Many cardiologists are on the fence about whether to test patients routinely for C-reactive protein (CRP), a marker for arterial inflammation. Proponents say CRP blood levels are at least as good at predicting heart attack risk as cholesterol levels. Dissenters . . . well, dissent. Research in last week's Journal of the American Medical Association may soften the position of some naysayers.
The study of 15,632 initially healthy women confirmed previous findings that people with high C-reactive protein had triple the heart attack risk of those with the lowest CRP levels. After adjusting for risk factors such as age, high blood pressure, smoking and diabetes, researchers found CRP is a strong predictor of risk not only for those with high cholesterol but also for those with lower cholesterol. People with good cholesterol numbers and high CRP had twice the risk of heart attack as similar people with normal CRP levels.
Lead author Paul Ridker, a cardiologist at Brigham and Women's Hospital in Boston, said half of all heart attacks happen to people with normal or low cholesterol. "If you have low cholesterol but a high CRP," he said, the study shows you are "at much higher risk than anticipated."
Who Needs It? Sharonne Hayes, director of the Mayo Clinic's Women's Heart Clinic in Rochester, Minn., said "data is mounting" for using the test for patients at intermediate risk -- those with borderline-high cholesterol and a family history of heart disease. But she's not ready to test routinely.
"The average person doesn't need to worry about it," said Eric Topol, chairman of cardiovascular medicine at the Cleveland Clinic. But someone who has two or more risk factors for heart disease -- obesity, family history, high cholesterol, high blood pressure or smoking -- "probably should have their CRP tested." The $15 test can be done with the same blood drawn for cholesterol testing. Exercise and weight loss also help to lower CRP.
What Else? The study also found that tests measuring non-HDL cholesterol was a better predictor of risk than tests for just HDL and LDL cholesterol. "My hope as a clinician," said Ridker, "is that we can use this information together to better target our therapies."
-- Elizabeth Agnvall