a professor of cardiology at Monash University in Queensland, Australia.

"There was no evaporation. They all continued to progress," said Nicholls.

There are several possible explanations why icosapent ethyl slows buildup of plaque in the arteries, Nicholls said.

The drug has been shown to reduce triglyceride levels, which contribute to plaque formation. In this study, triglycerides declined, Budoff said.

But the antioxidant and anti-inflammatory effects of the fish oil drug should also be considered as potential contributors, Nicholls said.

Newer trials have tended to support the value of fish oil drugs in controlling arterial plaques, after years of mixed results, Lloyd-Jones and Nicholls said. Both experts were not involved with the new trial.

That's probably because earlier trials did not have people on high enough doses of purified fish oil supplements, Nicholls said.

Other high-dose fish oil clinical trials are ongoing, and will provide further evidence in the near future, Lloyd-Jones said.

More information

The Cleveland Clinic has more about fish oil and heart health.

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