Imaging Plaques to Predict and Better Manage Patients With Acute Coronary Events

Abstract

Culprit lesions of patients who have had an acute coronary syndrome commonly are ruptured coronary plaques with superimposed thrombus. The precursor of such lesions is an inflamed thin-capped fibroatheroma. These plaques can be imaged by means of invasive techniques such as intravascular ultrasound (and derived techniques), optical coherence tomography and near-infrared spectroscopy. Very often these patients exhibit similar (multiple) plaques beyond the culprit lesion. These remote plaques can be assessed non invasively by computed tomography angiography and magnetic resonance imaging and also using invasive imaging. The detection of these remote plaques is not only feasible, but also in natural history studies have been associated with clinical coronary events. Different systemic pharmacological treatments have been studied (mostly statins) with modest success and therefore newer approaches are being tested. Local treatment for such lesions is in its infancy and larger, prospective and randomized trials are needed. This review will describe the pathological and imaging findings in culprit lesions of patients with acute coronary syndrome and as well as the assessment of remote plaques. In addition, the pharmacological and local treatment options will be reviewed.

Disruption of Glut1 in Hematopoietic Stem Cells Prevents Myelopoiesis and Enhanced Glucose Flux in Atheromatous Plaques of ApoE −/− Mice

“…6K). Thus, we showed that Glut1 connects the enhanced glucose uptake in atheromatous plaques of ApoE −/− mice, 27–30 with their myelopoiesis through regulation of HSPC maintenance and myelomonocytic fate.…”

“…27–30 However, a recent study has called into question the relevance of these observations, as macrophage-specific overexpression of Glut1 did not aggravate atherosclerosis in mice compared to Glut1 sufficient controls, 46 reflecting the need for a better understanding of the underlying mechanisms. Our study provides direct evidence that Glut1 connects the enhanced glucose uptake in atheromatous plaques of ApoE −/− mice with their myelopoiesis through Glut1-dependent regulation of HSPC maintenance and myelomonocytic fate.…”

“…21,25 More recently, Oburoglu et al, have also reported that glucose utilization can dictate the myeloid lineage commitment in human HSCs. 26 Intriguingly, increased hematopoietic metabolic activity can be visualized by non-invasive PET-CT imaging with 18 FDG, a glucose analog, not only in inflamed atherosclerotic plaques, 27–30 but also in the spleen of patients with cardiovascular diseases, 31,32 reflecting most likely an extramedullary hematopoiesis. 33 However, the relevance of these observations as well as the underlying mechanisms are not fully understood.…”

Imaging Systemic Inflammatory Networks in Ischemic Heart Disease

“…More specifically, imaging can report on stromal immune cell activity in multiple tissues in living patients. In addition to coronary imaging (recently reviewed elsewhere (41)), as comorbidities aggravate cardiovascular disease via inflammatory crosstalk, noncardiovascular organs may also be of interest and therefore constitute another putative therapeutic target. To understand systems-wide immune action after MI, particularly connections of cardiovascular with immune and hematopoietic organs, future imaging studies should focus not only on the ischemic heart, but also on remote myocardium, local lymph nodes, nonculprit atherosclerotic lesions, spleen, and bone marrow, and integrate these data with analysis of blood.…”

Imaging of atherosclerosis

“…43 However, because of increased noise and artifacts, image interpretation can be difficult; furthermore, IVUS has insufficient spatial resolution to reliably and reproducibly detect thin fibrous cap. 44 OCT uses near infrared light (1.3 μm wavelength) emitted through a fiberoptic wire with rotating lens to achieve exceptionally high spatial resolution (10-15 μm), providing accurate measurement of fibrous cap thickness with strong correlation to histology, 45 and good sensitivity and specificity to distinguish plaque type. 46 However, correct differentiation between calcium and lipid pool can be challenging with OCT, and its limited tissue penetration (1-3 mm) makes assessment of the entire plaque volume impossible.…”