Now the question is: What does that mean for people in general?
The Centers for Disease Control and Prevention is tackling that very topic, having convened a meeting of experts several weeks ago to discuss whether elevated CRP levels should be listed as a risk factor for cardiovascular disease. The agency is expected to issue a statement on CRP in the next few weeks.
"The sense of the meeting was that it was an important issue to be looked at, but a lot of work needs to be done," says Dr. Valentin Fuster, director of the cardiovascular institute at Mount Sinai School of Medicine in New York City and one of the half-dozen experts at the meeting.
"One of the great concerns was to what extent the test is specific enough," Fuster says. "How many people have high CRP levels, but never develop heart disease? We have to be careful about jumping into clinical applications of this."
The new study, appearing in the April 30 issue Circulation, measured levels of CRP in the post-mortem blood samples of 302 people who died sudden deaths.
"Those levels were elevated in people who died suddenly from cardiovascular disease, as opposed to other things," says Dr. Allen P. Burke, associate chairman of the department of cardiovascular pathology at the U. S. Armed Forces Institute of Pathology and a member of the research team.
Analysis of the data indicates that measurements of CRP levels could be "an addition to our armory of risk factor analysis," Burke says. "In the past, it has been demonstrated an elevated CRP is a risk for heart attacks. Now it is demonstrated to be a risk for sudden death."
The body produces CRP as a response to inflammatory conditions such as acute infection or burns. The molecule is released when blood vessels leading to the heart are constricted.
The new study "supports the concept that inflammation plays an important role in coronary artery disease," Fuster says. However, it leaves open the question of whether elevated CRP levels themselves increase the risk of heart disease.
The experts who sat around the table at the CDC meeting generally said "CRP is an interesting molecule with significant implications, but there is a way to go before we look at it as a risk factor," Fuster says.
There are indications that elevated CRP levels are not uncommon, he says, and so it might cause unnecessary alarm to say that everyone with high blood CRP levels is at risk of sudden death. A classic way to answer the question would be a study that followed a large number of people for years to see whether those with high CRP levels are more likely to have a heart attack, stroke or other cardiovascular event.
What To Do
"The subject is still under discussion, but we have to be careful about making people scared about this," Fuster says.