When it comes to predicting who’s at risk of suffering a heart attack or other major cardiac event, physicians have long relied on detecting high levels of C-reactive protein (CRP), an inflammatory biomarker. But new research suggests CRP may not be the only game in town.
Scientists at Intermountain Medical Center Heart Institute in Salt Lake City, working with LipoScience Laboratories, have determined that a new biomarker called GlycA can also be used as a predictor of major cardiac events. Like CRP, GlycA can be detected with blood tests. And patients who have high levels of both biomarkers face an even higher risk, according to a press release. The researchers presented their findings during the American College of Cardiologists scientific session in Washington, D.C., last week.
The new research emanated from a previous study, during which the Intermountain team identified GlycA by scanning blood samples with nuclear magnetic resonance imaging. They were looking for several clues, including particle numbers in LDL cholesterol—the so-called bad cholesterol that’s a known contributor to heart disease. That research showed that GlycA contributes to inflammation, which in turn raises the risk that cholesterol plaques in the heart will rupture.
Unlike CRP, however, GlycA doesn’t predict coronary artery disease. And the presence of one biomarker doesn’t predict levels of the second, according to the release. The scientists made their discoveries by following 3,000 patients undergoing coronary angiography.
"Some patients had a high level of one and a low level of the other and vice versa,” said lead author J. Brent Muhlestein, M.D., co-director of cardiology research at Intermountain Medical Center, in a release. “But the two proteins independently predicted future risk, and if you had both, it was the worst scenario completely.”
Heart disease is the leading cause of death for both men and women, accounting for one in four deaths, according to the Centers for Disease Control and Prevention. It is sometimes called a “silent killer” because it often doesn’t cause noticeable symptoms. That’s why many physicians routinely order CRP testing as part of their patients’ annual physicals.
Several research groups and companies have been searching for other diagnostic methods to supplement CRP testing. Machine learning company Zebra Medical Vision, for example, developed two algorithms that could enhance the ability to predict cardiovascular risk using CT scans. And in December, scientists at the Gladstone Institutes who have been studying congenital heart disease in one family pinpointed a mutation in the Gata4 gene that they believe could open up new treatment options for heart disease.
Intermountain’s Muhlestein says future research there will be designed to define GlycA’s underlying physiology, so his team can better understand the link between the biomarker and inflammation. Ultimately, researchers hope to be able to use GlycA to point to specific treatments, such as cholesterol-lowering statins, that may reduce the risk of adverse cardiovascular events in people who have elevated levels of the new biomarker.