Arterial plaque is a problem for cardiovascular health. Plaque is the result of fatty lipid substances, cholesterol, cellular waste, calcium, and fibrin building up on artery walls.
It’s a gradual process that can start in childhood and have few symptoms, but as it progresses, artery walls become thicker and stiffer, and the openings available for blood flow become narrower. When a major artery becomes blocked by plaque, it can result in a stroke or heart attack.
Researchers at the University of British Columbia, led by professor of medicine G. B. John Mancini, carried out a meta-analysis of 23 published studies. By combining these studies, they were able to analyze the outcomes of over 7,400 patients being treated with lipid-lowering drugs like statins.
The study examined how reduced plaque volumes might affect risk of major cardiovascular events like heart attack and stroke, and the results were published in JAMA Cardiology.
They found that a reduction as small as 1 percent in the volume of artery blockage by plaques decreased the risk of a major cardiovascular event by 25 percent.
At first glance it may seem surprising that such a small reduction in volume could come with such a large benefit, but plaques are complex deposits made up of many components. Looking at a slice through one would reveal a fatty lipid pool sealed underneath a fibrous cap.
If that cap ruptures, something particularly dangerous happens: the lipid pool is rapidly released and mixes with blood, and that fatty mixture can quickly block a major artery.
The authors found that lipid-lowering drugs not only reduce plaque volume, but they also change plaque composition and reduce inflammation; the fibrous cap gets thicker and more stable, thereby reducing the likelihood of a blockage that might cause a heart attack or stroke.
Even small reductions in plaque volume have a stabilizing effect that reduces risk of severe outcomes. By combining data from many studies, this review adds to the evidence that lipid-lowering therapies can be powerful tools for helping people manage their health.