OCT-Derived Plaque Morphology and FFR-Determined Hemodynamic Relevance in Intermediate Coronary Stenoses.

BACKGROUND: optical coherence tomography (OCT) might allow identifying lesion features reportedly associated with plaque vulnerability and increased risk of clinical events. Previous studies on correlation between OCT and functional lesion significance indices reported contradictory results, yet integration of complementary information from both modalities is gaining increased interest. The aim of the study was to compare plaque morphology using OCT in hemodynamically relevant vs. non-relevant lesions by fractional flow reserve (FFR). METHODS: consecutive patients with intermediate grade coronary stenoses by angiography were evaluated by both FFR and OCT in this single-center study. Stenoses were labeled hemodynamically relevant in case of the FFR ≤ 0.80. Minimal lumen area (MLA), fibrous cap thickness (FCT), minimal cap thickness over the calcium, angle of the calcium, and necrotic core within the lesions were evaluated. RESULTS: a total of 105 patients (124 vessels) were analyzed. Of them, 65 patients were identified with at least one lesion identified as hemodynamically relevant by FFR (72 vessels, 58.1%). Lesions with FFR ≤0.80 presented with lower mean and minimal lumen area (3.46 ± 1.29 vs. 4.65 ± 2.19, p =0.001 and 1.84 ± 0.97 vs. 2.66 ± 1.40, p = 0.001) compared to patients with FFR > 0.80. No differences were found between groups in the mean and minimal FCT, mean, and maximal necrotic core, calcium angle, as well as the overall rate of calcified and lipid plaques. CONCLUSION: hemodynamic relevance of intermediate grade lesions correlated moderately with the luminal assessment by OCT. No differences were identified in the plaque morphology between relevant and non-relevant coronary stenoses by FFR.

Reproducibility of optical coherence tomography in vein grafts used for coronary revascularization.

BACKGROUND: Optical coherence tomography (OCT) is a high-resolution imaging modality able to provide near-histological images of vessel walls making it possible to distinguish intima and media layers of the vessel wall separately. The use of this imaging technique is increasing while data on the variability and reliability is lacking. The aim of this study was to investigate the reproducibility of frequency-domain OCT in vein grafts used for coronary revascularization. METHODS: Five pullbacks were analyzed by the same analyst with a 1-month delay (intraobserver) and by two different analysts (interobserver). Five pairs of pullbacks from the same catheters and vein graft were also analyzed (inter pullback). RESULTS: Optical coherence tomography showed low variability in intra- and interobserver analysis with relative differences of mean media and intima thicknesses and areas of less than 5% for most parameters. Relative differences of the same parameters in the inter pullback analysis were in the 5-15% range. Intra- and interobserver reliability was excellent (intraclass correlation coefficient [ICC] > 0.90) for intima thickness and intima, media and intima-media area measurements. Inter pullback reliability was good (ICC: 0.75-0.90) for intima and intima-media area measurements, and moderate to good for mean intima thickness measurements (ICC: 0.79; 0.7338-0.8284). CONCLUSIONS: Optical coherence tomography provides good reproducibility for the measurements of parameters relevant for the development of atherosclerosis in vein grafts. CLINICAL TRIAL REGISTRATION: ID NCT01834846.

The effect of aging and muscle type on the quality characteristics and lipid oxidation of lamb meat.

The research carried out on meat from 45 ram lambs of the Polish merino breed allowed to determine the effect of meat aging and muscle type on physicochemical characteristics and oxidative stability of lipids. Analysis of physicochemical traits (pH, meat color, expressed juice, cooking loss, shear force, moisture, protein, fat and total collagen content) was performed on fresh and meat aged for 14 d in the longissimus lumborum (LL) and gluteus medius (GM) muscles. The meat aging determined all physicochemical characteristics except protein and fat content. More changes in pH and meat color parameters were defined in the GM muscle compared to the LL muscle. The increase in the tenderness of meat expressed as a reduction ( P < 0.05 ) of shear force values was observed in both muscles aged for 14 d. A lower value ( P < 0.05 ) of the shear force, despite the higher content of collagen, was determined in the GM muscle compared to LL. The investigated muscles differed in the degree of lipid peroxidation expressed as thiobarbituric acid-reactive substances (TBARS) in both fresh and aged meat. The TBARS value was lower ( P < 0.05 ) in the LL muscle than in GM. In the longissimus lumborum muscle, the significantly lower content of polyunsaturated fatty acids (PUFAs) and PUFA n-6 has been recorded. The oxidation stability was not influenced by the meat aging.

Highly-calcific carotid lesions endovascular management in symptomatic and increased-stroke-risk asymptomatic patients using the CGuard™ dual-layer carotid stent system: Analysis from the PARADIGM study.

OBJECTIVES: To assess feasibility, safety, angiographic, and clinical outcome of highly-calcific carotid stenosis (HCCS) endovascular management using CGuard™ dual-layer carotid stents. BACKGROUND: HCCS has been a challenge to carotid artery stenting (CAS) using conventional stents. CGuard combines a high-radial-force open-cell frame conformability with MicroNet sealing properties. METHODS: The PARADIGM study is prospectively assessing routine CGuard use in all-comer carotid revascularization patients; the focus of the present analysis is HCCS versus non-HCCS lesions. Angiographic HCCS (core laboratory evaluation) required calcific segment length to lesion length ≥2/3, minimal calcification thickness ≥3 mm, circularity (≥3 quadrants), and calcification severity grade ≥3 (carotid calcification severity scoring system [CCSS]; G0-G4). RESULTS: One hundred and one consecutive patients (51-86 years, 54.4% symptomatic; 106 lesions) received CAS (16 HCCS and 90 non-HCCS); eight others (two HCCS) were treated surgically. CCSS evaluation was reproducible, with weighted kappa (95% CI) of 0.73 (0.58-0.88) and 0.83 (0.71-0.94) for inter- and intra-observer reproducibility respectively. HCCS postdilatation pressures were higher than those in non-HCCS; 22 (20-24) versus 20 (18-24) atm, p = .028; median (Q1-Q3). Angiography-optimized HCCS-CAS was feasible and free of contrast extravasation or clinical complications. Overall residual diameter stenosis was single-digit but it was higher in HCCS; 9 (4-17) versus 3 (1-7) %, p = .002. At 30 days and 12 months HCCS in-stent velocities were normal and there were no adverse clinical events. CONCLUSION: CGuard HCCS endovascular management was feasible and safe. A novel algorithm to grade carotid artery calcification severity was reproducible and applicable in clinical study setting. Larger HCCS series and longer-term follow-up are warranted.

In vivo comparison of key quantitative parameters measured with 3D peripheral angiography, 2D peripheral quantitative angiography and intravascular ultrasound.

The aim of this study was to compare the measures of luminal stenosis between the two-dimensional (2D) and three-dimensional (3D) Quantitative Vessel Analysis (QVA) generated by CAAS QVA software and intravascular ultrasound (IVUS). Invasive contrast angiography is considered gold standard for diagnostic imaging and intervention in both coronary and peripheral arterial disease. However, it is based on 2D images depicting complicated 3D arterial anatomy. To overcome these limitations, 3D QVA has been developed to bridge the gap between 2D QVA and endovascular imaging. Thirty porcine femoral angiograms (common, profunda and superficial) with matching intravascular ultrasound (IVUS) pullbacks featuring variable degree of stenosis were analysed by 2D QVA, 3D QVA and quantitative IVUS. All 3 modalities provided similar data regarding the length of the investigated segment. Median lumen diameter was nearly identical in IVUS (4.69 mm) and in 3D QVA (4.76 mm) but quite a bit lower in 2D QVA (4.47 mm, Kruskal-Wallis test p = 0.1648). Lumen area measured in 2D QVA was lower than in IVUS and in 3D QVA. Lumen areas rendered by IVUS and 3D QVA were similar. Bland-Altman plots showed that the lowest differences were observed between IVUS and 3D QVA. IVUS and 3D QVA results were consistently higher than 2D QVA. 3D QVA is a useful surrogate of IVUS for precise luminal morphology measurements of peripheral arteries, rendering results that are much closer to IVUS than 2D QVA can provide.

Fully Automated Lumen Segmentation Method for Intracoronary Optical Coherence Tomography.

Background: Optical coherence tomography (OCT) is an innovative imaging technique that generates high-resolution intracoronary images. In the last few years, the need for more precise analysis regarding coronary artery disease to achieve optimal treatment has made intravascular imaging an area of primary importance in interventional cardiology. One of the main challenges in OCT image analysis is the accurate detection of lumen which is significant for the further prognosis. Method: In this research, we present a new approach to the segmentation of lumen in OCT images. The proposed work is focused on designing an efficient automatic algorithm containing the following steps: preprocessing (artifacts removal: speckle noise, circular rings, and guide wire), conversion between polar and Cartesian coordinates, and segmentation algorithm. Results: The implemented method was tasted on 667 OCT frames. The lumen border was extracted with a high correlation compared to the ground truth: 0.97 ICC (0.97-0.98). Conclusions: Proposed algorithm allows for fully automated lumen segmentation on optical coherence tomography images. This tool may be applied to automated quantitative lumen analysis.