Plaques, intravascular

C. L. de Korte, G. Pasterkamp, A. F. van der Steen, H. A. Woutman and N. Bom, Characterization of plaque components with intravascular ultrasound elastography in human femoral and coronary arteries in vitro, Circulation, 2000, 102, 617-623. 

Using flexible endoscopic catheters, intravascular fluorescence spectroscopy and imaging demonstrated that atherosclerotic plaques and other vascular abnormalities can be identified and characterized based either on endogenous fluorophores [11] or exogenous fluorescent dyes [146,147]. 

Fig. 8.2 (A) Intravascular ultrasound (IVUS) image of a coronary artery using Revolution 45 MHz IVUS imaging catheter. (B) Plaque composition imaging using volcano VH IVUS system. Green areas represent Fibrous plaque. Yellow is fibro-fatty areas. Red is the necrotic core and white represents areas of dense calcium...

ACS represents a prothrombotic state not just confined to the culprit lesion, with evidence of a pan coronary process and generalized platelet activation. Multiple vulnerable plaques in nonculprit vessels have been identified by angioscopy or intravascular ultrasound in ACS. Protracted treatment with clopidogrel induces antiplatelet activity that provides early benefits, and may limit thrombotic events within the following months. In the CURE study, the curves of major vascular events continue to diverge and showed an additional benefit from one-month follow-up to one year. 

In addition, a recent study in which reconstituted HDL was infused into human subjects after acute coronary syndromes showed a significant reduction in plaque volume in the coronary arteries as assessed by intravascular ultrasound (32). 

Petronio AS, Amoroso G, Limbruno U, et al. Simvastatin does not inhibit intimal hyperplasia and restenosis but promotes plaque regression in normocholesterolemic patients undergoing coronary stenting a randomized study with intravascular ultrasound. Am Heart J 2005 149 520-526. 

Similar studies have used intravascular ultrasound (IVUS) at six-month follow-up to evaluate differences in target-lesion healing and have found less intimal hyperplasia and late lumen loss due to increased plaque burden in patients who had received DES without ICB for the treatment of BMS ISR (41). On the other hand, other IVUS-guided studies have described a significant black-hole phenomenon in patients who have undergone ICB. The black hole, a homogeneous, echolucent intraluminal entity depicted on IVUS, is felt to be a result of an impaired response to endothelial injury and an altered molecular proliferative response (Fig. 2). This intraluminal tissue, which accounted for —50% of the neo-intimal growth in areas of restenosis after radioactive stent... 

Rioufol G, Finet G, Ginon I, et al. Multiple atherosclerotic plaque rupture in acute coronary syndrome a three-vessel intravascular ultrasound study, Circulation 2002 106 ... 

In another study of 45 patients with ACS, the relationship between plaque rupture, CRR and prognosis was investigated with intravascular ultrasound (21). These 45 patients had a first acute myocardial infarction with or without ST segment elevation. Intravascular ultrasound was performed in the patients before any percutaneous coronary intervention and within six hours of symptoms (21). The remaining coronary vasculature was examined within one month. Forty-five culprit arteries and 84 other coronary arteries were examined with intravascular ultrasound. They found that plaque ruptures in 47% of the arteries at the culprit site in the acute phase of the myocardial infarction. In addition, intravascular ultrasound revealed 17 occult plaque ruptures at remote sites in 24% of the patients (21), These findings suggest that some patients with acute myocardial infarctions have multiple plaque ruptures in other coronary arteries and the culprit artery. 

In the preceding two examples, Raman spectra were obtained from tissues and cell samples ex vivo. Recently, Buschman et al. (46) were able to measure Raman spectra of sheep arterial walls in vivo using a miniature fiberoptic probe. They have demonstrated that the in vivo intravascular Raman signal obtained directly from a blood vessel is a simple summation of signals from the blood vessel wall and blood itself. This technique may be useful in predicting the risk of arterial plaque rapture and determining plaque composition in human arteries. 

Recent studies using intravascular ultrasound provided evidence that indeed the reduction in epicardial atherosclerotic plaque volume in patients undergoing a percutaneous coronary intervention in acute myocardial infarction60 or unstable angina61 induces microembolization and thus contributes to inadequate reperfusion, as assessed by TIMI frame count,60 and microinfarcts, as assessed by creatine kinase (CK)-MB release.61... 

J. Zamorano, R. Erbel, J. Ge, G. Gorge, P. Kearney, L. Koch, A. Scholte and J. Meyer, Spontaneous plaque rupture visualized by intravascular ultrasound, Eur Heart J15, 131-133 (1994). 

J. Ge, F. Chirillo, J. Schwedtmann, G. Gorge, M. Haude, D. Baumgart, V. Shah, C. von Birgelen, S. Sack, H. Boudoulas and R. Erbel, Screening of ruptured plaques in patients with coronary artery disease by intravascular ultrasound, Heart 81, 621 -627 (1999). 

M. Gossl, C. von Birgelen, G. S. Mintz, D. Bose, H. Eggebrecht, D. Baumgart, M. Haude and R. Erbel, Volumetric assessment of ulcerated ruptured coronary plaques with three-dimensional intravascular ultrasound in vivo, Am J Cardiol 91, 992-996 (2003). 

R9. Rioufol, G., Finet, G., Ginon, I., Andre-Fouet, X., Rossi, R., Vialle, E., Desjoyaux, E., Convert, G., Huret, J. F., and Tabib, A., Multiple atherosclerotic plaque rupture in acute coronary syndrome A three-vessel intravascular ultrasound study. Circulation 106, 804-808 (2002). 

K. Fall, A. Maehara, and G. S. Mintz, Intravascular Imaging in Patients with Acute Coronary Syndromes and Unstable Coronary Plaques, Curr. Cardiovasc. Imaging Rep., 4(4), 269 (2011). 

Kim, S.-W., Mintz, G. S., Ohlmann, P., et al. (2006) Frequency and Severity of Plaque Prolapse Within Cypher and Taxus Stents as Determined by Sequential Intravascular Ultrasound Analysis, Am. J. Cardiol., 98, 1206. 

Sonka, M., Liang, W., Zhang, X., et al. (1995) Three-dimensional automated segmentation of coronary wall and plaque from intravascular ultrasound pullback sequences. Proceedings of Computers in Cardiology Vienna, Austria, 637 0. 

Nair, A., Kuban, B. D., Obuchowski, N. and Vince, D. G. (2001) Assessing spectral algorithms to predict atherosclerotic plaque composition with normalized and raw intravascular ultrasound data. Ultrasound in Medicine and Biology, 27, 1319-31. 

Nair, A., Kuban, B., Tuczu, E. M., et al. (2002) Coronary Plaque Classification With Intravascular Ultrasound Radiofrequency Data Analysis, Circulation, 106, 2200-6. 

Sangiorgi, G. M., Clementi, F., Cola, C. and Biondi-Zoccai, G. (2007) Plaque vulnerability and related coronary event prediction by intravascular ultrasound with virtual histology Idquolt s a long way to tipperaryrdquo . Catheterization and Cardiovascular Interventions, 70, 203-10. 

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