Newer Blood Tests May Not Improve Heart Risk Assessment

ByABC News
June 30, 2009, 6:02 PM

July 1 -- TUESDAY, June 30 (HealthDay News) -- Newer biomarkers of cardiac risk, such as inflammation-linked C-reactive protein (CRP), add little or no predictive power to older, established factors such as smoking, obesity, high cholesterol and physical activity, two major studies find.

The newer blood-borne markers have been touted as a better way of assessing heart risk, but recent studies have suggested otherwise.

In fact, the lead author of one of the new studies said his team reported essentially the same finding in an analysis of data from the Framingham Heart Study nearly three years ago.

"A lot of people said [those findings] made sense, but others said the study had limitations -- small numbers, not enough follow-up," said Dr. Thomas Wang, associate director of the Heart Failure Service at Massachusetts General Hospital in Boston.

So, he collaborated with Swedish researchers in a study with larger numbers -- more than 5,000 participants -- who were followed for a longer time, an average of 12.8 years. They looked at more offbeat biomarkers and used newer statistical methods for evaluating risk.

"The long and short of it was that we had the same conclusion -- that these biomarkers add a little bit but not a lot," Wang said. "There is not enough evidence to recommend that any of these biomarkers be routinely measured."

The six biomarkers surveyed in the study were CRP, an indicator of inflammation; cystatin C; lipoprotein-associated phospholipase 2; midregional proadrenomedullin; midregional proatrial natriuretic peptide; and N-terminal pro-B type natriuretic peptide.

Five of the biomarkers did help predict future heart problems, and three predicted problems in models that adjusted for conventional risk factors, but the improvement over usual risk factor assessments was "minimal" and "did not reclassify a substantial proportion of individuals to higher or lower risk categories," said the report, published July 1 in the Journal of the American Medical Association.