CRP blood test not always necessary when diagnosing risk of heart disease
BY DR. KOMOROFF Universal Uclick
Monday, December 17, 2012
12/17/12 at 3:29 AM
Dear Doctor K: The last time I had blood work, my doctor didn't check my CRP level. Wouldn't my CRP level have given him a better idea of my risk of heart disease?
Dear Reader: You ask a good question. Let me say up front that this test has been developed and studied by a colleague at Harvard Medical School, and revenue from the test comes to the hospital where I practice.
Also, I'm talking only about the use of the CRP test in people who are not known to have heart disease.
The C-reactive protein (CRP) blood test measures inflammation in the body. We now know that many heart attacks and strokes occur because cholesterol-rich plaques of atherosclerosis rupture. When that happens, blood clots form that can cut off the blood supply to part of the heart or brain. Plaques rupture because of inflammation inside them.
Studies have shown that the CRP test does help estimate a person's risk for heart disease. The question is whether the test should be used in everyone.
A recent article in the New England Journal of Medicine looked at 52 studies that included 240,000 people. The researchers added the CRP results to risk factors, such as diabetes or high cholesterol. Using all of this information, they classified people by their risk of cardiovascular disease and whether they needed preventive treatment.
It turned out that the CRP tests would have prevented only one heart attack or stroke for every 400 to 500 people screened. In other words, the CRP test added little information about cardiovascular disease risk, beyond what the standard risk factors already showed, in the average person.
Several authoritative groups recommend that the test be performed in people who are at intermediate risk for heart disease based on other factors: high blood pressure (hypertension), smoking, high levels of LDL cholesterol, diabetes, or relatives who have developed heart disease at a young age.
Write Dr. K at www.AskDoctorK.com or c/o Universal Uclick, 1130 Walnut, Kansas City, MO 64106