German study links protein marker, heart disease risk

CHICAGO -- Doctors might be able to gauge their patients' risk of death or heart attack by measuring levels of a growth-factor protein in their blood, a German study suggests.

The report adds the protein to a growing list of biomarkers for inflammation that could help predict a person's risk of heart disease and that can be detected through a simple blood test.

The newly recognized marker, called "placental growth factor protein," or PlGF, has been shown to contribute to inflammation in the arteries. Animal research has shown that blocking its effects suppresses the growth of fatty plaques in the arteries.

The latest findings, which appear today in the Journal of the American Medical Association, suggest that testing for PlGF might be more effective at predicting patient risk than measuring some other inflammation markers, including C-reactive protein, or CRP.

That is because PlGF appears to be released primarily from cells inside blood vessel walls, whereas CRP levels might rise in response to inflammation or infection elsewhere in the body.

Still, the lead researcher, Dr. Christopher Heeschen of Johann Wolfgang Goethe University in Frankfurt, said more studies confirming the results are needed before doctors can rely on PlGF as an early warning sign.

The discovery of the protein's link to heart disease could also lead to treatments that would protect against heart damage by blocking the protein's effects, Heeschen said.

The study involved 1,173 patients, mostly men, who had suffered either severe chest pain or mild heart attacks.

Blood tests showed high PlGF levels in more than 300 patients. Those patients were about three times more likely than those with low levels to die or have heart attacks within 30 days of when their symptoms began.

The study "is an important step forward," but also raises questions, including whether the protein would be useful in assessing risk in the general population, said Dr. Robert Bonow, a Northwestern University cardiologist and former president of the American Heart Association.

The German research will probably help lead to a new minimally invasive way of testing patients with chest pain, said Dr. Eric Topol, the Cleveland Clinic's cardiology chief.

"No one would ever have thought that through a few proteins you could know what's going on in the artery walls," Topol said.

He predicted that in the next few years patients with chest pain will routinely be given blood tests for inflammatory proteins.