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Ductal stenting (DS) is an interesting palliation for neonates with duct-dependent pulmonary circulation. With the introduction of drug-eluting stents (DES), which have a lower rate of restenosis and longer patency, these stents have replaced bare metal stents (BMS) in the global market. DES release Rapamycin group drugs, which have anti-proliferative and immunosuppressive effects. While the released drug amount is negligible in adult patients, it can lead to high blood levels in neonates, potentially increasing their risk of infections. We conducted a retrospective observational study on infants (under 2 months of age) with duct-dependent pulmonary circulation who underwent successful DS procedures between September 2013 and September 2023. Infants who received at least one DES were categorized into the DES group, while those receiving only BMS were categorized into the BMS group. We compared the prevalence of sepsis (both clinical and proven) and mortality between the two groups. We identified 53 infants (58.4% males), comprising 30 (56.6%) in the DES group and 23 (43.4%) in the BMS group. In the DES group, there were 11 cases (36.7%) of sepsis, including 8 clinical and 3 culture-positive cases. In contrast, the BMS group had 4 cases (13%) of sepsis, all of which were clinical (p = 0.053). Three patients (5.6%) died due to sepsis: two from the DES group and one from the BMS group. Six patients were suspected of having immunodeficiency (22q11.2 deletion or asplenia), with three in each group. Among these, only one patient in the DES group developed clinical sepsis. Our findings indicate that drug elution did not significantly increase the risk of infection following DS in newborns.

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Reducing the price of expensive medical products through centralized procurement is generally considered an effective way to save public medical resources. Against this background, this paper presents an analysis of the impact of centralized procurement in China by comparing the treatment costs and patterns for acute myocardial infarction (AMI) patients before and after the introduction of this method of purchasing, with specific reference to the use of coronary stents. We found that, after the implementation of centralized procurement for coronary stents, the total expenditure of AMI cases receiving percutaneous coronary interventions with stent implantation (PCI with stents) dropped by 23.4%. The use rate of PCI with stents decreased by 32.5%, with the most significant decrease being evident in cases in which two stents were used simultaneously (32.9%). Meanwhile, percutaneous coronary interventions with balloon implantation (PCI with balloons) increased by 31.5% and coronary artery bypass grafting (CABG) increased by 80.3%. Based on these patterns, it can be observed that the use of centralized procurement significantly reduced the profits of the relevant medical manufacturers, forcing them to decrease their marketing investments, weakening their influence on providers, and ultimately resulting in a more principled use of coronary stents. We therefore conclude that, with reference to the data cited, the centralized procurement program led not only to a reduction in procurement prices but also to decreased overuse of these expensive medical products.

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PURPOSE: We aimed to identify the optimal reconstruction settings based on qualitative and quantitative image quality parameters on standard and ultra-high resolution (UHR) images using photon-counting CT (PCCT). METHOD: We analysed 45 patients, 29 with standard and 16 with UHR acquisition, applying both smoother and sharper kernel settings. Coronary CT angiography images were performed on a dual-source PCCT system using standard (0.4/0.6 mm slice thickness, Bv40/Bv44 kernels, QIR levels 0-4) or UHR acquisition (0.2/0.4 mm slice thickness, Bv44/Bv56 kernels, QIR levels 0-4). Qualitative image quality was assessed using a 4-point Likert scale. Image noise (SD), signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated in both the proximal and distal segments. RESULTS: On standard resolution, larger slice thickness resulted in an average increase of 12.5 % in CNR, whereas sharper kernel led to an average 8.7 % decrease in CNR. Highest CNR was measured on 0.6 mm, Bv40, QIR4 images and lowest on 0.4 mm, Bv44, QIR0 images: 25.8 ± 4.1vs.8.3 ± 1.6 (p < 0.001). On UHR images, highest CNR was observed on 0.4 mm, Bv40, QIR4 and lowest on 0.2 mm, Bv56 and QIR0 images: 21.5 ± 3.9vs.3.6 ± 0.8 (p < 0.001). Highest qualitative image quality was found on images with Bv44 kernel and QIR level 3/4 with both slice thicknesses on standard reconstruction. Additionally, Bv56 with QIR4 on 0.2 mm slice thickness images showed highest subjective image quality. Preserved distal vessel visualization was detected using QIR 2-4, Bv56 and 0.2 mm slice thickness. CONCLUSIONS: Photon-counting CT demonstrated high qualitative and quantitative image quality for the assessment of coronaries and stents.

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BACKGROUND: The 1-year clinical outcomes of the Absorb GT1 Japan post-market surveillance (PMS) suggested that an appropriate intracoronary imaging-guided bioresorbable vascular scaffold (BVS) implantation technique may reduce the risk of target lesion failure (TLF) and scaffold thrombosis (ST) associated with the Absorb GT1 BVS. The long-term outcomes through 5 years are now available. METHODS AND RESULTS: This study enrolled 135 consecutive patients (n=139 lesions) with ischemic heart disease in whom percutaneous coronary intervention (PCI) with the Absorb GT1 BVS was attempted. Adequate lesion preparation, imaging-guided appropriate sizing, and high-pressure post-dilatation using a non-compliant balloon were strongly encouraged. All patients had at least 1 Absorb GT1 successfully implanted at the index procedure. Intracoronary imaging was performed in all patients (optical coherence tomography: 127/139 [91.4%] lesions) and adherence to the implantation technique recommendations was excellent: predilatation, 100% (139/139) lesions; post-dilatation, 98.6% (137/139) lesions; mean (±SD) post-dilatation pressure, 18.8±3.5 atm. At 5 years, the follow-up rate was 87.4% (118/135). No definite/probable ST was reported through 5 years. The cumulative TLF rate was 5.1% (6/118), including 2 cardiac deaths, 1 target vessel-attributable myocardial infarction, and 3 ischemia-driven target lesion revascularizations. CONCLUSIONS: Appropriate intracoronary imaging-guided BVS implantation, including the proactive use of pre- and post-balloon dilatation during implantation may be beneficial, reducing the risk of TLF and ST through 5 years.

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Background: The high-definition standard (HD-standard) scan mode has been proven to display stents better than the standard (STND) scan mode but with more image noise. Deep learning image reconstruction (DLIR) is capable of reducing image noise. This study examined the impact of HD-standard scan mode with DLIR algorithms on stent and coronary artery image quality in coronary computed tomography angiography (CCTA) via a comparison with conventional STND scan mode and adaptive statistical iterative reconstruction-Veo (ASIR-V) algorithms. Methods: The data of 121 patients who underwent HD-standard mode scans (group A: N=47, with coronary stent) or STND mode scans (group B: N=74, without coronary stent) were retrospectively collected. All images were reconstructed with ASIR-V at a level of 50% (ASIR-V50%) and a level of 80% (ASIR-V80%) and with DLIR at medium (DLIR-M) and high (DLIR-H) levels. The noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), artifact index (AI), and in-stent diameter were measured as objective evaluation parameters. Subjective assessment involved a 5-point scale for overall image quality, image noise, stent appearance, stent artifacts, vascular sharpness, and diagnostic confidence. Diagnostic confidence was evaluated based on the presence or absence of significant stenosis (≥50% lumen reduction). Both subjective and objective evaluations were conducted by two radiologists independently, with kappa and intraclass correlation statistics being used to test the interobserver agreement. Results: There were 76 evaluable stents in group A, and the DLIR-H algorithm significantly outperformed other algorithms, demonstrating the lowest noise (41.6±7.1/41.3±7.2) and AI (32.4±8.9/31.2±10.1), the highest SNR (14.6±3.5/15.0±3.5) and CNR (13.6±3.8/13.9±3.8), and the largest in-stent diameter (2.18±0.61/2.19±0.61) in representing true stent diameter (all P values <0.01), as well as the highest score in each subjective evaluation parameter. In group B, a total of 296 coronary arteries were evaluated, and the DLIR-H algorithm provided the best objective image quality, with statistically superior noise, SNR, and CNR compared with the other algorithms (all P values <0.05). Moreover, the HD-standard mode scan with DLIR provided better image quality and a lower radiation dose than did the STND mode scan with ASIR-V (P<0.01). Conclusions: HD-standard scan mode with DLIR-H improves image quality of both stents and coronary arteries on CCTA under a lower radiation dose.

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BACKGROUND: Patients with acute coronary syndromes (ACS) may have worse outcomes after percutaneous coronary intervention compared to patients without ACS. AIMS: To compare 5-year efficacy and safety outcomes in patients with and without ACS treated with biodegradable polymers, the ultrathin strut sirolimus-eluting Orsiro stent (O-SES) or the biolimus-eluting Nobori stent (N-BES). METHODS: The Scandinavian Organisation for Randomized Trials with Clinical Outcome VII is a randomized trial comparing O-SES and N-BES in an all-comer setting. Of 2525 patients, 1329 (53%) patients had ACS and 1196 (47%) patients were without ACS. Endpoints were target lesion failure (TLF) (a composite of cardiac death, target lesion myocardial infarction, or target lesion revascularization) and definite stent thrombosis within 5 years. RESULTS: At 5-year follow-up, TLF did not differ significantly between patients with and without ACS (12.3% vs. 13.2%; rate ratio (RR) 1.00; 95% confidence interval (CI): 0.70-1.44), whereas the risk of definite stent thrombosis was increased in patients with ACS (2.3% vs. 1.3; RR: 2.01 [95% CI: 1.01-3.98]). In patients with ACS, the rate of TLF was similar between O-SES and N-BES (12.4% vs. 12.3%; RR: 1.02; 95% CI: 0.74-1.40). The reduced risk of definite stent thrombosis in O-SES treated ACS patients within the first year (0.2% vs. 1.6%; RR: 0.12; 95% CI: 0.02-0.93) was not maintained after 5 years (1.8% vs. 2.7%; RR: 0.77; 95% CI: 0.37-1.63). CONCLUSION: Patients with ACS had an increased risk of stent thrombosis regardless of the stent type used. Long-term outcomes were similar for ACS patients treated with O-SES or N-BES at 5 years.

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Background: The advent of coronary stents has resulted in many more many lives being saved from acute myocardial infarction (AMI). However, the high price associated with this method of treatment also imposes a heavy economic burden on healthcare systems. As a country making significant use of coronary stents, in 2021, China introduced a program around this method of treatment grounded in centralized procurement and it is the focus of this paper to assess the impact of this policy on AMI treatments. Methods: The patients with AMI are selected as the study group, and the patients with pre-cerebral vascular stenosis are selected as the control group, and individual-level medical insurance settlement data are collected from the years 2018, 2019, and 2021. Differences-in-differences methodology is used to analyze the impacts of this program on the probability changes in respect of AMI patients receiving stent therapy, as well as changes relating to cost, length of stay and 30-day readmission. Results: The results show that the reform has led to a reduction in the probability of AMI patients using stents to 51% of the original rate. Additionally, the average cost is shown to have decreased by 41%, and no significant changes can be found in respect of the length of stay and 30-day readmission. Conclusion: In sum, the centralized procurement program is shown to reduce not only the medical expenses incurred by treating patients with AMI, but also the use of coronary stents, resulting in changes to the treatment patterns of patients with AMI.

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Cardiovascular disease, including ischemic heart disease, is the leading cause of death worldwide, and percutaneous coronary interventions (PCIs) have been demonstrated to improve the prognosis of these patients on top of optimal medical therapy. PCIs have evolved from plain old balloon angioplasty to coronary stent implantation at the end of the last century. There has been a constant technical and scientific improvement in stent technology from bare metal stents to the era of drug-eluting stents (DESs) to overcome clinical challenges such as target lesion failure related to in-stent restenosis or stent thrombosis. A better understanding of the underlying mechanisms of these adverse events has led DESs to evolve from first-generation DESs to thinner and ultrathin third-generation DESs with improved polymer biocompatibility that seems to have reached a peak in efficiency. This review aims to provide a brief historical overview of the evolution of coronary DES platforms and an update on clinical studies and major characteristics of the most currently used DESs.

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One of the prominent reasons for mortality and morbidity worldwide is coronary artery disease (CAD), an ailment that manifests itself by the narrowing of the artery with the deposition of plaque. The definitive mode of action for dealing with this condition is using a medical device known as a stent at the affected location. This extremely important tubular equipment helps tremendously with vessel support. It also helps by keeping the path of blood flow clear for the heart muscle masses, its crucial nutrients, and oxygen supply. Several generations of stents have been continuously developed to improve patient outcomes and reduce side effects post-stent implantation. As we move from bare metal stents (BMSs) to drug-eluting stents (DESs) and, more recently, to bioabsorbable stents, the research area continues to develop. The use of this biomedical device has increased the standard of living in many cases; therefore, it is much needed to work on the possible growth areas in the cardiovascular stents and improve them to such an extent that the patients suffering from cardiovascular ailments get to live a comfortable life. Most articles deal with stents that are available for current use and their various types. They also cover the topic of stent optimization, as it is one of the key factors in enhancing stent usability and plays a prominent role in optimizing stent placement in the vessels of the body. To keep in touch with advances in stent technology over the past few decades, this article reviews advances in the devices, working on how available stents can be optimized to create new stents.

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Current guidelines recommend delaying noncardiac surgery for 6 months after drug eluting stent implantation. However, this recommendation is largely based on limited evidence and various event definitions. Whether early surgery within 6 months of coronary stent implantation increases myocardial injury in patients with normal preoperative high-sensitivity cardiac troponin I (hs-cTnI) has not yet been investigated. This retrospective study assessed patients who received coronary stent implantation and underwent noncardiac surgery (vascular, abdominal, or thoracic) between 2010 and 2017 with normal preoperative hs-cTnI (n = 186). Patients were divided into early (within 6 months of PCI) and late (after 6 months of PCI) groups. The primary endpoint was the incidence of myocardial injury as diagnosed by hs-cTnI within 3 days post-operation. The secondary outcomes were myocardial infarction, stent thrombosis, emergent coronary revascularization, major bleeding (bleeding requiring transfusion or intracranial bleeding), stroke, renal failure, heart failure, or death within 30 days post-operation. Inverse probability treatment weighting (IPTW) was carried out to adjust for the intergroup baseline differences. Myocardial injury occurred in 28.6% (8/28) and 27.8% (44/158) of the early and late groups, respectively, with no difference between groups (odds ratio [OR] 1.067, 95% confidence interval [CI] 0.404, 2.482; p = 0.886). Secondary outcomes did not differ between the groups. IPTW analysis also showed no differences in myocardial injury and secondary outcomes between the groups. In conclusion, early surgery within 6 months after coronary stent implantation did not increase the incidence of myocardial injury in patients with normal preoperative hs-cTnI.

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BACKGROUND: Early-generation "sandwich-design" polytetrafluorethylene (PTFE) covered coronary stents (CS) are associated with a high frequency of adverse events. New-generation single layer PTFE-CS offers the potential to enhanced procedural efficacy and improves clinical safety. Data from a dedicated study, concerning outcomes after treatment with single-layer PTFE-CS in patients undergoing percutaneous coronary intervention are scant. METHODS: This is a retrospective multicenter registry including 30 patients undergoing implantation of 39 single-layer PTFE-CS (BeGraft-coronary Stent Graft System, Bentley InnoMed GmbH, Hechingen, Germany) in native coronary arteries or saphenous bypass grafts, in 3 centers in Europe, between May 2013 and May 2019. Endpoints of interest were procedural success (placement of covered stent), binary-angiographic restenosis (BAR), percent diameter stenosis (% DS) and late-lumen loss at 6-8 months follow-up angiography, rates of target lesion revascularization (TLR), myocardial infarction (MI), stent thrombosis (ST) and mortality at 12 months. RESULTS: 28 patients underwent implantation of 37 CS due to coronary artery perforation 2 patients due to coronary artery aneurysm. Technical success was achieved in all patients (100 %). More than one stent was implanted in 7 patients (25 %) all in the perforation group. Follow-up angiography was available in 23 patients (77 %) showing favorable results: BAR = 21.8 %, %DS = 30.3 ± 27.5; LLL = 0.16 ± 0.81 mm. At 12 months all patients were alive, rates of TLR were low (3 patients, 10.0 %), there was one case of late stent thrombosis (3.3 %) and one MI (3.3 %). CONCLUSIONS: In this dedicated study, implantation of a new single layer PTFE-CS for the treatment of native coronary arteries or saphenous vein grafts after perforation or due to aneurysm showed high technical success rates and favorable angiographic and clinical efficacy. Clinical safety outcomes are encouraging, but larger prospective studies are needed to determine long-term safety of this device.

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BACKGROUND: Diabetes was reported to be associated with an impaired response to clopidogrel. OBJECTIVES: The aim of this study was to evaluate the safety and efficacy of clopidogrel monotherapy after very short dual antiplatelet therapy (DAPT) in patients with diabetes undergoing percutaneous coronary intervention (PCI). METHODS: A subgroup analysis was conducted on the basis of diabetes in the STOPDAPT-2 (Short and Optimal Duration of Dual Antiplatelet Therapy After Everolimus-Eluting Cobalt-Chromium Stent-2) Total Cohort (N = 5,997) (STOPDAPT-2, n = 3,009; STOPDAPT-2 ACS [Short and Optimal Duration of Dual Antiplatelet Therapy After Everolimus-Eluting Cobalt-Chromium Stent-2 for the Patients With ACS], n = 2,988), which randomly compared 1-month DAPT followed by clopidogrel monotherapy with 12-month DAPT with aspirin and clopidogrel after cobalt-chromium everolimus-eluting stent implantation. The primary endpoint was a composite of cardiovascular (cardiovascular death, myocardial infarction, definite stent thrombosis, or stroke) or bleeding (TIMI [Thrombolysis In Myocardial Infarction] major or minor) endpoints at 1 year. RESULTS: There were 2,030 patients with diabetes (33.8%) and 3967 patients without diabetes (66.2%). Regardless of diabetes, the risk of 1-month DAPT relative to 12-month DAPT was not significant for the primary endpoint (diabetes, 3.58% vs 4.12% [HR: 0.87; 95% CI: 0.56-1.37; P = 0.55]; nondiabetes, 2.46% vs 2.49% [HR: 0.99; 95% CI: 0.67-1.48; P = 0.97]; Pinteraction = 0.67) and for the cardiovascular endpoint (diabetes, 3.28% vs 3.05% [HR: 1.10; 95% CI: 0.67-1.81; P = 0.70]; nondiabetes, 1.95% vs 1.43% [HR: 1.38; 95% CI: 0.85-2.25; P = 0.20]; Pinteraction = 0.52), while it was lower for the bleeding endpoint (diabetes, 0.30% vs 1.50% [HR: 0.20; 95% CI: 0.06-0.68; P = 0.01]; nondiabetes, 0.61% vs 1.21% [HR: 0.51; 95% CI: 0.25-1.01; P = 0.054]; Pinteraction = 0.19). CONCLUSIONS: Clopidogrel monotherapy after 1-month DAPT compared with 12-month DAPT reduced major bleeding events without an increase in cardiovascular events regardless of diabetes, although the findings should be considered as hypothesis generating, especially in patients with acute coronary syndrome, because of the inconclusive result in the STOPDAPT-2 ACS trial. (Short and Optimal Duration of Dual Antiplatelet Therapy After Everolimus-Eluting Cobalt-Chromium Stent-2 [STOPDAPT-2], NCT02619760; Short and Optimal Duration of Dual Antiplatelet Therapy After Everolimus-Eluting Cobalt-Chromium Stent-2 for the Patients With ACS [STOPDAPT-2 ACS], NCT03462498).

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The success of a PCI is best defined by three related components: post-procedure angiographic outcomes, procedural events, and longer-term clinical outcomes. Stenting of long and complex lesions is associated with higher risk of stent thrombosis and restenosis even at long term follow-up. Tapered lesions (i.e., a significant mismatch between proximal and distal reference lumen diameters (RLD)) of the target coronary artery lesion may pose particular challenges during PCI and impact outcomes.

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The introduction of the drug-eluting (DES) stent to percutaneous coronary intervention (PCI) had a significant impact on patient management of coronary artery disease and has been called the "third revolution" in interventional cardiology after the first 2 revolutions of balloon angioplasty and bare-metal stents. The promise of adaptive remodeling, restoration of vasomotion, late luminal enlargement, and retained potential for future coronary artery bypass grafting at the site of previous PCI has been the driving force behind bioresorbable stent/scaffold (BRS) technology development. Moreover, because of the inherent risk of late and very late stent thrombosis, BRS potentially offers a solution and recent years have seen heightened interest, hype, and hope. In this current review, we are aiming to shed light on strength and weakness of various BRS including the future perspective. (AU)

La introducción del stent liberador de fármacos (DES) en la intervención coronaria percutánea (ICP) tuvo un impacto significativo en el tratamiento de los pacientes con enfermedad de las arterias coronarias y se ha denominado la "tercera revolución" en cardiología intervencionista después de las dos primeras revoluciones de la angioplastia con balón y stents de metal desnudo. La promesa de remodelación adaptativa, restauración de la vasomoción, agrandamiento luminal tardío y potencial retenido para futuros injertos de derivación de la arteria coronaria en el sitio de la PCI anterior ha sido la fuerza impulsora detrás del desarrollo de la tecnología de stent/armazón biorreabsorbible (BRS). Además, debido al riesgo inherente de trombosis del stent tardía y muy tardía, la BRS ofrece potencialmente una solución y en los últimos años se ha visto un mayor interés, entusiasmo y esperanza. En esta revisión actual, nuestro objetivo es arrojar luz sobre la fortaleza y la debilidad de varios BRS, incluida la perspectiva futura. (AU)

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BACKGROUND: The clinical value of residual quantitative flow ratio (rQFR), a novel function of QFR technique, is unknown. AIM: We investigated the clinical value of rQFR, aimed to predict residual ischemia after virtual percutaneous coronary intervention (vPCI). METHODS: This is a substudy of the COE-PERSPECTIVE registry, which investigated the prognostic value of post-PCI fractional flow reserve (FFR). From pre-PCI angiograms, QFR and rQFR were analyzed and their diagnostic performance was assessed at blinded fashion using pre-PCI FFR and post-PCI FFR as reference, respectively. The prognostic value of rQFR after vPCI was assessed according to vessel-oriented composite outcome (VOCO) at 2 years. RESULTS: We analyzed 274 patients (274 vessels) with FFR-based ischemic causing lesions (49%) from 555 screened patients. Pre-PCI QFR and FFR were 0.63 ± 0.10 and 0.66 ± 0.11 (R = 0.756, p < 0.001). rQFR after vPCI and FFR after real PCI were 0.93 ± 0.06 and 0.86 ± 0.07 (R = 0.528, p < 0.001). The mean difference between rQFR and post-PCI FFR was 0.068 (95% limit of agreement: -0.05 to 0.19). Diagnostic performance of rQFR to predict residual ischemia after PCI was good (area under the curve [AUC]: 0.856 [0.804-0.909], p < 0.001). rQFR predicted well the incidence of 2-year VOCO after index PCI (AUC: 0.712 [0.555-0.869], p = 0.041), being similar to that of actual post-PCI FFR (AUC: 0.691 [0.512-0.870], p = 0.061). rQFR ≤0.89 was associated with increased risk of 2-year VOCO (hazard ratio [HR]: 12.9 [2.32-71.3], p = 0.0035). This difference was mainly driven by a higher rate of target vessel revascularization (HR: 16.98 [2.33-123.29], p = 0.0051). CONCLUSIONS: rQFR estimated from pre-PCI angiography and virtual coronary stenting mildly overestimated functional benefit of PCI. However, it well predicted suboptimal functional result and long-term vessel-related clinical events. CLINICAL TRIAL REGISTRATION: Influence of fractional flow reserve on the Clinical OutcomEs of PERcutaneouS Coronary Intervention (COE-PESPECTIVE) Registry, NCT01873560.

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Intravascular lithotripsy (IVL) uses acoustic shock waves in a balloon-based delivery system to modify severely calcified atherosclerotic coronary vascular lesions in preparation for stent implantation. IVL results in circumferential and longitudinal calcium fracture, which improves transmural vessel compliance and facilitates subsequent stent expansion without requiring high-pressure balloon dilation. Clinical trials have demonstrated IVL to be safe (low rates of major adverse cardiac events in hospital and to 1 year; low rates of severe angiographic complications), effective (high rates of procedural success), and easy to use (little or no learning curve) when applied in the treatment of severely calcified coronary arteries.

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This study describes the internal structure of materials used to produce medical stents. A two-level elastoviscoplastic mathematical model, which sets the parameters and describes the processes at the grain level, was developed and numerically implemented. A separate study was conducted to identify the most dangerous deformation modes in the balloon-expandable stent placement using the finite-element method in COMSOL Multiphysics. As a result, the challenging strain state type required for setting the kinematic loading on a representative macrovolume in the two-level model was obtained. A yield surface for different deformation paths in the principal deformation space for stainless steel AISI 316L was obtained and the effect of grain size on the deformation behavior of this material was explored using the developed model.