Table 1.
Cardiac computed tomography derived parameters: pros, cons, and clinical value.
| Parameters | Pros | Cons | Clinical value |
|---|---|---|---|
| CACS | - Low radiation - No contrast - Quick - Inexpensive - Reproducible | - Unclear value of serial CCT assessments - Must consider pre-test probability of CAD | - Good correlation with long-term risk of cardiac events - Incremental predictive value on top of traditional risk factors |
| Anatomic assessment | |||
| Stenosis and plaque volume | - Precise evaluation of presence and extent of non-obstructive lesions | - CCTA has moderate to high sensitivity and specificity in lesion severity | - Degree of stenosis correlates well with mortality risk - Severe plaque burden correlates with adverse cardiac outcomes - Plaque progression on serial CCTAs correlates with risk of ACS |
| High-risk plaque features | - Dynamic morphology of plaques not captured - Need to consider additional thrombophilic factors | - Predict plaque rupture/ erosion - Respond well to statin use | |
| Positive remodeling | - Correlates with TCFA and culprit lesions in ACS | ||
| Low attenuation | - Influenced by contrast concentration, plaque burden, slice thickness, image noise, tube voltage - Challenging distinction of lipid vs. fibrous-rich plaques | -Lower attenuation in ruptured plaques and in ACS compared to stable lesions and stable angina | |
| Napkin-ring sign | - Good specificity | - Modest sensitivity | - Correlates with TCFA and future cardiac events |
| Spotty calcification | - Micro-calcifications cannot be visualized with CCTA | - Correlates with accelerated CAD progression and culprit plaques in ACS | |
| Hemodynamic assessment | |||
| FFR | -Functional assessment of lesion | - Gray zone; No evidence-based cut-off value | - FFR > 0.75–0.8 indicates hemodynamically significant stenosis - Negative CT-FFR can safely defer invasive angiography |
| CTP | - Identification of of myocardial perfusion defects - Detection of hemodynamically significant stenosis | - Absolute quantification of myocardial blood flow similar to PET - Incremental diagnostic value over CCTA alone and CT-FFR for the identification of hemodynamically significant CAD - Incremental predictive value over CCTA, CT-FFR, or clinical risk factors for the prediction of future major adverse cardiac events | |
| ESS | - Lower accuracy (except if CCTA is fused with intracoronary imaging techniques) | - In native arteries: associated with initiation and progression of atherosclerosis, development of high-risk plaques, need for revascularization, and major adverse events - In stented arteries: associated with neo-intima hyperplasia and neo-atherosclerosis | |
| PVAT | - No data available regarding risk-reduction therapies (e.g., statins) | - Higher FAI associated with: ° CAD ° ACS culprit lesions ° All-cause mortality ° Cardiac mortality | |
CACS, Coronary artery calcium score; CCT, Cardiac computed tomography; CAD, Coronary artery disease; CCTA, Cardiac computed tomography angiography; ACS, Acute coronary syndromes; TCFA, thin cap fibroatheroma; FFR, Fractional flow reserve; CT-FFR, Computed tomography-FFR; CTP, Computed tomography perfusion; PET, Positron emission tomography; ESS, Endothelial shear stress; PVAT, Perivascular adipose tissue; FAI, Fat attenuation index.