Researchers Evaluate Safer, More Convenient Heart Disease Test
May 22, 2000 -- Last Friday, Jose Armstrong had a magnetic resonance imaging test (MRI) for heart disease. He lay in a narrow chamber for about an hour, bombarded by FM radio waves, while his doctors observed the blood flow through his heart, giving him occasional instructions though earphones.
Later the same day, Armstrong had an angiogram -- another, much more common way to evaluate the heart. His doctors injected a local anesthetic into his groin, inserted very thin tubing into an artery, and pushed it upward until it entered blood vessels in his heart. A dye was injected into the tube, and X-rays allowed his doctors to see whether the arteries in his heart were blocked.
Both of these tests are somewhat unusual experiences, Armstrong says. "The MRI can be intimidating, because you lie in a narrow, enclosed space. But fortunately I'm not claustrophobic. During the angiogram, you feel a rush of heat when they release the dye into your artery." Most importantly, Armstrong adds, "the angiogram is an intrusion into your body, while the MRI gives your doctors a picture of your heart without any intrusion." Armstrong, 65, lives in Ponce, Puerto Rico. He was visiting his daughter in New York City when he developed chest pain and went to Mt. Sinai Medical Center for treatment.
"The angiogram is the currently accepted diagnostic tool for coronary artery blockages," says Zahi Fayad, PhD, who has been studying MRIs and heart disease for 10 years. "We also did an MRI on Mr. Armstrong as part of our ongoing research, so we can compare the results of the two tests." Fayad is assistant professor of medicine at Mt. Sinai School of Medicine in New York City and director of cardiovascular imaging at Mount Sinai Medical Center.
A just-released study says MRI can be an effective way to evaluate patients after they have had an angioplasty -- which is a procedure to open blocked heart arteries. About 500,000 people have angioplasties each year. During this procedure, a tiny balloon is inserted into closed heart arteries and inflated to open them back up. Unfortunately, in about a third of cases, the arteries close back up within six months. Currently, the angiogram is the accepted test to see whether this has happened. However, because it involves threading a fine tube into the heart, it carries some risks.