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In-stent restenosis (ISR) is one of the main limitations of percutaneous coronary intervention (PCI) therapy with drug-eluting stents (DES) implantation. The aim of this study was to determine if circulating microRNAs (miRNAs) have diagnostic capability for determining ISR in a cohort of matched patients. Blood samples were collected from 55 patients who underwent previously PCI and were readmitted for a new coronary angiography. Patients were divided into subgroups comprising patients who presented ISR or not (non-ISR). A microarray analysis determined that up to 49 miRNAs were differentially expressed between ISR and non-ISR patients. Of these, 10 miRNAs are related to vascular smooth muscle and endothelial cells proliferation, migration, and differentiation, well-known hallmarks of vascular remodeling. Additionally, we identified that the expression of miR-30b-5p is significantly lower in serum samples of ISR patients, as compared to non-ISR. A further analysis demonstrated that miR-30b-5p provides better values of the receiver operator characteristic curve than other miRNAs and biochemical parameters. Finally, the in-silico analysis suggests that miR-30b-5p is predicted to target 62 genes involved in different signaling pathways involved in vascular remodeling. In conclusion, we determined for the first time that circulating mi-R30b-5p can reliably prognose restenosis in patient with implanted DES, which could be potentially helpful in the establishment of an early diagnosis and therapy of ISR. ; This research was funded by the INSTITUTE OF CARLOS III, grant number: PI18/01197); AGENCIA ESTATAL DE INVESTIGACIÓN, grant number: PID2019-104084GB-C22/ AEI/10.13039/501100011033); the ANDALUSIA GOVERNMENT, grant number: PI-0313-2016. This study was co-financed by FEDER Funds.

Background and aim: Obstructive coronary disease is one of the most important causes of death worldwide. Percutaneous coronary intervention is one of the most important treatments of this pathology. Using of coronary artery stents represented a major advance in interventional cardiology. While bare metal stents (BMS) set the reference point for improved safety over balloon-angioplasty, first-generation drug-eluting stents demonstrated significant improvements in efficacy, but not necessarily safety, and further technologic developments have focused on optimizing both. Methods: We studied 228 patients with STEMI in the last 6 months, divided in 2 groups – in the first group are 122 patients (53.5%) who developed in stent restenosis and the second group has 106 patients had no signs of restenosis (46.5%). The mean time of performing the angiographic reevaluation was 111 days for the first group and 154 days for the second group. The clinical signs that indicate the need of coronary reevaluation was stable angina (116, 50.87%), acute coronary syndrome (58, 25.4%) and asymptomatic patients (64, 28.9%). The cardiovascular risk factors correlate with high risk of restenosis was diabetes (24.3% in first group and 12.2% in the second one, p=0.004), active smoking (p=0.010) and metabolic syndrome (p=0.003). The stent's length >28mm, stent's diameter ≤ 2.5 mm and chronic occlusion correlate with high risk of in-stent restenosis in BMS. Conclusion: Understanding the importance of risk factors control, will reduce the risk of restenosis, of other cardiovascular event, even sudden death.

Zhen-hua Zhou,1 Jing Peng,1 Zhao-you Meng,1 Lin Chen,1 Jia-Lu Huang,1 He-qing Huang,1 Li Li,2 Wen Zeng,2 Yong Wei,2 Chu-Hong Zhu,2 Kang-Ning Chen1 1Department of Neurology, Cerebrovascular Disease Research Institute, Southwest Hospital, 2Department of Anatomy, Key Laboratory for Biomechanics of Chongqing, Third Military Medical University, Chongqing, People's Republic of China Background: Carotid artery stenosis is a major risk factor for ischemic stroke. Although carotid angioplasty and stenting using an embolic protection device has been introduced as a less invasive carotid revascularization approach, in-stent restenosis limits its long-term efficacy and safety. The objective of this study was to test the anti-restenosis effects of local stent-mediated delivery of the A20 gene in a porcine carotid artery model.Materials and methods: The pCDNA3.1EHA20 was firmly attached onto stents that had been collagen coated and treated with N-succinimidyl-3-(2-pyridyldithiol)propionate solution and anti-DNA immunoglobulin fixation. Anti-restenosis effects of modified vs control (the bare-metal stent and pCDNA3.1 void vector) stents were assessed by Western blot and scanning electron microscopy, as well as by morphological and inflammatory reaction analyses.Results: Stent-delivered A20 gene was locally expressed in porcine carotids in association with significantly greater extent of re-endothelialization at day 14 and of neointimal hyperplasia inhibition at 3 months than stenting without A20 gene expression.Conclusion: The A20-gene-eluting stent inhibits neointimal hyperplasia while promoting re-endothelialization and therefore constitutes a novel potential alternative to prevent restenosis while minimizing complications. Keywords: restenosis, A20, gene therapy, stent, endothelialization

BACKGROUND: Coronary stent
restenosis is a neointimal hyperplasia, which leads to the
obstruction of the previously treated lesion. Its incidence
is around 10%. The treatment is a new intervention with
balloon angioplasty and implantation of a new stent to
reestablish blood flow. OBJECTIVE: To determine if there is
a difference between the different treatment strategies
against intrastent restenosis such as the bioabsorbable
endoprosthesis, drug-eluting stent and drug-eluting
balloon, evaluated by angiography after 12 months of being
treated an intrastent stenosis. MATERIALS AND METHODS:
Observational, ambispective, crosssectional and comparative
study consisting of the evaluation of patients with
angina-compatible disease in the following 12 months to the
treatment for intrastent stenosis. We reviewed the
angiographies of the patients who entered the Cath Lab of
the Hospital Central Militar for evaluation of intrastent
restenosis due to previous balloon angioplasty or previous
coronary intervention with implantation of a drug-eluting
or bioabsorbable stent after angina. RESULTS: Three groups
were treated with intrastent stenosis, the first using
bioabsorbable stent, the second with drug-eluting stent and
another group treated with a medicated balloon; in the
control angiographies performed on patients with angina, a
statistically significant difference was found in the
therapy used for intrastent stenosis (15.7%, 65.1%, 70%, p
< 0.001), with a higher success rate in bioabsorbable
stent group in relation to the other two therapies.
However, there was no difference in the treatment of
intrastent stenosis with the use of drug-eluting stents vs.
medicated balloon (65.1%, 70%, p < 0.75).

Part 7: Perceptional Systems ; International audience ; The increase of life expectancy in the European Union, and the high risk of cardiovascular diseases associated with age, are some of the main factors to contribute to the rise of healthcare costs. An intelligent stent (e-stent), capable of obtaining and transmitting real-time measurements of physiological parameters for its clinical consultation, can be a useful tool for long-term monitoring, diagnostic, and early warning system for arterial blockage without patient hospitalization. In this paper, a behavioural model of capacitive Micro-Electro-Mechanical (MEMS) pressure sensor is proposed and simulated under several restenosis conditions. Special attention has been given to the need of an accurate fault model, obtained from realistic finite-element simulations,to ensure long-term reliability; particularly for those faults whose behavior cannot be easily described by an analytical model.

Intro -- Authored Books -- By Author -- Preface -- Acknowledgments -- Contents -- Contributors -- Chapter 1: 1950-1970s: Where We Came From -- References -- Chapter 2: 1970s: Growth and Innovation -- References -- Chapter 3: 1980s: Expanding the Practice -- Adjunctive Therapy for PTCA -- Leadership Changes -- Directional Coronary Atherectomy -- PTCA and CABG -- Contrast Nephropathy -- Imaging and Radiation Exposure -- Vasodilators -- References -- Chapter 4: 1990s: Another Move -- Directional Coronary Atherectomy -- Excimer Laser -- Rotational Atherectomy -- Restenosis -- Development of Animal Laboratory Practice -- Acute Ischemic Syndromes: Pathophysiology -- Patient Subsets Undergoing Intervention -- Chronic Total Occlusion -- Treatment of Multivessel CAD -- Mobile Cardiac Cath Lab -- Facility Expansion -- Disappointments -- References -- Chapter 5: 1980-1990: Structural Heart Interventions -- Aortic Balloon Valvuloplasty -- Mitral Balloon Valvuloplasty -- Atrial Septal Defects -- Atrial Septostomy -- Education and Teaching -- Cardiac Imaging -- Summary -- References -- Chapter 6: 2000s: New Field of Focus -- Acute Ischemic Syndromes -- Stent Implantation -- Randomized Clinical Trials and Multicenter Registries -- Mayo Clinic PTCA Registry -- Carotid Stenting -- Restenosis -- Stents, Restenosis, and Vascular Brachytherapy -- Stent Thrombosis -- Procedural Risk and Strategies of Care -- Radial Access -- Imaging Advances -- Practice Advancements -- Traning and Education -- Leadership -- References -- Chapter 7: 2000s: Structural Heart Disease -- Percutaneous Balloon Mitral Valvuloplasty -- Balloon Aortic Valvuloplasty -- Transcatheter Aortic Valve Replacement -- Early TAVR -- Paravalvular Leak Closure -- Mitral Edge-to-Edge Repair -- Importance of Hemodynamic Assessment -- Left Atrial Appendage Occlusion.

To follow up the restenosis in arteries stented during an angioplasty is an important current clinical problem. A new approach to monitor the growth of neointimal tissue inside the stent is proposed on the basis of electrical impedance spectroscopy (EIS) sensors and the oscillation-based test (OBT) circuit technique. A mathematical model was developed to analytically describe the histological composition of the neointima, employing its conductivity and permittivity data. The bioimpedance model was validated against a finite element analysis (FEA) using COMSOL Multiphysics software. A satisfactory correlation between the analytical model and FEA simulation was achieved in most cases, detecting some deviations introduced by the thin "double layer" that separates the neointima and the blood. It is hereby shown how to apply conformal transformations to obtain bioimpedance electrical models for stack-layered tissues over coplanar electrodes. Particularly, this can be applied to characterize the neointima in real-time. This technique is either suitable as a main mechanism for restenosis follow-up or it can be combined with proposed intelligent stents for blood pressure measurements to auto-calibrate the sensibility loss caused by the adherence of the tissue on the micro-electro-mechanical sensors (MEMSs). ; This work was carried out in collaboration with the Cardiology Department of the UHMV Hospital, Santander (Spain) and was funded by the Spanish Government's "Ministerio de Economía, Industria y Competitividad" under the joint projects TEC2013-46242-C3-1-P and TEC2013-46242-C3, co-financed with FEDER.

BACKGROUND: The dual-layer nitinol CASPER stent was designed to prevent plaque prolapse into its strut and periprocedural stroke. OBJECTIVE: To conduct a clinical trial for government approval of the device in patients at either high or normal risk for carotid endarterectomy (CEA). METHODS: Eligible patients had ≥50% symptomatic stenosis or ≥80% asymptomatic stenosis according to the North American Symptomatic Carotid Endarterectomy Trial methods (peak systolic velocity 130 and 230 cm/s on ultrasonography, respectively). The primary endpoint was the lack of major adverse events (MAEs), defined as death, stroke, and myocardial infarction within 30 days, and ipsilateral stroke within 1 year. The performance goal was set at 90.5%. MAE rates were also compared between the CEA high- and normal-risk groups. RESULTS: 140 carotid artery stenting procedures, including 40% of patients at high risk and 60% at normal risk for CEA, were performed in 13 institutes. MAEs occurred in two cases (one intraprocedural and one postprocedural stroke), and the MAE rate was 1.4%. The non-MAE rate was 98.6% according to Kaplan-Meier analysis, which was superior to the previously set performance goal. The deployment success, target lesion revascularization (TLR), in-stent restenosis, and cerebrovascular event rates were 99.3%, 2.4%, 8.5%, and 7.2%, respectively. The MAE rate in patients with normal CEA risk was 1.2%, which was similar to the high-risk CEA group, with no significant difference due to the small number of MAEs. CONCLUSIONS: The MAE rate following use of the CASPER stent was low (1.4%). The MAE, deployment success, TLR, in-stenosis, and cerebrovascular event rates were similar to those of previous reports.

Existing biodegradable Magnesium Alloy Stents (MAS) have several drawbacks, such as high restenosis, hasty degradation, and bulky cross-section, that limit their widespread application in a current clinical practice. To find the optimum stent with the smallest possible cross-section and adequate scaffolding ability, a 3D finite element model of 25 MAS stents of different cross-sectional dimensions were analysed while localized corrosion was underway. For the stent geometric design, a generic sine-wave ring of biodegradable magnesium alloy (AZ31) was selected. Previous studies have shown that the long-term performance of MAS was characterized by two key features: Stent Recoil Percent (SRP) and Stent Radial Stiffness (SRS). In this research, the variation with time of these two features during the corrosion phase was monitored for the 25 stents. To find the optimum profile design of the stent subjectively (without using optimization codes and with much less computational costs), radial recoil was limited to 27 % (corresponding to about 10 % probability of in-stent diameter stenosis after an almost complete degradation) and the stent with the highest radial stiffness was selected.The comparison of the recoil performance of 25 stents during the heterogeneous corrosion phase showed that four stents would satisfy the recoil criterion and among these four, the one having a width of 0.161 mm and a thickness of 0.110 mm, showed a 24 % – 49 % higher radial stiffness at the end of the corrosion phase. Accordingly, this stent, which also showed a 23.28 % mass loss, was selected as the optimum choice and it has a thinner cross-sectional profile than commercially available MAS, which leads to a greater deliverability and lower rates of restenosis.

BACKGROUND: Stent thrombosis (ST) is a serious complication following coronary stenting. Intravascular optical coherence tomography (OCT) may provide insights into mechanistic processes leading to ST. We performed a prospective, multicenter study to evaluate OCT findings in patients with ST. METHODS: Consecutive patients presenting with ST were prospectively enrolled in a registry by using a centralized telephone registration system. After angiographic confirmation of ST, OCT imaging of the culprit vessel was performed with frequency domain OCT. Clinical data were collected according to a standardized protocol. OCT acquisitions were analyzed at a core laboratory. Dominant and contributing findings were adjudicated by an imaging adjudication committee. RESULTS: Two hundred thirty-one patients presenting with ST underwent OCT imaging; 14 (6.1%) had image quality precluding further analysis. Of the remaining patients, 62 (28.6%) and 155 (71.4%) presented with early and late/very late ST, respectively. The underlying stent type was a new-generation drug-eluting stent in 50.3%. Mean reference vessel diameter was 2.9+/-0.6 mm and mean reference vessel area was 6.8+/-2.6 mm(2). Stent underexpansion (stent expansion index <0.8) was observed in 44.4% of patients. The predicted average probability (95% confidence interval) that any frame had uncovered (or thrombus-covered) struts was 99.3% (96.1-99.9), 96.6% (92.4-98.5), 34.3% (15.0-60.7), and 9.6% (6.2-14.5) and malapposed struts was 21.8% (8.4-45.6), 8.5% (4.6-15.3), 6.7% (2.5-16.3), and 2.0% (1.2-3.3) for acute, subacute, late, and very late ST, respectively. The most common dominant finding adjudicated for acute ST was uncovered struts (66.7% of cases); for subacute ST, the most common dominant finding was uncovered struts (61.7%) and underexpansion (25.5%); for late ST, the most common dominant finding was uncovered struts (33.3%) and severe restenosis (19.1%); and for very late ST, the most common dominant finding was neoatherosclerosis (31.3%) and uncovered struts (20.2%). In patients presenting very late ST, uncovered stent struts were a common dominant finding in drug-eluting stents, and neoatherosclerosis was a common dominant finding in bare metal stents. CONCLUSIONS: In patients with ST, uncovered and malapposed struts were frequently observed with the incidence of both decreasing with longer time intervals between stent implantation and presentation. The most frequent dominant observation varied according to time intervals from index stenting: uncovered struts and underexpansion in acute/subacute ST and neoatherosclerosis and uncovered struts in late/very late ST. ; The research leading to these results has received funding from the European Union Seventh Framework Program FP7/2007 to 2013 under grant agreement HEALTH-F2-2010 to 260309 (PRESTIGE). Funding for open access publication is provided by the European Commission.

Background: Stent thrombosis (ST) is a serious complication following coronary stenting. Intravascular optical coherence tomography (OCT) may provide insights into mechanistic processes leading to ST. We performed a prospective, multicenter study to evaluate OCT findings in patients with ST. Methods: Consecutive patients presenting with ST were prospectively enrolled in a registry by using a centralized telephone registration system. After angiographic confirmation of ST, OCT imaging of the culprit vessel was performed with frequency domain OCT. Clinical data were collected according to a standardized protocol. OCT acquisitions were analyzed at a core laboratory. Dominant and contributing findings were adjudicated by an imaging adjudication committee. Results: Two hundred thirty-one patients presenting with ST underwent OCT imaging; 14 (6.1%) had image quality precluding further analysis. Of the remaining patients, 62 (28.6%) and 155 (71.4%) presented with early and late/very late ST, respectively. The underlying stent type was a newgeneration drug-eluting stent in 50.3%. Mean reference vessel diameter was 2.9±0.6 mm and mean reference vessel area was 6.8±2.6 mm 2 . Stent underexpansion (stent expansion index < 0.8) was observed in 44.4% of patients. The predicted average probability (95% confidence interval) that any frame had uncovered (or thrombus-covered) struts was 99.3% (96.1-99.9), 96.6% (92.4-98.5), 34.3% (15.0-60.7), and 9.6% (6.2-14.5) and malapposed struts was 21.8% (8.4-45.6), 8.5% (4.6-15.3), 6.7% (2.5-16.3), and 2.0% (1.2-3.3) for acute, subacute, late, and very late ST, respectively. The most common dominant finding adjudicated for acute ST was uncovered struts (66.7% of cases); for subacute ST, the most common dominant finding was uncovered struts (61.7%) and underexpansion (25.5%); for late ST, the most common dominant finding was uncovered struts (33.3%) and severe restenosis (19.1%); and for very late ST, the most common dominant finding was neoatherosclerosis (31.3%) and uncovered struts (20.2%). In patients presenting very late ST, uncovered stent struts were a common dominant finding in drug-eluting stents, and neoatherosclerosis was a common dominant finding in bare metal stents. Conclusions: In patients with ST, uncovered and malapposed struts were frequently observed with the incidence of both decreasing with longer time intervals between stent implantation and presentation. The most frequent dominant observation varied according to time intervals from index stenting: uncovered struts and underexpansion in acute/subacute ST and neoatherosclerosis and uncovered struts in late/very late ST ; Funding: The research leading to these results has received funding from the European Union Seventh Framework Programme FP7/2007-2013 under grant agreement n° HEALTH-F2-2010-260309 (PRESTIGE). Funding for open access publication is provided by the European Commission

Stenting technique is employed worldwide for treating atherosclerotic vessel and tracheal stenosis. Both diseases can be treated by means of metallic stents which present advantages but are affected by the main problem of restenosis of the stented area. In this study we have built a rabbit trachea numerical model and we have analyzed it before and after insertion and opening of two types of commercial stent: a Zilver® FlexTM Stent and a WallStentTM. In experimental parallel work, two types of stent were implanted in 30 New Zealand rabbits divided in two groups of 10 animals corresponding to each stent type and a third group made up of 10 animals without stent. The tracheal wall response was assessed by means of computerized tomography by endoscopy, macroscopic findings and histopathological study 90 days after stent deployment. Three idealized trachea models, one model for each group, were created in order to perform the computational study. The animal model was used to validate the numerical findings and to attempt to find qualitative correlations between numerical and experimental results. Experimental findings such as inflammation, granuloma and abnormal tissue growth, assessed from histomorphometric analyses were compared with derived numerical parameters such as wall shear stress (WSS) and maximum principal stress. The direct comparison of these parameters and the biological response supports the hypothesis that WSS and tensile stresses may lead to a greater tracheal epithelium response within the stented region, with the latter seeming to have the dominant role. This study may be helpful for improving stent design and demonstrates the feasibility offered by in-silico investigated tracheal structural and fluid dynamics. ; This study was supported by the CIBER-BBN financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund and by the Spanish Ministry of Science and Technology through Research Project DPI2013-44391-P; the Department of Industry and Innovation (Government of Aragón) through the research group Grant T88 (Fondo Social Europeo). The experimental study was supported by the Instituto de Salud Carlos III, through research project PI08/1424 and was performed by the Minimally Invasive Techniques Research Group (GITMI) of Aragón Government. The experimental tests have been performed by the ICTS 'NANBIOSIS', more specifically by the Tissue & Scaffold Characterization Unit (U13) of the CIBER in Bioengineering, Biomaterials & Nanomedicne (CIBER-BBN) at the University of Zaragoza.

Bioresorbable cardiovascular applications are increasing in demand as fixed medical devices cause episodes of late restenosis. The autologous treatment is, so far, the gold standard for vascular grafts due to the similarities to the replaced tissue. Thus, the possibility of customizing each application to its end user is ideal for treating pathologies within a dynamic system that receives constant stimuli, such as the cardiovascular system. Direct Ink Writing (DIW) is increasingly utilized for biomedical purposes because it can create composite bioinks by combining polymers and materials from other domains to create DIW-printable materials that provide characteristics of interest, such as anticoagulation, mechanical resistance, or radiopacity. In addition, bioinks can be tailored to encounter the optimal rheological properties for the DIW purpose. This review delves into a novel emerging field of cardiovascular medical applications, where this technology is applied in the tubular 3D printing approach. Cardiovascular stents and vascular grafts manufactured with this new technology are reviewed. The advantages and limitations of blending inks with cells, composite materials, or drugs are highlighted. Furthermore, the printing parameters and the different possibilities of designing these medical applications have been explored ; The authors acknowledge the financial support from MINECO, grant (DPI 2016 77156R), the European Union FEDER funds (BASE 3D; 001-P-001646) and the support of the Catalan Government (2017SGR00385)