A new blood test may help determine heart disease risk even in those patients who have healthy cholesterol levels, according to researchers. The new "high sensitivity CRP" test detects a protein called C-reactive (CRP), which is produced in the liver and indicates when arteries are inflamed. From a C-reactive protein study of more than 20,000 healthy post-menopausal women, researchers say the CRP test can help predict a first heart attack.
According to researcher Dr. Paul Ridker, associate professor of medicine at Harvard School of Medicine, women with elevated CRP levels are four times as likely to have heart attacks compared with women who have low CRP levels. Dr. Ridker and researchers studied 12 separate markers for heart attacks, including high cholesterol levels, cigarette smoking, diabetes, and obesity. CRP was the single strongest predictor of a heart attack, said Dr. Ridker.
If physicians were to begin widespread use of the CRP test, it would serve as a supplement to cholesterol tests and other preventive measures (such as low-fat diet, exercise, no smoking). The CRP test was approved by the U.S. Food and Drug Administration (FDA) in November 1999. Emerging research on CRP has caused researchers to re-think their theories about how heart attacks occur. Researchers now believe that while high cholesterol causes hardened fatty build-up, heart attacks occur when inflamed arteries cause chunks of fatty deposits to break off and clog an artery.
Physicians and heart specialists are optimistic about the effectiveness of the CRP test. Former American Heart Association president Dr. Sidney Smith says other research shows CRP levels help prevent a second heart attack (since patients who know they have high CRP levels are more likely to take preventive measures to reduce their chances of a heart attack). Jonathan Abrams, MD, an expert in heart disease prevention called the study a "blockbuster." William O’Neill, MD, director of cardiology at William Beaumont Hospital in Detroit, Michigan believes the CRP test will help physicians identify 30% to 50% of first heart attack victims who do not otherwise seem to be at significant risk for heart disease. The average cost of a CRP test is around $20.
If patients are found to have high CRP levels, physicians recommend exercising, lowering blood pressure, losing weight, maintaining a healthy diet, and not smoking. Cholesterol-lowering drugs called statins may also help fight artery inflammation, but researchers are still uncertain whether lowering cholesterol will lower CRP.
A few physicians would like to see further research before the CRP test gets too much publicity. Dr. Daniel G. Blanchard, a cardiologist at the University of California at San Diego Medical Center says he would like to see additional studies which confirm the effectiveness of the CRP test. Dr. Ridker’s study included only women, but researchers believe the CRP test would also be effective in men. Women, who have traditionally been excluded from cardiac research, are more likely to die of heart disease than breast cancer and all other cancers combined.
- The March 22, 2000 Associated Press report by Linda A. Johnson, "New Heart Disease Test," is available at http://www.abcnews.go.com/sections/living/DailyNews/crp000322.html
- To learn more about heart disease, please visit http://www.imaginis.com/heart-disease/
