Noninvasive diagnosis of vulnerable coronary plaque

Table 1 Concepts related to vulnerable coronary plaque[16]

Culprit lesion	Coronary lesion considered to be responsible for the clinical event, usually plaque complicated by intraluminal thrombosis
Thrombosed plaque	Plaque with an overlying thrombus extending into the vessel lumen either occlusive or non-occlusive
Eroded plaque	Thrombosed plaque (mainly fibrotic or proteoglycan-rich) due to loss or dysfunction of endothelial cells without associated rupture
Plaque with calcified nodule	Heavily calcified protruding plaque with loss or dysfunction of endothelial cells
Vulnerable, high-risk or thrombosis prone plaque	Plaque at increased risk of thrombosis and rapid stenosis progression TCFA: Inflamed plaque with a thin cap covering a lipid-rich necrotic core
Vulnerable patient	Patient at high-risk to experience a cardiovascular ischemic event due to a high atherosclerotic burden, high-risk plaques and/or thrombogenic blood

TCFA: Thin-cap fibroatheroma.

Table 2 Diagnostic tests for noninvasive evaluation of coronary vulnerable plaque

	CCT	CMR	PET
Plaque characterization	Plaque morphology	Plaque morphology Tissue characterization of plaque	Inflammation (FDG) Macrophage infiltration (new tracers)
Vulnerable features	Positive remodeling Low attenuation Spotty calcification Napkin-ring sign	Positive remodeling T1 hyperintensity Late gadolinium enhancement	Increased tracer uptake
Clinical relevance	Strong association with ACS Prediction of slow-flow after PCI Evaluation of response to statins	Initial data of association of T1 hyperintense plaques with slow-flow, ACS and response to statins	Differentiation between ACS and stable coronary disease
Limitations	Radiation exposure Heavy calcification Overlap in attenuation ranges Inability to detect plaque erosion	Direct relation between spatial resolution and acquisition time Susceptibility to motion artifacts	Low spatial and temporal resolution Myocardial background uptake Expensive and limited availability

CCT: Coronary computed tomography; CMR: Cardiac magnetic resonance; PET: Positron emission tomography; ACS: Acute coronary syndrome; PCI: Percutaneous coronary intervention; FDG: Fluorodeoxyglucose.