WEDNESDAY, Jan. 5, 2005 (HealthDayNews) -- Blood levels of a molecule called C-reactive protein are just as important as cholesterol readings when measuring cardiovascular risk, say two studies that looked at the issue in different groups of patients.
The findings should lead to new thinking about how to measure the risk of heart attack and stroke, for doctors as well as patients, said Dr. Paul M. Ridker, director of the center for cardiovascular disease prevention at Brigham and Women's Hospital in Boston, and leader of one of the studies.
"The overwhelming message is that we can no longer simply measure cholesterol if we want to do the best job for our patients because the reductions in CRP levels that we get appear as important as reductions in cholesterol levels," Ridker said.
It is striking that both trials, reported in the Jan. 6 issue of the New England Journal of Medicine, got almost identical results, said Dr. Steven E. Nissen, a cardiologist at the Cleveland Clinic Foundation, who led the other study.
"We worked independently," Nissen said. "Two different research groups using two different data bases came to virtually the same conclusion from two different perspectives. If you take the two together, there is really a profound change in thinking about cardiovascular risk."
C-reactive protein (CRP) is a marker of inflammation, and it works in tandem with LDL cholesterol -- the bad kind -- to increase the risk of cardiovascular problems, Ridker said. LDL cholesterol forms the fatty plaques that accumulate in arteries to block blood flow, he said, and "inflammation is causing those plaques to rupture and cause heart attack and stroke."
Both studies dealt with people who had coronary conditions and were treated with statins, drugs marketed because they reduce LDL cholesterol levels but have also been found to reduce CRP levels.
The Boston study included 3,745 patients with acute coronary syndromes who were given statins. As expected, the incidence of heart attack and death from heart disease was related to LDL cholesterol levels. The rate of adverse events was roughly 50 percent lower in persons with LDL levels less than 70 milligrams per deciliter of blood.
"However, a virtually identical difference was observed between those who had CRP levels of less than 2 milligrams per liter after statin therapy and those who had higher levels," the researchers reported.
The Cleveland study included 502 patients with coronary disease who were given statins and whose arteries were assessed by ultrasound for 18 months. Again, lower cholesterol levels meant slower progression of arterial blockage, but "the decrease in CRP levels was independently and significantly correlated with the rate of progression," the study said.
"When I saw those data I changed my practice," Nissen said. "I now follow CRP levels of my patients carefully."
That should become standard practice, Ridker said. A simple test for CRP blood levels has been available for about two years, but it's not commonly used by many physicians, he said, and people who are immensely concerned about their cholesterol levels rarely think about CRP.
"Physicians and patients need to think about what I call dual targets, not only lowering cholesterol but also CRP," Ridker said.
The same lifestyle measures recommended for good coronary health -- proper diet, exercise and weight loss -- can reduce CRP levels, Ridker and Nissen said. The only drugs known to be effective against CRP are statins, "but these data will also stir tremendous pharmaceutical interest in developing agents that directly impact inflammation," Ridker added.
The American Heart Association has more on the role of inflammation and C-reactive protein in cardiovascular disease.