Multidetector Computed Tomography as a Potential Modality to Detect Subclinical Atherosclerosis (pp.49-82)
Authors: (Kohichiro Iwasaki, Shozo Kusachi, Department of Cardiology, Okayama Kyokuto Hospital, Japan, and others)
Abstract: Coronary artery disease is a leading cause of mortality and morbidity in the developing and developed countries. In approximately 50% of patients with newly diagnosed coronary artery disease, the first presentation is either acute myocardial infarction or sudden cardiac death. Global risk scores are developed to stratify the risk of coronary artery disease. However recent research has revealed that the global risk score significantly underestimates or misclassifies risk in key subsets of the population. Many data also demonstrate that the major determinant of risk for atherosclerotic cardiovascular disease in asymptomatic adults is the presence of the underlying disease itself, namely subclinical atherosclerosis.
Multidetector computed tomography (MDCT) has emerged as a promising modality to evaluate coronary artery disease. MDCT has an excellent capacity to detect hemodynamically relevant stenosis and its ability to detect and characterize coronary plaque noninvasively is increasingly recognized. Recent studies using MDCT demonstrate that the prevalence of subclinical atherosclerosis in asymptomatic patients with low to intermediate risk is high. Especially, asymptomatic diabetic patients and asymptomatic patients with abnormal carotid finding have high prevalence of subclinical atherosclerosis. Also recent studies demonstrate that the coronary plaques that are prone to subsequent acute coronary syndrome are often associated with positive remodeling and low attenuation plaque, suggesting that once a patient is identified to be at high risk of having an adverse cardiac event by clinical risk assessment, imaging with MDCT would help better identify those at greater risk of acute coronary events.
Thus it is time to change the paradigm for testing for coronary artery disease from detection of a symptomatic luminal obstruction to preclinical arterial wall atherosclerosis.
There is increasing need to detect disease at earlier stages so that asymptomatic patients with atherosclerosis in need of aggressive medical management can be identified. We believe that MDCT has a potential to fulfill these needs.