University of Kentucky researchers have developed a new way to detect the plaques in blood vessels that are most likely to rupture and cause heart attacks and strokes.
The research findings were published in the Oct. 27 issue of the American Heart Association journal Circulation, and are being discussed this week at the American Heart Association meeting in Dallas, Texas.
Using technology called near-infrared spectroscopy, the team of UK researchers has identified vulnerable atherosclerotic plaques in samples of human aortic tissue. Plaque is the material composed of cholesterol and other fatty substances that contribute to atherosclerosis, the process in which the heart's arteries become choked, narrowing the vessel and reducing blood flow.
Most people have plaques in their blood vessels. Scientists such as the UK team are trying to find a way to determine which plaques are harmful and which are benign. Plaques - mostly composed of fatty pools of cholesterol - develop on the walls of blood vessels and can impede blood flow. A fibrous cap typically covers plaques, but the thinner the cap, the more susceptible the plaque is to rupturing, causing a heart attack or stroke.
Members of the UK research team are Pedro R. Moreno, M.D., assistant professor of medicine; James E. Muller, M.D., director of the Linda and Jack Gill Heart Institute at UK and professor of medicine; Robert A. Lodder, Ph.D., associate professor of pharmacy; William O'Connor, M.D., professor of pathology and laboratory medicine; Valeri Vyalkov, M.D., coordinator of research and clinical trial, cardiovascular medicine; and Kraman Purushothaman, M.D., research associate, pathology and laboratory medicine.
"We are modifying near-infrared spectroscopy, which uses laser light, to identify the thickness of the fibrous caps, the size of the lipid pool and the macrophage infiltration," Moreno said.
Macrophages are "scavenging" white blood cells that help rid the body of bacteria and other hazardous substances. In attempting to collect and eliminate fat and cholesterol from the bloodstream, they may become so laden with these materials they become immobilized, die and add to the plaque in the artery wall - in much the same way small sea creatures die and layer the ocean floor. In addition, these "stuffed cells" release toxic substances that rupture the fibrous cap, which is responsible for the clogged arteries that underlie heart attacks and stroke.
"With further refinement, this new spectroscopy technology could be incorporated into a catheter and produce a better picture of what's going on inside the coronary arteries of living patients, allowing us to treat these plaques and diminish the devastating effects of heart disease," Moreno said.
This advancement is based on the work of Lodder and colleagues who are based in the Advanced Science and Technology Commercialization Center (ASTeCC), UK's high technology business incubator located in the center of campus. One of the goals of the center is to facilitate such interdisciplinary research advances.
Near-infrared spectroscopy identifies the composition of different substances according to their light absorption and has been in commercial use to grade the amount of fat in food.