Age-related differences in virtual histology-intravascular ultrasound findings in patients with coronary artery disease

The Role of Virtual Histology Intravascular Ultrasound in the Identification of Coronary Artery Plaque Vulnerability in Acute Coronary Syndromes

Markers of coronary plaque vulnerability, such as a high lipid burden, increased inflammatory activity, and a thin fibrous cap, have been identified in histological studies. In vivo, grayscale intravascular ultrasound (IVUS) provides more in-depth information on coronary artery plaque burden than conventional angiography but is unable to accurately distinguish between noncalcific tissue types within the plaque. An analysis of IVUS radiofrequency backscatter based on spectral pattern recognition, such as virtual histology IVUS, allows detailed scrutiny of plaque composition and classification of coronary lesions. This review discusses the virtual histology IVUS technology and its accuracy in identifying vulnerable plaque features, focusing on its use in predicting patient outcomes after acute coronary syndrome, and its limitations in clinical practice.

Visualization of coronary plaque in type 2 diabetes mellitus patients using a new 40 MHz intravascular ultrasound imaging system

BACKGROUND

Previous epidemiological studies demonstrated plaque vulnerability to be high in diabetic patients. iMap-intravascular ultrasound (IVUS) is a recently developed radiofrequency 40 MHz IVUS imaging system for tissue characterization. This study aimed to characterize coronary plaque in target lesions of diabetic patients using iMap-IVUS.

METHODS

We studied 175 treated vessels in 146 patients with stable angina pectoris and analyzed plaque components of culprit lesions by iMAP-IVUS. Patients were divided into 2 groups: non-diabetic (non-DM: 112 vessels, 93 patients) and diabetic (DM: 63 vessels, 53 patients).

RESULTS

In gray-scale IVUS 2D analysis, there were no differences in IVUS parameters. In 3D analysis, the DM group tended to have a larger plaque volume (p=0.07) and plaque burden (p=0.10). At minimum lumen sites, the absolute lipidic and necrotic areas (0.84 ± 0.44 mm(2) vs. 0.58 ± 0.41 mm(2), p<0.001, and 2.42 ± 1.65 mm(2) vs. 1.46 ± 1.76 mm(2), p<0.001, respectively) and percent lipidic and necrotic areas were significantly greater in the DM than in the non-DM group (8.39 ± 3.38% vs. 5.25 ± 2.30%, p<0.0001, and 23.65 ± 11.54% vs. 12.99 ± 10.71%, p<0.0001, respectively). In addition, the absolute lipidic and necrotic volumes (11.75 ± 10.59 mm(3) vs. 8.18 ± 6.24 mm(3), p<0.01, and 29.99 ± 28.90 mm(3) vs. 19.44 ± 19.35 mm(3), p<0.01, respectively) and percent lipidic and necrotic volumes were significantly greater in the DM than in the non-DM group (6.27 ± 1.92% vs. 5.13 ± 1.82%, p<0.0001, and 16.54 ± 7.56% vs. 12.08 ± 6.05%, p<0.0001, respectively).

CONCLUSION

Characterization of coronary plaque by iMAP-IVUS in diabetic patients showed increased lipidic amount and necrotic plaque volume relative to subjects without DM.

Chlamydia pneumoniae heat shock protein 60 is associated with apoptotic signaling pathway in human atheromatous plaques of coronary artery disease patients

BACKGROUND

Chlamydia pneumoniae heat shock protein (HSP) 60 is known to contribute to the activation of inflammation. In addition, there are contradictory reports on C. pneumoniae and their role in activation of pathways (apoptotic/antiapoptotic/necrosis) in coronary artery disease (CAD). Hence, more studies are required to know the actual role of C. pneumoniae in activation of apoptotic/antiapoptotic/necrosis pathways.

METHODS AND RESULTS

In this study, two sets of patient groups (cHSP60 positive and cHSP60 negative) were included and gene expression was studied by cDNA micro array and real time polymerase chain reaction arrays. Expression of Caspase-3, 8, 9, c-FLIP, PPAR-γ, PGC-1α, and Gsk-3b were also evaluated at protein level by immunoblotting. In cHSP60 positive CAD patients significantly higher (p<0.001) mRNA expression was found for CCL4, CXCL4, CXCL9, IL-8, CD40LG, CD8, TGFβ1, TGFβ2, APOE, EGR1, CTGF, APOB, LDLR, LPA, and LPL, whereas significantly lower (p<0.001) mRNA expression was detected for CD4, IL1F10, IFNA2, and IL-10 as compared to cHSP60 negative CAD patients. Additionally, at protein level expression of Caspase-3 (p=0.027), 8 (p=0.028), and 9 (p=0.037) were higher and c-FLIP (p=0.028) and PPAR-γ (p=0.95) expression were comparable in cHSP60 positive CAD patients compared to cHSP60 negative CAD patients.

CONCLUSION

Genes/proteins of pre-apoptotic caspase dependent/independent pathways, chemokines, and inflammatory cytokines receptors were significantly up-regulated in human atheromatous plaques of cHSP60 positive CAD patients suggesting an association of cHSP60 with CAD.