Blood Test Could Save More From Heart Attacks
June 27, 2001 -- Popular drugs that can hammer down cholesterol levels may very well be a panacea for preventing heart attacks, too. But who should receive these drugs? Experts already know that the drugs, called statins, can prevent a second heart attack. Now more research shows that a simple test can help identify who else can benefit from them.
Statins were first shown to reduce the risk of a second heart attack in people with high cholesterol, and then they were shown to prevent a first heart attack in people with high cholesterol. A report in the June 28 issue of The New England Journal of Medicine nowshows that statins can prevent a first heart attack in people with normal cholesterol levels. They work by reducing levels of a protein called CRP.
An increase in CRP indicates inflammation. Inflammation in the arteries probably makes plaque -- the fatty substance that builds up on artery walls -- unstable and more likely to break apart, explains study author Paul Ridker, MD, PhD. When plaque breaks or fractures, a blood clot can form. That clot can then block blood flow to the heart and cause a heart attack.
Therefore, if CRP is higher than normal, "the risk for heart attack is higher than normal," Ridker tells WebMD. This is true "even if a person has normal cholesterol levels." High cholesterol also is a risk factor for heart attacks.
And statins are just as effective at lowering CRP -- and reducing the CRP-associated risk for heart attack -- as they are for lowering cholesterol, Ridker adds. That says a lot since statins are the primary treatment for high cholesterol.
What's more, doctors can use a simple blood test to measure CRP and determine who will benefit from statin therapy.
The test used by heart specialists is called a high-sensitivity CRP test and is now available in most major heart centers, says Kenny Jailal, MD, a professor of medicine at the University of Texas Southwestern Medical Center at Dallas. He cautions, however, that because CRP goes up in the presence of inflammation, a one-time finding of elevated CRP does not necessarily confirm an increased risk for heart attacks. So Jailal recommends at least two CRP measurements to confirm the true level.