Non-Contrast and Contrast-Enhanced Cardiac Computed Tomography Imaging in the Diagnostic and Prognostic Evaluation of Coronary Artery Disease

Abstract

In recent decades, cardiac computed tomography (CT) has emerged as a powerful non-invasive tool for risk stratification, as well as the detection and characterization of coronary artery disease (CAD), which remains the main cause of morbidity and mortality in the world. Advances in technology have favored the increasing use of cardiac CT by allowing better performance with lower radiation doses. Coronary artery calcium, as assessed by non-contrast CT, is considered to be the best marker of subclinical atherosclerosis, and its use is recommended for the refinement of risk assessment in low-to-intermediate risk individuals. In addition, coronary CT angiography (CCTA) has become a gate-keeper to invasive coronary angiography (ICA) and revascularization in patients with acute chest pain by allowing the assessment not only of the extent of lumen stenosis, but also of its hemodynamic significance if combined with the measurement of fractional flow reserve or perfusion imaging. Moreover, CCTA provides a unique incremental value over functional testing and ICA by imaging the vessel wall, thus allowing the assessment of plaque burden, composition, and instability features, in addition to perivascular adipose tissue attenuation, which is a marker of vascular inflammation. There exists the potential to identify the non-obstructive lesions at high risk of progression to plaque rupture by combining all of these measures.

The Role of Epicardial Adipose Tissue in Acute Coronary Syndromes, Post-Infarct Remodeling and Cardiac Regeneration

“…CT enables the measurement of EAT thickness and volume. Additionally, attenuation (density) can be measured, and its less negative values serve as a marker of inflammation within the tissue [144]. Moreover, it grants an assessment of these parameters in the pericoronary adipose tissue (PCAT), which is the fat layer surrounding coronary vessels [145].…”

Evaluation central to good outcomes in percutaneous treatment of coronary artery disease

“…In CTCA a CT scan is taken at rest, then a second scan after a bolus of contrast has been given intravenously to outline the lumen of the coronary arteries 8 . From the rest images the amount of calcium in the coronary arteries is determined, an almost inevitable correlate of coronary atheroma (and useful data as the coronary calcium load correlates with the presence and extent of coronary obstruction; it also correlates with prognosis).…”

Imaging biomarkers in cardiac CT: moving beyond simple coronary anatomical assessment

“…Current prevention strategies rely on the risk stratification, acting with pharmacological treatments or lifestyle habits, and early detection of obstructive coronary artery disease (CAD). Clinical scores systems, electrocardiogram and echocardiogram demonstrated low sensitivity and specificity for the early diagnosis of CAD and prediction of major cardiovascular events (MACE) risk [ 2 , 3 ]. In the last decades, cardiac computed tomography angiography (CCTA) has gained a preeminent role in the evaluation of symptomatic patients with suspected CAD, thanks to its high diagnostic accuracy and high negative predictive value.…”