Sept. 20, 2004 -- Tests that screen for markers of inflammation in the blood may be able to help doctors determine which people with chest pain are headed for trouble and which can wait before undergoing heart surgery.
A new European study shows that elevated levels of these markers, such as C-reactive protein (CRP) and others, may be signs of rapidly clogging arteries in people with otherwise stable chest pain (angina).
Researchers say it's the first study to show that inflammatory markers may predict a rapidly progression of coronary heart disease or stenosis (narrowing of the arteries) of the heart in people with chest pain.
When the arteries that supply blood to the heart become narrowed, it often causes chest pain. When someone comes into an emergency room complaining of chest pain and is not having a heart attack, yet has evidence of narrowing of the arteries, it's difficult to determine how quickly the disease is progressing or how pressing the need for heart surgery might be.
Clogging of the coronary arteries can lead to a heart attack. Yet no studies have found a relationship between the degree of narrowing and the risk of rapid progression of atherosclerosis in these arteries.
Researchers say these findings show that screening people with chest pain for blood markers of inflammation may provide clues as to how serious their heart disease may be. Inflammation has been shown to be associated with the development of atherosclerotic lesions in the walls of arteries. Screening for these markers can help guide health care providers in making decisions about surgery to restore blood flow, such as angioplasty or bypass surgery.
Inflammation and Chest Pain
Previous studies have already linked C-reactive protein and other markers to higher heart disease risks. But in this study, researchers looked at whether elevated levels of inflammation markers might be associated with rapidly progressing narrowing of the arteries in people with chest pain.
The results appear in the Sept. 21 issue of Circulation: Journal of the American Heart Association.
Researchers followed 124 people with coronary artery disease and chest pain that had never escalated to a heart attack or other problems for three months or more. The patients had imaging tests to measure the degree of narrowing of the arteries and then had a second test three to 12 months later.
The study showed that 28% of the participants experienced significant progression of their heart disease. Of these nearly half had a 10% or greater reduction in the diameter of their arteries, and a fourth had a greater than 30% reduction, almost a fifth developed a new atherosclerotic lesion, and 6% developed complete blockage of a coronary artery.
Researchers found four markers of inflammation, including C-reactive protein, neopterin, MMP-9, and sICAM, predicted rapid artery blockage and levels of these markers were higher in those who experienced a rapid progression of their disease.
For example, people who had elevated neopterin levels were five times more likely to experience a rapid progression of their disease compared with those who had low levels of this marker. People who had C-reactive protein levels in the middle range had three times the risk of progression than those with the lowest levels.
"The study is important because it confirms a role for inflammation in the rapid progression of [heart disease], and may open new areas of research to identify and test agents that may reduce inflammation," says researcher Juan Carlos Kaski, MD, professor of cardiovascular science at the University of London, in a news release.