Electron-beam computed tomography (EBCT) is more accurate than conventional catheter angiography for identifying which adult patients face the greatest risk of sudden death from congenital abnormalities in the arteries supplying blood to the heart, according to a study in the September 2005 issue of Catheterization and Cardiovascular Interventions: Journal of the Society for Cardiovascular Angiography and Interventions.
The study found that both EBCT and conventional x-ray angiography were able to detect the abnormalities--for example, a left coronary artery originating from the right side of the aorta, or vice versa--but EBCT trumped angiography in more than one-third of cases when determining whether the artery traveled perilously between the aorta and pulmonary artery, or followed a safer path around the two "great vessels."
An artery that passes between the aorta and pulmonary artery makes a sharp bend at its origin. In addition, it can be squeezed between the great vessels as the heart beats. Under the right conditions--such as strenuous athletic activity--blood flow through the artery may be blocked, causing a heart attack or even sudden death.
"The most crucial clinical question is whether the artery is coursing between the aorta and pulmonary artery. Angiography did not always give us the correct answer, but it was very easy to tell using EBCT," said Dr. Esat Memisoglu, an assistant professor of radiology at St. Louis University Hospital.
The study, which was conducted at a heart hospital and imaging center in Istanbul, Turkey, involved 28 adults who had had conventional x-ray angiography for chest pain or shortness of breath and later underwent an EBCT study. In half of the patients, angiography showed a congenital abnormality in the coronary arteries. The other 14 patients served as a control group.
The radiologists who interpreted the EBCT studies were not informed of the results of the angiographic study. In 5 of 14 cases, EBCT disagreed with angiography when characterizing the pathway the abnormal artery followed between, or around, the great vessels. Later, joint review by the cardiologist and radiologist concluded the EBCT findings to be correct.