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Extrinsic compression of the left main coronary artery (LMCA) can occur in patients with severe pulmonary hypertension and enlarged pulmonary artery trunk. It has been usually described in the setting of congenital defects such as atrial septal defect, ventricular septal defect, and, more rarely, isolated persistent ductus arteriosus. Functional and structural evaluation of such patients can currently be performed noninvasively with the use of cardiac CT scanning and/or MRI. The optimal management of symptomatic patients remains unknown. We report a case of extrinsic compression of the LMCA in a symptomatic patient with Eisenmenger syndrome who underwent unprotected LMCA stent implantation. We also performed a literature review of the reported cases concerning patients treated with LMCA stent implantation for the management of this condition. [ABSTRACT FROM AUTHOR]

Background and Aims: Observational registries have suggested that optical coherence tomography (OCT) imaging-derived parameters may predict adverse events after drug-eluting stent (DES) implantation. The present analysis sought to determine the OCT predictors of clinical outcomes from the large-scale ILUMIEN IV trial., Methods: ILUMIEN IV was a prospective, single-blind trial of 2487 patients with diabetes or high-risk lesions randomized to OCT-guided versus angiography-guided DES implantation. All patients underwent final OCT imaging (blinded in the angiography-guided arm). From more than 20 candidates, the independent OCT predictors of 2-year target lesion failure (TLF; the primary endpoint), cardiac death or target-vessel myocardial infarction (TV-MI), ischaemia-driven target lesion revascularization (ID-TLR), and stent thrombosis were analysed by multivariable Cox proportional hazard regression in single treated lesions., Results: A total of 2128 patients had a single treated lesion with core laboratory-analysed final OCT. The 2-year Kaplan-Meier rates of TLF, cardiac death or TV-MI, ID-TLR, and stent thrombosis were 6.3% (n = 130), 3.3% (n = 68), 4.3% (n = 87), and 0.9% (n = 18), respectively. The independent predictors of 2-year TLF were a smaller minimal stent area (per 1 mm2 increase: hazard ratio 0.76, 95% confidence interval 0.68-0.89, P < .0001) and proximal edge dissection (hazard ratio 1.77, 95% confidence interval 1.20-2.62, P = .004). The independent predictors of cardiac death or TV-MI were smaller minimal stent area and longer stent length; of ID-TLR were smaller intra-stent flow area and proximal edge dissection; and of stent thrombosis was smaller minimal stent expansion., Conclusions: In the ILUMIEN IV trial, the most important OCT-derived post-DES predictors of both safety and effectiveness outcomes were parameters related to stent area, expansion and flow, proximal edge dissection, and stent length., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Background: ILUMIEN IV was the first large-scale, multicenter, randomized trial comparing optical coherence tomography (OCT)-guided vs angiography-guided stent implantation in patients with high-risk clinical characteristics and/or complex angiographic lesions., Objectives: The authors aimed to specifically examine outcomes in the complex angiographic lesions subgroup., Methods: From the original trial population (N = 2,487), high-risk patients without complex angiographic lesions were excluded (n = 514). Complex angiographic lesion characteristics included: 1) long or multiple lesions with intended total stent length ≥28 mm; 2) bifurcation lesion with intended 2-stent strategy; 3) severely calcified lesion; 4) chronic total occlusion; or 5) in-stent restenosis. The study endpoints were: 1) final minimal stent area (MSA); 2) 2-year composite of serious major adverse cardiovascular events (MACEs) (cardiac death, target-vessel myocardial infarction [MI], or stent thrombosis); and 3) 2-year effectiveness, defined as target-vessel failure (TVF), a composite of cardiac death, target-vessel MI, or ischemia-driven target-vessel revascularization., Results: The postpercutaneous coronary intervention (PCI) MSA was larger in the OCT-guided (n = 992) vs angiography-guided (n = 981) group (5.56 ± 1.95 mm 2 vs 5.26 ± 1.81 mm 2 ; difference, 0.30; 95% CI: 0.14-0.47; P < 0.001). Compared with angiography-guided PCI, OCT-guided PCI resulted in a lower risk of serious MACE (3.1% vs 4.9%; HR: 0.63; 95% CI: 0.40-0.99; P = 0.04). TVF was not significantly different between groups (7.3% vs 8.8%; HR: 0.82; 95% CI: 0.59-1.12; P = 0.20)., Conclusions: In complex angiographic lesions, OCT-guided PCI led to a larger MSA and reduced the serious MACE, the composite of cardiac death, target-vessel MI, or stent thrombosis, compared with angiography-guided PCI at 2 years, but did not significantly improve TVF. (Optical Coherence Tomography Guided Coronary Stent Implantation Compared to Angiography: A Multicenter Randomized Trial in PCI; NCT03507777)., Competing Interests: Funding Support and Author Disclosures Abbott Vascular provided funding for this study. Dr Ali has received institutional grants from Abbott, Abiomed, Acist Medical, Boston Scientific, Cardiovascular Systems Inc, Medtronic, Opsens Medical, Philips, and Shockwave Medical; has received personal fees from Amgen, AstraZeneca, and Boston Scientific; and has received equity from Elucid, Lifelink, SpectraWAVE, Shockwave, and Vital Connect. Dr Landmesser has received lecture fees and advisory fees from AstraZeneca, Amgen, Sanofi, Berlin Chemie, and Abbott; has received advisory fees from The Medicines Company; and has received grant support, lecture fees, and advisory fees from Bayer and Novartis. Dr Maehara has been a consultant for Boston Scientific; has received speaker honoraria from Nipro; and is on the advisory board of SpectraWAVE. Dr Matsumura is a consultant for Terumo and Boston Scientific. Dr Leistner has received personal fees and nonfinancial support from Abbott Vascular; has received personal fees from Boston Scientific; and has received grants from DZHK (German Center for Cardiovascular Research). Dr Guagliumi has received grants from Boston Scientific during the conduct of the TRANSFORM-OCT main study; has received research grants from Abbott Vascular, InfraReDx, and Amgen; and is a consultant for Abbot and InfraReDx. Dr Canova is a consultant for Abbott Vascular and Boston Scientific; and has received grants from Amarin Pharma Inc, Amgen, Bristol Myers Squibb Company, Daiichi-Sankyo, Sanofi, and Terumo. Dr Price has received consulting honoraria, speaker fees, and proctoring fees from Abbott Vascular and Boston Scientific; has received consulting honoraria from W.L. Gore, Biotronik, and Philips Medical; has received consulting honoraria and speaker fees from Medtronic; has received consulting honoraria from Shockwave and Innovheart; and has equity in InterShunt. Dr Hill has received speaker honoraria and institutional grants from Abbott, Abiomed, Boston Scientific, and Shockwave Medical; and has received equity from Shockwave. Dr Akasaka has received institutional research grants from Abbott Japan, Daiichi-Sankyo, Nipro, and Terumo; and serves as a consultant for Terumo. Dr Bezerra serves as a consultant for Abbott Vascular and Gentuity. Dr Wijns has received institutional research grants and personal honoraria from Micro Port. Drs McGreevy, McNutt, Nie, and Phalakornkule, and Ms Buccola are employees of Abbott Vascular. Dr Stone has received speaker honoraria from Medtronic, Pulnovo, Infraredx, Abiomed, Amgen, and Boehringer Ingelheim; has served as a consultant to Valfix, TherOx, Robocath, HeartFlow, Ablative Solutions, Vectorious, Miracor, Neovasc, Ancora, Elucid Bio, Occlutech, CorFlow, Apollo Therapeutics, Impulse Dynamics, Cardiomech, Adona Medical, Daiichi-Sankyo, Oxitope, HighLife, Elixir, Remote Cardiac Enablement, Aria, Abiomed, Cardiac Success, and Millennia Biopharma; and has equity/options from Ancora, Cagent, Applied Therapeutics, Biostar family of funds, SpectraWAVE, Orchestra Biomed, Aria, Cardiac Success, Valfix, and Xenter; and his employer, Mount Sinai Hospital, receives research support from Abbott, Abiomed, Bioventrix, Cardiovascular Systems, Inc, Phillips, Biosense Webster, Shockwave, Vascular Dynamics, Pulnovo, and V-Wave. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2024 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Intravascular imaging and intracoronary physiology may both be used to guide and optimize percutaneous coronary intervention; however, they are rarely used together. The virtual flow reserve (VFR) is an optical coherence tomography (OCT)-based model of fractional flow reserve (FFR) facilitating the assessment of the physiological significance of coronary lesions. We aimed to validate the VFR assessment of intermediate coronary artery stenoses., Methods: FUSION (Validation of OCT-Based Functional Diagnosis of Coronary Stenosis) was a multicenter, prospective, observational study comparing OCT-derived VFR to invasive FFR. VFR was mathematically derived from a lumped parameter flow model based on 3-dimensional lumen morphology. Patients undergoing coronary angiography with intermediate angiographic stenosis (40%-90%) requiring physiological assessment were enrolled. Investigational sites were blinded to the VFR analysis, and all OCT and FFR data were reviewed by an independent core laboratory. The coprimary end points were the sensitivity and specificity of VFR against FFR as the reference standard, each of which was tested against prespecified performance goals., Results: After core laboratory review, 266 vessels in 224 patients from 25 US centers were included in the analysis. The mean angiographic diameter stenosis was 65.5%±14.9%, and the mean FFR was 0.83±0.11. Overall accuracy, sensitivity, and specificity of VFR versus FFR using a binary cutoff point of 0.80 were 82.0%, 80.4%, and 82.9%, respectively. The 97.5% lower confidence bound met the prespecified performance goal for sensitivity (71.6% versus 70%; P =0.01) and specificity (76.6% versus 75%; P =0.01). The area under the curve was 0.88 (95% CI, 0.84-0.92; P <0.0001)., Conclusions: OCT-derived VFR demonstrates high sensitivity and specificity for predicting invasive FFR. Integrating high-resolution intravascular imaging with imaging-derived physiology may provide synergistic benefits as an adjunct to percutaneous coronary intervention., Registration: URL: https://clinicaltrials.gov; Unique identifier: NCT04356027., Competing Interests: Disclosures Dr Jeremias is a consultant for Abbott Vascular, Philips/Volcano, ACIST Medical Systems, Shockwave, and CathWorks. M. Matsumura is a consultant for TERUMO and Boston Scientific. Dr Maehara is a consultant for Boston Scientific, received speaker honoraria from Nipro, and is on the adversary board of SpectraWAVE. Dr Fearon received institutional research grants from Abbott and Medtronic, is a consultant for CathWorks, and has stock options in HeartFlow. Dr Samady received institutional grant support from Medtronic and the National Institutes of Health, is a consultant for Abbott and Philips, and has an equity holding in Covanos. J. Rapkin, J. Buccola, and Drs Gopinath and Teraphongphom are employees of Abbott Vascular. Dr Ali received institutional grant support from Abbott, Abiomed, ACIST, Amgen, Boston Scientific, CathWorks, Canon, Conavi, HeartFlow, Inari, Medtronic, Inc, the National Institutes of Health, Nipro, OpSens Medical, Medis, Philips, Shockwave, Siemens, SpectraWAVE, and Teleflex; received consulting fees from Abiomed, AstraZeneca, Boston Scientific, CathWorks, OpSens, Philips, and Shockwave; and has equity holding in Elucid, Lifelink, SpectraWAVE, Shockwave, and VitalConnect. The other authors report no conflicts.

Thin-cap fibroatheroma (TCFA) is a prominent risk factor for plaque rupture. Intravascular optical coherence tomography (IVOCT) enables identification of fibrous cap (FC), measurement of FC thicknesses, and assessment of plaque vulnerability. We developed a fully-automated deep learning method for FC segmentation. This study included 32,531 images across 227 pullbacks from two registries (TRANSFORM-OCT and UHCMC). Images were semi-automatically labeled using our OCTOPUS with expert editing using established guidelines. We employed preprocessing including guidewire shadow detection, lumen segmentation, pixel-shifting, and Gaussian filtering on raw IVOCT (r,θ) images. Data were augmented in a natural way by changing θ in spiral acquisitions and by changing intensity and noise values. We used a modified SegResNet and comparison networks to segment FCs. We employed transfer learning from our existing much larger, fully-labeled calcification IVOCT dataset to reduce deep-learning training. Postprocessing with a morphological operation enhanced segmentation performance. Overall, our method consistently delivered better FC segmentation results (Dice: 0.837 ± 0.012) than other deep-learning methods. Transfer learning reduced training time by 84% and reduced the need for more training samples. Our method showed a high level of generalizability, evidenced by highly-consistent segmentations across five-fold cross-validation (sensitivity: 85.0 ± 0.3%, Dice: 0.846 ± 0.011) and the held-out test (sensitivity: 84.9%, Dice: 0.816) sets. In addition, we found excellent agreement of FC thickness with ground truth (2.95 ± 20.73 µm), giving clinically insignificant bias. There was excellent reproducibility in pre- and post-stenting pullbacks (average FC angle: 200.9 ± 128.0°/202.0 ± 121.1°). Our fully automated, deep-learning FC segmentation method demonstrated excellent performance, generalizability, and reproducibility on multi-center datasets. It will be useful for multiple research purposes and potentially for planning stent deployments that avoid placing a stent edge over an FC., (© 2024. The Author(s).)

It can be difficult/impossible to fully expand a coronary artery stent in a heavily calcified coronary artery lesion. Under-expanded stents are linked to later complications. Here we used machine/deep learning to analyze calcifications in pre-stent intravascular optical coherence tomography (IVOCT) images and predicted the success of vessel expansion. Pre- and post-stent IVOCT image data were obtained from 110 coronary lesions. Lumen and calcifications in pre-stent images were segmented using deep learning, and lesion features were extracted. We analyzed stent expansion along the lesion, enabling frame, segmental, and whole-lesion analyses. We trained regression models to predict the post-stent lumen area and then computed the stent expansion index (SEI). Best performance (root-mean-square-error = 0.04 ± 0.02 mm 2 , r = 0.94 ± 0.04, p < 0.0001) was achieved when we used features from both lumen and calcification to train a Gaussian regression model for segmental analysis of 31 frames in length. Stents with minimum SEI > 80% were classified as "well-expanded;" others were "under-expanded." Under-expansion classification results (e.g., AUC = 0.85 ± 0.02) were significantly improved over a previous, simple calculation, as well as other machine learning solutions. Promising results suggest that such methods can identify lesions at risk of under-expansion that would be candidates for intervention lesion preparation (e.g., atherectomy)., (© 2023. Springer Nature Limited.)

Background: Data regarding clinical outcomes after optical coherence tomography (OCT)-guided percutaneous coronary intervention (PCI) as compared with angiography-guided PCI are limited., Methods: In this prospective, randomized, single-blind trial, we randomly assigned patients with medication-treated diabetes or complex coronary-artery lesions to undergo OCT-guided PCI or angiography-guided PCI. A final blinded OCT procedure was performed in patients in the angiography group. The two primary efficacy end points were the minimum stent area after PCI as assessed with OCT and target-vessel failure at 2 years, defined as a composite of death from cardiac causes, target-vessel myocardial infarction, or ischemia-driven target-vessel revascularization. Safety was also assessed., Results: The trial was conducted at 80 sites in 18 countries. A total of 2487 patients underwent randomization: 1233 patients were assigned to undergo OCT-guided PCI, and 1254 to undergo angiography-guided PCI. The minimum stent area after PCI was 5.72±2.04 mm 2 in the OCT group and 5.36±1.87 mm 2 in the angiography group (mean difference, 0.36 mm 2 ; 95% confidence interval [CI], 0.21 to 0.51; P<0.001). Target-vessel failure within 2 years occurred in 88 patients in the OCT group and in 99 patients in the angiography group (Kaplan-Meier estimates, 7.4% and 8.2%, respectively; hazard ratio, 0.90; 95% CI, 0.67 to 1.19; P = 0.45). OCT-related adverse events occurred in 1 patient in the OCT group and in 2 patients in the angiography group. Stent thrombosis within 2 years occurred in 6 patients (0.5%) in the OCT group and in 17 patients (1.4%) in the angiography group., Conclusions: Among patients undergoing PCI, OCT guidance resulted in a larger minimum stent area than angiography guidance, but there was no apparent between-group difference in the percentage of patients with target-vessel failure at 2 years. (Funded by Abbott; ILUMIEN IV: OPTIMAL PCI ClinicalTrials.gov number, NCT03507777.)., (Copyright © 2023 Massachusetts Medical Society.)

In this work, stenting in non-calcified and heavily calcified coronary arteries was quantified in terms of diameter-pressure relationships and load transfer from the balloon to the artery. The efficacy of post-dilation in non-calcified and heavily calcified coronary arteries was also characterized in terms of load sharing and the changes in tissue mechanics. Our results have shown that stent expansion exhibits a cylindrical shape in non-calcified lesions, while it exhibits a dog bone shape in heavily calcified lesions. Load-sharing analysis has shown that only a small portion of the pressure load (1.4 N, 0.8% of total pressure load) was transferred to the non-calcified lesion, while a large amount of the pressure load (19 N, 12%) was transferred to the heavily calcified lesion. In addition, the increasing inflation pressure (from 10 to 20 atm) can effectively increase the minimal lumen diameter (from 1.48 to 2.82 mm) of the heavily calcified lesion, the stress (from 1.5 to 8.4 MPa) and the strain energy in the calcification (1.77 mJ to 26.5 mJ), which are associated with the potential of calcification fracture. Results indicated that increasing inflation pressure can be an effective way to improve the stent expansion if a dog bone shape of the stenting profile is observed. Considering the risk of a balloon burst, our results support the design and application of the high-pressure balloon for post-dilation. This work also sheds some light on the stent design and choice of stent materials for improving the stent expansion at the dog bone region and mitigating stresses on arterial tissues., (© 2023. Springer Nature Limited.)

Competing Interests: Disclosures None.

Background: The aim of the study was to compare healing (assessed by optical coherence tomography [OCT]) of biolimus A9 (BES) and everolimus drug-eluting stents (EES) at 9-month follow-up in patients with ST-segment elevation myocardial infarction (STEMI) treated by primary percutaneous coronary intervention (pPCI). Nine-month clinical and angiographic data were also compared in both groups as well as clinical data at 5 years of follow-up., Methods: A total of 201 patients with STEMI were enrolled in the study and randomized either to pPCI with BES or EES implantation. All patients were scheduled for 9 months of angiographic and OCT follow-up., Results: The rate of major adverse cardiovascular events (MACE) was comparable at 9 months in both groups (5% in BES vs. 6% in the EES group; p = 0.87). Angiographic data were also comparable between both groups. The main finding at 9-month OCT analysis was the greatly reduced extent of mean neointimal area at the cost of a higher proportion of uncovered struts in the BES group (1.3 mm² vs. 0.9 mm²; p = 0.0001 and 15.9% vs. 7.0%; p = 0.0001, respectively). At 5 years of clinical follow-up the rate of MACE was comparable between both groups (16.8% vs. 14.0%, p = 0.74)., Conclusions: The study demonstrates a very low rate of MACE and good 9-month stent strut coverage of second-generation BES and EES in patients with STEMI. BES showed greatly reduced extent of mean neointimal hyperplasia area at the cost of a higher proportion of uncovered struts when compared to EES. The rate of MACE was low and comparable in both groups at 5 years.

Background and Objective: Compared with other imaging modalities, intravascular optical coherence tomography (IVOCT) has significant advantages for guiding percutaneous coronary interventions, assessing their outcomes, and characterizing plaque components. To aid IVOCT research studies, we developed the Optical Coherence TOmography PlaqUe and Stent (OCTOPUS) analysis software, which provides highly automated, comprehensive analysis of coronary plaques and stents in IVOCT images., Methods: User specifications for OCTOPUS were obtained from detailed, iterative discussions with IVOCT analysts in the Cardiovascular Imaging Core Laboratory at University Hospitals Cleveland Medical Center, a leading laboratory for IVOCT image analysis. To automate image analysis results, the software includes several important algorithmic steps: pre-processing, deep learning plaque segmentation, machine learning identification of stent struts, and registration of pullbacks for sequential comparisons. Intuitive, interactive visualization and manual editing of segmentations were included in the software. Quantifications include stent deployment characteristics (e.g., stent area and stent strut malapposition), strut level analysis, calcium angle, and calcium thickness measurements. Interactive visualizations include ( x,y ) anatomical, en face, and longitudinal views with optional overlays (e.g., segmented calcifications). To compare images over time, linked visualizations were enabled to display up to four registered vessel segments at a time., Results: OCTOPUS has been deployed for nearly 1 year and is currently being used in multiple IVOCT studies. Underlying plaque segmentation algorithm yielded excellent pixel-wise results (86.2% sensitivity and 0.781 F1 score). Using OCTOPUS on 34 new pullbacks, we determined that following automated segmentation, only 13% and 23% of frames needed any manual touch up for detailed lumen and calcification labeling, respectively. Only up to 3.8% of plaque pixels were modified, leading to an average editing time of only 7.5 s/frame, an approximately 80% reduction compared to manual analysis. Regarding stent analysis, sensitivity and precision were both greater than 90%, and each strut was successfully classified as either covered or uncovered with high sensitivity (94%) and specificity (90%). We demonstrated use cases for sequential analysis. To analyze plaque progression, we loaded multiple pullbacks acquired at different points (e.g., pre-stent, 3-month follow-up, and 18-month follow-up) and evaluated frame-level development of in-stent neo-atherosclerosis. In ex vivo cadaver experiments, the OCTOPUS software enabled visualization and quantitative evaluation of irregular stent deployment in the presence of calcifications identified in pre-stent images., Conclusions: We introduced and evaluated the clinical application of a highly automated software package, OCTOPUS, for quantitative plaque and stent analysis in IVOCT images. The software is currently used as an offline tool for research purposes; however, the software's embedded algorithms may also be useful for real-time treatment planning., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

Background/purpose: Matching phasic pressure tracings between a fluid-filled catheter and high-fidelity pressure wire has received limited attention, although each part contributes half of the information to clinical decisions. We aimed to study the impact of a novel and automated method for improving the phasic calibration of a fluid-filled catheter by accounting for its oscillatory behavior., Methods/materials: Retrospective analysis of drift check tracings was performed using our algorithm that corrects for mean difference (offset), temporal delays (timing), differential sensitivity of the manifold transducer and pressure wire sensor (gain), and the oscillatory behavior of the fluid-filled catheter described by its resonant frequency and damping factor (how quickly oscillations disappear after a change in pressure)., Results: Among 2886 cases, correcting for oscillations showed a large improvement in 28 % and a medium improvement in 41 % (decrease in root mean square error >0.5 mmHg to <1 or 1-2 mmHg, respectively). 96 % of oscillators were underdamped with median damping factor 0.27 and frequency 10.6 Hz. Fractional flow reserve or baseline Pd/Pa demonstrated no clinically important bias when ignoring oscillations. However, uncorrected subcycle non-hyperemic pressure ratios (NHPR) displayed both bias and scatter., Conclusions: By automatically accounting for the oscillatory behavior of a fluid-filled catheter system, phasic matching against a high-fidelity pressure wire can be improved compared to standard equalization methods. The majority of tracings contain artifacts, mainly due to underdamped oscillations, and neglecting them leads to biased estimates of equalization parameters. No clinically important bias exists for whole-cycle metrics, in contrast to significant effects on subcycle NHPR., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Thin-cap fibroatheroma (TCFA) and plaque rupture have been recognized as the most frequent risk factor for thrombosis and acute coronary syndrome. Intravascular optical coherence tomography (IVOCT) can identify TCFA and assess cap thickness, which provides an opportunity to assess plaque vulnerability. We developed an automated method that can detect lipidous plaque and assess fibrous cap thickness in IVOCT images. This study analyzed a total of 4360 IVOCT image frames of 77 lesions among 41 patients. Expert cardiologists manually labeled lipidous plaque based on established criteria. To improve segmentation performance, preprocessing included lumen segmentation, pixel-shifting, and noise filtering on the raw polar (r, θ) IVOCT images. We used the DeepLab-v3 plus deep learning model to classify lipidous plaque pixels. After lipid detection, we automatically detected the outer border of the fibrous cap using a special dynamic programming algorithm and assessed the cap thickness. Our method provided excellent discriminability of lipid plaque with a sensitivity of 85.8% and A-line Dice coefficient of 0.837. By comparing lipid angle measurements between two analysts following editing of our automated software, we found good agreement by Bland-Altman analysis (difference 6.7° ± 17°; mean ~ 196°). Our method accurately detected the fibrous cap from the detected lipid plaque. Automated analysis required a significant modification for only 5.5% frames. Furthermore, our method showed a good agreement of fibrous cap thickness between two analysts with Bland-Altman analysis (4.2 ± 14.6 µm; mean ~ 175 µm), indicating little bias between users and good reproducibility of the measurement. We developed a fully automated method for fibrous cap quantification in IVOCT images, resulting in good agreement with determinations by analysts. The method has great potential to enable highly automated, repeatable, and comprehensive evaluations of TCFAs., (© 2022. The Author(s).)

Microvessels in vascular plaque are associated with plaque progression and are found in plaque rupture and intra-plaque hemorrhage. To analyze this characteristic of vulnerability, we developed an automated deep learning method for detecting microvessels in intravascular optical coherence tomography (IVOCT) images. A total of 8403 IVOCT image frames from 85 lesions and 37 normal segments were analyzed. Manual annotation was performed using a dedicated software (OCTOPUS) previously developed by our group. Data augmentation in the polar ( r , θ ) domain was applied to raw IVOCT images to ensure that microvessels appear at all possible angles. Pre-processing methods included guidewire/shadow detection, lumen segmentation, pixel shifting, and noise reduction. DeepLab v3+ was used to segment microvessel candidates. A bounding box on each candidate was classified as either microvessel or non-microvessel using a shallow convolutional neural network. For better classification, we used data augmentation (i.e., angle rotation) on bounding boxes with a microvessel during network training. Data augmentation and pre-processing steps improved microvessel segmentation performance significantly, yielding a method with Dice of 0.71 ± 0.10 and pixel-wise sensitivity/specificity of 87.7 ± 6.6%/99.8 ± 0.1%. The network for classifying microvessels from candidates performed exceptionally well, with sensitivity of 99.5 ± 0.3%, specificity of 98.8 ± 1.0%, and accuracy of 99.1 ± 0.5%. The classification step eliminated the majority of residual false positives and the Dice coefficient increased from 0.71 to 0.73. In addition, our method produced 698 image frames with microvessels present, compared with 730 from manual analysis, representing a 4.4% difference. When compared with the manual method, the automated method improved microvessel continuity, implying improved segmentation performance. The method will be useful for research purposes as well as potential future treatment planning.

Introduction: Interventional cardiologists make adjustments in the presence of coronary calcifications known to limit stent expansion, but proper balloon sizing, plaque-modification approaches, and high-pressure regimens are not well established. Intravascular optical coherence tomography (IVOCT) provides high-resolution images of coronary tissues, including detailed imaging of calcifications, and accurate measurements of stent deployment, providing a means for detailed study of stent deployment., Objective: Evaluate stent expansion in an ex vivo model of calcified coronary arteries as a function of balloon size and high-pressure, post-dilatation strategies., Methods: We conducted experiments on cadaver hearts with calcified coronary lesions. We assessed stent expansion as a function of size and pressure of non-compliant (NC) balloons (i.e., nominal, 0.5, 1.0, and 1.5 mm balloons at 10, 20 and 30 atm). IVOCT images were acquired pre-stent, post-stent, and at all post-dilatations. Stent expansion was calculated using minimum expansion index (MEI)., Results: We analyzed 134 IVOCT pullbacks from ten ex-vivo experiments. The mean distal and proximal reference lumen diameters were 2.2 ± 0.5 mm and 2.5 ± 0.7 mm, respectively, 80% of times using a 3.0 mm diameter stent. Overall, based on stent sizing, a good expansion (MEI ≥ 80%) was reached using the 1:1 NC balloon at 20 atm, and expansion > 100% was reached using the 1:1 NC balloon at 30 atm. In the subgroup analysis, comparing low-calcified and high-calcified lesions, good expansion (MEI ≥ 80%) was reached using the 1:1 NC balloon at nominal pressure (10 atm) versus using 1:1 NC balloon at 30 atm, respectively. Significant vessel rupture was identified in all the vessels mainly upon post-dilatation with larger balloons, and 60% of the experiments (6 vessels, 3 in each calcium subgroup) presented rupture with the +1.0 mm NC balloon at 20 atm., Conclusion: When treating calcified lesions, good stent expansion was reached using smaller balloons at higher pressures without coronary injuries, whereas bigger balloons yielded unpredictable expansion even at lower pressures and demonstrated potential harmful damages to the vessels. As these findings could help physicians with appropriate planning of stent post-dilatation for calcified lesions, it will be important to clinically evaluate the recommended protocol., Competing Interests: Declaration of competing interest None of the authors have conflicts of interest regarding this paper., (Copyright © 2022. Published by Elsevier Inc.)

The computational fluid dynamic method has been widely used to quantify the hemodynamic alterations in a diseased artery and investigate surgery outcomes. The artery model reconstructed based on optical coherence tomography (OCT) images generally does not include the side branches. However, the side branches may significantly affect the hemodynamic assessment in a clinical setting, i.e., the fractional flow reserve (FFR), defined as the ratio of mean distal coronary pressure to mean aortic pressure. In this work, the effect of the side branches on FFR estimation was inspected with both idealized and optical coherence tomography (OCT)-reconstructed coronary artery models. The electrical analogy of blood flow was further used to understand the impact of the side branches (diameter and location) on FFR estimation. Results have shown that the side branches decrease the total resistance of the vessel tree, resulting in a higher inlet flowrate. The side branches located at the downstream of the stenosis led to a lower FFR value, while the ones at the upstream had a minimal impact on the FFR estimation. Side branches with a diameter larger than one third of the main vessel diameter are suggested to be considered for a proper FFR estimation. The findings in this study could be extended to other coronary artery imaging modalities and facilitate treatment planning., Competing Interests: Conflicts of Interest: Hiram G. Bezerra: Consulting Honorárias from Abbott Vascular; All other authors declare no conflict of interest.

Background: Percutaneous left atrial appendage occlusion (LAAO) with the Watchman device is FDA approved for stroke prevention in patients with nonvalvular atrial fibrillation who have an appropriate indication. During the COVID-19 pandemic, a same-day discharge protocol (SDDP) was employed to improve resource utilization, relieve hospital occupation, and reduce the possible risk of in-hospital virus transmission., Objectives: We sought to analyze the safety, feasibility, and cost effectiveness for SDDP in patients receiving LAAO., Methods: A prospective analysis of 142 consecutive patients, 119 treated prior to SDDP and 23 who underwent SDDP following LAAO with cardiac computed tomography angiography (CTA)-guided pre-procedural planning and intracardiac echocardiogram (ICE). Procedures were performed in a single, large academic hospital in the United States. In-hospital and 45-day procedural success, adverse events, length of procedure, and length-of-stay were evaluated., Results: Baseline patient characteristics including mean CHA2DS2VASc scores and mean HAS-BLED scores were similar in both groups. All procedures were successful. There was no significant difference in rates of procedural complications or in-hospital adverse events. The mean procedure time in the SDDP group was 11 minutes longer than in the conventional group (62.1 ± 5.9 vs 51.1 ± 21; P=.01). Outcomes at 45-day follow-up were similar. SDDP was associated with a reduced length of stay compared with conventional strategy and a 15% reduction in total costs., Conclusions: Same-day discharge strategy for LAAO appears safe, feasible and could become the new standard approach for LAAO. A protocol including CTA pre-procedural planning, ICE-guided deployment and conscious sedation reduces hospital occupation and lowers costs.

Microchannel formation is known to be a significant marker of plaque vulnerability, plaque rupture, and intraplaque hemorrhage, which are responsible for plaque progression. We developed a fully-automated method for detecting microchannels in intravascular optical coherence tomography (IVOCT) images using deep learning. A total of 3,075 IVOCT image frames across 41 patients having 62 microchannel segments were analyzed. Microchannel was manually annotated by expert cardiologists, according to previously established criteria. In order to improve segmentation performance, pre-processing including guidewire detection/removal, lumen segmentation, pixel-shifting, and noise filtering was applied to the raw ( r , θ ) IVOCT image. We used the DeepLab-v3 plus deep learning model with the Xception backbone network for identifying microchannel candidates. After microchannel candidate detection, each candidate was classified as either microchannel or no-microchannel using a convolutional neural network (CNN) classification model. Our method provided excellent segmentation of microchannel with a Dice coefficient of 0.811, sensitivity of 92.4%, and specificity of 99.9%. We found that pre-processing and data augmentation were very important to improve results. In addition, a CNN classification step was also helpful to rule out false positives. Furthermore, automated analysis missed only 3% of frames having microchannels and showed no false positives. Our method has great potential to enable highly automated, objective, repeatable, and comprehensive evaluations of vulnerable plaques and treatments. We believe that this method is promising for both research and clinical applications.

In this work, hemodynamic alterations in a patient-specific, heavily calcified coronary artery following stent deployment and post-dilations are quantified using in silico and ex-vivo approaches. Three-dimensional artery models were reconstructed from OCT images. Stent deployment and post-dilation with various inflation pressures were performed through both the finite element method (FEM) and ex vivo experiments. Results from FEM agreed very well with the ex-vivo measurements, interms of lumen areas, stent underexpansion, and strut malapposition. In addition, computational fluid dynamics (CFD) simulations were performed to delineate the hemodynamic alterations after stent deployment and post-dilations. A pressure time history at the inlet and a lumped parameter model (LPM) at the outlet were adopted to mimic the aortic pressure and the distal arterial tree, respectively. The pressure drop across the lesion, pertaining to the clinical measure of instantaneous wave-free flow ratio (iFR), was investigated. Results have shown that post-dilations are necessary for the lumen gain as well as the hemodynamic restoration towards hemostasis. Malapposed struts induced much higher shear rate, flow disturbances and lower time-averaged wall shear stress (TAWSS) around struts. Post-dilations mitigated the strut malapposition, and thus the shear rate. Moreover, stenting induced larger area of low TAWSS (<0.4 Pa) and lager volume of high shear rate (>2000 s -1 ), indicating higher risks of in-stent restenosis (ISR) and stent thrombosis (ST), respectively. Oscillatory shear index (OSI) and relative residence time (RRT) indicated the wall regions more prone to ISR are located near the malapposed stent struts., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Objectives: We reviewed the periprocedural events, accuracy of device selection, and outcomes of a series of patients receiving percutaneous left atrial appendage occlusion (LAAO) with cardiac computed tomography angiography (CTA)-guided preprocedural planning and intracardiac echocardiography (ICE)-guided device deployment., Background: Percutaneous LAAO with the Watchman device (Boston Scientific) is approved by the United States Food and Drug Administration for stroke prevention in patients with non-valvular atrial fibrillation with a demonstrated contraindication to oral anticoagulation. Cardiac CTA preprocedural planning with utilization of an ICE-guided deployment may be associated with favorable outcomes., Methods: A prospective analysis of 71 non-consecutive patients who underwent LAAO over an 18-month period with cardiac CTA-guided preprocedural planning and ICE was conducted. Procedures were performed in a single large, academic hospital in the United States. Procedural success, correlation of CTA preprocedural device sizing with final device size utilization, adverse events, length of procedure, and length of stay were evaluated., Results: Preprocedural cardiac CTA-guided device sizing was consistent with the final deployed device in 69 patients (97.2%) evaluated in this case series. Procedure success rate was 100%. All implants were performed using Watchman devices, 45 (63.4%) with the original 2.5 platform and 26 (36.6%) with the Watchman FLX platform. All patients were treated with conscious sedation and the mean length of stay was 1.45 ± 0.72 days. Only 2 adverse events occurred and both resolved., Conclusions: Cardiac CTA-guided preprocedural planning resulted in accurate device sizing in this patient sample and may be used in conjunction with ICE and conscious sedation for a same-day discharge strategy in select patients.

Stent deployment in a calcified coronary artery is often associated with suboptimal outcomes such as stent underexpansion and malapposition. Post-dilation after stent deployment is commonly used for optimal stent implantation. There is no guideline for choosing the post-dilation balloon diameter and inflation pressure. In this work, ex-vivo/in-silico experiments were performed to investigate the efficacy of post-dilation balloon diameter and inflation pressure in improving the stent expansion in a calcified lesion. Post-dilations with three balloon diameters (3 mm, 3.5 mm, and 4 mm) were performed. For each balloon diameter, three inflation pressures (10 atm, 20 atm, and 30 atm) were sequentially applied. In ex-vivo experiments, optical coherence tomography images were acquired during the stenting procedure, i.e., pre- and post-deployment of 3 mm diameter stent, as well as after each post-dilation. The results from in-silico experiments were compared with ex-vivo experiments in terms of lumen area. In addition, stretch ratio analysis was developed to predict the stent-induced lumen area, along with the strain analysis and the in-silico experiments. Results have shown that target lumen area could be achieved with an oversized nominal balloon diameter of +0.5 mm (i.e., 0.5 mm greater than reference lumen diameter) at an inflation pressure of 20 atm. After each post-dilation, fibrotic tissue demonstrated a larger strain, contributing to improved lumen gain. However, minimal changes were observed in calcification. Moreover, a strong correlation (R 2  = 0.95) between the stretch ratio of fibrotic tissue and lumen area after each post-dilation was observed. This indicated that the morphology of the fibrotic tissue could be a potential marker to predict the lumen gain. The detailed mechanistic quantifications of a single lesion cannot be generalized to all clinical cases. However, this work could be used to provide a fundamental understanding of the post-dilations, to develop experimental protocols for producing generalized guidelines, and to exploit their potential for optimal pre- and post-stent strategies., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Objective: To evaluate the feasibility of using the DyeVert™ Plus EZ Contrast Reduction System in optical coherence tomography (OCT)-guided percutaneous coronary intervention (PCI) procedures and to assess OCT image quality., Background: OCT is employed as a powerful intravascular imaging modality; however, it requires blood displacement via contrast injection during image acquisition, thereby posing risk of nephrotoxicity. The DyeVert System is designed to reduce and facilitate monitoring of contrast media volume (CMV) delivered, without diminishing image quality., Methods: We conducted a prospective clinical feasibility study to determine whether the DyeVert System is non-inferior to manual contrast injection in reducing CMV without lessening image quality during OCT-guided PCI procedures. Eligible participants were ≥ 18 years of age, indicated for coronary OCT, and able to provide informed consent. The primary endpoint was CMV saved during angiography; the secondary endpoint was image quality as evaluated by operators in real time and by an independent core laboratory that also assessed images from a control group that underwent comparable procedures performed without the DyeVert System., Results: Fourteen participants underwent 15 coronary OCT procedures using the DyeVert System. Mean age among participants was 67 ± 11 years, and 11 (78%) were male. Mean eGFR was 71 ± 20 mL/min/1.73m 2 . Mean attempted CMV administration was 342.01 ± 129.8 mL; mean CMV delivered was 216.21 ± 88.87 mL, representing CMV savings of 37.5 ± 5.3%. Results from quantified OCT analysis suggest that the clear region of interest (ROI) in the DyeVert group was non-inferior (p < .0001) to the control group. There were no device-related adverse events., Conclusions: The DyeVert™ Plus EZ Contrast Reduction System reduced CMV and preserved an image quality that was non-inferior to OCT-guided PCI procedures without using the contrast reducing device., Competing Interests: Declaration of competing interest Dr. Bezerra receives consulting fees from Abbott Vascular, Inc. Other authors report no relevant conflicts of interest with this manuscript., (Copyright © 2020 Elsevier Inc. All rights reserved.)

This study was aimed to compare the vascular healing process of a SYNERGY stent with that of a PROMUS PREMIER stent in patients with acute coronary syndrome (ACS). In 71 patients with ACS, undergoing coronary stent implantation using the SYNERGY stent (n = 52) or PROMUS PREMIER stent (n = 19), we measured circulating CD34+/CD133+/CD45 null cells and CD34+/KDR+ cells and observed vascular healing at the stented sites using optical coherence tomography (OCT) and coronary angioscopy. On the day 7, circulating CD34+/CD133+/CD45 null cells increased in SYNERGY group (P < 0.0001), while it did not change in PROMUS group. The CD34+/KDR+ cells also increased in SYNERGY group (P < 0.0001) but less significantly in the PROMUS group (P < 0.05). The OCT-based neointimal thickness (P < 0.0005) and neointimal coverage rate (P < 0.05) at 12 months were greater in SYNERGY group, compared with PROMUS group. The coronary angioscopy-based neointimal coverage grade at 12 months was also greater in SYNERGY group (P < 0.001). In overall patients, the change in CD34+/KDR+ cells on the day 7 correlated with the OCT-based neointimal thickness at 12 months (R = 0.288, P < 0.05). SYNERGY stent seems to have potential advantages over PROMUS PREMIER stent for ACS patients in terms of vascular healing process at the stented sites., (© 2021. The Author(s).)

Introduction: A volumetric approach to measure stent expansion derived from optical coherence tomography (OCT) is superior in regards to clinical outcomes when compared to the conventional method. The current software already performs a semi-automatic assessment and it is available as a clinical tool, however data is still scarce. We evaluated the stent expansion analysis that uses a volumetric vessel model, called minimum expansion index - MEI and compared to the conventional model, which utilizes the minimum stent area expansion (MSAx) indexed to the references, and its potential impact on procedural decision-making strategy in percutaneous coronary intervention., Methods: This was a prospective, all-comers single center study, from all patients undergoing OCT-guided PCI between September 2018 and May 2019. We utilized the APTIVUE™ OPTIS 5.2 software (Abbott, Santa Clara, CA) to evaluate MEI and MSAx measurements after reference adjustments., Results: We included 100 patients with mean age of 64 ± 12.5 years, 68% were men, and the main arteries analyzed through OCT were LAD (48%), RCA (31%) and LCx (21%). The mean MEI was 77.6% ± 16.7% and the mean MSAx was 71.6% ± 16.9%. MEI location differed from MSAx in 70% of cases, and in those cases the mean distance between MEI and MSAx was 15.3 mm ± 12.4 mm. In 53% of the times, the stent underexpansion based on MEI was located proximally to the MSAx by 18.1 mm ± 11.8 mm. Furthermore, in 42% of the total cases, MEI would change the intervention strategy based on the stent underexpansion being in a different location ≥10 mm in comparison to MSAx (34%) associated with the discrepancy between expansion indexes for MEI and MSAx (22%)., Conclusion: We concluded that MEI location did not correlate to the conventional MSAx in two thirds of the cases. Moreover, compared to MEI, the MSAx assessment yielded lower expansion values in different stent positions, potentially changing the appropriate post-stent optimization, which thus would impact the decision-making strategy in almost half of the patients., Competing Interests: Declaration of competing interest Dr. Bezerra is a consultant for Abbott Vascular Inc. None of the other authors have conflicts of interest., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Epicardial adipose tissue (EAT) as a source of pro-inflammatory cytokines tightly linked to metabolic abnormalities. Data regarding the associations of EAT with adipocyte fatty acid-binding protein (A-FABP), a cytokine implicated in the cardiometabolic syndrome, might play an important part in mediating the association between EAT and cardiac structure/function in preserved ejection fraction heart failure (HFpEF). We conducted a prospective cohort study comprising 252 prospectively enrolled study participants classified as healthy ( n = 40), high-risk ( n = 161), or HFpEF ( n = 51). EAT was assessed using echocardiography and compared between the three groups and related to A-FABP, cardiac structural/functional assessment utilizing myocardial deformations (strain/strain rates) and HF outcomes. EAT thickness was highest in participants with HFpEF (9.7 ± 1.7 mm) and those at high-risk (8.2 ± 1.5 mm) and lowest in healthy controls (6.4 ± 1.9 mm, p < 0.001). Higher EAT correlated with the presence of cardiometabolic syndrome, diabetes and renal insufficiency independent of BMI and waist circumference ( p interaction for all > 0.1), and was associated with reduced LV global longitudinal strain (GLS) and LV mass-independent systolic/diastolic strain rates (SRs/SRe) (all p < 0.05). Higher A-FABP levels were associated with greater EAT thickness ( p interaction > 0.1). Importantly, in the combined control cohort, A-FABP levels mediated the association between EAT and new onset HF. Excessive EAT is independently associated with the metabolic syndrome, renal insufficiency, and higher A-FABP levels. The association between EAT and new onset HF is mediated by A-FABP, suggesting a metabolic link between EAT and HF.

Aims: Randomised trials have demonstrated improvement in clinical outcomes with intravascular ultrasound (IVUS)-guided percutaneous coronary intervention (PCI) compared with angiography-guided PCI. The ILUMIEN III trial demonstrated non-inferiority of an optical coherence tomography (OCT)- versus IVUS-guided PCI strategy in achieving similar post-PCI lumen dimensions. ILUMIEN IV is a large-scale, multicentre, randomised trial designed to demonstrate the superiority of OCT- versus angiography-guided stent implantation in patients with high-risk clinical characteristics (diabetes) and/or complex angiographic lesions in achieving larger post-PCI lumen dimensions and improving clinical outcomes., Methods and Results: ILUMIEN IV is a prospective, single-blind clinical investigation that will randomise between 2,490 and 3,656 patients using an adaptive design to OCT-guided versus angiography-guided coronary stent implantation in a 1:1 ratio. The primary endpoints are: (1) post-PCI minimal stent area assessed by OCT in each randomised arm, and (2) target vessel failure, the composite of cardiac death, target vessel myocardial infarction, or ischaemia-driven target vessel revascularisation. Clinical follow-up will continue for up to two years. The trial is currently enrolling, and the principal results are expected in 2022., Conclusions: The large-scale ILUMIEN IV randomised controlled trial will evaluate the effectiveness of OCT-guided versus angiography-guided PCI in improving post-PCI lumen dimensions and clinical outcomes in patients with diabetes and/or with complex coronary lesions., Trial Registration: NCT03507777.

Purpose: Myocardial perfusion imaging using computed tomography (MPI-CT) and coronary CT angiography (CTA) have the potential to make CT an ideal noninvasive imaging gatekeeper exam for invasive coronary angiography. However, beam hardening can prevent accurate blood flow estimation in dynamic MPI-CT and can create artifacts that resemble flow deficits in single-shot MPI-CT. In this work, we compare four automatic beam hardening correction algorithms (ABHCs) applied to CT images, for their ability to produce accurate single images of contrast and accurate MPI flow maps using images from conventional CT systems, without energy sensitivity., Methods: Previously, we reported a method, herein called ABHC-1, where we iteratively optimized a cost function sensitive to beam hardening artifacts in MPI-CT images and used a low order polynomial correction on projections of segmentation-processed CT images. Here, we report results from two new algorithms with higher order polynomial corrections, ABHC-2 and ABHC-3 (with three and seven free parameters, respectively), having potentially better correction but likely reduced estimability. Additionally, we compared results to an algorithm reported by others in the literature (ABHC-NH). Comparisons were made on a digital static phantom with simulated water, bone, and iodine regions; on a digital dynamic anthropomorphic phantom, with simulated blood flow; and on preclinical porcine experiments. We obtained CT images on a prototype spectral detector CT (Philips Healthcare) scanner that provided both conventional and virtual keV images, allowing us to quantitatively compare corrected CT images to virtual keV images. To test these methods' parameter optimization sensitivity to noise, we evaluated results on images obtained using different mAs., Results: In images of the static phantom, ABHC-2 reduced beam hardening artifacts better than our previous ABHC-1 algorithm, giving artifacts smaller than 1.8 HU, even in the presence of high noise which should affect parameter optimization. Taken together, the quality of static phantom results ordered ABHC-2> ABHC-3> ABHC-1>> ABHC-NH. In an anthropomorphic MPI-CT simulator with homogeneous myocardial blood flow of 100 ml⋅min -1 ⋅100 g -1 , blood flow estimation results were 122 ± 24 (FBP), 135 ± 24 (ABHC-NH), 104 ± 14 (ABHC-1), 100 ± 12 (ABHC-2), and 108 ± 18 (ABHC-3) ml⋅min -1 ⋅100 g -1 , showing ABHC-2 as a clear winner. Visual and quantitative evaluations showed much improved homogeneity of myocardial flow with ABHC-2, nearly eliminating substantial artifacts in uncorrected flow maps which could be misconstrued as flow deficits. ABHC-2 performed universally better than ABHC-1, ABHC-3, and ABHC-NH in simulations with different acquisitions (varying noise and kVp values). In the presence of a simulated flow deficit, all ABHC methods retained the flow deficit, and ABHC-2 gave the most accurate flow ratio and homogeneity. ABHC-3 corrected phantom flow values were slightly better than ABHC-2, in noiseless images, suggesting that reduced quality in noisy images was due to reduced estimability. In an experiment with a pig expected to have uniform flow, ABHC-2 applied to conventional images improved flow maps to compare favorably to those from 70keV images., Conclusion: The automated algorithm can be used with different parametric BH correction models. ABHC-2 improved MPI-CT blood flow estimation as compared to other approaches and was robust to noisy images. In simulation and preclinical experiments, ABHC-2 gave results approaching gold standard 70 keV measurements., (© 2020 American Association of Physicists in Medicine.)

The rate of in-stent restenosis (ISR) has become increasingly prevalent with the exponential growth in stent implantation due to an aging population and a higher life expectancy, in addition to the high rates of obesity and diabetes. In this prospective, single operator, all-comer study, we sought to analyze the performance of ELCA followed by bioresorbable vascular scaffold (BVS) placement in patients undergoing percutaneous coronary intervention (PCI) for ISR. A total of 13 patients had ISR treated with a combination of ELCA and BVS, with 9 patients having matched OCT pre, post ELCA and post BVS. Mean age was 65 ± 11.22 and 83% of the patients were male. Hypertension and dyslipidemia were present in 100% of the patients and smoking and diabetes in 50%. After the procedure, we did not detect residual stenosis over 10% in any patient, resulting in a technical success of 100%. No patients had MACE during their hospital stay or within the next six months, resulting in a procedure success of 100%. The mean lumen area increased 0.35 mm 2 from pre procedure to post ELCA and 3.58 mm 2 from post ELCA to post BVS. The final difference, from pre procedure to post BVS, was a 3.93 mm 2 lumen area gain. The mean lumen diameter increased 0.11 mm from baseline to ELCA, 0.95 mm from post laser to BVS implantation and 1.06 mm from pre procedure to post BVS. The NIH area reduced 0.48 mm 2 from pre to post ELCA, 1.13mm 2 from post ELCA to BVS implantation and 1.61 mm 2 from baseline to post BVS implantation. We conclude that ELCA is a safe and feasible debulking method to approach ISR, with high rates of post-procedural BVS success, within six months follow-up., Competing Interests: Declaration of competing interest Dr. Bezerra is a consultant for Philips and Abbott. None of the other authors have conflicts of interest., (Copyright © 2020 Elsevier Inc. All rights reserved.)