Heart biomarker high in African-Americans

A biomarker linked to heart problems in high-risk patients could increase the possibility of premature death in low-risk populations, and is especially high in African-Americans, a team of UT Southwestern Medical Center researchers has found.

The biomarker, called soluble ST2 or sST2, could become useful as part of a battery of blood tests to assess cardiac risk, said Anand Rohatgi, M.D., Assistant Professor of Internal Medicine at UT Southwestern.

“We want to put together the best-performing cardiovascular biomarkers into an all-star team. The next step is to combine sST2 into a multi-marker panel for cardiovascular risk prediction,” said Dr. Rohatgi, senior author of the study, which appeared in the journal Clinical Chemistry.

The study is also the first to show a race-specific association of sST2 levels in the general population.

ST2 is a cellular receptor for interleukin-33, which helps modulate inflammation and immune response. Heart cells and endothelial cells under stress release a soluble form of the molecule.

In people with acute or chronic heart failure, high blood levels of sST2 correlate with a higher risk of death and adverse outcomes such as recurrent heart failure or heart attacks.

For the study, the researchers followed 3,294 participants from the Dallas Heart Study, a multi-ethnic population-based sample of healthy adults from Dallas County. They found that 44 percent of African-American participants had detectable blood levels of sST2, compared with 21 percent of white or Hispanic participants.

Over a median follow-up time of 8.3 years, 164 of the study participants died, with 65 deaths from cardiovascular causes. The African-American participants with the highest levels of sST2 were at higher risk of death from all causes, compared with those with undetectable levels.

There were also 185 nonfatal cardiovascular events among the study participants, but sST2 levels did not correlate with this risk, suggesting that ST2 may confer an increased risk of death via non-cardiovascular causes.