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Background: The success rate of percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) is lower and the risk for complications higher compared with other non-CTO PCI. Although interventionalists focus on intimal plaque characteristics, the coronary media is an important (especially for techniques involving antegrade dissection and re-entry) but poorly understood structure in CTO PCI., Objectives: The aim of the present study was to investigate coronary medial wall thinning in CTO lesions and determine how this thinning might affect CTO PCI., Methods: A total of 2,586 sections were investigated, from arteries with evidence of CTO from 54 subjects (1,383 sections) and arteries without evidence of CTO from 54 subjects with non-coronary-related deaths (1,203 sections) after matching for age, gender, body weight, and body height., Results: The medial thickness in subjects with CTO was lower than that in those with non-coronary-related death (P < 0.001). In subjects with CTO, CTO lesions had thinner medial walls compared with those with lower luminal narrowing (P < 0.001). At the CTO distal segments, the 6- to 12-mm distal segment from the distal end of the CTO had significantly less luminal narrowing (P < 0.001), and similar medial thickness, compared with the distal end of the CTO. Immunohistochemical analysis revealed that short-duration CTO had more cleaved caspase-3-positive cells in media and had significantly more CD3 + , CD4 + , CD8 + , and CD4 + CD28 null T cells compared with long-duration CTO., Conclusions: CTO lesions demonstrated coronary medial thinning compared with non-CTO lesions. Further investigation of the cause-and-effect relationship among inflammation, apoptosis, and coronary medial wall thinning is warranted in future mechanistic studies., Competing Interests: Funding Support and Author Disclosures This study was supported by the CVPath Institute. Drs Virmani and Finn have received institutional research support from the National Institutes of Health (grant HL141425), a Leducq Foundation grant, 480 Biomedical, 4C Medical, 4Tech, Abbott, AccuMedical, Amgen, Biosensors, Boston Scientific, Cagent Vascular, Cardiac Implants, CeloNova BioSciences, Claret Medical, Concept Medical, Cook, Cardiovascular Systems, DuNing, Edwards Lifesciences, Emboline, Endotronix, Envision Scientific, Lutonix Bard, Gateway, LifeTech, LimFlow, MedAlliance, Medtronic, Mercator, Merill, MicroPort Medical, MicroVention, Mitralign, Mitra Assist, North American Science Associates, Nanova, Neovasc, Nipro, Novogate, Occlutech, OrbusNeich Medical, Phenox, Profusa, Protembis, Qool, Recor, Senseonics, Shockwave Medical, SINOMED, Spectranetics, Surmodics, Symic, Vesper, W.L. Gore, and Xeltis. Dr Finn has received honoraria from Abbott Vascular, Biosensors, Boston Scientific, CeloNova BioSciences, Cook Medical, Cardiovascular Systems, Lutonix Bard, Sinomed, and Terumo; and is a consultant to Amgen, Abbott Vascular, Boston Scientific, CeloNova BioSciences, Cook Medical, Lutonix Bard, and Sinomed. Dr Virmani has received honoraria from Abbott Vascular, Biosensors, Boston Scientific, CeloNova BioSciences, Cook Medical, Cordis, Cardiovascular Systems, Lutonix Bard, Medtronic, OrbusNeich Medical, SINOMED, Recor, Terumo, W.L. Gore, and Spectranetics; and is a consultant for Abbott Vascular, Boston Scientific, CeloNova BioSciences, Cook Medical, Cordis, Cardiovascular Systems, Edwards Lifesciences, Lutonix Bard, Medtronic, OrbusNeich Medical, Recor, SINOMED, Spectranetics, Surmodics, Terumo, W. L. Gore, and Xeltis. Dr Konishi has received a research grant from the Ito Foundation. 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: A deeper understanding of coronary medial thickness is important for coronary intervention because media thickness can limit the safety and effectiveness of interventional techniques. However, there is a paucity of detailed data on human coronary medial thickness so far., Materials and Methods: We investigated the thickness of the media by histologic analysis. A total of 230 sections from 10 individuals from the CVPath autopsy registry who died from non-coronary deaths were evaluated. We performed pathological analysis on 13 segments of the following primary vessels from coronary arteries: the left main trunk, proximal left anterior descending artery (LAD), mid LAD, distal LAD, proximal left circumflex artery (LCX), mid LCX, distal LCX, proximal right coronary artery (RCA), mid RCA, and the distal RCA. The following side branches were also evaluated: diagonal, obtuse margin, and posterior descending artery branches., Results: The average age of the studied individuals was 60.4±12.3 years. The median medial thickness for all sections was 0.202 (0.149-0.263) mm. The median medial thickness of the main branches was significantly higher compared to that of the side branches (p<0.001). Although the medial thicknesses of the main branch of LAD and LCX were significantly decreased from proximal to distal segments (p = 0.010, p = 0.006, respectively), the medial thickness of the main branch of RCA was not significantly decreased from proximal to distal (p = 0.170). The thickness of the media was positively correlated with vessel diameter, while it was negatively correlated with luminal narrowing (p<0.001 and p<0.001, respectively)., Conclusions: The human coronary arteries demonstrate variation in medial thickness which tends to vary depending upon an epicardial coronary artery itself, as well as its segments and branches. Understanding these variations in medial thickness can be useful for both the interventionalists and interventional product development teams., Competing Interests: Competing Interest Statement: R.V. and A.V.F. have received institutional research support from NIH (HL141425), Leducq Foundation Grant; 480 Biomedical; 4C Medical; 4Tech; Abbott; Accumedical; Amgen; Biosensors; Boston Scientific; Cagent Vascular; Cardiac Implants; Celonova; Claret Medical; Concept Medical; Cook; CSI; DuNing, Inc; Edwards LifeSciences; Emboline; Endotronix; Envision Scientific; Lutonix/Bard; Gateway; Lifetech; Limflo; MedAlliance; Medtronic; Mercator; Merill; Microport Medical; Microvention; Mitraalign; Mitra Assist; NAMSA; Nanova; Neovasc; NIPRO; Novogate; Occulotech; OrbusNeich Medical; Phenox; Profusa; Protembis; Qool; Recor; Senseonics; Shockwave; Sinomed; Spectranetics; Surmodics; Symic; Vesper; W.L. Gore; Xeltis. A.V.F. has received honoraria from Abbott Vascular; Biosensors; Boston Scientific; Celonova; Cook Medical; CSI; Lutonix Bard; Sinomed; Terumo Corporation; and is a consultant to Amgen; Abbott Vascular; Boston Scientific; Celonova; Cook Medical; Lutonix Bard; Sinomed. R.V. has received honoraria from Abbott Vascular; Biosensors; Boston Scientific; Celonova; Cook Medical; Cordis; CSI; Lutonix Bard; Medtronic; OrbusNeich Medical; CeloNova; SINO Medical Technology; ReCore; Terumo Corporation; W. L. Gore; Spectranetics; and is a consultant for Abbott Vascular; Boston Scientific; Celonova; Cook Medical; Cordis; CSI; Edwards Lifescience; Lutonix Bard; Medtronic; OrbusNeich Medical; ReCore; Sinomededical Technology; Spectranetics; Surmodics; Terumo Corporation; W. L. Gore; Xeltis. T. K. receives research grants from The Ito foundation. The other authors declare no competing interests." This does not alter our adherence to PLOS ONE policies on sharing data and materials., (Copyright: © 2023 Konishi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Recent clinical studies are testing strategies for short (1-3 months) dual antiplatelet therapy following newer-generation drug-eluting stent (DES) placement. However, detailed biological responses to newer-generation DES remain unknown in humans., Aims: We sought to evaluate early pathologic responses to abluminal biodegradable polymer-coated (BP-) DES compared with circumferential durable polymer-coated (DP-) DES in human autopsy cases., Methods: The study included 38 coronary lesions with newer-generation DES implanted for <90 days (DP-DES=24, BP-DES=14) in 26 autopsy cases. The degree of strut coverage was defined as follows: grade 0 (bare), grade 1 (with fibrin or tissues/cells without endothelium), grade 2 (with single-layered endothelium), and grade 3 (with endothelium and underlying smooth muscle cell layers)., Results:  The duration following implantation was similar in DP- and BP-DES (median=20 vs 17 days). A total of 2,022 struts (DP-DES=1,297, BP-DES=725) were pathologically analysed. Focal grade 2 coverage was observed as early as 5 days after the implantation in both stents. The multilevel mixed-effects ordered logistic regression model demonstrated that BP-DES exhibited greater strut coverage compared with DP-DES (odds ratio [OR]: 3.64, 95% confidence interval [CI]: 1.37-9.67; p=0.009), which remained significant after adjustment for the duration following implantation and underlying tissue characteristics (OR: 2.74, 95% CI: 1.10-6.80; p=0.030). The predictive probability of grade 2 and 3 coverage was comparably limited at 30 days (DP-DES=17.1%, BP-DES=28.7%) and increased at 90 days (DP-DES=76.5%, BP-DES=86.6%). Both stents showed low inflammation and a similar degree of fibrin deposition., Conclusions: Single-layered endothelial coverage begins in the days after newer-generation DES placement, and BP-DES potentially exhibit faster strut coverage with smooth muscle cell infiltration than DP-DES in humans. Nevertheless, vessel healing remains suboptimal in both stents at 30 days.

In-stent restenosis (ISR) remains a potential complication after percutaneous coronary intervention, even in the era of drug-eluting stents, and its treatment remains suboptimal. Neoatherosclerosis is an important component of the pathology of ISR and is accelerated in drug-eluting stents compared with bare-metal stents. Coronary angiography is the gold standard for evaluating the morphology of ISR, although computed tomography angiography is emerging as an alternative noninvasive modality to evaluate the presence of ISR. Drug-coated balloons and stent reimplantation are the current mainstays of treatment for ISR, and the choice of treatment should be based on clinical background and lesion morphology., Competing Interests: Disclosure CVPath Institute received Grant/Research/Clinical Trial Support from NIH-HL141425, Leducq Foundation Grant, 4C Medical, 4Tech, Abbott Vascular, Ablative Solutions, Absorption Systems, Advanced NanoTherapies, Aerwave Medical, Alivas, Amgen, Asahi Medical, Aurios Medical, Avantec Vascular, BD, Biosensors, Biotronik, Biotyx Medical, Bolt Medical, Boston Scientific, Canon USA, Cardiac Implants, Cardiawave, CardioMech, Cardionomic, Celonova, Cerus EndoVascular, Chansu Vascular Technologies, Childrens National Medical Center, Concept Medical, Cook Medical, Cooper Health, Cormaze Technologies GmbH, CRL/AccelLab, Croivalve, CSI, Dexcom, Edwards Lifesciences, Elucid Bioimaging, Emboline, Endotronix, Envision, Filterlex, Imperative Care, Innovalve, Innovative Cardiovascular Solutions, Intact Vascular, Interface Biolgics, Intershunt Technologies, Invatin Technologies, Lahav CRO, Limflow, L&J Biosciences, Lutonix, Lyra Therapeutics, Mayo Clinic, Maywell, MD Start, MedAlliance, Medanex, Medtronic, Mercator, Microport, Microvention, Neovasc, Nephronyx, Nova Vascular, Nyra Medical, Occultech, Olympus, Ohio Health, OrbusNeich, Ossio, Phenox, Pi-Cardia, Polares Medical, Polyvascular, Profusa, ProKidney LLC, Protembis, Pulse Biosciences, Qool Therapeutics, Recombinetics, Recor Medical, Regencor, Renata Medical, Restore Medical, Ripple Therapeutics, Rush University, Sanofi, Shockwave, Sahajan and Medical Technologies, SoundPipe, Spartan Micro, Spectrawave, Surmodics, Terumo Corporation, The Jacobs Institute, Transmural Systems, Transverse Medical, TruLeaf Medical, UCSF, UPMC, Vascudyne, Vesper, Vetex Medical, Whiteswell, WL Gore, and Xeltis. A.V. Finn received consultant fees/honoraria from Abbott Vascular, Amgen, Biosensors, Boston Scientific, Celonova, Cook Medical, CSI, Lutonix Bard, Sinomed, and Terumo Corporation. R. Virmani is a consultant of Abbott Vascular, Boston Scientific, Celonova, OrbusNeich Medical, Terumo Corporation, W. L. Gore, Edwards Lifesciences, Cook Medical, CSI, ReCor Medical, SinoMedical Sciences Technology, Surmodics, Bard BD and is a Scientific Advisory Board Member of Medtronic and Xeltis. Kenji Kawai has no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Since optical coherence tomography (OCT) was first performed in humans two decades ago, this imaging modality has been widely adopted in research on coronary atherosclerosis and adopted clinically for the optimization of percutaneous coronary intervention. In the past 10 years, substantial advances have been made in the understanding of in vivo vascular biology using OCT. Identification by OCT of culprit plaque pathology could potentially lead to a major shift in the management of patients with acute coronary syndromes. Detection by OCT of healed coronary plaque has been important in our understanding of the mechanisms involved in plaque destabilization and healing with the rapid progression of atherosclerosis. Accurate detection by OCT of sequelae from percutaneous coronary interventions that might be missed by angiography could improve clinical outcomes. In addition, OCT has become an essential diagnostic modality for myocardial infarction with non-obstructive coronary arteries. Insight into neoatherosclerosis from OCT could improve our understanding of the mechanisms of very late stent thrombosis. The appropriate use of OCT depends on accurate interpretation and understanding of the clinical significance of OCT findings. In this Review, we summarize the state of the art in cardiac OCT and facilitate the uniform use of this modality in coronary atherosclerosis. Contributions have been made by clinicians and investigators worldwide with extensive experience in OCT, with the aim that this document will serve as a standard reference for future research and clinical application., (© 2022. Springer Nature Limited.)

Introduction: Late stent thrombosis caused by delayed vascular healing and prolonged local inflammation were major drawbacks of 1 st generation drug-eluting stents (DES). Strut design, biocompatibility of polymer, and drug-release profiles were improved in 2 nd and 3rdgeneration DES. Accordingly, the indications for percutaneous coronary intervention with DES have been expanded to more complex patients and lesions. Despite these improvements, significant barriers such as greater flexibility in the duration of dual-antiplatelet therapy (DAPT) as well as reducing long-term stent-related events remain. To achieve ideal short- and long-term results, these existing limitations need to be overcome., Areas Covered: We will discuss the current limitations of coronary DES and how they might be overcome from pathological and clinical viewpoints., Expert Opinion: Optimizing DAPT duration after stent implantation and prevention of in-stent neoatherosclerosis are two major issues in current DES. Overcoming these drawbacks is a prerequisite toward achieving better short- and long-term clinical outcomes. New technologies including platform design, polymer types, and anti-proliferative agent itself might lead to further improvements. Although the initial experience with bioresorbable scaffold/stents (BRS) was disappointing, positive results of clinical studies regarding novel BRS are raising expectations. Overall, further device innovation is desired for overcoming the limitations of current DES.

Introduction : In-stent restenosis (ISR) has been one of the biggest limitations to the success of percutaneous coronary intervention for the treatment of coronary artery disease (CAD). The introduction of drug-eluting stent (DES) was a revolution in the treatment of CAD because these devices drastically reduced ISR to very low levels (<5%). Subsequently, newer generation DES treatments have overcome the drawbacks of first-generation DES, i.e. delayed endothelialization, and late stent thrombosis. However, the issue of late ISR, including neoatherosclerosis after DES implantation especially in high-risk patients and complex lesions, still exists as a challenge to be overcome. Areas covered : We discuss the mechanisms of ISR development including neoatherosclerosis, past and current clinical status of ISR, and methods to predict and overcome this issue from pathological and clinical points of view. Expert opinion : The initial drawbacks of first-generation DES, such as delayed endothelial healing and subsequent risk of late stent thrombosis, have been improved upon by the current generation DES. To achieve better long-term clinical outcomes, further titration of drug-release and polymer degradation profile, strut thickness as well as material innovation are needed.

Background: Recent clinical studies have suggested the feasibility of 1-month dual antiplatelet therapy (DAPT) for patients receiving drug-eluting stent (DES). Although our previous ex-vivo swine arteriovenous (AV) shunt studies under low dose heparin treatment suggested superior thromboresistance of fluoropolymer-coated everolimus-eluting stent (FP-EES) when compared to other polymer-based DESs, the relative thromboresistance of different DESs under single antiplatelet therapy (SAPT) has never been examined. This study aimed to evaluate platelet adhesion under SAPT in competitive DESs in the in vitro flow loop model and ex vivo swine AV shunt model., Methods: The thrombogenicity of FP-EES, BioLinx polymer zotarolimus-eluting stent (BL-ZES), and biodegradable polymer everolimus-eluting stent (BP-EES) was assessed acutely using the swine AV shunt model under aspirin or clopidogrel SAPT. Stents were immunostained using antibodies against platelets and inflammatory markers and evaluated by confocal microscopy. Also, the adhesion of platelet and albumin on the three DESs was assessed by an in-vitro flow loop model using human platelets under aspirin SAPT and fluorescent albumin, respectively., Results: In the shunt model, FP-EES showed significantly less platelet and inflammatory cell adhesion than BL-ZES and BP-EES. In the flow loop model, FP-EES showed significantly less platelet coverage and more albumin adsorption than BL-ZES and BP-EES., Conclusions: These results suggest FP-EES may have particular advantage for short-term DAPT compared to other DESs., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Primary percutaneous coronary intervention (PPCI) has dramatically changed the outcome of patients with ST-elevation myocardial infarction (STEMI). However, despite improvements in interventional technology, registry data show little recent change in the prognosis of patients who survive STEMI, with a significant incidence of cardiogenic shock, heart failure, and cardiac death. Despite a technically successful PPCI procedure, a variable proportion of patients experience suboptimal myocardial reperfusion. Large infarct size and coronary microvascular injury, as the consequence of ischaemia-reperfusion injury and distal embolization of atherothrombotic debris, account for suboptimal long-term prognosis of STEMI patients. In order to address this unmet therapeutic need, a broad-range of device-based treatments has been developed. These device-based therapies can be categorized according to the pathophysiological pathways they target: (i) techniques to prevent distal atherothrombotic embolization, (ii) techniques to prevent or mitigate ischaemia/reperfusion injury, and (iii) techniques to enhance coronary microvascular function/integrity. This review is an overview of these novel technologies with a focus on their pathophysiological background, procedural details, available evidence, and with a critical perspective about their potential future implementation in the clinical care of STEMI patients., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2021. For permissions, please email: journals.permissions@oup.com.)

Background: The relative thrombogenicity and albumin adsorption and retention of different durable polymers used in coronary stents has not been tested., Aims: This study sought to compare the thromboresistance and albumin binding capacity of different durable polymer drug-eluting stents (DES) using dedicated preclinical and in vitro models., Methods: In an ex vivo swine arteriovenous shunt model, a fluoropolymer everolimus-eluting stent (FP-EES) (n=14) was compared with two durable polymer DES, the BioLinx polymer-coated zotarolimus-eluting stent (BL-ZES) (n=9) and a CarboSil elastomer polymer-coated ridaforolimus-eluting stent (EP-RES) (n=6), and bare metal stents (BMS) (n=10). Stents underwent immunostaining using a cocktail of antiplatelet antibodies and a marker for inflammation and were then evaluated by confocal microscopy (CM). Albumin retention was assessed using a flow loop model with labelled human serum albumin (FP-EES [n=8], BL-ZES [n=4], EP-RES [n=4], and BMS [n=7]), and scanned by CM., Results: The area of platelet adherence (normalised to total stent surface area) was lower in the order FP-EES (9.8%), BL-ZES (32.7%), EP-RES (87.6%) and BMS (202.0%), and inflammatory cell density was least for FP-EES

Background: Short-term dual antiplatelet therapy (DAPT) is a suitable strategy after stent implantation especially in patients at high risk for bleeding. The thromboresistant characteristics and the healing profile permanent polymer stents such as the Resolute Onyx- drug-eluting stent (DES) has never been tested against the current approved stents for short-term DAPT, the polymer free (PF) biolimus-eluting stent (PF-BES) and bare metal stents (BMS) in dedicated preclinical models., Methods: An ex-vivo porcine arteriovenous shunt and in-vivo flow loop model were used to evaluate thromboresistance. The healing profile was assessed in the rabbit model at 28 days by confocal microscopy (CM), scanning electron microscopy (SEM) and histology. Onyx-DES was separately compared with Onyx-BMS in first experiment and PF-BES in second experiment., Results: In an ex-vivo shunt model, CM and SEM showed significantly less platelet adhesion for Onyx-DES relative to Onyx-BMS and PF-BES. In a flow loop model using human blood, platelet adhesion was also significantly less in Onyx-DES as compared to PF-BES and Onyx-BMS. In the healing study, Onyx-BMS showed significantly greater healing profile relative to Onyx-DES as expected, whereas Onyx-DES showed equivalent endothelial coverage by SEM and significantly less Evan's blue uptake and comparable colocalization of p120 and vascular endothelial-cadherin when compared with PF-BES., Conclusions: Onyx-DES showed qualities of thomboresistance and healing which appear to be compatible with short-term DAPT. Thromboresistance was superior to PF-BES and healing was equivalent to PF-BES in this pre-clinical study. Onyx-DES might provide advantages when considering short-term DAPT especially in patients at high risk of bleeding., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Aims: The advantage of biodegradable-polymer drug-eluting stents (BP-DES) versus durable-polymer (DP) DES remains uncertain. We compared neointimal formation and endothelial barrier function of new BP sirolimus-eluting stents (BP-SES, BuMA Supreme®) to other contemporary BP-DES, DP-DES, and bare metal stents (BMS)., Methods and Results: Light microscopic assessment in swine coronary arteries showed comparable neointimal formation between BP-SES and DP everolimus-eluting stent (DP-EES). The performance of BP-SES was compared with DP-EES (Xience Xpedition®), BP-EES (Synergy®), and BMS (Multi-Link Vision®) at 45- and 90-days in rabbit ilio-femoral arteries using Evans blue dye (EBD) followed by immunostaining for endothelial barrier proteins (p120/vascular endothelial-cadherin [VE-cad]) to evaluate endothelial barrier function and scanning electron microscopy (SEM) to determine strut tissue coverage. BMS followed by BP-SES and BP-EES exhibited smaller EBD positive areas versus that of DP-EES at 45- and 90-days. p120/VE-cad immunostaining and SEM-determined strut coverage was greater at 45- and 90-days for BMS followed by all DESs. Regardless of stent type, the lack of p120/VE-cad co-localization showed greater leukocyte and platelet aggregation., Conclusion: Three types of DES showed different endothelial healing pattern regardless their equivalent suppression of neointimal formation., Competing Interests: Declaration of competing interest CVPath Institute has received institutional research support from R01 HL141425 Leducq Foundation Grant; 480 Biomedical; 4C Medical; 4Tech; Abbott; Accumedical; Amgen; Biosensors; Boston Scientific; Cardiac Implants; Celonova; Claret Medical; Concept Medical; Cook; CSI; DuNing, Inc.; Edwards LifeSciences; Emboline; Endotronix; Envision Scientific; Lutonix/Bard; Gateway; Lifetech; Limflo; MedAlliance; Medtronic; Mercator; Merill; Microport Medical; Microvention; Mitraalign; Mitra assist; NAMSA; Nanova; Neovasc; NIPRO; Novogate; Occulotech; OrbusNeich Medical; Phenox; Profusa; Protembis; Qool; Recor; Senseonics; Shockwave; Sinomed; Spectranetics; Surmodics; Symic; Vesper; W.L. Gore; Xeltis. A.F. has received honoraria from Abbott Vascular; Biosensors; Boston Scientific; Celonova; Cook Medical; CSI; Lutonix Bard; Sinomed; Terumo Corporation; and is a consultant Amgen; Abbott Vascular; Boston Scientific; Celonova; Cook Medical; Lutonix Bard; Sinomed. R.V. has received honoraria from Abbott Vascular; Biosensors; Boston Scientific; Celonova; Cook Medical; Cordis; CSI; Lutonix Bard; Medtronic; OrbusNeich Medical; SINO Medical Technology; ReCore; Terumo Corporation; W. L. Gore; Spectranetics; and is a consultant Abbott Vascular; Boston Scientific; Celonova; Cook Medical; Cordis; CSI; Edwards Lifescience; Lutonix Bard; Medtronic; OrbusNeich Medical; ReCore; Sinomededical Technology; Spectranetics; Surmodics; Terumo Corporation; W. L. Gore; Xeltis. A.C. receives research grants from University Hospital RWTH Aachen. Other authors report no conflicts of interest., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Struts have been considered as covered when tissue overlying the struts is >0 μm by optical coherence tomography (OCT). However, there is no confirmatory study to validate this definition by histology which is the gold standard. The aim of the present study was to assess the appropriate cutoff value of neointimal thickness of stent strut coverage by OCT with histology confirmation., Methods: We performed ex vivo OCT imaging of human coronary arteries with stents at autopsy. A total of 46 stents in 39 vessels from 25 patients were examined in this study, and a total of 165 cross-sectional images were co-registered with histology to determine the optimal cutoff value for strut coverage by OCT which was defined as luminal endothelial cells with 2 abluminal layers of smooth muscles cells and matrix. Considering the resolution of OCT is 10 to 20 μm, the cutoff values were assessed at ≥20, ≥40, and ≥60 μm., Results: A total of 2235 struts were reviewed by histology, 1216 were considered as well-matched struts which were analyzed in this study. By histology, 160 struts were identified as uncovered, while 1056 struts were covered. The OCT assessment without consideration of neointimal thickness yielded a poor specificity of 37.5% and sensitivity 100%. Of 3 cutoff values, the cutoff value of ≥40 μm yielded the best sensitivity (99.3%), specificity (91.0%), positive predictive value (98.6%), and negative predictive value (95.6%) as compared with ≥20 and ≥60 μm., Conclusions: Neointimal thickness ≥40 μm by OCT yielded the most accurate cutoff value to identify stent strut coverage validated by histology.

Aims: Vascular calcification is routinely encountered in percutaneous coronary intervention (PCI) and severe coronary calcification is a known predictor of in-stent restenosis and stent thrombosis. However, the histopathologic mechanisms behind such events have not been systematically described., Methods and Results: From our registry of 1211 stents, a total of 134 newer-generation drug-eluting stents (DES) (Xience, Resolute-Integrity, PROMUS-Element, and Synergy) with duration of implant ≥30 days were histologically analysed. The extent of calcification of the stented lesions was evaluated radiographically and divided into severe (SC, n = 46) and non-severely calcified lesions (NC, n = 88). The percent-uncovered struts per section {SC vs. NC; median 2.4 [interquartile range (IQR) 0.0-19.0] % vs. 0.0 (IQR 0.0-4.6) %, P = 0.02} and the presence of severe medial tears (MTs) (59% vs. 44%, respectively, P = 0.03) were greater in SC than NC. In addition, SC had a higher prevalence of ≥3 consecutive struts lying directly in contact with surface calcified area (3SC) (52% vs. 8%, respectively, P < 0.0001). Multivariate analysis demonstrated that sections with duration of implantation ≤6 months [odds ratio (OR): 7.7, P < 0.0001], 3SC (OR: 6.5, P < 0.0001), strut malapposition (OR: 5.0, P < 0.0001), and lack of MTs (OR: 2.5, P = 0.0005) were independent predictors of uncovered struts. Prevalence of neoatherosclerosis was significantly lower in SC than that of NC (24% vs. 44%, P = 0.02)., Conclusion: Severe calcification, especially surface calcified area is an independent predictor of uncovered struts and delayed healing after newer-generation DES implantation. These data expand of knowledge of the vascular responses of stenting of calcified arteries and suggests further understand of how best to deal with calcification in patients undergoing PCI., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: journals.permissions@oup.com.)

Implantation of drug-eluting stents (DES) is the dominant treatment strategy for patients with symptomatic coronary artery disease. However, the first-generation DES had substantial drawbacks, including delayed healing, local hypersensitivity reactions and neoatherosclerosis, which all led to a steady increase in major adverse cardiovascular events over time. Subsequently, newer-generation DES were introduced with thinner struts, different scaffold designs (to improve deliverability while maintaining radial strength), different durable and biodegradable polymers - and in some cases no polymer (to improve vascular biocompatibility) - and new antiproliferative drug types and doses. Currently, >30 different DES are commercially available in Europe, with fewer available in the USA but with many new entrants coming onto the US market in the next few years. Never before have cardiologists been faced with so many choices of stent, each with its own unique design. In this Review, we detail preclinical and pathology studies for each stent design, examining thromboresistance, speed of neointimal coverage and completeness of healing, including endothelialization. We conclude by discussing how these design characteristics might affect the potential for shortening the minimum duration of dual antiplatelet therapy needed after coronary intervention.

Fully bioresorbable scaffolds (BRS) were designed to overcome the limitations of metallic drug-eluting stents, which permanently cage the vessel wall, thereby preventing normal coronary vasomotion, preclude bypass grafting and can provoke long-term foreign-body responses. Although multiple scaffolds have been or are in development, the Absorb Bioresorbable Vascular Scaffold (BVS; Abbott Vascular) was the first FDA-approved device and was widely expected to fulfil the dream of interventional cardiologists of a transient scaffold that would disappear 'when the job was done' and would not hamper further treatment options. Although early, small studies and even large, randomized trials showed beneficial outcomes up to 1 year of follow-up, longer-term results have been disappointing, with increased rates of device thrombosis and target-lesion revascularization. The Absorb BVS device was withdrawn from the market because of low demand. In this Review, we summarize the preclinical and clinical data available for BRS to understand how the vascular biological reactions to these devices differ from biological reactions to metallic drug-eluting stents and how these responses translate into clinical outcomes. We also discuss next-generation BRS and outline modifications that are needed to improve the long-term outcomes with these devices so that they eventually become a viable option for patients with symptomatic obstructive coronary artery disease.

Background: Despite the increasing use of left main (LM) percutaneous coronary intervention (LM-PCI), there have been no pathological studies devoted to understanding the causes of LM stent failure. We aimed to systematically determine the pathological mechanisms of LM stent failure., Methods and Results: From the CVPath Stent registry, a total of 46 lesions were identified to have LM-PCI. Pathologic stent failure (PSF) was defined as stent thrombosis, restenosis and in-stent chronic total occlusion (CTO). Failed and patent LM stented lesions were pathologically assessed to determine predictors of PSF. Malapposition and uncovered struts were numerically greater in the LM ostium, body, and bifurcation while neointimal thickness was relatively greater in bifurcation and proximal circumflex. In this study cohort, half of the lesions (n = 23) showed PSF. Stent thrombosis (ST, n = 18) was the major mode of PSF followed by in-stent CTO (n = 4) and restenosis (n = 1). Failed lesions showed significantly greater prevalence of malapposition >20% of struts/section (65% vs. 13%, P < 0.01), stent struts crossing an ostial side branch >30% of the circumference (48% vs. 13%, P < 0.01) and uncovered struts >30% (57% vs. 18%, P = 0.03). In multivariate analysis, the prevalence of malapposition >20% was the strongest risk factor for PSF (Odds ratio 8.0, 95% confidence interval 1.8-45.4, P < 0.01) followed by struts crossing an ostial side branch >30% (Odds ratio 4.2, 95% confidence interval 0.8-24.7, P = 0.09)., Conclusion: Our data demonstrate the main pathological predictors for LM stent failure are malapposition and struts crossing an ostial side branch and suggest that imaging-guided PCI may be important., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Objectives: The aim of this study was to explore the pathology of in-stent chronic total occlusion (IS-CTO) in bare-metal (BMS) versus drug-eluting stents (DES)., Background: Despite a relatively high prevalence of IS-CTO, little is known about the underlying etiology and histopathologic characteristics of the occlusion., Methods: From CVPath Institute's stent registry of human native coronary arteries, the authors identified 56 lesions (32 BMS and 24 DES) from 54 patients with IS-CTO. Sections of stented coronary arteries were examined for histological features of IS-CTO. The underlying mechanisms of IS-CTO were determined along with the histopathological characteristics., Results: The pathological prevalence of IS-CTO was significantly higher in BMS versus DES cases at autopsy (11.7% vs. 5.9%; p = 0.01). The most frequent etiology of IS-CTO was acute thrombotic occlusion (51% in BMS vs. 67% in DES), followed by restenosis (31% vs. 8%) and neoatherosclerotic rupture (9% vs. 4%). The proximal lumen pattern was abrupt in 67% of BMS and in 57% of DES, whereas the distal lumen was tapered in 68% of BMS and in 74% of DES. BMS showed longer fibrous cap of IS-CTO than DES in both proximal (4.6 mm vs. 1.6 mm; p = 0.06) and distal (5.3 mm vs. 2.0 mm; p = 0.06)., Conclusions: At autopsy, IS-CTO was observed more frequently in BMS versus DES, with acute thrombotic occlusion being the most frequent cause, followed by restenosis (especially in BMS) and neoatherosclerotic rupture. Our findings shed new light upon the frequency, mechanisms, and pathology of IS-CTO., (Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objectives: The aim of this study was to identify histological features that correlate with terms commonly used to describe optical coherence tomographic (OCT) and optical frequency-domain imaging (OFDI) images of stented vessels, by means of a histopathological validation study using stented human coronary arteries., Background: OCT imaging and OFDI are used to evaluate vascular responses to stent implantation. Descriptive terms such as "peristrut low attenuation" and "heterogeneous" have been used to describe neointimal characteristics that may have clinical relevance. However, only limited histopathological correlations are available., Methods: Using the CVPath stent registry, 19 cases were identified in whom implantation duration was >30 days and OCT imaging or OFDI and histological findings were available. Consecutive OCT or OFDI frames (n = 1,063) of stented coronary arteries were categorized according to their predominant imaging features in 1-mm intervals. Coregistration of OCT or OFDI frames and histopathological cross sections was performed in 111 frames., Results: Seven distinct OCT or OFDI patterns were found: homogenous (45%), layered (15%), high intensity with high attenuation (14%), intraluminal protruding masses (8%), peristrut low attenuation (7%), heterogeneous (2%), and honeycomb (1%). Histopathologically, the homogenous pattern correlated most often with smooth muscle cells within collagenous/proteoglycan matrix and less often with organized thrombus. The layered pattern correlated with healed neointimal rupture or erosion, peristrut neovascularization, or smooth muscle cells within collagen/proteoglycan matrix. High intensity with high attenuation correlated with superficial macrophage accumulation in the majority of cases, but with other histological findings in 30% of cases. The diagnostic accuracy was greater in restenotic lesions. The only OCT or OFDI finding that had a single histological feature was the honeycomb pattern., Conclusions: This study suggests a lack of correlation between OCT image patterns and distinct histological tissue characteristics., (Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objectives: We sought to pool data from all studies with reported strut-level data in human subjects evaluated by optical coherence tomography (OCT) surveillance and to compare the aggregate data of stent strut coverage on a longitudinal temporal timeline from initial implantation for different coronary stent subtypes., Background: Delayed strut coverage following drug-eluting stent (DES) implantation is an important contributor to late stent thrombosis (LST). OCT can detect stent strut coverage., Methods: We conducted a systematic search of published or presented studies reporting OCT stent strut coverage of bare-metal stents (BMS) and DES in PubMed, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials to June 2014. Data from 3,515 patients with strut-level data on 731,761 struts were analyzed., Results: The temporal kinetics of strut coverage differed according to stent type. The rate of strut coverage, reflected by the calculated regression coefficient, was found to be the highest in BMS, followed by early generation zotarolimus-eluting stent, everolimus-eluting stent, newer-generation zotarolimus-eluting stent, paclitaxel-eluting stent, and sirolimus-eluting stent (p < 0.0001)., Conclusions: Aggregate rates of stent strut coverage assessed by OCT surveillance differed according to stent type. The clinical implications of these differences require further study but may underlie the differences in rates of stent thrombosis observed in clinical trials with different stent types. © 2015 Wiley Periodicals, Inc., (© 2015 Wiley Periodicals, Inc.)

Objectives: The study interrogated an autopsy registry to investigate the histopathologic features of early stent thrombosis (ST) in patients presenting with acute coronary syndrome (ACS)., Background: The occurrence of early ST following percutaneous coronary intervention (PCI) for ACS remains a clinical problem despite advances in stent technology in both bare-metal and drug-eluting stents., Methods: Sixty-seven stented coronary lesions from 59 patients who presented with ACS and died within 30 days were included. Stented segments were cross sectioned at 3 to 4 mm intervals and evaluated by light microscopy, and morphometric analysis was performed., Results: Early ST (<30 days of PCI) was identified in 34 (58%) of the 59 patients. Early ST was dependent on the underlying plaque morphology and underlying thrombus burden: presence of necrotic core prolapse was more frequent in thrombosed lesions compared with patent lesions (70% vs. 43%, p = 0.045) and maximal underlying thrombus thickness was significantly greater in thrombosed versus patent lesions. All 3 patients with false lumen stenting had ST. Detailed analysis revealed that the percent of necrotic core prolapse, medial tear, or incomplete apposition was significantly greater in the early ST compared with patent group (28% vs.11%, p < 0.001; 27% vs. 15% p = 0.004; and 34% vs. 18% p = 0.008, respectively). Multivariate analysis revealed that maximal depth of strut penetration, % strut with medial tear, and % struts with incomplete apposition were the primary indicators of early ST., Conclusions: The current autopsy study highlights the impact of thrombus burden and suboptimal stent implantation in unstable lesions as a trigger of early ST, suggesting that improvement in implantation technique and refinement of stent design may improve clinical outcomes of ACS patients., (Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: With hybrid coronary revascularization (HCR), minimally invasive left internal mammary artery (LIMA) to left anterior descending coronary artery (LAD) grafting is combined with percutaneous coronary intervention (PCI) of non-LAD vessels. The purpose of this study was to examine the short-term clinical and angiographic results in one of the largest HCR series to date., Methods: From 2003 to 2012, 300 consecutive patients (aged 64±12 years, female 31.7%, predicted risk of mortality 1.6%±2.1%) underwent HCR on an intent-to-treat basis at a single institution. After robotic or thoracoscopic LIMA harvest, off-pump LIMA to LAD grafting was performed through a 3- to 4-cm sternal-sparing, non-rib-spreading thoracotomy. PCI was utilized to treat non-LAD lesions either before, after, or concomitant with the surgical procedure., Results: Of the 300 patients undergoing HCR on an intent-to-treat basis, HCR was performed with surgery first in 192 patients (64.0%), PCI first in 56 (18.7%), and as a concomitant procedure in 21 (7.0%). Of the 31 patients (10.1%) who did not undergo HCR, 24 patients (8.0%) did not have PCI and thus were incompletely revascularized. For all patients, 30-day mortality, stroke, and nonfatal myocardial infarction occurred in 4 (1.3%), 3 (1.0%), and 4 (1.3%), respectively. Angiographic LIMA evaluation was performed in 248 patients and revealed a FitzGibbon A LIMA patency rate of 97.6% (242 of 248 patients). Repeat revascularization was required in 13 of 300 patients (4.3%)., Conclusions: Hybrid coronary revascularization represents an alternative approach for patients with multivessel coronary disease with excellent short-term outcomes. It provides a minimally invasive alternative to traditional coronary artery bypass graft surgery and may prove more durable than multivessel PCI., (Copyright © 2014 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

A comprehensive acute coronary syndrome (ACS) protocol was developed to improve the quality of care for patients admitted with definite or probable ACS. These protocols were constructed to streamline the practice for diverse clinicians who care for ACS patients across a variety of clinical settings. They are applicable in the emergency department, the cardiac catheterization laboratory, and the inpatient settings for hospitals with primary percutaneous coronary intervention capability. These protocols standardized the care by selecting the best therapy for each clinical scenario based on available established guidelines to insure the safest and highest value (quality/cost) medical care.

Introduction: Coronary bifurcation lesions are involved in up to 20% of all percutaneous coronary interventions (PCI). However, bifurcation lesion intervention is associated with a high complication rate, and optimal treatment of coronary bifurcation is an ongoing debate. Areas covered: Both different stenting techniques and a variety of devices have been suggested for bifurcation treatment, including the use of conventional coronary stents, bioresorbable vascular scaffolds (BVS), drug-eluting balloons (DEB), and stents dedicated to bifurcations. This review will summarize different therapeutic approaches with their advantages and shortcomings, with special emphasis on histopathologic and physiologic effects of each treatment strategy. Expert opinion: Histopathology and clinical data have shown that a more simple treatment strategy is beneficial in bifurcation lesions, achieving superior results. Bifurcation interventions through balloon angioplasty or placement of stents can importantly alter the bifurcation's geometry and accordingly modify local flow conditions. Computational fluid dynamics (CFD) studies have shown that the outcome of bifurcation interventions is governed by local hemodynamic shear conditions. Minimizing detrimental flow conditions as much as possible should be the ultimate strategy to achieve long-term success of bifurcation interventions. [ABSTRACT FROM AUTHOR]

Introduction: Bare metal stents (BMS) and drug eluting stents (DES) have been deployed in single and overlap configurations, the latter mostly to cover long-lesions. Both type of stents in overlap configuration increases the risk of adverse events. Areas covered: We present the rationale for either BMS or DES usage utilizing both preclinical and clinical studies for the use of single vs. overlapped stents. Further, employing experimental and pathological studies, we discuss the disadvantages of stent overlapping vs. single stenting and propose that vessel injury, local blood flow disturbance, higher drug/polymer dose are mechanisms leading to poor clinical outcomes including in-stent restenosis (ISR), delayed arterial healing, thrombosis, and hypersensitivity reactions. We also explore whether newer generation (2nd generation) DES with reduced strut thickness, optimized drug release profiles, better polymer biocompatibility minimize the disadvantages of stent overlap seen in 1st generation DES. Finally, we examine the reasons why fully bioabsorbable scaffolds resulted in increased adverse events. Expert commentary: DES innovations have minimized the risk of ISR and repeat revascularization. In contradistinction to 1st generation DES, major adverse cardiac events (MACE) is similar between single and overlapped stents in 2nd generation DES, suggestion stent design play an important role in clinical outcomes. [ABSTRACT FROM AUTHOR]

The technology of percutaneous coronary intervention (PCI) is constantly being refined in order to overcome the shortcomings of present day technologies. Even though current generation metallic drug-eluting stents (DES) perform very well in the short-term, concerns still exist about their long-term efficacy. Late clinical complications including late stent thrombosis (ST), restenosis, and neoatherosclerosis still exist and many of these events may be attributed to either the metallic platform and/or the drug and polymer left behind in the arterial wall. To overcome this limitation, the concept of totally bioresorbable vascular scaffolds (BRS) was invented with the idea that by eliminating long-term exposure of the vessel wall to the metal backbone, drug, and polymer, late outcomes would improve. The Absorb-bioabsorbable vascular scaffold (Absorb-BVS) represented the most advanced attempt to make such a device, with thicker struts, greater vessel surface area coverage and less radial force versus contemporary DES. Unfortunately, almost one year after its initial approval by the U.S. Food and Drug Administration, this scaffold was withdrawn from the market due to declining devise utilization driven by the concerns about scaffold thrombosis (ScT) seen in both early and late time points. Additionally, the specific causes of ScT have not yet been fully elucidated. In this review, we discuss the platform, vascular response, and clinical data of past and current metallic coronary stents with the Absorb-BVS and newer generation BRS, concentrating on their material/design and the mechanisms of thrombotic complications from the pre-clinical, pathologic, and clinical viewpoints. [ABSTRACT FROM AUTHOR]

Aims The aim of our study was to investigate chronic total occlusion (CTO) in human coronary arteries to clarify the difference between CTO with prior coronary artery bypass graft (CABG) and those without prior CABG. Methods and results A total of 95 CTO lesions from 82 patients (61.6 ± 14.0 years, male 87.8%) were divided into the following three groups: CTO with CABG (n = 34) (CTO+CABG), CTO without CABG—of long-duration (n = 49) (LD-CTO) and short-duration (n = 12) (SD-CTO). A histopathological comparison of the plaque characteristics of CTO, proximal and distal lumen morphology, and negative remodelling between groups was performed. A total of 1127 sections were evaluated. Differences in plaque characteristics were observed between groups as follows: necrotic core area was highest in SD-CTO (18.6%) (LD-CTO: 7.8%; CTO+CABG: 4.5%; P = 0.02); calcified area was greatest in CTO+CABG (29.2%) (LD-CTO: 16.8%; SD-CTO: 12.1%; P = 0.009); and negative remodelling was least in SD-CTO [remodelling index (RI) 0.86] [CTO+CABG (RI): 0.72 and LD-CTO (RI): 0.68; P < 0.001]. Approximately 50% of proximal lumens showed characteristics of abrupt closure, whereas the majority of distal lumen patterns were tapered (79%) (P < 0.0001). Conclusion These pathological differences in calcification, negative remodelling, and presence of necrotic core along with proximal and distal tapering, which has been associated with greater success, help explain the differences in success rates of percutaneous coronary intervention in CTO patients with and without CABG. [ABSTRACT FROM PUBLISHER]

Background/purpose: Coronary artery bypass graft (CABG) in the presence of metallic permanent stents may be challenging. We explored the feasibility of performing CABG in 1-year Magmaris resorbable scaffold implants in healthy Yucatan pigs.Methods/materials: One animal received Magmaris 3.0 × 20.0-mm scaffolds in the left anterior descending (LAD), left circumflex (LCx), and right coronary arteries (RCA) under fluoroscopy. After 376 days, the animal underwent off-pump CABG at the scaffold site, including a single "end-to-side" anastomosis involving the right internal mammary artery (RIMA) to the LAD. The LAD was grafted in the territory of the previous scaffold as demonstrated by angiogram and the D1 and D2 landmarks.Results: Digital radiography of the intact heart showed all degraded scaffolds widely expanded and uniformly positioned in the vessel wall in their expected locations. The proximal and distal radiopaque markers were clearly visible. The anastomosis was clearly identified by titanium branch clips, and the RIMA bypass was surrounded by connective tissue, which was further dissected before micro-computed tomography (CT) imaging. On the micro-CT images, calcification of the device was rare. The anastomosis site appeared intact, and the LAD at treatment site was widely open.Conclusions: Our limited early feasibility study in a healthy animal demonstrates the practicality of CABG in a Magmaris scaffold after 1 year despite the persistence of visible degradation product, suggesting that the prior coronary device implant does not preclude future coronary surgery. [ABSTRACT FROM AUTHOR]

Background: Cardiac injury is common in patients who are hospitalized with coronavirus disease 2019 (COVID-19) and portends poorer prognosis. However, the mechanism and the type of myocardial damage associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remain uncertain.Methods: We conducted a systematic pathological analysis of 40 hearts from hospitalized patients dying of COVID-19 in Bergamo, Italy, to determine the pathological mechanisms of cardiac injury. We divided the hearts according to presence or absence of acute myocyte necrosis and then determined the underlying mechanisms of cardiac injury.Results: Of the 40 hearts examined, 14 (35%) had evidence of myocyte necrosis, predominantly of the left ventricle. Compared with subjects without necrosis, subjects with necrosis tended to be female, have chronic kidney disease, and have shorter symptom onset to admission. The incidence of severe coronary artery disease (ie, >75% cross-sectional narrowing) was not significantly different between those with and without necrosis. Three of 14 (21.4%) subjects with myocyte necrosis showed evidence of acute myocardial infarction, defined as ≥1 cm2 area of necrosis, whereas 11 of 14 (78.6%) showed evidence of focal (>20 necrotic myocytes with an area of ≥0.05 mm2 but <1 cm2) myocyte necrosis. Cardiac thrombi were present in 11 of 14 (78.6%) cases with necrosis, with 2 of 14 (14.2%) having epicardial coronary artery thrombi, whereas 9 of 14 (64.3%) had microthrombi in myocardial capillaries, arterioles, and small muscular arteries. We compared cardiac microthrombi from COVID-19-positive autopsy cases to intramyocardial thromboemboli from COVID-19 cases as well as to aspirated thrombi obtained during primary percutaneous coronary intervention from uninfected and COVID-19-infected patients presenting with ST-segment-elevation myocardial infarction. Microthrombi had significantly greater fibrin and terminal complement C5b-9 immunostaining compared with intramyocardial thromboemboli from COVID-19-negative subjects and with aspirated thrombi. There were no significant differences between the constituents of thrombi aspirated from COVID-19-positive and -negative patients with ST-segment-elevation myocardial infarction.Conclusions: The most common pathological cause of myocyte necrosis was microthrombi. Microthrombi were different in composition from intramyocardial thromboemboli from COVID-19-negative subjects and from coronary thrombi retrieved from COVID-19-positive and -negative patients with ST-segment-elevation myocardial infarction. Tailored antithrombotic strategies may be useful to counteract the cardiac effects of COVID-19 infection. [ABSTRACT FROM AUTHOR]

Over the past 2 decades, chronic total occlusion (CTO) percutaneous coronary intervention has developed into its own subspecialty of interventional cardiology. Dedicated terminology, techniques, devices, courses, and training programs have enabled progressive advancements. However, only a few randomized trials have been performed to evaluate the safety and efficacy of CTO percutaneous coronary intervention. Moreover, several published observational studies have shown conflicting data. Part of the paucity of clinical data stems from the fact that prior studies have been suboptimally designed and performed. The absence of standardized end points and the discrepancy in definitions also prevent consistency and uniform interpretability of reported results in CTO intervention. To standardize the field, we therefore assembled a broad consortium comprising academicians, practicing physicians, researchers, medical society representatives, and regulators (US Food and Drug Administration) to develop methods, end points, biomarkers, parameters, data, materials, processes, procedures, evaluations, tools, and techniques for CTO interventions. This article summarizes the effort and is organized into 3 sections: key elements and procedural definitions, end point definitions, and clinical trial design principles. The Chronic Total Occlusion Academic Research Consortium is a first step toward improved comparability and interpretability of study results, supplying an increasingly growing body of CTO percutaneous coronary intervention evidence. [ABSTRACT FROM AUTHOR]

Background Treatment options for patients with coronary artery disease at high risk for bleeding complications are limited. The aim of the current preclinical study was to evaluate neointimal coverage, endothelial recovery, inflammation and thrombogenicity in a novel thin-strut (71 μm thickness) Cobalt Chromium (CoCr) stent modified with a nano-thin Polyzene®-F (PzF) surface coating. Methods and results Twenty-eight single PzF nano-coated stents and 20 bare metal control stents (BMS) were implanted in the coronary arteries of 24 pigs, with scheduled 5- (n = 5), 28- (n = 13), and 90-day (n = 6) follow-up in addition to overlapping configuration (n = 6 each), examined at 28-days. Histomorphometric analysis showed significantly lower neointimal thickness in PzF nano-coated stents than BMS controls at both 28- and 90-days (p = 0.023 and 0.005) and reduced inflammation (p = 0.06 and 0.13). Endothelial coverage over luminal surfaces at all time points was similar between nano-coated stents and BMS controls. We conducted supplementary in-vitro experiments using human monocytes and an ex-vivo swine carotid-jugular arterio-venous shunt model to better understand the healing properties afforded by the PzF nano-coating. Overall, the PzF-nano-coating showed reduced monocyte adhesion and thrombus formation compared to the un-coated controls. Conclusions Stents modified with a nano-thin PzF-coating implanted in healthy swine indicate favorable vascular healing properties shown by reduced neointimal hyperplasia and inflammation, along with resistance to thrombus formation in an ex-vivo shunt model over unmodified stents. [ABSTRACT FROM AUTHOR]