Antonis Karanasos

In vivo measurement of plaque neovascularisation and thermal heterogeneity in intermediate lesions of human carotid arteries

Objectives Both neoangiogenesis and inflammation contribute in atherosclerosis progression. Contrast-enhanced ultrasound (CEUS) provides visualisation of plaque neovascularisation. Microwave radiometry (MR) allows in vivo non-invasive measurement of temperature of tissues, reflecting inflammatory activation. We assessed the association of carotid plaque temperature, measured by MR, with plaque neovascularisation assessed by CEUS in intermediate lesions. Methods Consecutive patients with coronary artery disease and carotid atherosclerosis underwent carotid ultrasound imaging, CEUS and MR. Plaque texture, plaque surface and plaque echogenicity were analysed. Contrast enhancement (CE) by CEUS was defined as the % percentage of signal intensity difference, prior and post contrast infusion. Thermal heterogeneity (ΔT) was assigned as maximal temperature along the carotid artery minus minimum. Results Eighty-six carotid arteries of 48 patients were included. Fatty plaques had higher CE% and ΔT compared with mixed and calcified (p<0.01 for all comparisons). Heterogeneous plaques had higher CE% and ΔT compared with homogenous (p<0.01 for all comparisons). Plaques with irregular surface had higher CE% and ΔT compared with plaques with regular (p<0.01 for all comparisons). There was a good correlation between ΔT and CE (R=0.60, p<0.001). Conclusions Carotid plaque neovascularisation on CEUS examination is associated with increased thermal heterogeneity and ultrasound characteristics of plaque vulnerability in intermediate lesions.

Multiple plaque morphologies assessed by optical coherence tomography in a patient with acute coronary syndrome

A 64-year-old male patient presented at the emergency department with chest pain. ST-segment depression (1 mm) was present in leads V4–V6, and cardiac troponin was elevated (10.4 ng/ml). He was treated medically, and he did not have any chest pain thereafter. We performed coronary angiography 60 h later, which revealed a proximal lesion in the left circumflex artery with a …

Prognostic clinical and angiographic characteristics for the development of a new significant lesion in remote segments after successful percutaneous coronary intervention

BACKGROUND The majority of cardiovascular events in patients undergoing PCI arise from the progression of NCL during the long-term follow-up period. The purpose of the study was to investigate the clinical and angiographic factors related to the progression of non-culprit lesions (NCL) of patients undergoing percutaneous coronary interventions (PCI). METHODS One hundred and seventeen patients that underwent two coronary angiograms with a time interval greater than 3 months were enrolled. All patients underwent PCI as a treatment for the culprit lesion. In the second coronary angiography we investigated whether they had a new culprit lesion clearly differentiated from the one of the first angiogram. The demographic characteristics, the clinical syndrome responsible for the first PCI and the procedural characteristics were recorded. Quantitative coronary angiography was performed at the culprit lesion of the second angiography and in the same lesion in the first angiography. RESULTS Multivariate analysis showed that the independent variables for the development of a significant lesion at the follow-up requiring intervention were: the presence of complex lesion (53.78% vs 36.22%, p<0.001, OR=39.42), acute myocardial infarction (AMI) at the initial diagnosis (36.3% vs 32.4%, p<0.001, OR=3.9), and smoking (46.15% vs 53.84%, p=0.03, OR=0.29). CONCLUSIONS Patients with AMI and complex morphology of NCL have increased risk for a new intervention after successful PCI. Smoking at the time of the follow up, was associated with fewer coronary interventions.

Optimal branch selection in alcohol septal ablation

Alcohol septal ablation is an emerging technique for the reduction of the subaortic gradient in hypertrophic obstructive cardiomyopathy. The selection of the branch to be ablated is not always obvious, however, and the use of Myocardial Contrast Echocardiography assists in the proper localization of the perfusion area of each branch. We present a case of alcohol septal ablation in a 78-year old woman, in whom the choice of the optimal branch for septal ablation was performed after careful evaluation of the echocardiographic images, in accordance with the angiographic appearance. Alcohol septal ablation was performed without complications and resulted in reduction of the subaortic gradient and improvement of the patients functional capacity.

Differences in Drug-Eluting Stents Used in Coronary Artery Disease

The introduction of drug-eluting stents (DES) has improved the efficacy of percutaneous coronary intervention by addressing the issue of neointimal proliferation, a pathology contributing to restenosis. First-generation stents eluting sirolimus or paclitaxel were joined by second-generation stents, such as the everolimus- and the zotarolimus-eluting stents, promising increased safety and efficacy. As a result, there is a plethora of drug-eluting stents available, with differences in the stent platform, the polymer coating and the eluted drug, which translate into differences in biological markers of efficacy, such as late loss. However, it remains controversial whether these discrepancies have an impact on clinical markers of safety and efficacy, or if the improved efficacy of DES is a class effect. This article reviews the differences between DES by looking into the biological differences and into trials and registries of DES.

Percutaneous Coronary Intervention in Chronic Stable Angina

Although the therapeutic advantage of percutaneous coronary intervention in acute coronary syndromes have been proved in numerous studies, its position in the treatment of stable angina remains a controversial issue. The results of the recent studies did not lead into definite answers for the proper treatment of chronic coronary artery disease. The identification of the patients that will benefit from the interventional approach is necessary and is probably based on the proper screening for myocardial ischemia with noninvasive diagnostic techniques. In this review article, we mention the most recent studies for the treatment of chronic stable angina with respect to clinical outcome and economical consequences.

In vivo measurement of plaque neovascularisation and thermal heterogeneity in intermediate lesions of human carotid arteries. The authors' reply.

We thank Dr Marijan Bosevski for his comments and appreciate his interest in our recent publication. In this letter, Dr Bosevski addresses an important issue concerning the potential prognostic implication of carotid plaque thermal heterogeneity or/ and plaque neoangiogenesis, when added in current risk stratification models to improve the overall predictive ability for cardiovascular events. Although our study was not oriented towards prognosis, this is certainly an issue worthy of further discussion. Since the last few years, there has been a particular interest in identifying novel atherosclerotic plaque features that may have additive predictive value in current risk stratification models. Among other plaque features, inflammation and neoangiogenesis seem to play a central role in plaque destabilisation. The aforementioned plaque features have not been assessed as potential prognostic factors and their role in risk stratification of vulnerable patients has not been elucidated because only recently have novel imaging modalities enabled their reliable identification. Our study showed that both these features coincide in intermediate lesions of carotid arteries of patients with coronary artery disease. Interestingly, both features were pronounced in plaques with sonographic characteristics of plaque vulnerability. Moreover, in a previous study in carotid arteries of patients with advanced carotid atherosclerosis scheduled for carotid intervention, we have shown that increased carotid plaque thermal heterogeneity was associated with histological evidence of inflammatory activation and neovascularisation. Concerning current evidence linking these plaque features to prognosis, limited data are available. Increased thermal heterogeneity in coronary arteries of patients undergoing percutaneous coronary intervention was associated with worse clinical outcome. As inflammation can be detected locally by measuring thermal heterogeneity in carotid atheromatic plaques, theoretically adding this information in our prognostic models, one would expect to increase the prognostic accuracy of cardiovascular risk assessment. Accordingly, limited data are available regarding the impact of intense carotid plaque neoangiogenesis on prognosis. In a recent study, the degree of contrast enhancement in carotid plaques correlated with cerebrovascular symptoms and symptomatic patients had more intense contrast enhancement in carotid plaques than asymptomatic patients. Contrast-enhanced ultrasound and/or microwave radiometry may serve as valuable tools for primary and secondary prevention of cardiovascular events. The potential additional predictive value of contrast-enhanced ultrasound and/or microwave radiometry measurements on plaque risk stratification remains to be elucidated in prospective serial studies.

Carotid plaque typisation: a novel risk marker?

The Authors’ reply We thank Dr Bosevski1 for his commentary in our study and share his interest concerning the identification of carotid atherosclerosis indices that may provide additive prognostic value to current risk stratification models in vulnerable patients.2 Indeed, this is an issue that is becoming increasingly important for the prognosis of vulnerable patients, mostly because the accuracy of carotid intima-media thickness as a marker of atherosclerosis has been questioned.3 In our study, we demonstrated that carotid plaque neovascularisation and …

ASSESSMENT BY OPTICAL COHERENCE TOMOGRAPHY OF A DEDICATED DRUG ELUTING STENT WITH BIODEGRADABLE POLYMER FOR THE INHIBITION OF NEOVASCULARIZATION AND NEOINTIMAL HYPERPLASIA

Methods: Ten New Zealand white rabbits were fed with atherogenic diet for 3 weeks. Eleven biodegradable bevacizumab-eluting stents (BES) were implanted in the distal aorta. The control group consisted of 7 New Zealand white rabbits treated with 7 bare metal stents covered by biodegradable polymer. All animals were treated with aspirin and clopidogrel for 4 weeks. Follow-up angiography and Optical Coherence Tomography (OCT) study were scheduled at 4 weeks. OCT images of each stent were analyzed and each strut was examined for apposition. A strut was defined as embedded when it was buried in the intima for more than half of its thickness, protruding when apposed to the intima but not embedded, and malapposed when there was no intimal contact. Tissues were obtained for immunohistological analysis

IN VIVO COMPARISON OF MORPHOLOGICAL CHARACTERISTICS OF CULPRIT LESIONS BETWEEN PATIENTS WITH ST ELEVATION MYOCARDIAL INFARCTION AND NON ST ELEVATION ACUTE CORONARY SYNDROME. AN OPTICAL COHERENCE TOMOGRAPHY STUDY.

Background: Plaque rupture is mainly implicated in the pathogenesis of acute coronary syndrome (ACS). There are no in vivo studies regarding the relationship between the clinical type of ACS and morphology of plaque. Optical coherence tomography has enabled the discrimination between microstructures of vulnerable plaque in vivo. We hypothesized that there are distinct differences in the morphology of ruptured plaques between patients with non-ST elevation ACS (NSTACS) and patients with ST elevation myocardial infarction (STEMI).