Cutting Arterial Plaque By Just 1% Drops Heart Attack Risk By 25%

20 Years of evidence on cholesterol-lowering therapy

The study builds on the reputation of lipid-lowering therapies as some of the most effective pharmacological treatments for heart disease.

“This study is the most up-to-date systematic review and meta-analysis that confirms an association between plaque regression and reduction in major adverse cardiovascular events,” said Dr. G.B. John Mancini, a professor of medicine at the University of British Columbia and lead author of the research.

Mancini’s research fills in the gaps of some commonly understood truths about heart disease and treatment. Namely, the use of lipid-lowering therapies is associated with reduced risk of heart attack and stroke. They also reduce the amount of plaque in arteries.

However, this research is the first time researchers have been able to directly demonstrate that reducing plaque is directly associated with a lower risk of adverse cardiovascular events.

“Inducing a reduction of plaque volume by aggressive and sustained lipid-lowering should be of value in improving health, but the direct relationship, as shown in the current analysis, has been difficult to show through any individual study,” said Mancini.

He explained that while studies on the subject exist, the trials are often too short or include too few people to make them conclusive on their own.

That’s the value of a meta-analysis: by taking a zoomed-out picture and using smaller data sets together, you are able to identify trends that may not be obvious or conclusive on their own.

“We now provide evidence for the beneficial association between plaque regression and reduction of major adverse cardiovascular events through sophisticated meta-regression analysis of all the available studies,” said Mancini.

Dr. David J. Maron, a cardiologist and professor of medicine at Stanford who was not affiliated with the research, told Healthline that the findings are “highly credible” and consistent with prior data.

“[The study] is taking new data and strengthening the conclusion that plaque regression is associated with a reduction in cardiovascular events,” he told Healthline.

The research also provides insight into the biological mechanisms of why reducing plaque improves heart health.

“We used to think that regression would reduce the risk of events by increasing the diameter of the coronary arteries. But, what we’ve come to learn is although, yes, you can shrink the plaque a little, the important thing is changing the composition of the plaque,” Maron said.

What is arterial plaque and atherosclerosis?

The technical name for the build-up of plaque in the arteries is known as atherosclerosis.

Atherosclerosis can reduce blood flow, leading to symptoms like chest pain called angina, and increases the risk of heart attack and stroke.

However, the most dangerous outcome of atherosclerosis is when the plaque ruptures, which is the most common cause of a heart attack.

Not all plaque is created equal, and the composition of atherosclerotic plaque is indicative of whether a rupture is likely to occur.

Plaques consist of a lipid pool overlaid with a fibrous cap of smooth muscle tissue.

If the cap is too thin, it can rupture, causing the lipid pool to mix with blood, causing a heart or stroke due to a blood clot or arterial occlusion.

Lipid-lowering therapies work not only by reducing the amount of plaque but also by affecting compositional changes to make plaque more stable.

“The plaques become not only smaller, but they become more structurally stable; the fibrous cap becomes thicker, the lipid core becomes smaller, and inflammation decreases. Thus, sustained lipid lowering reduces cardiovascular events and sustained lipid lowering induces regression and plaque remodeling,” said Mancini.

Statins are effective despite hesitancy

Lipid-lowering therapies, as their name would suggest, work by lowering the amount of cholesterol in the bloodstream. More specifically, the lower the amount of low-density lipoprotein (LDL) cholesterol in the bloodstream.

LDL cholesterol is often called “bad” cholesterol, whereas high-density lipoprotein (HDL) cholesterol is “good” because it takes cholesterol out of circulation and carries it back to the liver.

Statins are the most popular form of lipid-lowering therapy. Today, more than 40 million people in the United States take statins, making it the most prescribed class of drug in the United States.

More novel lipid-lowering therapies known as PCSK9 inhibitors have also been approved by the FDA. PCSK9 inhibitors also work by reducing LDL cholesterol in the body. However, they are typically only prescribed if statins and lifestyle changes, like diet and exercise, haven’t been effective in lowering cholesterol.

While some people may have hesitancy around the use of statins, research has found that they are mostly safe, and effective.

Mancini and Maron contend that this new research provides more proof of that.

“There’s such compelling evidence about the benefits of statins,” said Maron. “Here’s just one more line of evidence. We already know that statins reduce events in large clinical trials, but this gives us insight into the mechanism.”

The bottom line

A meta-analysis of over 20 research studies published over the past 20 years found that reducing plaque in the arteries was associated with lowering risk of heart attack and stroke.

Reducing arterial plaque even by as little as 1% had as much as a 25% reduction in odds of adverse cardiovascular events.

Lipid-lowering therapies, like statins, are effective in lowering cholesterol, reducing plaque, and improving risk of heart attack and stroke.