September 7 , 1999
Volume 52, No. 3
Study explains how aspirin cuts chest pain
Aspirin spells relief for individuals with chest pain caused by heart disease, according to a study that describes how the commonly used pain reliever may work.
In Circulation: Journal of the American Heart Association, researchers from London and Athens found that aspirin can reduce chemicals that cause inflammation, contributing to the progression of heart disease and leading to symptoms such as chest pain, or angina.
Angina is the pain or discomfort in the chest caused when an area of the heart muscle is not getting enough blood. It is a common symptom of coronary artery disease, where atherosclerosis deposits have greatly narrowed one or more arteries that supply the heart. Angina usually occurs during exercise or stress, although patients with more severe angina can experience pain even at rest. People with angina are at risk for suffering a heart attack.
Aspirin can reduce the risk of heart attacks in patients with ischemic heart disease. How aspirin does this is only partially understood; scientists know that aspirin helps prevent the formation of blood clots that can trigger a heart attack, but this study shows it may also interfere with the inflammatory response associated with atherosclerosis, said Petros Nihoyannopoulos of London's Imperial College School of Medicine, National Heart & Lung Institute and Hammersmith Hospital.
The study measured blood plasma levels of cytokines--chemicals released when the endothelial cells that line blood vessels are damaged--in 60 patients with chronic stable angina and 24 matched controls. Cytokines promote inflammatory reactions that are believed to play a role in the development and progression of atherosclerosis and ischemic heart disease. The study also measured the plasma levels of C-reactive protein (CRP); high levels of CRP usually are a sign of active inflammation.
While high blood levels of cytokines and CRP have been found in patients with heart attacks or more severe unstable angina, this is the first study to show that they are also elevated in patients with chronic stable angina, the authors reported. Compared with healthy controls, the patients with angina had more than twice the median blood levels of both cytokines and CRP.
In the second part of the study, 40 patients who had documented ischemia were treated either with aspirin or placebo for three weeks. After three weeks patients who had received aspirin were placed on placebo, and those who got placebo were given aspirin for three more weeks. The dose of aspirin was 300 milligrams a day, which often is recommended for patients with coronary artery disease. Compared with those on placebo, patients who took aspirin had significant reductions in CRP and two of the three measured cytokines.
By impairing the dilation of the blood vessels and by promoting the formation of tiny blood clots, the cytokines may reduce the flow of blood to the heart muscle, thereby facilitating or prolonging ischemic events, the authors suggested. They concluded that aspirin may protect the hearts of patients with coronary artery disease in part by reducing the level of these pro-inflammatory chemicals.
"Wellness" is sponsored by the BSHE Department of the Rollins
School of Public Health.