MONDAY, Sept. 20, 2004 (HealthDayNews) -- High blood levels of an inflammatory marker called C-reactive protein seem to be a strong indicator of heart disease, and they might someday prove as useful as cholesterol or blood pressure testing in assessing patient risk, British researchers report.
They also found that inflammatory cell activity plays a key role in the dangerous narrowing of coronary arteries seen in many heart patients.
That's important, because "many of the traditional risk factors such as smoking, hypertension, obesity, hypercholesterolemia exert their deleterious effects via inflammatory mechanisms," explained study author Dr. Juan Carlos Kaski, of St. George's Hospital Medical School in London. He believes treatments that target inflammatory mechanisms will prove "extremely beneficial" in preserving artery health.
The study appears in the Sept. 21 issue of Circulation.
C-reactive protein (CRP) is produced by the liver in response to inflammation. "It's not specific of heart problems," Kaski said, "but rather a general indicator of ongoing inflammation anywhere in the body."
Atherosclerosis, a gradual narrowing of arteries, has a strong inflammatory component, and in recent years researchers have begun to understand that constant, elevated blood levels of CRP pointed to increased cardiovascular risk.
In this most recent study, Kaski's team used angiograms -- X-rays that gauge blockage of coronary arteries -- to track changes in arterial health in 124 heart patients with angina over a 12-month period. More than a quarter of these patients went on to develop an increased narrowing or blockage of at least one coronary artery.
The researchers found blood levels of four inflammatory markers, including CRP, were good predictors of increased arterial risk. For example, patients in the mid-range of CRP measurements were at nearly three times the risk of progressing to blockage than those in the low range.
The study "adds to the totality of evidence" that specific blood levels of CRP occurring over a period of time are a good indicator of arterial damage and heart disease risk, said Dr. Roger Blumenthal, director of Johns Hopkins Ciccarone Preventive Cardiology Center, and a spokesman for the American Heart Association.
While some doctors are beginning to test patients regularly for CRP, others are waiting for more evidence of a confirmed association. At this point in time, however, Blumenthal believes CRP to be "a very reasonable test to consider in a person with another risk factor or two for heart disease when doctors are trying to consider how aggressive to be in terms of cholesterol and blood pressure management, or whether or not they should go on aspirin."
Kaski cautioned that "more work needs to be done before this marker can be used routinely, in the same way we are currently using cholesterol measurements." But he said it's "conceivable that in the not so distant future CRP measurements will be incorporated into our diagnostic/prognostic armamentarium."
In the meantime, research continues into treatments that target and reduce inflammation as a means of fighting arterial disease. According to Kaski, many drugs already on hand do just that, including popular statin medications and ACE inhibitors. "Inflammation is a clear target in the fight against inflammatory disease," he said.
To learn more about C-reactive protein, visit the American Heart Association.