Coronary Optical Coherence Tomography Research Articles

The association of cholesterol crystals and non-culprit plaque characteristics in AMI patients: an OCT study

Objective: To analyze plaque characteristics of non-culprit coronary lesions with cholesterol crystals in patients with acute myocardial infarction(AMI) by using optical coherence tomography(OCT). We also investigated the potential association between cholesterol crystals with plaque rupture and healed plaque at non-culprit segment. Methods: This study was a retrospective cohort study. Between January 2017 and December 2017, patients with AMI who underwent 3-vessel OCT imaging were included in this study. Patients were divided into two groups according to the presence or absence of cholesterol crystals at the non-culprit lesions. All patients underwent coronary angiography and OCT examination, and non-culprit plaque characteristics were compared between the two groups. The generalized estimating equation log-binomial multirariate regression model was used to assess the relationship between non-culprit lesions with cholesterol crystals and plaque rupture and plaque healing. The follow-up data collection ended in October 2023. Kaplan-Meier survival curves were plotted, and log-rank tests were used to compare the cumulative incidence of major adverse cardiovascular events between the two groups. Results: A total of 173 AMI patients were included (aged (56.8±11.6) years; 124 men (71.7%)). Among 710 non-culprit lesions identified by OCT, there were 102 (14.4%) in cholesterol crystals group and 608 (85.6%) in non-cholesterol crystals group. Compared with non-culprit lesions without cholesterol crystals, those with cholesterol crystals had smaller minimum lumen diameter, severer diameter stenosis, and longer lesion length (all P<0.01). The prevalence of plaque rupture (17.6% (18/102) vs. 4.9% (30/608), P=0.001) and thin-cap fibroatheroma (31.4% (32/102) vs. 11.5% (70/608), P<0.01) was higher in the cholesterol crystals groups than in the non-cholesterol crystals group. In addition, vulnerable plaque characteristics such as (44.1% (45/102) vs. 25.8% (157/608), P<0.01), macrophages were more frequently observed in non-culprit lesions with cholesterol crystals. The generalized estimating equation log-binomial multivariate regression analyses showed that non-culprit cholesterol crystals were positively correlated with healed plaque (OR=1.583, 95%CI: 1.004-2.495, P=0.048). Conversely, cholesterol crystals were not associated with plaque rupture (OR=1.632, 95%CI: 0.745-3.576, P=0.221). The follow-up time was 2 142 (1 880, 2 198) days. Non-culprit cholesterol crystals were not related to the major adverse cardiovascular events in patients with AMI (log-rank P=0.558). Conclusions: Among AMI patients, non-culprit lesions with cholesterol crystals presented with severer luminal stenosis and increased plaque vulnerability. The presence of non-culprit cholesterol crystals was associated with rather than plaque rupture.

Predictive value of plaque characteristics for identification of lesions causing ischemia

BackgroundFunctional assessment using fractional flow reserve (FFR) and anatomical assessment using optical coherence tomography (OCT) are used in clinical practice for patients with intermediate coronary stenosis. Moreover, coronary computed tomography angiography (CTA) is a common noninvasive imaging technique for evaluating suspected coronary artery disease before being referred for angiography. This study aimed to investigate the association between FFR and plaque characteristics assessed using coronary CTA and OCT for intermediate coronary stenosis. MethodsBased on a prospective multicenter registry, 159 patients having 339 coronary lesions with intermediate stenosis were included. All patients underwent coronary CTA before being referred for coronary angiography, and both FFR measurements and OCT examinations were performed during angiography. A stenotic lesion identified with FFR ≤0.80 was deemed diagnostic of an ischemia-causing lesion. The predictive value of plaque characteristics assessed using coronary CTA and OCT for identifying lesions causing ischemia was analyzed. ResultsStenosis severity and plaque characteristics on coronary CTA and OCT differed between lesions that caused ischemia and those that did not. In multivariate analysis, low attenuation plaque on coronary CTA (odds ratio [OR]=2.78; P=0.038), thrombus (OR=5.13; P=0.042), plaque rupture (OR=3.25; P=0.017), and intimal vasculature on OCT (OR=2.57; P=0.012) were independent predictors of ischemic lesions. Increasing the number of these plaque characteristics offered incremental improvement in predicting the lesions causing ischemia. ConclusionsComprehensive anatomical evaluation of coronary stenosis may provide additional supportive information for predicting the lesions causing ischemia.

Structurally constrained and pathology-aware convolutional transformer generative adversarial network for virtual histology staining of human coronary optical coherence tomography images.

There is a significant need for the generation of virtual histological information from coronary optical coherence tomography (OCT) images to better guide the treatment of coronary artery disease (CAD). However, existing methods either require a large pixel-wise paired training dataset or have limited capability to map pathological regions. The aim of this work is to generate virtual histological information from coronary OCT images, without a pixel-wise paired training dataset while capable of providing pathological patterns. We design a structurally constrained, pathology-aware, transformer generative adversarial network, namely structurally constrained pathology-aware convolutional transformer generative adversarial network (SCPAT-GAN), to generate virtual stained H&E histology from OCT images. We quantitatively evaluate the quality of virtual stained histology images by measuring the Fréchet inception distance (FID) and perceptual hash value (PHV). Moreover, we invite experienced pathologists to evaluate the virtual stained images. Furthermore, we visually inspect the virtual stained image generated by SCPAT-GAN. Also, we perform an ablation study to validate the design of the proposed SCPAT-GAN. Finally, we demonstrate 3D virtual stained histology images. Compared to previous research, the proposed SCPAT-GAN achieves better FID and PHV scores. The visual inspection suggests that the virtual histology images generated by SCPAT-GAN resemble both normal and pathological features without artifacts. As confirmed by the pathologists, the virtual stained images have good quality compared to real histology images. The ablation study confirms the effectiveness of the combination of proposed pathological awareness and structural constraining modules. The proposed SCPAT-GAN is the first to demonstrate the feasibility of generating both normal and pathological patterns without pixel-wisely supervised training. We expect the SCPAT-GAN to assist in the clinical evaluation of treating the CAD by providing 2D and 3D histopathological visualizations.

Iso-osmolar vs low-osmolar contrast agents for coronary optical coherence tomography: a blinded prospective randomized controlled study.

The impact of contrast type on coronary optical coherence tomography (OCT) imaging has received limited research. We conducted a blinded, prospective, single-center, randomized, controlled crossover study comparing iso-osmolar contrast media (IOCM) with low-osmolar contrast media (LOCM) in patients undergoing clinically indicated coronary OCT imaging. Patients were randomly assigned to undergo OCT imaging with either IOCM or LOCM as the initial contrast medium. Following a washout period, a second run of OCT imaging of the same coronary vessel was performed using the other contrast medium. A total of 62 patients were randomized to IOCM first (n = 31) or LOCM first (n = 31). Mean patient age was 65.9 ± 11.2 years and 74.2% were male, with high prevalence of dyslipidemia (82.3%) and prior myocardial infarction (41.9%). Percutaneous coronary intervention was performed in 60 cases (96.8%) and the left anterior descending artery was the most common target vessel (53.3%). The contrast volume used for OCT imaging was similar for IOCM and LOCM (8.0 [6.9, 9.0] mL vs 8.0 [6.7, 9.0] mL; P = .89), as was the length of clear OCT images (70.0 [62.8, 74.0] mm for IOCM vs 70.0 [64.0, 74.0] mm for LOCM; P = .65). Electrocardiographic changes were observed in 11 runs with IOCM (ventricular repolarization changes in 9 runs and premature ventricular contractions [PVCs] in 2 runs) vs 12 runs with LOCM (ventricular repolarization changes in 9 runs and PVCs in 3 runs). The use of IOCM in coronary OCT is associated with similar contrast volume and clear imaging length when compared with LOCM.

Rapid automated lumen segmentation of coronary optical coherence tomography images followed by 3D reconstruction of coronary arteries.

Optical coherence tomography has emerged as an important intracoronary imaging technique for coronary artery disease diagnosis as it produces high-resolution cross-sectional images of luminal and plaque morphology. Precise and fast lumen segmentation is essential for efficient OCT morphometric analysis. However, due to the presence of various image artifacts, including side branches, luminal blood artifacts, and complicated lesions, this remains a challenging task. Our research study proposes a rapid automatic segmentation method that utilizes nonuniform rational B-spline to connect limited pixel points and identify the edges of the OCT lumen. The proposed method suppresses image noise and accurately extracts the lumen border with a high correlation to ground truth images based on the area, minimal diameter, and maximal diameter. We evaluated the method using 3300 OCT frames from 10 patients and found that it achieved favorable results. The average time taken for automatic segmentation by the proposed method is 0.17s per frame. Additionally, the proposed method includes seamless vessel reconstruction following the lumen segmentation. The developed automated system provides an accurate, efficient, robust, and user-friendly platform for coronary lumen segmentation and reconstruction, which can pave the way for improved assessment of the coronary artery lumen morphology.

Diagnostic accuracy of a novel optical coherence tomography-based fractional flow reserve algorithm for assessment of coronary stenosis significance.

This study aimed to introduce a novel optical coherence tomography-derived fractional flow reserve (FFR) computational approach and assess the diagnostic performance of the algorithm for assessing physiological function. The fusion of coronary optical coherence tomography and angiography was used to generate a novel FFR algorithm (AccuFFRoct) to evaluate functional ischemia of coronary stenosis. In the current study, a total of 34 consecutive patients were included, and AccuFFRoct was used to calculate the FFR for these patients. With the wire-measured FFR as the reference standard, we evaluated the performance of our approach by accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Per vessel accuracy, sensitivity, specificity, PPV, and NPV for AccuFFRoct in identifying hemodynamically significant coronary stenosis were 93.8%, 94.7%, 92.3%, 94.7%, and 92.3%, respectively, were found. Good correlation (Pearson's correlation coefficient r = 0.80, p < 0.001) between AccuFFRoct and FFR was observed. The Bland-Altman analysis showed a mean difference value of -0.037 (limits of agreement: -0.189 to 0.115). The area under the receiver-operating characteristic curve (AUC) of AccuFFRoct in identifying physiologically significant stenosis was 0.94, which was higher than the minimum lumen area (MLA, AUC = 0.91) and significantly higher than the diameter stenosis (%DS, AUC = 0.78). This clinical study shows the efficiency and accuracy of AccuFFRoct for clinical implementation when using invasive FFR measurement as a reference. It could provide important insights into coronary imaging superior to current methods based on the degree of coronary artery stenosis.

Abstract 14321: High Sensitivity C-Reactive Protein is Associated With Plaque Vulnerability and Increased Incidence of Adverse Events in Patients With Stable Coronary Disease

Introduction: Higher level of high sensitivity C-reactive protein (hsCRP) is associated with an increased risk of cardiovascular events in patients with coronary artery disease (CAD). However, the pathogenesis of the worse clinical outcomes in CAD patients with high hsCRP remains to be elucidated. Hypothesis: Higher hsCRP is associated with a higher prevalence of vulnerable characteristics in coronary plaques and an increased incidence of adverse events in patients with CAD. Methods: A total of 793 consecutive patients with stable CAD, who underwent intra coronary optical coherence tomography (OCT) imaging of the culprit vessel during percutaneous coronary intervention were included. Patients were classified into the higher hsCRP group (hsCRP ≥ 0.2 mg/dL, n=247) or the lower hsCRP group (hsCRP &lt; 0.2 mg/dL, n=546). OCT characteristics and clinical outcomes were investigated according to the level of hsCRP. Results: The prevalence of thin-cap fibroatheroma (TCFA) (32.0% vs. 20.9%, p &lt;0.001) and plaque with macrophage (53.9% vs. 46.2%, p =0.045) was significantly higher in the higher hsCRP group than in the lower hsCRP group (Panel A). The incidence of myocardial infarction was significantly higher in the higher hsCRP group than in the lower hsCRP group (log-rank p =0.006) during a median 938 days follow-up (Panel B) although the incidence of the composite of major adverse cardiac events was comparable (log-rank p =0.282). Among the four groups classified by the hsCRP level and the presence of TCFA, the incidence of myocardial infarction was the highest in the group with higher hsCRP and TCFA (log-rank p =0.017). Conclusions: Higher level of hsCRP was associated with a higher prevalence of vulnerable characteristics in coronary plaques and worse clinical outcomes in patients with stable CAD. The risk of recurrent myocardial infarction in patients with high hsCRP levels was further increased by the presence of TCFA.

Frequency-aware optical coherence tomography image super-resolution via conditional generative adversarial neural network.

Optical coherence tomography (OCT) has stimulated a wide range of medical image-based diagnosis and treatment in fields such as cardiology and ophthalmology. Such applications can be further facilitated by deep learning-based super-resolution technology, which improves the capability of resolving morphological structures. However, existing deep learning-based method only focuses on spatial distribution and disregards frequency fidelity in image reconstruction, leading to a frequency bias. To overcome this limitation, we propose a frequency-aware super-resolution framework that integrates three critical frequency-based modules (i.e., frequency transformation, frequency skip connection, and frequency alignment) and frequency-based loss function into a conditional generative adversarial network (cGAN). We conducted a large-scale quantitative study from an existing coronary OCT dataset to demonstrate the superiority of our proposed framework over existing deep learning frameworks. In addition, we confirmed the generalizability of our framework by applying it to fish corneal images and rat retinal images, demonstrating its capability to super-resolve morphological details in eye imaging.

Calcium evaluation using coronary computed tomography in combination with optical coherence tomography.

Optical coherence tomography (OCT) can assess calcium thickness, a key factor for predicting good stent expansion; however, it underestimates coronary calcium severity due to its penetration limitation. This study aimed to evaluate computed tomography (CT) and OCT images to assess calcification. We investigated 25 left anterior descending arteries of 25 patients, using coronary CT and OCT, and assessed their calcification. Of the 25 vessels, 1811 pairs of CT and OCT cross-sectional images were co-registered. Of the 1811 cross-sectional CT images, calcification was not detectable in 256 (14.1%) of the corresponding OCT images due to limited penetration. In the 1555 OCT calcium-detectable images, the maximum calcium thickness was not detectable in 763 (49.1%) images compared to the CT images. In CT images of slices corresponding to undetected calcium in OCT images, the angle, thickness, and maximum density of calcium were significantly smaller compared to slices corresponding to detected calcium in OCT. Calcium with an undetectable maximum thickness in the corresponding OCT image had a significantly greater calcium angle, thickness, and density than calcium with a detectable maximum thickness. There was an excellent correlation between CT and OCT with respect to calcium angle ( R= 0.82, P < 0.001). The calcium thickness on the OCT image had a stronger correlation with the maximum density on the corresponding CT image (R = 0.73, P < 0.001) than with the calcium thickness on the CT image (R = 0.61, P < 0.001). Cross-sectional CT imaging allows for pre-procedural assessment of calcium morphology and severity and could complement the lack of information on calcium severity in OCT-guided percutaneous coronary intervention.

Peripheral atherosclerosis in acute coronary syndrome patients with plaque rupture vs plaque erosion: A prospective coronary optical coherence tomography and peripheral ultrasound study

Plaque rupture (PR) and plaque erosion (PE) are two distinct, different, and most common culprit lesion morphologies responsible for acute coronary syndrome (ACS). However, the prevalence, distribution, and characteristics of peripheral atherosclerosis in ACS patients with PR vs PE has never been studied. The aim of this study was to assess peripheral atherosclerosis burden and vulnerability evaluated by vascular ultrasound in ACS patients with coronary PR versus PE identified by optical coherence tomography (OCT). Between October 2018 and December 2019, 297 ACS patients who underwent preintervention OCT examination of the culprit coronary artery were enrolled. Peripheral ultrasound examinations of carotid, femoral, and popliteal arteries were performed before discharge. Overall, 265/297 (89.2%) patients had at least one atherosclerotic plaque in a peripheral arterial bed. Compared with coronary PE, patients with coronary PR had a higher prevalence of peripheral atherosclerotic plaques (93.4% vs 79.1%, P<0.001), regardless of location: carotid, femoral, or popliteal arteries. The number of peripheral plaques per patient was significantly larger in the coronary PR group than coronary PE (4 [2-7] vs 2 [1-5], P<0.001). Additionally, there was a greater prevalence of peripheral vulnerable characteristics including plaque surface irregularity, heterogeneous plaque, and calcification in patients with coronary PR versus PE. Peripheral atherosclerosis exists commonly in patients presenting with ACS. Patients with coronary PR had greater peripheral atherosclerosis burden and more peripheral vulnerability compared to those with coronary PE, suggesting that comprehensive evaluation of peripheral atherosclerosis and multidisciplinary cooperative management maybe necessary, especially in patients with PR. clinicaltrials.gov (NCT03971864).

Sk-Conv and SPP-based UNet for lesion segmentation of coronary optical coherence tomography.

Coronary artery disease (CAD) manifests with a blockage the coronary arteries, usually due to plaque buildup, and has a serious impact on the human life. Atherosclerotic plaques, including fibrous plaques, lipid plaques, and calcified plaques can lead to occurrence of CAD. Optical coherence tomography (OCT) is employed in the clinical practice as it clearly provides a detailed display of the lesion plaques, thereby assessing the patient's condition. Analyzing the OCT images manually is a very tedious and time-consuming task for the clinicians. Therefore, automatic segmentation of the coronary OCT images is necessary. In view of the good utility of Unet network in the segmentation of medical images, the present study proposed the development of a Unet network based on Sk-Conv and spatial pyramid pooling modules to segment the coronary OCT images. In order to extract multi-scale features, these two modules were added at the bottom of UNet. Meanwhile, ablation experiments are designed to verify each module is effective. After testing, our model achieves 0.8935 on f1 score and 0.7497 on mIOU. Compared to the current advanced models, our model performs better. Our model achieves good results on OCT sequences.

Deep learning empowered highly compressive SS-OCT via learnable spectral-spatial sub-sampling.

With the rapid advances of light source technology, the A-line imaging rate of swept-source optical coherence tomography (SS-OCT) has experienced a great increase in the past three decades. The bandwidths of data acquisition, data transfer, and data storage, which can easily reach several hundred megabytes per second, have now been considered major bottlenecks for modern SS-OCT system design. To address these issues, various compression schemes have been previously proposed. However, most of the current methods focus on enhancing the capability of the reconstruction algorithm and can only provide a data compression ratio (DCR) up to 4 without impairing the image quality. In this Letter, we proposed a novel design paradigm, in which the sub-sampling pattern for interferogram acquisition is jointly optimized with the reconstruction algorithm in an end-to-end manner. To validate the idea, we retrospectively apply the proposed method on an ex vivo human coronary optical coherence tomography (OCT) dataset. The proposed method could reach a maximum DCR of ∼62.5 with peak signal-to-noise ratio (PSNR) of 24.2 dB, while a DCR of ∼27.78 could yield a visually pleasant image with a PSNR of ∼24.6 dB. We believe the proposed system could be a viable remedy for the ever-growing data issue in SS-OCT.

Toward reliable calcification detection: calibration of uncertainty in object detection from coronary optical coherence tomography images.

Optical coherence tomography (OCT) has become increasingly essential in assisting the treatment of coronary artery disease (CAD). However, unidentified calcified regions within a narrowed artery could impair the outcome of the treatment. Fast and objective identification is paramount to automatically procuring accurate readings on calcifications within the artery. We aim to rapidly identify calcification in coronary OCT images using a bounding box and reduce the prediction bias in automated prediction models. We first adopt a deep learning-based object detection model to rapidly draw the calcified region from coronary OCT images using a bounding box. We measure the uncertainty of predictions based on the expected calibration errors, thus assessing the certainty level of detection results. To calibrate confidence scores of predictions, we implement dependent logistic calibration using each detection result's confidence and center coordinates. We implemented an object detection module to draw the boundary of the calcified region at a rate of 140 frames per second. With the calibrated confidence score of each prediction, we lower the uncertainty of predictions in calcification detection and eliminate the estimation bias from various object detection methods. The calibrated confidence of prediction results in a confidence error of , suggesting that the confidence calibration on calcification detection could provide a more trustworthy result. Given the rapid detection and effective calibration of the proposed work, we expect that it can assist in clinical evaluation of treating the CAD during the imaging-guided procedure.

Correction to: Coronary Optical Coherence Tomography and Cardiac Magnetic Resonance Imaging to Determine Underlying Causes of Myocardial Infarction With Nonobstructive Coronary Arteries in Women.

HomeCirculationVol. 147, No. 8Correction to: Coronary Optical Coherence Tomography and Cardiac Magnetic Resonance Imaging to Determine Underlying Causes of Myocardial Infarction With Nonobstructive Coronary Arteries in Women Free AccessCorrectionPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessCorrectionPDF/EPUBCorrection to: Coronary Optical Coherence Tomography and Cardiac Magnetic Resonance Imaging to Determine Underlying Causes of Myocardial Infarction With Nonobstructive Coronary Arteries in Women Originally published20 Feb 2023https://doi.org/10.1161/CIR.0000000000001132Circulation. 2023;147:e624This article corrects the followingCoronary Optical Coherence Tomography and Cardiac Magnetic Resonance Imaging to Determine Underlying Causes of Myocardial Infarction With Nonobstructive Coronary Arteries in WomenIn the article by Reynolds and Hochman, “Coronary Optical Coherence Tomography and Cardiac Magnetic Resonance Imaging to Determine Underlying Causes of Myocardial Infarction With Nonobstructive Coronary Arteries in Women,” which published online on November 14, 2020, and appears in the February 16, 2021, issue of the journal (Circulation.2021;143:624–640. DOI: 10.1161/CIRCULATIONAHA.120.052008), a correction is needed.The links to the Supplemental Material were incorrect.The corrections have been made to the current online version of the article, which is available at https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.120.052008.FootnotesCirculation is available at www.ahajournals.org/journal/circ Previous Back to top Next FiguresReferencesRelatedDetailsRelated articlesCoronary Optical Coherence Tomography and Cardiac Magnetic Resonance Imaging to Determine Underlying Causes of Myocardial Infarction With Nonobstructive Coronary Arteries in WomenHarmony R. Reynolds, et al. Circulation. 2021;143:624-640 February 21, 2023Vol 147, Issue 8 Advertisement Article InformationMetrics © 2023 American Heart Association, Inc.https://doi.org/10.1161/CIR.0000000000001132 Originally publishedFebruary 20, 2023 PDF download Advertisement

Third-Generation Sirolimus‐Eluting Bioresorbable Tyrocore Scaffold Implantation in Patients with ST‐Segment Elevation Myocardial Infarction: Baseline and 6-Month OCT and Clinical Outcomes—a FANTOM STEMI Pilot Study

PurposeThe aim of this study was to evaluate the safety and efficacy of the Fantom BRS 6 months after implantation using the optical coherence tomography (OCT) imaging.MethodsTwenty STEMI patients treated with a sirolimus‐eluting Fantom BRS were enrolled into a prospective, single-arm, serial observational study. The scaffold sizing, positioning and optimisation were guided by OCT imaging. The primary endpoint was device‐orientated composite endpoints (DOCE), comprised of cardiac death, target-vessel-related myocardial infarction and target lesion failure. To evaluate the device performance at the scaffold level, we performed a quantitative coronary angiography (QCA) and OCT imaging at 6 months.ResultsThe primary endpoint did not occur in any patient within the 6-month follow‐up. There were no major adverse cardiac events (MACEs) or DOCEs, no cases of scaffold thrombosis, target lesion revascularization and no deaths. In QCA, we observed a decrease in the minimum and mean lumen diameter in the in-scaffold region and in the proximal and distal peri-scaffold region. Similarly, the minimum lumen area and reference vessel diameter had decreased in both QCA and OCT. The OCT imaging showed improvement in the expansion index and malposition rate.ConclusionA serial 6-month OCT imaging after implantation of a third-generation Tyrocore-based bioresorbable coronary scaffold indicated good coverage of the struts with excellent healing of the scaffold, low neointima growth and no signs of neoatherosclerosis.

Radial wall strain: a novel angiographic measure of plaque composition and vulnerability.

The lipid-to-cap ratio (LCR) and thin-cap fibroatheroma (TCFA) derived from optical coherence tomography (OCT) are indicative of plaque vulnerability. We aimed to explore the association of a novel method to estimate radial wall strain (RWS) from angiography with plaque composition and features of vulnerability assessed by OCT. Anonymised data from patients with intermediate stenosis who underwent coronary angiography (CAG) and OCT were analysed in a core laboratory. Angiography-derived RWSmax was computed as the maximum deformation of lumen diameter throughout the cardiac cycle, expressed as a percentage of the largest lumen diameter. The LCR and TCFA were automatically determined on OCT images by a recently validated algorithm based on artificial intelligence. OCT and CAG images from 114 patients (124 vessels) were analysed. The average time for the analysis of RWSmax was 57 (39-82) seconds. The RWSmax in the interrogated plaques was 12% (10-15%) and correlated positively with the LCR (r=0.584; p<0.001) and lipidic plaque burden (r=0.411; p<0.001), and negatively with fibrous cap thickness (r= -0.439; p<0.001). An RWSmax >12% was an angiographic predictor for an LCR >0.33 (area under the curve [AUC]=0.86, 95% confidence interval [CI]: 0.78-0.91; p<0.001) and TCFA (AUC=0.72, 95% CI: 0.63-0.80; p<0.001). Lesions with RWSmax >12% had a higher prevalence of TCFA (22.0% versus 1.5%; p<0.001), thinner fibrous cap thickness (71 μm versus 101 μm; p<0.001), larger lipidic plaque burden (23.3% versus 15.4%; p<0.001), and higher maximum LCR (0.41 versus 0.18; p<0.001) compared to lesions with RWSmax ≤12%. Angiography-derived RWS was significantly correlated with plaque composition and known OCT features of plaque vulnerability in patients with intermediate coronary stenosis.

Role of genetics in the development of cardiac allograft vasculopathy.

The association between genetic polymorphisms and early cardiac allograft vasculopathy (CAV) development is relatively unexplored. Identification of genes involved in the CAV process may offer new insights into pathophysiology and lead to a wider range of therapeutic options. This prospective study of 109 patients investigated 44 single nucleotide polymorphisms (SNPs) within the susceptibility loci potentially related to coronary artery disease, carotid artery intima-media thickness (cIMT), and in nitric oxide synthase gene. Genotyping was done by the Fluidigm SNP Typeassays and Fluidigm 48.48 Dynamic ArrayIFC. The intima thickness progression (IT) was evaluated by coronary optical coherence tomography performed 1 month and 12 months after heart transplantation (HTx). During the first post-HTx year, the mean intima thickness (IT) increased by 24.0 ± 34.2 µm (p < 0.001) and lumen area decreased by ‒0.9 ± 1.8 mm2 (p < 0.001). The rs1570360 (A/G) SNP of the vascular endothelial growth factor A (VEGFA) gene showed the strongest association with intima thickness progression, even in the presence of the traditional CAV risk factors. SNPs previously related to carotid artery intima-media thickness rs11785239 (PRAG1), rs6584389 (PAX2), rs13225723 (LINC02577) and rs17477177 (CCDC71L), were among the five most significantly associated with IT progression but lost their significance once traditional CAV risk factors had been added. Results of this study suggest that genetic variability may play an important role in CAV development. The vascular endothelial growth factor A gene SNP rs1570360 showed the strongest association with intima thickness (IT) progression measured by OCT, even in the presence of the traditional CAV risk factors (Tab. 3, Fig. 3, Ref. 36). Text in PDF www.elis.sk Keywords: cardiac allograft vasculopathy, optical coherence tomography, vascular endothelial growth factor A, intimal thickening, genetic polymorphism.

837 COMPLETE MAGNESIUM BIORESORBABLE SCAFFOLD ABSORPTION AT 1-YEAR OF INTRACORONARY IMAGING FOLLOW UP

Abstract Background the development of bioresorbable scaffolds (BRSs) has been conceived as revolution in interventional cardiology for the prospective improvements in the treatment of coronary artery disease. However, metallic drug eluting stent (DES) demonstrated greater safety and efficacy than bioresorbable vascular scaffold (BVS) Absorb in dedicated trials culminating in the commercial withdrawal of Absorb device in 2017. Nevertheless, the progressive absorption of the scaffold and the restoration of physiological coronary artery characteristics attracted attention, so currently research on BRSs is in progress. Case presentation a 58-year-old woman was admitted in our department after an episode of typical angina at rest without significant troponin elevation. The electrocardiogram showed T wave inversion in lateral leads. Hypokinesia of distal septum and anterior wall and mildly reduced left ventricular ejection fraction (LVEF 50%) were observed on echocardiography. Her cardiovascular risk factors included obesity, arterial hypertension, dyslipidaemia, family history of ischemic heart disease and former smoking. Her past medical history was remarkable for chronic kidney disease (CKD EPI eGFR 50 ml/min) and previous connective tissue disease. Coronary angiography highlighted a critical stenosis in the middle segment of left anterior descending artery (LAD). Optical coherence tomography (OCT) imaging showed recanalized and organized throumbus and calcific plaques. After adequate predilatation and stent sizing by OCT, a 3×25 mm Magnesium-based BVS (Magmaris, Biotronik AG, Buelach, Switzerland) was implanted. OCT confirmed good expansion and apposition of the stent after postdilatation. Patient was discharged on dual antiplatelet therapy (DAPT) for 12 months, anti-remodeling cardiac and lipid-lowering therapy. One year later, the patient underwent and elective coronary angiography and OCT control showing a complete reabsorption of the Magmaris BVS with positive remodelling and luminal enlargement of the vessel. The patient was asymptomatic throughout the year with a good performance status. Conclusion The present case illustrates an example of imaging-based revascularization with BVS Magmaris and optimal intracoronary imaging result at 1 year follow up in agreement with the last available evidence. The last European Society of Cardiology/European Association for Cardio-Thoracic Surgery Guidelines on myocardial revascularization recommends the use of BVS only in the context of clinical controlled studies. However, encouraging results obtained and what expected from the current studies with Magmaris scaffolds, might change indications considering the potential benefit about the restoration of natural vasomotion, the reduced risk of neoatherosclerosis and the positive vascular remodelling following the scaffold absorption.

Human Coronary Plaque Optical Coherence Tomography Image Repairing, Multilayer Segmentation and Impact on Plaque Stress/Strain Calculations.

Coronary vessel layer structure may have a considerable impact on plaque stress/strain calculations. Most current plaque models use single-layer vessel structures due to the lack of available multilayer segmentation techniques. In this paper, an automatic multilayer segmentation and repair method was developed to segment coronary optical coherence tomography (OCT) images to obtain multilayer vessel geometries for biomechanical model construction. Intravascular OCT data were acquired from six patients (one male; mean age: 70.0) using a protocol approved by the local institutional review board with informed consent obtained. A total of 436 OCT slices were selected in this study. Manually segmented data were used as the gold standard for method development and validation. The edge detection method and cubic spline surface fitting were applied to detect and repair the internal elastic membrane (IEM), external elastic membrane (EEM) and adventitia-periadventitia interface (ADV). The mean errors of automatic contours compared to manually segmented contours were 1.40%, 4.34% and 6.97%, respectively. The single-layer mean plaque stress value from lumen was 117.91 kPa, 10.79% lower than that from three-layer models (132.33 kPa). On the adventitia, the single-layer mean plaque stress value was 50.46 kPa, 156.28% higher than that from three-layer models (19.74 kPa). The proposed segmentation technique may have wide applications in vulnerable plaque research.

Inflammatory Phenotype by OCT Coronary Imaging: Specific Features Among De Novo Lesions, In-Stent Neointima, and In-Stent Neo-Atherosclerosis.

Coronary stenosis can be caused de novo atherosclerosis, in-stent restenosis, and in-stent neoatherosclerosis, three entities that develop from a diverse pathophysiological milieu. This study aims to investigate, using optical coherence tomography (OCT), whether or not coronary lesions related to these processes differ in their local inflammatory profile. Retrospective analysis of patients with diagnosed or suspected coronary lesions who had undergone OCT imaging for clinical reasons. Macrophage and intra-plaque neovascularization were assessed by OCT and used as surrogates of local inflammation. A significance level of < 0.05 was adopted as statistically significant. From the 121 lesions, 74 were de novo, 29 were restenosis, and 18 were neoatherosclerosis. Neovascularization was found in 65.8% of de novo, 10.3% in restenosis, and 94.4% in neoatherosclerosis (p<0.01 for all). The volume of neovascularization was different among lesion types (950 vs. 0 vs. 6220, respectively [median values in 1000 x µm3/mm]; p<0.01 for all), which were significantly higher in neoatherosclerosis and lower in restenosis. The presence of macrophages differed among the lesions (95.9% in de novo vs. 6.9% in restenosis vs. 100% in neoatherosclerosis [p<0.01 for all]). Moreover, the intensity of macrophagic infiltration was different among lesion types (2.5 vs. 0.0 vs. 4.5, respectively [median values of macrophage score]; p<0.01 for all), significantly higher in neoatheroscleosis and lower in restenosis. When compared using coronary OCT, de novo atherosclerosis, in-stent restenosis, and neoatherosclerosis presented markedly different inflammatory phenotypes.