Bits of molecular "trash" in blood may be good indicators of heart disease

Washington, Feb 20 (ANI): Scientists at the Duke University Medical Center believe tiny molecules in blood may tell a big story about cardiovascular disease risk.

The study analyzed metabolites, the molecular debris left over after the body breaks food down into energy sources and building blocks of cells and tissues.

This the first research to discover specific metabolic profiles associated with coronary artery disease, heart attacks and death among patients who have undergone coronary catheterization.

Svati Shah, a cardiologist in the Duke Heart Center, the Duke Center for Human Genetics and the lead author of the study and William Kraus, professor of medicine at Duke and the senior author of the study, wanted to find if they could isolate and identify particular metabolites associated with coronary artery disease.

They began their study with information in Duke's CATHGEN biorepository, which holds health records and blood samples from nearly 10,000 patients who had come to Duke over the past eight years for catheterization. Collaboration with Christopher B. Newgard, director of Duke's Sarah W. Stedman Center for Nutrition and Metabolism, allowed Shah, Kraus and others to accurately quantify and characterize the metabolites.

Researchers selected 174 patients who had experienced early-onset coronary artery disease (CAD) and compared them to 174 controls who had undergone catheterization but who were not found to have CAD. They used a panel of 69 metabolites previously identified as potentially involved in the development of CAD to examine the metabolic profiles in both groups.

Shah said: "We found two sets, or clusters of metabolites that seemed to differentiate between the two groups."

Thereafter, they tested the two sets of metabolites to see if they could make a difference between patients of any age who had CAD and those who did not. Again, the two sets of metabolites were able to discriminate between the two groups.

The researchers also created an "event group" comprising 314 patients from all groups, who suffered a heart attack or death during a follow-up period of almost three years, so as to assess the ability of the metabolites to predict risk of heart attack or death. They compared metabolic profiles between those who suffered a heart attack or death with those who did not. Using multiple analytic and statistical methods, they found two factors that were clearly associated with coronary artery disease and one factor that predicted greater risk of heart attack or death among patients with coronary artery disease.

Shah said: "When we added these biomarkers to traditional clinical risk models, we found that they increased the accuracy of projected risk."Although previous studies have suggested that certain metabolites are associated with the presence and severity of CAD, researchers have not been able to identify most of the individual molecules within those profiles, "which in the end meant that these studies were not that clinically useful," said Shah.

Kraus said: "Here, we specifically selected clusters of metabolites that we know are involved in multiple pathways of lipid, protein and glucose metabolism - pathways that are often disrupted in CAD -- and we showed that they are indeed associated with CAD and subsequent risk of cardiac events.

"These metabolic profiles may be a way from routine clinical use, but we feel they are a good first step in that direction."

The study has appeared online in the April issue of the journal Circulation Genetics. (ANI)