If multi-slice computed tomography (MSCT) shows that a patient has plaque build-up in the artery walls, does it also mean that there is actual reduced blood flow in the artery" New research shows that more often than not, the plaque in coronary artery walls does not necessarily harm blood flow to the heart. Two distinct non-invasive imaging tests were used to examine complimentary characteristics of coronary artery disease (CAD) plaque build-up and artery blockage. The research, led by Jeroen J. Bax, MD, PhD, Department of Cardiology at the Leiden University Medical Center in the Netherlands, appears in the Dec. 19 edition of the Journal of the American College of Cardiology.
In a quest to find new, non-invasive ways to detect the blockage of coronary arteries, researchers sought to determine whether MSCT, a promising non-invasive imaging technique that detects narrowing of the coronary arteries due to plaque build-up (atherosclerosis), can also accurately identify reduced blood flow in the arteries due to the blockage (ischemia).
The study compared MSCT to another non-invasive imaging technique, myocardial perfusion imaging (MPI) with single-photon emission computed tomography (SPECT), among patients with a moderate risk of CAD to find the answer. CAD occurs when a buildup of plaque in the arteries prevents oxygen-rich blood from nourishing the heart muscle.
Results of the study show that only 45 percent of patients who were shown to have atherosclerosis through the use of MCST were also found to have ischemia through the use of MPI. In fact, only half of the patients who were shown to have obstructive CAD -- defined as having fifty percent or more narrowing of the coronary arteries -- through the use of MSCT were shown to have ischemia, based on the results of the MPI test. In other words, the narrowing of the coronary arteries (stenosis) wasnt harming the blood flow to the heart.