In vivo correlation between morphological characteristics of coronary plaques and functional characteristics of carotid arteries in acute coronary syndrome.

BACKGROUND: Carotid artery temperature heterogeneity (ΔΤ) measured by microwave radiometry (MWR) has been associated with future cardiovascular events including acute coronary syndromes. The vulnerable plaques of the coronary arterial tree, that can be ideally depicted by intracoronary imaging such as optical coherence tomography (OCT) have anatomical characteristics such as the thin fibrous cap (TCFA), that make them vulnerable to rupture. The scope of the study was to assess the implication of the carotid artery temperature heterogeneity on the culprit coronary plaque morphology in patients presenting with acute myocardial infarction. METHODS: 34 patients presented with an acute myocardial infarction were enrolled in the study. All patients underwent percutaneous coronary intervention (PCI) and OCT for the evaluation of the anatomical characteristics of the culprit lesion. After the completion of the PCI all patients underwent carotid ultrasound and MWR of both carotid arteries and thermal heterogeneity of the carotid arteries was assessed. Blood samples were collected for high sensitivity C-reactive protein (CRP) analysis. RESULTS: Thirty four patients, 21 with STEMI (61.76%) and 13 (38.23%) with NSTEMI, were included in the study. Patients with ruptured plaques had significantly increased hsCRP compared to patients that did not have a ruptured plaque (14.41±4.02 vs 9.9±2.5, P<0.005). Thermal heterogeneity, was significantly increased in ruptured plaques compared to no ruptured ones (1.01±0.31 vs 0.51±0.14°C, P=0.001), and in plaques with TCFA compared to those without a TCFA (0.82±0.37 vs 0.60±0.05°C, P=0.001). Diabetes mellitus, ΔΤ and hsCRP, were entered in the multivariate analysis, from which DM (OR 4.12; 95% CI 0.77-22.07; P=0.07) and ΔΤ (OR for 0.1°C increase 1.43; 95% CI 1.03-1.98; P=0.03) remained in the final analysis, and only ΔΤ was independently associated with the presence of the TCFA. Regarding plaque rupture, STEMI, hsCRP, and ΔT were entered in the multivariate analysis from which hsCRP (OR 1.51; 95% CI 0.99-2.28; P=0.051) and ΔΤ (OR for 0.1°C increase 3.40; 95% CI 1.29-8.96; P=0.013) remained in the final analysis with the ΔT being the only variable.

Trans-femoral TAVI: Successful hemostasis of a totally calcified femoral artery ("calcium tube") with the Manta© device.

We describe a case of trans-femoral trans-catheter aortic valve implantation (TF-TAVI) wherein the use of a novel collagen plug-based device (i.e. Manta© device) was very successful in arterial 16 French sheath hemostasis despite an extremely hostile peripheral vessel anatomy due to calcification.

Implications of the local hemodynamic forces on the formation and destabilization of neoatherosclerotic lesions.

OBJECTIVE: To examine the implications of endothelial shear stress (ESS) distribution in the formation of neoatherosclerotic lesions. METHODS: Thirty six patients with neoatherosclerotic lesions on optical coherence tomography (OCT) were included in this study. The OCT data were used to reconstruct coronary anatomy. Blood flow simulation was performed in the models reconstructed from the stent borders which it was assumed that represented the lumen surface at baseline, immediate after stent implantation, and the estimated ESS was associated with the neointima burden, neoatherosclerotic burden and neointima characteristics. In segments with neointima rupture blood flow simulation was also performed in the model representing the lumen surface before rupture and the ESS was estimated at the ruptured site. RESULTS: An inverse association was noted between baseline ESS and the incidence and the burden of neoatherosclerotic (ß = -0.60, P < 0.001, and ß = -4.05, P < 0.001, respectively) and lipid-rich neoatherosclerotic tissue (ß = -0.54, P < 0.001, and ß = -3.60, P < 0.001, respectively). Segments exposed to low ESS (<1 Pa) were more likely to exhibit macrophages accumulation (28.2% vs 10.9%, P < 0.001), thrombus (11.0% vs 2.6%, P < 0.001) and evidence of neointima discontinuities (8.1% vs 0.9%, P < 0.001) compared to those exposed to normal or high ESS. In segments with neointima rupture the ESS was high at the rupture site compared to the average ESS over the culprit lesion (4.00 ±â€¯3.65 Pa vs 3.14 ±â€¯2.90 Pa, P < 0.001). CONCLUSIONS: Local EES is associated with neoatherosclerotic lesion characteristics, which suggests involvement of ESS in the formation of vulnerable plaques in stented segments.

Inhibition of Aortic Valve Calcification by Local Delivery of Zoledronic Acid-an Experimental Study.

The aim of this study was to evaluate in an experimental model of aortic valve (AV) stenosis the effectiveness of zoledronate on the inhibition of calcification. Sixteen New Zealand rabbits were placed on vitamin D-enriched diet for 3 weeks. All animals underwent PET/CT at baseline and before euthanasia to assess calcification. Thereafter, the AVs of eight animals were treated with local delivery of 500 µg/l zoledronate. A placebo mixture was administered in the remaining eight animals. Standardized uptake values were corrected for blood pool activity, providing mean tissue to background ratios (TBRmean). In the zoledronate group, there was no progression of AV calcification (TBRmean 1.20 ± 0.12 vs 1.17 ± 0.78,p = 0.29), while AV calcification progressed in the placebo group (1.22 ± 0.15 vs 1.53 ± 0.23,p = 0.006). Ascending aorta (AA) calcification progressed in both zoledronate and placebo groups. Histology confirmed the results of the PET/CT. Inhibition of AV calcification by local delivery of zoledronate is feasible and effective.

A novel hybrid approach for reconstruction of coronary bifurcations using angiography and OCT.

The aim of this study is to present a new method for three-dimensional (3D) reconstruction of coronary bifurcations using biplane Coronary Angiographies and Optical Coherence Tomography (OCT) imaging. The method is based on a five step approach by improving a previous validated work in order to reconstruct coronary arterial bifurcations. In the first step the lumen borders are detected on the Frequency Domain (FD) OCT images. In the second step a semi-automated method is implemented on two angiographies for the extraction of the 2D bifurcation coronary artery centerline. In the third step the 3D path of the bifurcation artery is extracted based on a back projection algorithm. In the fourth step the lumen borders are placed onto the 3D catheter path. Finally, in the fifth step the intersection of the main and side branches produces the reconstructed model of the coronary bifurcation artery. Data from three patients are acquired for the validation of the proposed methodology and the results are compared against a reconstruction method using quantitative coronary angiography (QCA). The comparison between the two methods is achieved using morphological measures of the vessels as well as comparison of the wall shear stress (WSS) mean values.

Everolimus-eluting bioresorbable vascular scaffolds implanted in coronary bifurcation lesions: Impact of polymeric wide struts on side-branch impairment.

BACKGROUND: Limited data are available on bioresorbable vascular scaffolds (BVS) performance in bifurcations lesions and on the impact of BVS wider struts on side-branch impairment. METHODS: Patients with at least one coronary bifurcation lesion involving a side-branch ≥2mm in diameter and treated with at least one BVS were examined. Procedural and angiographic data were collected and a dedicated methodology for off-line quantitative coronary angiography (QCA) in bifurcation was applied (eleven-segment model), to assess side-branch impairment occurring any time during the procedure. Two- and three-dimensional QCA were used. Optical coherence tomography (OCT) analysis was performed in a subgroup of patients and long-term clinical outcomes reported. RESULTS: A total of 102 patients with 107 lesions, were evaluated. Device- and procedural-successes were 99.1% and 94.3%, respectively. Side-branch impairment occurring any time during the procedure was reported in 13 bifurcations (12.1%) and at the end of the procedure in 6.5%. Side-branch minimal lumen diameter (Pre: 1.45±0.41mm vs Final: 1.48±0.42mm, p=0.587) %diameter-stenosis (Pre: 26.93±16.89% vs Final: 27.80±15.57%, p=0.904) and minimal lumen area (Pre: 1.97±0.89mm(2) vs Final: 2.17±1.09mm(2), p=0.334), were not significantly affected by BVS implantation. Mean malapposed struts at the bifurcation polygon-of-confluence were 0.63±1.11. CONCLUSIONS: The results of the present investigation suggest feasibility and relative safety of BVS implantation in coronary bifurcations. BVS wide struts have a low impact on side-branch impairment when considering bifurcations with side-branch diameter≥2mm.

Validation of renal artery dimensions measured by magnetic resonance angiography in patients referred for renal sympathetic denervation.

RATIONALE AND OBJECTIVES: Magnetic resonance angiography (MRA) is a well-established modality for the assessment of renal artery stenosis. Using dedicated quantitative analyses, MRA can become a useful tool for assessing renal artery dimensions in patients referred for renal sympathetic denervation (RDN) and for providing accurate measurements of vascular response after RDN. The purpose of this study was to test the reproducibility of a novel MRA quantitative imaging tool and to validate these measurements against intravascular ultrasound (IVUS). MATERIALS AND METHODS: In nine patients referred for renal denervation, renal artery dimensions were measured. Bland-Altman analysis was used to assess the intraobserver and interobserver reproducibility. RESULTS: Mean lumen diameter was 5.8 ± 0.7 mm, with a very good intraobserver and interobserver variability of 0.7% (reproducibility: bias, 0 mm; standard deviation [SD], 0.1 mm) and 1.2% (bias, 0 mm; SD, 0.1 mm), respectively. Mean total lumen volume was 1035.3 ± 403.6 mm(3) with good intraobserver and interobserver variability of 2.9% (bias, -9.7 mm(3); SD, 34.0 mm(3)) and 2.8% (bias, -11.4 mm(3); SD, 42.4 mm(3)). The correlation (Pearson R) between mean lumen diameter measured with MRA and IVUS was 0.750 (P = .002). CONCLUSIONS: Using a novel MRA quantitative imaging tool, renal artery dimensions can be measured with good reproducibility and accuracy. MRA-derived diameters and volumes correlated well with IVUS measurements.

Rapid exchange ultra-thin microcatheter using fibre-optic sensing technology for measurement of intracoronary fractional flow reserve.

AIMS: The present report describes a novel coronary fractional flow reserve (FFR) system which allows FFR assessment using a rapid exchange microcatheter (RXi). METHODS AND RESULTS: The RXi microcatheter is compatible with standard 0.014" coronary guidewires facilitating lesion negotiation and FFR assessment in a wide range of coronary anatomies. In case of serial lesions, a microcatheter would have the important advantage of allowing multiple pullbacks while maintaining wire access to the vessel. The RXi is a fibre-optic sensor technology-based device. This technology might allow reduction in signal drift. The RXi microcatheter's fibre-optic sensor is located 5 mm from the distal tip. The microcatheter profile at the sensor site is 0.027"0.036". The segment of the catheter which is intended to reside within the target lesion is proximal to the sensor and has dimensions decreased to 0.020"0.025"; these dimensions are comparable to a 0.022" circular-shaped wire. CONCLUSIONS: The RXi microcatheter FFR system represents a novel technology that could allow easier lesion negotiation, maintaining guidewire position, facilitating pullbacks for assessment of serial lesions and simplifying the obtainment of post-intervention FFR measurements. The optical sensing technology could additionally result in less signal drift. Further investigations are required to evaluate the clinical value of this technology fully.

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.

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.

The impact of new generation drug-eluting stent implantation on patients with chronic kidney disease and a single lesion in the proximal segment of the left anterior descending artery.

INTRODUCTION: The impact of drug-eluting stents (DES) has not been extensively investigated in patients with moderate to severe renal dysfunction, as these patients are consistently excluded from randomised studies. We sought to assess prospectively the effectiveness and safety of the new-generation DES in patients with moderate chronic kidney disease (CKD) and an isolated de novo lesion in the proximal segment of the left anterior descending artery (pLAD). METHODS: We evaluated 400 consecutive patients with a pLAD lesion. There were 96 patients with moderate CKD (estimated glomerular filtration rate 59 ml/min/1.73 m2) and 304 without CKD. Major adverse cardiac events (MACE) were defined as death, non-fatal myocardial infarction and target lesion revascularisation (TLR). Clinical or telephone follow up was performed. RESULTS: There was a significantly higher incidence of mortality in patients with CKD (n=4) as compared with non-CKD (n=2) (4.16% versus 0.65%, respectively, p=0.03). The rate of non-fatal myocardial infarction was similar in the 2 cohorts (p=0.59), as was the TLR rate (p=0.99). Overall, there were no significant differences regarding MACE between the 2 groups of patients (p=0.19) during the 13.62 ± 6.22 month follow-up period. The rate of angiographic stent thrombosis was 2.08% in the CKD group versus 0.98% in the non-CKD group (p=0.59). CONCLUSIONS: New generation DES implantation in patients with CKD and a pLAD lesion is effective and safe, with rates of TLR and stent thrombosis comparable to those in patients with normal renal function. However, the higher mortality in patients with CKD needs further evaluation.

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 patient's functional capacity.

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.