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Iron is considered as an attractive alternative material for bioresorbable scaffolds (BRS). The sirolimus eluting iron bioresorbable scaffold (IBS), developed by Biotyx Medical (Shenzhen, China), is the only iron-based BRS with an ultrathin-wall design. The study aims to investigate the long-term efficacy, safety, biocompatibility, and lumen changes during the biodegradation process of the IBS in a porcine model. A total of 90 IBSs and 70 cobalt-chromium everolimus eluting stents (EES) were randomly implanted into nonatherosclerotic coronary artery of healthy mini swine. The multimodality assessments including coronary angiography, optical coherence tomography, micro-computed tomography, magnetic resonance imaging, real-time polymerase chain reaction (PCR), and histopathological evaluations, were performed at different time points. There was no statistical difference in area stenosis between IBS group and EES group at 6 months, 1year, 2 years and 5 years. Although the scaffolded vessels narrowed at 9 months, expansive remodeling with increased mean lumen area was found at 3 and 5 years. The IBS struts remained intact at 6 months, and the corrosion was detectable at 9 months. At 5 years, the iron struts were completely degraded and absorbed in situ, without in-scaffold restenosis or thrombosis, lumen collapse, aneurysm formation, and chronic inflammation. No local or systemic toxicity and abnormal histopathologic manifestation were found in all experiments. Results from real-time PCR indicated that no sign of iron overload was reported in scaffolded segments. Therefore, the IBS shows comparable efficacy, safety, and biocompatibility with EES, and late lumen enlargement is considered as a unique feature in the IBS-implanted vessels.

Introduction: The higher scaffold thrombosis rates observed with the first-generation bioresorbable scaffolds (BRSs) compared to conventional drug-eluting stents were likely due in part to bioresorbable polymers having insufficient radial strength, necessitating larger strut profiles. Meta-analysis of the long-term outcomes from the first-generation Absorb bioresorbable vascular scaffold (BVS) showed that this period of excess risk ended at 3 years. Therefore, current attention has been focused on improving early outcomes by increasing the scaffold's tensile strength and reducing strut thickness. Areas covered: This review summaries the lessons learned from the first-generation BRS. It updates the long-term clinical outcomes of trials evaluating the ABSORB BVS and metallic alloy-based BRS. In addition, it reviews the next-generation BRSs manufactured in Asia. Expert opinion: Critical areas to improve the performance and safety of biodegradable scaffolds include further development in material science, surface modification, delivery systems, and long-term follow-up studies. [ABSTRACT FROM AUTHOR]

Bioresorbable stents represent a revolutionary treatment for coronary artery disease. Such a device offers the prospect for complete naturalization of artery lumen after strut resorption and restoration of vasomotion while curtailing the duration of dual anti‐platelet therapy. The prototype bioresorbable scaffold (BRS—ABSORB GT1) demonstrated good feasibility and safety in the initial studies compared to metallic drug eluting stent but later fell out of favor due to multiple report of stent thrombosis and target lesion failure. Unpredictable resorption of struts turned out to be one of the "Achilles heel" of the BRS and stent strut were still visible in vessel on optical coherence tomography (OCT) at 3 years. We report a case of differential resorption of two ABSORB BRS implanted simultaneously in the same patient by the same operator. Follow up coronary angiogram revealed only minimal plaques on right coronary artery (RCA) and left anterior descending artery (LAD). The BRS were identified on cine‐angiogram by their radio‐opaque markers at both ends. The OCT run in LAD artery revealed "ghost remnants" of BRS struts in LAD, whereas the RCA BRS had completely healed with minimal "ghost" struts. The ghost remnants of BRS resembled the original "Check box" appearance on OCT during the index implantation. [ABSTRACT FROM AUTHOR]

The rise in additive manufacturing (AM) offers myriad opportunities for 3D printed polymeric vascular scaffolds, such as customization and on‐the‐spot manufacturing, in vivo biodegradation, incorporation of drugs to prevent restenosis, and visibility under X‐ray. To maximize these benefits, informed scaffold design is critical. Polymeric bioresorbable vascular scaffolds (BVS) must undergo significant deformation prior to implantation in a diameter‐reduction process known as crimping that enables minimally invasive surgery. Understanding the behavior of vascular scaffolds in this step provides twofold benefits: first, it ensures the BVS is able to accommodate stresses occurring during this process to prevent failure, and further, it provides information on the radial strength of the BVS, a key metric to understanding its post‐implant performance in the artery. To capitalize on the fast manufacturing speed AM provides, a low time cost solution for understanding scaffold performance during this step is necessary. Through simulation of the BVS crimping process in ABAQUS using experimentally obtained bulk material properties, a qualitative analysis tool is developed that is capable of accurately comparing relative performance trends of varying BVS designs during crimping in a fraction of the time of experimental testing, thereby assisting in the integration of informed design into the additive manufacturing process. [ABSTRACT FROM AUTHOR]

Inflammation is known to play a crucial role in the development of coronary atherosclerosis and vascular healing after stenting. This study aimed to investigate the dynamic changes in inflammatory responses between XINSORB and TIVOLI scaffolds and their correlation with 3-year clinical outcomes. A total of 140 patients in the XINSORB group and 42 patients in the TIVOLI group were included in this prospective, single-center study, conducted in Shanghai tenth People's Hospital. Blood samples were collected at baseline, 24 h, 6 months, and 12 months after stent implantation to measure high sensitivity C-reactive protein (hsCRP), fibrinogen (FBG), white blood cell count (WBC), tumor necrosis factor (TNF), and interleukin-6 (IL-6). Receiver-operating characteristic curves and proportional hazards models were generated to evaluate the relationship between 24-h postoperative inflammatory indicators and 3-year patient-oriented composite endpoints (POCE). The levels of hsCRP, FBG, WBC, TNF, and IL-6 reached their peak levels 24 h after stenting and then gradually decreased to levels comparable to baseline at 6 and 12 months. During the 3-year follow-up, 11.4 % of the XINSORB cohort and 9.5 % of the TIVOLI cohort experienced POCE (P = 0.948). High levels of hsCRP and IL-6 24 h after the procedure were associated with clinical endpoints, and the combination of these two biomarkers improved the predictive ability of prognosis. There were no significant differences between the changes in the concentration of inflammatory biomarkers after XINSORB stents or drug-eluting stent implantation. Reduction in postoperative inflammatory levels may decrease the occurrence of clinical outcomes. This study provides insights into the dynamic changes of inflammatory responses and their correlation with clinical outcomes, which could have implications for the management of patients undergoing coronary stenting. The study has been registered on the official website of the China Clinical Trial Registry (ChiCTR1800014966). • Inflammation dynamics investigated in XINSORB and TIVOLI stents in coronary patients. • Elevated hsCRP and IL-6 levels linked to clinical endpoints at 3-year follow-up. • Study sheds light on inflammatory responses and long-term clinical outcomes in PCI. [ABSTRACT FROM AUTHOR]

Background: Chronic limb-threatening ischaemia can be a debilitating disease and may result in limb amputation if untreated. Atherosclerotic disease of the infra-popliteal arteries is particularly challenging to treat due to the small caliber of the vessels and the heavy burden of atherosclerotic plaque. Percutaneous transluminal angioplasty is the conventional first-line approach and is advantageous due to its minimal invasiveness, repeatability, and cost-effectiveness but is limited by high rates of elastic recoil, dissection, and short- to mid-term re-stenosis. Methods: This review analyses the growing body of published and presented clinical data from multiple randomised controlled trials that have investigated the role of coronary drug-eluting stents in the treatment of infrapopliteal disease. Results: Coronary drug-eluting stents demonstrate superior primary patency compared with angioplasty and/or bare metal stenting alone but are limited to application in short-segment disease and have not been widely adopted due to the nature of the permanent implant. Conclusions: Newer devices like drug-eluting resorbable scaffolds are promising as they allow the restoration of vessel wall vasomotion without a residual foreign body and can be used to treat longer, complex lesions. [ABSTRACT FROM AUTHOR]

Introduction: Acute coronary syndrome (ACS) is a well-known risk factor for adverse clinical outcomes in percutaneous coronary intervention (PCI). Therefore, evaluation of coronary stents in this challenging clinical scenario can provide unique information on device safety and efficacy. Bioresorbable scaffolds (BRS) were designed to overcome long-term complications related to permanent vessel caging with a permanent metallic drug-eluting stent (DES). Aim: We designed this study to evaluate the mid-term safety and efficiency of the Magmaris BRS in comparison to the leading new-generation ultrathin DES Ultimaster in the ACS population. Material and methods: We present a retrospective analysis of 2-year follow-up data. The primary outcomes consisted of death from cardiac causes, myocardial infarction, and in-stent thrombosis. The second main study endpoint was defined as target-lesion failure (TLF). Results: The study population consisted of two cohorts, the first of 193 patients treated with Magmaris implantation and the second of 169 patients treated with Ultimaster implantation. At the 2-year follow-up, there were no significant differences in both study cohorts in terms of primary outcome (5.1% vs. 11%; p = 0.051), and TLF (5.6% vs. 8%, p = 0.41). Conclusions: Treatment with a second-generation BRS (Magmaris) versus a novel second-generation DES (Ultimaster) in non-ST-elevation acute coronary syndrome (NSTE-ACS) was associated with similar rates of target lesion failure at 2-year follow-up. [ABSTRACT FROM AUTHOR]

Abstract Bioresorbable stents represent a revolutionary treatment for coronary artery disease. Such a device offers the prospect for complete naturalization of artery lumen after strut resorption and restoration of vasomotion while curtailing the duration of dual anti‐platelet therapy. The prototype bioresorbable scaffold (BRS—ABSORB GT1) demonstrated good feasibility and safety in the initial studies compared to metallic drug eluting stent but later fell out of favor due to multiple report of stent thrombosis and target lesion failure. Unpredictable resorption of struts turned out to be one of the “Achilles heel” of the BRS and stent strut were still visible in vessel on optical coherence tomography (OCT) at 3 years. We report a case of differential resorption of two ABSORB BRS implanted simultaneously in the same patient by the same operator. Follow up coronary angiogram revealed only minimal plaques on right coronary artery (RCA) and left anterior descending artery (LAD). The BRS were identified on cine‐angiogram by their radio‐opaque markers at both ends. The OCT run in LAD artery revealed “ghost remnants” of BRS struts in LAD, whereas the RCA BRS had completely healed with minimal “ghost” struts. The ghost remnants of BRS resembled the original “Check box” appearance on OCT during the index implantation.

Background: In order to advocate further research in bioresorbable scaffold (BVS) technology we report the final 5-year outcomes of the COBRA II study, the only randomized controlled trial (RCT) performed to investigate the safety, feasibility, and performance of Absorb BVS (Abbott Vascular) in true coronary bifurcations. Methods: COBRA II was a prospective single-center RCT. Fifteen patients with true coronary bifurcation lesions were randomized to bifurcation treatment with self-expanding biolimus-eluting Axxess bifurcation device (Biosensors International) combined with additional bioresorbable everolimus-eluting Absorb BVS in the bifurcation branches on (Axxess group) or to 2-stent mod-T stenting technique with Absorb BVS (mod-T group). Optical coherence tomography was performed post-procedure and at 30-months. The primary endpoint was change in minimal luminal area (MLA) on OCT from baseline to 30-months. Results: Fifteen patients with coronary bifurcation lesions were randomized to the Axxess group (n = 8) or Modified-T group (n = 7). At 30 months, MLAs were significantly smaller than post-procedure in the majority of bifurcation segments treated with BVS due to neointima formation, while MLAs in the proximal Axxess segment remained stable (primary endpoint).Five-year clinical follow-up was available for all patients. Only 1 major adverse cardiac event occurred; a patient underwent target lesion revascularization at 30 months in the Axxess group. There were no cases of cardiac death, spontaneous MI, or stent/scaffold thrombosis. Conclusions: In this small RCT bifurcation study, BVS luminal dimensions were significantly smaller at 30 months, with acute strut discontinuities and late Intraluminal dismantling frequently observed, although acceptable clinical outcomes were noted at 5 years.

Background: This study aimed to assess the relationship between stent parameters and platelet function, as well as the platelet reactivity profiles over time in patients treated with the Xinsorb scaffold. Methods: Adenosine diphosphate-induced maximal amplitude was measured as clopidogrel on-treatment platelet reactivity using thrombelastography. High residual platelet reactivity was defined as MAADP > 47 mm. Platelet function testing was induced at baseline, discharge, and 6- and 12-month visits. Results: A total of 40 individuals undergoing Xinsorb scaffold implantation and platelet function testing were included. No adverse events were recorded during follow-up. No correlation was observed among thrombelastography indices, stent diameters, and stent coverage surface area. Significant correlation was found between MAADP and lengths of stents (Spearman rank correlation = 0.324, P =.031). Multiple logistic regression analyses demonstrated that high levels of high-density lipoprotein cholesterol was an independent protective factor for high residual platelet reactivity (odds ratio = 0.049, 95% con-fidence interval = 0.011-0.296, P =.016). No significant risk factors were identified; MAADP presented to be 20.6 [13.1-36.2] mm, 26.8 [18.2-35.0] mm, and 30.0 [19.6-33.4] mm 48 hours, 6 months, and 12 months after procedure, respectively; 12-month MAADP was sig-nificantly higher than the 48-hour MAADP (P =.026). There was no obvious trend for platelet response status over time. Conclusion: Among patients on a clopidogrel-based dual antiplatelet treatment regimen following Xinsorb scaffold implantation, stent parameters had no significant effects on platelet reactivity. The high residual platelet reactivity phenotype is relatively stable over time. High residual platelet reactivity is more likely to occur in patients with lower high-density lipoprotein cholesterol levels.

Nanostructured porous silicon (pSi) is a synthetic silicon-based material. Its biocompatibility and bioresorbability in body fluids make pSi an appealing biomaterial for tissue engineering, with surfaces characteristics facilitating human cell adhesion and differentiation. The resorption kinetics of such porous biomaterials is crucial for in vivo bone regeneration, in order to adapt biomaterial resorption to tissue formation, and to control the release of loaded bioactive molecules. We investigated pSi as a bioactive scaffold for bone tissue engineering, with an emphasis on kinetics of pSi resorption and silicon release. PSi particles and chips were fabricated from crystalline silicon, and functionalized by oxidation and chemical grafting of amine groups to mimic biological structures. Materials resorption over time was investigated with Raman spectroscopy, infrared spectroscopy, and Scanning Electron Microscopy. Silicon release was followed by mass spectrometry. Particle degradation and inclusion in newly formed bone were studied in vivo. The in vitro experiments revealed that non-oxidized pSi had an accelerated initial dissolution in ddH2O and an inhibition of initial Si release in SBF. This high reactivity also led to transformation towards amorphous non-resorbable silica when incubated in SBF. PSi resorption started immediately with a maximal dissolution in the first 24 h. Later, the dissolution rate decreased over time. In comparison, the resorption process of oxidized pSi seemed delayed, but more continuous. This delayed dissolution increased the bioactivity and stability, leading to enhanced bone formation in vivo. Delayed pSi degradation provided a constant surge of silicic acid over time and promoted bone regeneration, demonstrating the high potential of pSi for bone tissue engineering: Oxidized pSi were almost completely resorbed after 2 months of healing, with remaining partially dissolved particles surrounded by newly formed bone. On the contrary, non-oxidized particles were still obviously present after 2 months with limited bone regeneration. This delayed resorption is consistent with the in vitro observations in SBF, and particles' transformation towards silica. [ABSTRACT FROM AUTHOR]

Purpose: This review aims to explore the history, research hotspots, and emerging trends of drug-eluting stents(DES)in the last two decades from the perspective of structural and temporal dynamics. Methods: Publications on DES were retrieved from WoSCC. The bibliometric tools including CiteSpace and HistCite were used to identify the historical features, the evolution of active topics, and emerging trends on the DES field. Results: In the last 20 years, the field of DES is still in the hot phase and there is a wide range of extensive scientific collaborations. In addition, active topics emerge in different periods, as evidenced by a total of 41 disciplines, 511 keywords, and 1377 papers with citation bursts. Keyword clustering anchored five emerging research subfields, namely #0 dual antiplatelet therapy, #3 drug-coated balloon, #4 bifurcation, 5# rotational atherectomy, and 6# quantitative flow ratio. The keyword alluvial map shows that the most persistent research concepts in this field are thrombosis, restenosis, etc., and the emerging keywords are paclitaxel eluting balloon, coated balloon, drug-eluting balloon, etc. There are 7 recent research subfields anchored by reference clustering, namely #2 dual antiplatelet therapy, #4 drug-coated balloon, #5 peripheral artery disease, #8 fractional flow reserve, #10 bioresorbable vascular scaffold, # 13 intravascular ultrasound, #14 biodegradable polymer. Conclusion: The findings based on the bibliometric studies provide the current status and trends in DES research and may help researchers to identify hot topics and explore new research directions in this field.

Additively manufactured scaffolds offer significant potential for treating bone defects, owing to their porous, customizable architecture and functionalization capabilities. Although various biomaterials have been investigated, metals – the most successful orthopedic material – have yet to yield satisfactory results. Conventional bio‐inert metals, such as titanium (Ti) and its alloys, are widely used for fixation devices and reconstructive implants, but their non‐bioresorbable nature and the mechanical property mismatch with human bones limit their application as porous scaffolds for bone regeneration. Advancements in additive manufacturing have facilitated the use of bioresorbable metals, including magnesium (Mg), zinc (Zn), and their alloys, as porous scaffolds via Laser Powder Bed Fusion (L‐PBF) technology. This in vivo study presents a comprehensive, side‐by‐side comparative analysis of the interactions between bone regeneration and additively manufactured bio‐inert/bioresorbable metal scaffolds, as well as their therapeutic outcomes. The research offers an in‐depth understanding of the metal scaffold‐assisted bone healing process, illustrating that Mg and Zn scaffolds contribute to the bone healing process in distinct ways, but ultimately deliver superior therapeutic outcomes compared to Ti scaffolds. These findings suggest that bioresorbable metal scaffolds hold considerable promise for the clinical treatment of bone defects in the near future. [ABSTRACT FROM AUTHOR]

This study sought to present an angiography-based computational model for serial assessment of superficial wall strain (SWS, dimensionless) of de-novo coronary stenoses treated with either bioresorbable scaffold (BRS) or drug-eluting stent (DES). A novel method for SWS allows the assessment of the mechanical status of arteries in-vivo, which may help for predicting cardiovascular outcomes. Patients with arterial stenosis treated with BRS (n = 21) or DES (n = 21) were included from ABSORB Cohort B1 and AIDA trials. The SWS analyses were performed along with quantitative coronary angiography (QCA) at pre-PCI, post-PCI, and 5-year follow-up. Measurements of QCA and SWS parameters were quantified at the treated segment and adjacent 5-mm proximal and distal edges. Before PCI, the peak SWS on the 'to be treated' segment (0.79 ± 0.36) was significantly higher than at both virtual edges (0.44 ± 0.14 and 0.45 ± 0.21; both p < 0.001). The peak SWS in the treated segment significantly decreased by 0.44 ± 0.13 (p < 0.001). The surface area of high SWS decreased from 69.97mm2 to 40.08mm2 (p = 0.002). The peak SWS in BRS group decreased to a similar extent (p = 0.775) from 0.81 ± 0.36 to 0.41 ± 0.14 (p < 0.001), compared with DES group from 0.77 ± 0.39 to 0.47 ± 0.13 (p = 0.001). Relocation of high SWS to device edges was often observed in both groups after PCI (35 of 82 cases, 41.7 %). At follow-up of BRS, the peak SWS remained unchanged compared to post-PCI (0.40 ± 0.12 versus 0.36 ± 0.09, p = 0.319). Angiography-based SWS provided valuable information about the mechanical status of coronary arteries. Device implantation led to a significant decrease of SWS to a similar extent with either polymer-based scaffolds or permanent metallic stents. [Display omitted] • Angiography-based superficial wall strain (SWS) is a new method for assessing the mechanical status of coronary arteries in-vivo. • Serial assessment of SWS of de-novo arteries treated with bioresorbable scaffold (BRS) or drug-eluting stent (DES) was performed. • At pre-PCI, the SWS in stenotic segments was significantly higher than at non-stenotic edges. • Following PCI, SWS in treated segments significantly decreased to a similar extent with BRS or DES, and remains low at long term in BRS group. Relocation of high SWS to device edges was observed in both groups. [ABSTRACT FROM AUTHOR]

[Display omitted] [ABSTRACT FROM AUTHOR]

Bioresorbable vascular scaffolds (BVS) were designed to improve late event-free survival compared with metallic drug-eluting stents. However, initial trials demonstrated worse early outcomes with BVS, in part due to suboptimal technique. In the large-scale, blinded ABSORB IV trial, polymeric everolimus-eluting BVS implanted with improved technique demonstrated noninferior 1-year outcomes compared with cobalt chromium everolimus-eluting stents (CoCr-EES). This study sought to evaluate the long-term outcomes from the ABSORB IV trial. We randomized 2,604 patients at 147 sites with stable or acute coronary syndromes to BVS with improved technique vs CoCr-EES. Patients, clinical assessors, and event adjudicators were blinded to randomization. Five-year follow-up was completed. Target lesion failure at 5 years occurred in 216 (17.5%) patients assigned to BVS and 180 (14.5%) patients assigned to CoCr-EES (P = 0.03). Device thrombosis within 5 years occurred in 21 (1.7%) BVS and 13 (1.1%) CoCr-EES patients (P = 0.15). Event rates were slightly greater with BVS than CoCr-EES through 3-year follow-up and were similar between 3 and 5 years. Angina, also centrally adjudicated, recurred within 5 years in 659 patients (cumulative rate 53.0%) assigned to BVS and 674 (53.3%) patients assigned to CoCr-EES (P = 0.63). In this large-scale, blinded randomized trial, despite the improved implantation technique, the absolute 5-year rate of target lesion failure was 3% greater after BVS compared with CoCr-EES. The risk period for increased events was limited to 3 years, the time point of complete scaffold bioresorption; event rates were similar thereafter. Angina recurrence after intervention was frequent during 5-year follow-up but was comparable with both devices.(Absorb IV Randomized Controlled Trial; NCT02173379) [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract Background Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor is the standard of care after coronary stenting, including coronary stenting involving bioresorbable scaffolds (BRSs). Current clinical guidelines recommend at least 12 months of DAPT after BRS implantation. However, the correlation between prolonged DAPT and net clinical benefits remains unknown. Methods The SPARTA trial is designed to be a prospective, randomized, parallel-group, clinical trial. It aims to compare the benefits and risks of DAPT applied for either 12 or 36 months after XINSORB BRS implantation. The primary endpoints are the incidence of the composite endpoint of major adverse cardiac events (MACEs), including all-cause death, any myocardial infarction (MI), and all revascularizations, as well as Bleeding Academic Research Consortium Definition (BARC) type 3 or 5 bleeding events. The secondary endpoints of the study include the device-oriented composite endpoint of target lesion failure (defined as cardiac death, target vessel-related MI, or ischemia-driven target lesion revascularization), target vessel failure (defined as cardiac death, MI, or ischemia-driven target vessel revascularization), scaffold thrombosis, and minor bleeding events. This trial will enroll 2106 subjects treated with the XINSORB BRS only. All subjects will receive DAPT after the index procedure for 12 (± 1) months. Subjects without MACEs or major bleeding will be randomized to receive either 24 additional months of DAPT or aspirin alone. Discussion This trial is designed to investigate the impact of extending the duration of DAPT up to 3 years after XINSORB BRS implantation by investigating the balance of risks and benefits in a broad population of treated patients. Trial registration ClinicalTrials.gov NCT04501900 . Registered on 6 August 2020.

This study aimed to investigate the long-term biocompatibility, safety, and degradation of the ultrathin nitrided iron bioresorbable scaffold (BRS) in vivo, encompassing the whole process of bioresorption in porcine coronary arteries. Fifty-two nitrided iron scaffolds (strut thickness of 70 μm) and 28 Vision Co–Cr stents were randomly implanted into coronary arteries of healthy mini-swine. The efficacy and safety of the nitrided iron scaffold were comparable with those of the Vision stentwithin 52 weeks after implantation. In addition, the long-term biocompatibility, safety, and bioresorption of the nitrided iron scaffold were evaluated by coronary angiography, optical coherence tomography, micro-computed tomography, scanning electron microscopy, energy dispersive spectrometry and histopathological evaluations at 4, 12, 26, 52 weeks and even at 7 years after implantation. In particular, a large number of struts were almost completely absorbed in situ at 7 years follow-up, which were first illustrated in this study. The lymphatic drainage pathway might serve as the potential clearance way of iron and its corrosion products.

Coronary artery spasm (CAS) can cause unstable angina, and the treatment of this disease is controversial. We report an elderly male patient who was admitted to hospital due to chest tightness. CAG showed that 70% stenosis in the middle of the right coronary artery (RCA). A bioresorbable scaffold (BRS) was implanted in the lesion under the guidance of optical coherence tomography (OCT). One year later, the patient's symptoms were relieved. The repeated CAG showed that the stent was good. BRS implantation under the guidance of treadmill test and OCT is one of treatment options for CAS patients. [ABSTRACT FROM AUTHOR]

(1) Background: The diagnostic accuracy of coronary computed tomography angiography (CCTA) for coronary artery disease (CAD) has greatly improved so CCTA represents a transition in the care of patients suffering from CAD. Magnesium-based bioresorbable stents (Mg-BRS) secure acute percutaneous coronary intervention (PCI) results without leaving, in the long term, a metallic caging effect. The purpose of this real-world study was to assess clinical and CCTA medium- and long-term follow-up of all our patients with implanted Mg-BRS. (2) Methods: The patency of 52 Mg-BRS implanted in 44 patients with de novo lesions (24 of which had acute coronary syndrome (ACS)) was evaluated by CCTA and compared to quantitative coronary angiography (QCA) post-implantation. (3) Results: ten events including four deaths occurred during a median follow-up of 48 months. CCTA was interpretable and in-stent measurements were successful at follow-up without being hindered by the stent strut's "blooming effect". Minimal in-stent diameters on CCTA were found to be 1.03 ± 0.60 mm smaller than the expected diameter after post-dilation on implantation (p < 0.05), a difference not found in comparing CCTA and QCA. (4) Conclusions: CCTA follow-up of implanted Mg-BRS is fully interpretable and we confirm the long-term Mg-BRS safety profile. [ABSTRACT FROM AUTHOR]

Abstract Additively manufactured scaffolds offer significant potential for treating bone defects, owing to their porous, customizable architecture and functionalization capabilities. Although various biomaterials have been investigated, metals – the most successful orthopedic material – have yet to yield satisfactory results. Conventional bio‐inert metals, such as titanium (Ti) and its alloys, are widely used for fixation devices and reconstructive implants, but their non‐bioresorbable nature and the mechanical property mismatch with human bones limit their application as porous scaffolds for bone regeneration. Advancements in additive manufacturing have facilitated the use of bioresorbable metals, including magnesium (Mg), zinc (Zn), and their alloys, as porous scaffolds via Laser Powder Bed Fusion (L‐PBF) technology. This in vivo study presents a comprehensive, side‐by‐side comparative analysis of the interactions between bone regeneration and additively manufactured bio‐inert/bioresorbable metal scaffolds, as well as their therapeutic outcomes. The research offers an in‐depth understanding of the metal scaffold‐assisted bone healing process, illustrating that Mg and Zn scaffolds contribute to the bone healing process in distinct ways, but ultimately deliver superior therapeutic outcomes compared to Ti scaffolds. These findings suggest that bioresorbable metal scaffolds hold considerable promise for the clinical treatment of bone defects in the near future.

Bioresorbable scaffolds (BRS) were developed to overcome the obstacles of metallic stents, mostly related to sustained presence of metallic foreign body in the coronary vessel. Following earlier success of single-arm BRS studies, randomized controlled trials of Absorb bioresorbable vascular scaffold (Abbott Vascular, Santa Clara, CA, USA) showed poor long-term clinical outcomes, particularly in terms of scaffold thrombosis. BRS made from magnesium alloy provide a promising alternative in terms of radial force, strut thickness and, potentially lower thrombogenicity. A recent clinical study demonstrated that magnesium-based BRS seems to be promising with regards to the risk of scaffold thrombosis. In this review, our aim is to describe the issues that prevented Absorb BVS from achieving favorable outcomes, provide current status of existing BRS technologies and the challenges that newer generation BRSs need to overcome, and the results of clinical studies for commercially available magnesium-based BRS, which remain the only BRS actively studied in clinical practice. [Display omitted] • Bioresorbable scaffolds (BRS) using magnesium alloy are still under development. • Current magnesium BRS seems to be promising regarding the risk of thrombosis. • Remaining issue is if the BRSs can provide sufficient radial force over a long time. [ABSTRACT FROM AUTHOR]

Background: Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor is the standard of care after coronary stenting, including coronary stenting involving bioresorbable scaffolds (BRSs). Current clinical guidelines recommend at least 12 months of DAPT after BRS implantation. However, the correlation between prolonged DAPT and net clinical benefits remains unknown. Methods: The SPARTA trial is designed to be a prospective, randomized, parallel-group, clinical trial. It aims to compare the benefits and risks of DAPT applied for either 12 or 36 months after XINSORB BRS implantation. The primary endpoints are the incidence of the composite endpoint of major adverse cardiac events (MACEs), including all-cause death, any myocardial infarction (MI), and all revascularizations, as well as Bleeding Academic Research Consortium Definition (BARC) type 3 or 5 bleeding events. The secondary endpoints of the study include the device-oriented composite endpoint of target lesion failure (defined as cardiac death, target vessel-related MI, or ischemia-driven target lesion revascularization), target vessel failure (defined as cardiac death, MI, or ischemia-driven target vessel revascularization), scaffold thrombosis, and minor bleeding events. This trial will enroll 2106 subjects treated with the XINSORB BRS only. All subjects will receive DAPT after the index procedure for 12 (± 1) months. Subjects without MACEs or major bleeding will be randomized to receive either 24 additional months of DAPT or aspirin alone. Discussion: This trial is designed to investigate the impact of extending the duration of DAPT up to 3 years after XINSORB BRS implantation by investigating the balance of risks and benefits in a broad population of treated patients. Trial registration: ClinicalTrials.gov NCT04501900. Registered on 6 August 2020. [ABSTRACT FROM AUTHOR]

Bioresorbable scaffolds have emerged as a new generation of vascular implants for the treatment of atherosclerosis, and designed to provide a temporary scaffold that is subsequently absorbed by blood vessels over time. Presently, there is insufficient data on the biological and mechanical responses of blood vessels accompanied by bioresorbable scaffolds (BRS) degradation. Therefore, it is necessary to investigate the inflexion point of degradation, the response of blood vessels, and the pathophysiological process of vascular, as results of such studies will be of great value for the design of next generation of BRS. In this study, abdominal aortas of SD rats were received 3-D printed poly-l-actide vascular scaffolds (PLS) for various durations up to 12 months. The response of PLS implanted aorta went through two distinct processes: (1) the neointima with desirable barrier function was obtained in 1 month, accompanied with slow degradation, inflammation, and intimal hyperplasia; (2) significant degradation occurred from 6 months, accompanied with decreasing inflammation and intimal hyperplasia, while the extracellular matrix recovered to normal vessels which indicate the positive remodeling. These in vivo results indicate that 6 months is a key turning point. This “two-stage degradation and vascular characteristics” is proposed to elucidate the long-term effects of PLS on vascular repair and demonstrated the potential of PLS in promoting endothelium function and positive remodeling, which highlights the benefits of PLS and shed some light in the future researches, such as drug combination coatings design.

Background: The optical coherence tomography (OCT)-deep learning (DL) emerged as a promising tool for automated plaque characterization. However, its findings have not been compared with optical and ultrasound signals. Objectives: The objective was to cross-validate the calcified plaque detected by OCT-DL, using comprehensive tissue characterization technologies including OCT-derived optical properties, intravascular ultrasound (IVUS)-virtual histology (VH) and echogenicity. Methods: Five years after bioresorbable scaffold (BRS) implantation, 15 patients underwent OCT and IVUS imaging. The unique platinum markers in BRS facilitated precise OCT-IVUS co-registration. Calcified plaque detected by OCT-DL were corroborated by/with optical properties, greyscale (GS)-IVUS, IVUS-VH and echogenicity. The concordance between OCT-DL and other modalities was assessed by kappa statistics. The calcium arc measured by different modalities were compared by orthogonal linear regression. Results: Forty-three calcified plaques were detected by DL in 72 matched anatomic slices, 41 (95%) were confirmed as pure (n = 29) or hybrid calcified plaque (n = 12) by optical properties. Weighted kappa between OCT-DL and GS-IVUS, IVUS-VH and echogenicity were 0.69, 0.60 and 0.60, respectively. After having excluded artifactual optical shadowing (n = 5) generated by guidewire or platinum marker, kappa increased to 0.77, 0.68 and 0.69, with agreement ranging between 90% and 93%. Calcium arc derived from OCT-DL showed moderate correlation and agreement with GS-IVUS (ICCa = 0.81, difference = 1.73 ± 15.25°), IVUS-VH (ICCa = 0.69, difference = -5.60 ± 21.19°) and echogenicity (ICCa = 0.65, difference = 10.28 ± 18.70°). Conclusion: OCT empowered by deep learning showed substantial agreement with optical and ultrasound signals. The comprehensive assessment provided by OCT and IVUS heralds the potential diagnostic value of combined IVUS-OCT catheters. [ABSTRACT FROM AUTHOR]

Objective: In this study, we propose distinct and novel types of scaffold geometries to improve the mechanical performance of Poly-L-lactic Acid (PLLA) bioresorbable vascular scaffolds (BVS), investigating how different geometries of PLLA BVS influence their mechanical performances through finite element analysis (FEA) and in vitro experiment methods., Methods: Four different types of scaffold geometries were modelled for FEA and manufactured for in vitro experiments. PLLA tubes with 110 μm thickness were used in manufacturing the scaffolds. For FEA measurements, material properties and bilinear material models were obtained from tensile testing using the PLLA tubes employed for manufacturing. Various measurements were conducted including crush resistance, radial strength in both the laser-cut and deployed state, three-point bending, and scaffold crimping/expansion test., Results: Overall, the FEA results were similar to the experimental results. Design A, which had a conventional open-cell geometry with straight bridges, showed inferior crush resistance and radial strength to those of the other tested geometries. Design B exhibited the most well-balanced scaffold performances in terms of radial strengths, crush resistance, three-point bending, and crimping/expansion behaviors. Notably, it showed minimum plastic strain during crimping and expanding deformations in FEA., Conclusions: Findings from such distinct and novel types of scaffold geometries shown by this study may provide a valuable understanding using PLLA scaffolds as cardiovascular devices., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

ObjectiveTo compare the efficacy and safety of bioresorbable scaffolds (BRS) with drug-eluting stents (DES) in patients with myocardial infarction undergoing percutaneous coronary interventions (PCI).MethodsWe performed a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing BRS with DES on clinical outcomes with at least 12 months follow-up. Electronic databases of PubMed, CENTRAL, EMBASE, and Web of Science from inception to 1 March 2022 were systematically searched to identify relevant studies. The primary outcome of this study was the device-oriented composite endpoint (DOCE) consisting of cardiac death, target-vessel myocardial infarction, and target lesion revascularization. Secondary outcomes were a composite of major adverse cardiac events (MACE, all-cause death, target-vessel myocardial infarction, or target vessel revascularization) and the patient-oriented composite endpoint (POCE, defined as a composite of all-cause death, myocardial infarction, or revascularization). The safety outcomes were definite/probable device thrombosis and adverse events.ResultsFour randomized clinical trials including 803 participants with a mean age of 60.5 ± 10.8 years were included in this analysis. Patients treated with BRS had a higher risk of the DOCE (RR 1.62, 95% CI: 1.02–2.57, P = 0.04) and MACE (RR 1.77, 95% CI: 1.02–3.08, P = 0.04) compared with patients treated with DES. No significant difference on the POCE (RR 1.33, 95% CI: 0.89–1.98, P = 0.16) and the definite/probable device thrombosis (RR 1.31, 95% CI: 0.46–3.77, P = 0.61) were observed between BRS and DES. No treatment-related serious adverse events were reported.ConclusionBRS was associated with a higher risk of DOCE and MACE compared with DES in patients undergoing PCI for myocardial infarction. Although this seems less effective in preventing DOCE, BRS appears as safe as DES.Systematic review registration[https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=321501], identifier [CRD 42022321501].

Nanostructured porous silicon (pSi) is a synthetic silicon-based material. Its biocompatibility and bioresorbability in body fluids make pSi an appealing biomaterial for tissue engineering, with surfaces characteristics facilitating human cell adhesion and differentiation. The resorption kinetics of such porous biomaterials is crucial for in vivo bone regeneration, in order to adapt biomaterial resorption to tissue formation, and to control the release of loaded bioactive molecules. We investigated pSi as a bioactive scaffold for bone tissue engineering, with an emphasis on kinetics of pSi resorption and silicon release. PSi particles and chips were fabricated from crystalline silicon, and functionalized by oxidation and chemical grafting of amine groups to mimic biological structures. Materials resorption over time was investigated with Raman spectroscopy, infrared spectroscopy, and Scanning Electron Microscopy. Silicon release was followed by mass spectrometry. Particle degradation and inclusion in newly formed bone were studied in vivo. The in vitro experiments revealed that non-oxidized pSi had an accelerated initial dissolution in ddH2O and an inhibition of initial Si release in SBF. This high reactivity also led to transformation towards amorphous non-resorbable silica when incubated in SBF. PSi resorption started immediately with a maximal dissolution in the first 24 h. Later, the dissolution rate decreased over time. In comparison, the resorption process of oxidized pSi seemed delayed, but more continuous. This delayed dissolution increased the bioactivity and stability, leading to enhanced bone formation in vivo. Delayed pSi degradation provided a constant surge of silicic acid over time and promoted bone regeneration, demonstrating the high potential of pSi for bone tissue engineering: Oxidized pSi were almost completely resorbed after 2 months of healing, with remaining partially dissolved particles surrounded by newly formed bone. On the contrary, non-oxidized particles were still obviously present after 2 months with limited bone regeneration. This delayed resorption is consistent with the in vitro observations in SBF, and particles’ transformation towards silica.

Introduction: Newer generation bioresorbable scaffolds (BRSs) with thinner struts and improved deliverability are expected to enhance safety and efficacy profiles. Bioheart (Bio-Heart, Shanghai, China) BRS is constructed from a PLLA (poly-l-lactic acid) backbone coated with a PDLLA (poly D-l-lactic acid) layer eluting sirolimus. We report 2-year serial intracoronary imaging findings.Methods: In this first-in-human study, 46 patients with single de novo lesions in native coronary vessels (vessel size 3.0-3.75 mm, lesion length ≤ 25 mm) were enrolled at a single institution. Baseline intravascular ultrasound (IVUS) and post-implantation IVUS and optical coherence tomography (OCT) examinations were mandatory. After successful implantations of BRS, the 46 patients were randomized to two different follow-up cohorts in a 2:1 ratio. Thirty patients in cohort 1 had to undergo angiography, IVUS, and OCT follow-ups at 6 and 24 months, respectively. The 16 patients in cohort 2 underwent the same types of imaging follow-ups at 12 and 36 months, respectively. Clinical follow-ups were scheduled uniformly in both cohorts at 1, 6, and 12 months and annually up to 5 years for all patients.Results: Between August and November 2016, a total of 54 patients were assessed. However, 8 patients could not meet all the inclusion criteria; thus, the remaining 46 patients (age 57.5 ± 8.7 years, 34.8% female, 50.0% with unstable angina, 26.1% diabetics) with 46 target lesions were enrolled in this study. All patients in both cohorts were required to complete clinical follow-up uniformly and regularly. In cohort 1, one patient had definite scaffold thrombosis within 6 months of follow-up; thus, after 6 months, cohort 1 had 96.7% patients . Imaging follow-up was available in 24 patients, and in-scaffold late loss was 0.44 ± 0.47 mm; intracoronary imaging confirmed the late loss was mainly due to to neointimal hyperplasia, but not scaffold recoil.Conclusions: Serial 2-year clinical and imaging follow-up results confirmed the preliminary safety and efficacy of Bioheart BRS for treatment of simple coronary lesions. [ABSTRACT FROM AUTHOR]

(1) Background: The diagnostic accuracy of coronary computed tomography angiography (CCTA) for coronary artery disease (CAD) has greatly improved so CCTA represents a transition in the care of patients suffering from CAD. Magnesium-based bioresorbable stents (Mg-BRS) secure acute percutaneous coronary intervention (PCI) results without leaving, in the long term, a metallic caging effect. The purpose of this real-world study was to assess clinical and CCTA medium- and long-term follow-up of all our patients with implanted Mg-BRS. (2) Methods: The patency of 52 Mg-BRS implanted in 44 patients with de novo lesions (24 of which had acute coronary syndrome (ACS)) was evaluated by CCTA and compared to quantitative coronary angiography (QCA) post-implantation. (3) Results: ten events including four deaths occurred during a median follow-up of 48 months. CCTA was interpretable and in-stent measurements were successful at follow-up without being hindered by the stent strut’s “blooming effect”. Minimal in-stent diameters on CCTA were found to be 1.03 ± 0.60 mm smaller than the expected diameter after post-dilation on implantation (p < 0.05), a difference not found in comparing CCTA and QCA. (4) Conclusions: CCTA follow-up of implanted Mg-BRS is fully interpretable and we confirm the long-term Mg-BRS safety profile.

Background: Quantitative flow ratio (QFR) is a novel angiography derived fractional flow reserve (FFR) technique. However, its diagnostic accuracy has only be validated in native coronary lesions but not in vessels after bioresorbable scaffold (BRS) implantation. This study aims to evaluate the diagnostic accuracy of residual QFR in coronary vessels immediately post-BRS implantation. Methods: This is a retrospective, two center, validation cohort study. 73 stable angina patients who received at least one de novo lesion of an everolimus eluting stent (EES)/BRS implantation with subsequent residual FFR assessment were screened. Patients with aorta-ostial stenoses, bridge vessels at the distal segment of targeted vessels, acute coronary syndrome, previous coronary artery bypass grafting, age <18 years, lack of ≥2 final angiographic projections were excluded. Contrast QFR assessment was performed blinded to FFR assessment. Results: A good correlation (r = 0.680, p < 0.001) was found between residual QFR and FFR. In the EES implantation cohort, a good correlation (r = 0.769, p < 0.001) was found between residual QFR and FFR, and a moderate correlation (r = 0.446, p = 0.038) in the BRS cohort. The area under the Receiver operator characteristic (ROC) curve for detecting FFR ≤ 0.86 was 0.883 for all patients. Conclusion: Residual QFR assessment after BRS implantation is feasible, and has a moderate correlation and agreement with residual FFR. QFR may be a promising tool similar to FFR to evaluate post-BRS effect. [ABSTRACT FROM AUTHOR]

Abstract Background Optical coherence tomography showed a great ability to identify adverse features during percutaneous coronary intervention with drug-eluting stents and resulted in better clinical outcomes. The study aimed to assess the impact of optical coherence tomography on intraoperative decision-making during implantation of Absorb bioresorbable scaffolds versus everolimus drug-eluting stents. Results We performed an observational study that included 223 consecutive patients post optical coherence tomography-guided implantation of either Absorb bioresorbable scaffolds (162 patients) or everolimus drug-eluting stents (61 patients). We studied the influence of optical coherence tomography on intraoperative decision-making during implantation of bioresorbable scaffolds versus drug-eluting stents by analyzing the total rate of optical coherence tomography-dependent modifications in each device. After satisfactory angiographic results, the total rate of required intervention for optical coherence tomography detected complications was significantly higher in the bioresorbable scaffolds arm compared to drug-eluting stents arm (47.8% versus 32.9%, respectively; p = 0.019). The additional modifications encompassed further optimization in the case of device underexpansion or struts malapposition, and even stenting in the case of strut fractures, or significant edge dissection. Conclusions Compared to drug-eluting stents, Absord scaffold was associated with a significantly higher rate of optical coherence tomography-identified intraprocedural complications necessitating further modifications. The study provides some hints on the reasons of scaffolds failure in current PCI practice; it offers a new insight for the enhancement of BRS safety and presents and adds to the growing literature for successful BRS utilization.

Abstract Background Bioresorbable scaffold (BRS) Absorb™ clinical use has been stopped due to higher rate of device thrombosis. Scaffold struts persist longer than 2 years in the vessel wall. Second generation devices are being developed. This study evaluates long-term invasive imaging in STEMI patients. Methods PRAGUE-19 study is an academic study enrolling consecutive STEMI patients with intention to implant Absorb™ BRS. A total of 83 STEMI patients between December 2012 and March 2014 fulfilled entry criteria. Coronary angiography and optical coherence tomography at 5 year follow-up was performed in 25 patients. Results Primary combined clinical endpoint (death, myocardial infarction or target vessel revascularization) occurred in 12.6% during the five-year follow-up with overall mortality 6.3%. Definite scaffold thrombosis occurred in 2 patients in the early phase after BRS implantation. Quantitative coronary angiography after 5 years demonstrated low late lumen loss of 0.11 ± 0.35 mm with binary restenosis rate of 0%. Optical coherence tomography demonstrated complete resorption of scaffold struts and mean lumen diameter of 3.25 ± 0.30 and 3.22 ± 0.49 (P = 0.73) at baseline and after 5 years, respectively. Three patients developed small coronary artery aneurysm in the treated segment. Conclusion Invasive imaging results 5 years after BRS implantation in STEMI showed complete resorption of scaffold struts and stable lumen vessel diameter. Trial registration ISRCTN43696201 (retrospectivelly registred, June 7th, 2019). https://www.isrctn.com/ISRCTN43696201 .

Stents are an indispensable tool in the percutaneous treatment of symptomatic coronary artery disease. Yet, stent failure due to restenosis or thrombosis may compromise their clinical benefit, carrying substantial morbidity and mortality. Despite improvements in device design and adjunctive medical treatment, stent failure still occurs during long-term follow-up, suggesting that this may be an issue that persists for many years, perhaps indefinitely. Numerous studies during the last decade have highlighted the previously underappreciated pivotal role of atherosclerosis in stent failure. We review evolving evidence on the role of atherosclerosis in stent restenosis and thrombosis, differentiating between de novo in-stent atherosclerosis development (i.e., neoatherosclerosis) and progression of pre-existing underlying atherosclerosis (i.e., paleoatherosclerosis), a distinction with potentially important clinical implications. We conclude with a concept that provides a unifying pathophysiology for these significant problems in the field of interventional cardiology based on the progression and destabilization of atherosclerosis.

Purpose: The purpose of the study is to evaluate the healing potential of a full-thickness tendon defect in the rotator cuff of rabbits using a bioabsorbable scaffold impregnated with bone marrow-mesenchymal stem cells (BM-MSCs) or rotator cuff-derived mesenchymal stem cells (RC-MSCs)., Methods: Sixteen adult rabbits were subjected to a full-thickness rotator cuff deficit. Rabbits were randomly assigned to four groups of four animals. In Group 0 (control), the deficit was left untreated. In Group 1, the deficit was treated with a single synthetic scaffold alone. In Group 2, the deficit was treated with the previous scaffold loaded with allogeneic BM-MSCs. In Group 3, the deficit was treated with the previous scaffold loaded with allogenic RC-MSCs. After animal sacrifice, tissue samples were subjected to histological and immunohistochemical analysis., Results: Group 1 showed the highest mean tendon maturing score (15.3 ± 0.9) postoperatively, being significantly higher, in comparison to groups 0, 2 and 3 (p = 0.01, 0.02 and 0.01, respectively). Group 1 showed the highest mean collagen I/collagen III ratio (1.4 ± 0.8) postoperatively but without any statistical significance., Conclusions: The utilization of MSCs in rotator cuff repair in a rabbit model has not been associated with an enhancement in tendon healing in 16 weeks postoperatively, in comparison to controls and bioabsorbable scaffolds. The addition of MSCs does not result in better rotator cuff healing., Level of Evidence: Not applicable. This is an animal study., (© 2024 European Society of Sports Traumatology, Knee Surgery and Arthroscopy.)

Purpose: Data regarding vessel healing by optical coherence tomography (OCT) after everolimus-eluting bioresorbable scaffolds (BRS) or everolimus-eluting metallic stent (EES) implantation in acute myocardial infarction (AMI) patients is scarce. We compared OCT findings after BRS or EES implantation in patients with AMI enrolled in a randomized trial. Methods: In ISAR-Absorb MI, AMI patients were randomized to BRS or EES implantation, with 6–8 month angiographic follow-up. This analysis includes patients who underwent OCT during surveillance angiography. Tissue characterization was done using grey-scale signal intensity analysis. The association between OCT findings and target lesion failure (TLF) at 2 years was investigated. Results: OCT was analyzed in 103 patients (2237 frames, 19,827 struts) at a median of 216 days post-implantation. Of these, 70 were treated with BRS versus 32 with EES. Pre-(92.8 vs. 68.7%, p = 0.002) and post-dilation (51.4 vs. 12.5%, p < 0.001) were more common in BRS as compared to EES. Strut coverage was higher in BRS vs. EES (97.5% vs. 90.9%, p < 0.001). Mean neointimal thickness was comparable in both groups [85.5 (61.9, 124.1) vs. 69.5 (32.7, 127.5) µm, respectively, p = 0.20]. Mature neointimal regions were numerically more common in BRS (43.0% vs. 24.6%; p = 0.35); this difference was statistically significant in ST-elevation myocardial infarction patients (40.9% vs. 21.1%, p = 0.03). At two-years, 8 (7.8%) patients experienced TLF. Mean neointimal area [0.61 (0.21, 1.33) vs. 0.41 (0.11, 0.75) mm2, p = 0.03] and mean neointimal coverage [106.1 (65.2, 214.8) vs. 80.5 (53.5, 122.1) µm, p < 0.01] were higher, with comparable tissue maturity, in lesions with versus without TLF. Conclusions: In selected patients who underwent OCT surveillance 6–8 months after coronary intervention for AMI with differing implantation characteristics depending on the device type used, vessel healing was more advanced in BRS compared with EES, particularly in the STEMI subgroup. [ABSTRACT FROM AUTHOR]

Aim: To compare the long-term outcomes of patients implanted with Absorb bioresorbable scaffold (BRS) with optimal versus suboptimal technique.Methods and Results: All patients who received an Absorb between March 2012 and January 2016 were selected from 19 Italian centers databases to assess the impact of an optimal implantation technique (CIAO criteria) on long-term device-oriented composite end-point (DOCE) - including cardiac death (CD), target-vessel myocardial infarction (TV-MI) and ischemia-driven target lesion revascularization (ID-TLR) - on its single components and on scaffold thrombosis (ScT). CIAO criteria consist of predilation (balloon/vessel ratio 1:1), correct sizing (BRS/proximal reference vessel diameter -RVD- ratio 0.8-1.2) and high-pressure postdilation with non-compliant (NC) balloon (≥20 atm for balloon/BRS ratio 1:1 or ≥16 atm for a 0.25-0.5 mm oversized balloon). Among the 1.434 patients analyzed, 464 (32.4%) fulfilled all CIAO criteria for every BRS implanted (CIAO 3 group), while 970 (67.6%) did not in at least one of the received BRS (CIAO 0-1-2 group). At 31.0 (interquartile range -IQR- 24.8-38.5) months follow-up, CIAO criteria did not impact on DOCE (8.2% vs. 8.0%, p = 0.92), ID-TLR (6.9% vs. 7.1%, p = 0.72) or ScT (1.9% vs. 1.8%, p = 0.80) in the overall population. At multivariate analysis overall BRS length (p = 0.001), severely calcified lesions (p = 0.03) and absence of CIAO criteria (CIAO 0, p = 0.005) were independent predictors of DOCE in long-term follow-up.Conclusion: Our data suggest that strict application of an optimal Absorb implantation technique doesn't improve long-term DOCE or ScT but may mitigate the worse outcome of patients with calcific lesions. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate the safety and efficacy of thinner strut Firesorb (100/125 μm) sirolimus-eluting bioresorbable scaffolds (BRS) versus cobalt-chromium everolimus-eluting stents (CoCr-EES) in patients with coronary artery disease. First-generation thicker strut BRS were associated with unexpected device-related adverse outcomes at long-term follow-up. Eligible patients with 1 or 2 de novo noncomplex coronary lesions were randomized to the Firesorb BRS group or CoCr-EES group in a 1:1 ratio. The primary endpoint was 1-year angiographic in-segment late loss (LL), powered for noninferiority testing. The key secondary endpoint was the 1-year proportion of covered struts assessed on optical coherence tomography, powered for noninferiority and subsequent superiority testing. A total of 433 participants from 28 Chinese centers were randomized to the Firesorb BRS group (n = 215) or CoCr-EES group (n = 218). Patient-level 1-year in-segment LL was 0.17 ± 0.27 mm in the Firesorb BRS group and 0.18 ± 0.37 mm in the CoCr-EES group (difference −0.01 mm; 95% confidence interval [CI]: −0.07 to 0.06; p noninferiority < 0.0001) in the intention-to-treat population and was 0.17 ± 0.27 mm in the Firesorb BRS group and 0.19 ± 0.37 mm in the CoCr-EES group (difference −0.005 mm; 95% CI: −0.07 to 0.06; p noninferiority < 0.0001) in the per-protocol set. The proportion of covered struts was 99.3% in the Firesorb BRS group and 98.8% in the CoCr-EES group (difference 0.8%; 95% CI: −0.5% to 2.1%; p noninferiority < 0.0001; p superiority = 0.21). One-year clinical outcomes were similar between groups. The thinner strut Firesorb BRS was noninferior to the CoCr-EES for the primary endpoint of 1-year angiographic in-segment LL and the key secondary endpoint of 1-year proportion of covered struts by optical coherence tomography. (A Trial of Firesorb in Patients With Coronary Artery Disease: FUTURE-II [FUTURE-II]; NCT02890160) [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract Background Percutaneous coronary intervention (PCI) in patients with diabetes mellitus (DM) remains challenging even with modern drug-eluting stents (DES) due to high rates of repeat revascularization. Everolimus-eluting bioresorbable scaffolds (EE-BRS) might allow for repeat intervention prolonging the time interval of percutaneous treatment options. Methods The ABSORB DM Benelux Study is a dedicated prospective, international study to evaluate the midterm safety and efficacy of EE-BRS in DM patients. All DM patients that received ≥ 1 EE-BRS for any indication were enrolled and prospectively followed. Study endpoints were major adverse cardiac events (MACE): a composite of all-cause death, any myocardial infarction (MI) and ischemic-driven target vessel revascularization (TVR); target lesion failure (TLF): a composite of cardiac death (CD), target vessel MI, and ischemic-driven target lesion revascularization (TLR), as well as definite or probable scaffold thrombosis (ScT). Results Between April 2015 till March 2017, 150 DM patients and 188 lesions were treated and followed up to 3 years. Device implantation success was 100%. MACE occurred in 15.2% (event rate of 8.8 per 100 PY). TLF was reported in 11.7% (7.0 events per 100 PY). CD, target vessel MI, ischemic-driven TLR occurred in 3.4%, 3.6% and 5.5% respectively, while ScT was observed in 1.4%. There were no occurrences of late or very late ScT. Conclusion EE-BRS treatment in DM patients shows comparable midterm safety and efficacy outcomes when historically compared with modern DES. New-generation EE-BRS might offer an attractive alternative to metallic DES in treatment of fast progressing atherosclerosis population as in DM patients. Trial registration NTR5447. Registered 05 October 2015, retrospectively registered

Background: After the bioresorbable PLLA-based vascular scaffold (Absorb BVS) was taken from the market due to its high adverse event rates, a magnesium-based scaffold (Magmaris) was introduced.Objective: To compare the acute performance of the sirolimus-eluting magnesium alloy Magmaris scaffold with that of the novolimus-eluting PLLA-based DESolve scaffold in terms of appropriate scaffold deployment using optical coherence tomography (OCT).Methods and Results: Data from the final OCT pullback of 98 patients were included (19 Magmaris, 79 DESolve) and analyzed at 1-mm intervals. The following indices were calculated: mean and minimal area, residual area stenosis, incomplete strut apposition, tissue prolapse, eccentricity index, symmetry index, strut fracture, and edge dissection. OCT showed a minimum lumen area for Magmaris vs. DESolve of 6.6 ± 1.6 vs. 6.0 ± 1.9 (p = 0.06). Scaffolds with residual area stenosis >20% were predominantly seen in the DESolve group (15.8 vs. 46.8%; p = 0.01). The mean eccentricity index did differ significantly (0.74 ± 0.06 vs. 0.63 ± 0.09; p < 0.001). No fractures were observed for Magmaris scaffolds, but 15.2% were documented for DESolve BRS (p < 0.001). Incomplete scaffold apposition area was significantly higher in the DESolve group (0.01 ± 0.02 vs. 1.05 ± 2.32 mm2; p < 0.001).Conclusion: This is the first study to compare the acute mechanical performance between Magmaris and DESolve in a real-world setting. The acute mechanical performance of Magmaris BRS seems to be superior to that of DESolve BRS, whereas OCT showed a good acute mechanical performance for both BRS in terms of generally accepted imaging criteria.

Introduction: The first-generation bioresorbable scaffolds (BRSs) had a large strut profile to compensate for the insufficient radial strength of bioresorbable polymer materials, resulting in higher scaffold thrombosis rates than conventional drug-eluting stents. To improve the clinical safety and efficacy, the new generation BRSs have been improved by optimal structure design, post-processing of bioresorbable polymer materials, or altering bioresorbable metallic alloys. Areas covered: This review summarizes the lessons learned from the first-generation BRS, updates the clinical outcomes of trials evaluating ABSORB bioresorbable vascular scaffold at long-term and bioresorbable metallic alloy-based devices, and examines recent outcomes of BRS treated in STEMI patients. This review also provides an overview of the current clinical data of seven BRSs manufactured in Asia, and of the BRSs extended application in other clinical arenas. Expert opinion: Drawbacks of the first-generation BRSs need to be addressed by the next generation of these stents with novel materials and technologies. Clinical research, including randomized controlled trials, are required to further evaluate BRSs application in coronary artery disease. The encouraging results of BRSs innovation applied in the peripheral arteries and gastrointestinal tracts support other potential clinical applications of BRS technology. [ABSTRACT FROM AUTHOR]

Purpose of Review: In this review, we discuss about the reasons behind the failure of the Absorb bioresorbable vascular scaffold (BVS) device and about the challenges the future holds for the next generation of the bioresorbable scaffold (BRS) technology. Recent Findings: Absorb BVS was burdened by intrinsic structural limitations which resulted in augmented rates of device thrombosis and clinical adverse events compared to current-generation metallic stent. Nevertheless, new generation devices with novel design and materials are in development. Summary: Second generation BRS have enhanced mechanical strength, smaller footprints, less thrombogenicity and modified bioresorption. These features, paired with proper patient and lesion selection and optimal "user-friendly" implant techniques, could possibly overcome the previous BRS generation limitations, rekindling physicians, and industry interest on this promising technology. [ABSTRACT FROM AUTHOR]

Iron is considered as an attractive alternative material for bioresorbable scaffolds (BRS). The sirolimus eluting iron bioresorbable scaffold (IBS), developed by Biotyx Medical (Shenzhen, China), is the only iron-based BRS with an ultrathin-wall design. The study aims to investigate the long-term efficacy, safety, biocompatibility, and lumen changes during the biodegradation process of the IBS in a porcine model. A total of 90 IBSs and 70 cobalt-chromium everolimus eluting stents (EES) were randomly implanted into nonatherosclerotic coronary artery of healthy mini swine. The multimodality assessments including coronary angiography, optical coherence tomography, micro-computed tomography, magnetic resonance imaging, real-time polymerase chain reaction (PCR), and histopathological evaluations, were performed at different time points. There was no statistical difference in area stenosis between IBS group and EES group at 6 months, 1year, 2 years and 5 years. Although the scaffolded vessels narrowed at 9 months, expansive remodeling with increased mean lumen area was found at 3 and 5 years. The IBS struts remained intact at 6 months, and the corrosion was detectable at 9 months. At 5 years, the iron struts were completely degraded and absorbed in situ, without in-scaffold restenosis or thrombosis, lumen collapse, aneurysm formation, and chronic inflammation. No local or systemic toxicity and abnormal histopathologic manifestation were found in all experiments. Results from real-time PCR indicated that no sign of iron overload was reported in scaffolded segments. Therefore, the IBS shows comparable efficacy, safety, and biocompatibility with EES, and late lumen enlargement is considered as a unique feature in the IBS-implanted vessels., Competing Interests: H. Qiu and R. L. Gao received institutional research grants from Biotyx Medical (Shenzhen) Co. Ltd., Shenzhen. China. G. Zhang, D. Y. Zhang, H. P. Qi, and Y. D. Lu are employees of Biotyx Medical (Shenzhen) Co. Ltd. Y. F. Zheng is an editor-in-chief for Bioactive Materials and was not involved in the editorial review or the decision to publish this article. All other authors have no relationships relevant to the contents of this paper to disclose., (© 2024 The Authors.)

Metallic drug-eluting stents have led to significant improvements in clinical outcomes but are inherently limited by their caging of the vessel wall. Fully bioresorbable scaffolds (BRS) have emerged in an effort to overcome these limitations, allowing a “leave nothing behind” approach. Although theoretically appealing, the initial experience with BRS technology was limited by increased rates of scaffold thrombosis compared with contemporary stents. This review gives a broad outline of the current BRS technologies and outlines the refinements in BRS design, procedural approach, lesion selection, and post-procedural care that resulted from early BRS trials.

Purpose: Our previous studies have confirmed the safety and efficacy of the novel fully bioresorbable PLLA scaffold (PowerScaffold®) at 12 months implantation. In the present study, the scaffold absorption and coronary vessel remodeling at 4 years were evaluated. Methods: After PowerScaffold® were implanted into 13 coronary arteries of 6 miniature pigs, quantitative coronary angiography (QCA) was performed at 15 days and 4 years follow-up to measure the mean lumen diameter (MLD), late lumen loss (LLL), and % stenosis of the coronary arteries. Optical coherence tomography (OCT) was performed to obtain the strut footprints at 4 years before euthanization for histological analysis. In addition, 2 PowerScaffold® were implanted into 2 miniature pigs for 2 years as supplementary data. All stented arteries were dissected and stained with HE, Masson, EVG, and Alcian blue to observe struts, cells, fibrinoid, elastin, and proteoglycans, respectively. Results: There were no significant differences in MLD, LLL and % stenosis in stented coronary arteries between 15 days and 4 years by QCA. At 4 years, most strut sites were indiscernible and replaced by extracellular matrix and connective tissue by histology. Both strut/vessel wall interaction and strut coverage were shown 100% by OCT. Conclusion: At 4 years, the scaffold struts were completely embedded into vessel wall and mostly replaced by regenerated tissue. There was no sign of in-stent stenosis in all stented arteries. [ABSTRACT FROM AUTHOR]

Background: Acute coronary syndromes most commonly arise from thrombosis of lipid-rich coronary atheromas that have large plaque burden despite angiographically appearing mild.Objectives: This study sought to examine the outcomes of percutaneous coronary intervention (PCI) of non-flow-limiting vulnerable plaques.Methods: Three-vessel imaging was performed with a combination intravascular ultrasound (IVUS) and near-infrared spectroscopy (NIRS) catheter after successful PCI of all flow-limiting coronary lesions in 898 patients presenting with myocardial infarction (MI). Patients with an angiographically nonobstructive stenosis not intended for PCI but with IVUS plaque burden of ≥65% were randomized to treatment of the lesion with a bioresorbable vascular scaffold (BVS) plus guideline-directed medical therapy (GDMT) versus GDMT alone. The primary powered effectiveness endpoint was the IVUS-derived minimum lumen area (MLA) at protocol-driven 25-month follow-up. The primary (nonpowered) safety endpoint was randomized target lesion failure (cardiac death, target vessel-related MI, or clinically driven target lesion revascularization) at 24 months. The secondary (nonpowered) clinical effectiveness endpoint was randomized lesion-related major adverse cardiac events (cardiac death, MI, unstable angina, or progressive angina) at latest follow-up.Results: A total of 182 patients were randomized (93 BVS, 89 GDMT alone) at 15 centers. The median angiographic diameter stenosis of the randomized lesions was 41.6%; by near-infrared spectroscopy-IVUS, the median plaque burden was 73.7%, the median MLA was 2.9 mm2, and the median maximum lipid plaque content was 33.4%. Angiographic follow-up at 25 months was completed in 167 patients (91.8%), and the median clinical follow-up was 4.1 years. The follow-up MLA in BVS-treated lesions was 6.9 ± 2.6 mm2 compared with 3.0 ± 1.0 mm2 in GDMT alone-treated lesions (least square means difference: 3.9 mm2; 95% confidence interval: 3.3 to 4.5; p < 0.0001). Target lesion failure at 24 months occurred in similar rates of BVS-treated and GDMT alone-treated patients (4.3% vs. 4.5%; p = 0.96). Randomized lesion-related major adverse cardiac events occurred in 4.3% of BVS-treated patients versus 10.7% of GDMT alone-treated patients (odds ratio: 0.38; 95% confidence interval: 0.11 to 1.28; p = 0.12).Conclusions: PCI of angiographically mild lesions with large plaque burden was safe, substantially enlarged the follow-up MLA, and was associated with favorable long-term clinical outcomes, warranting the performance of an adequately powered randomized trial. (PROSPECT ABSORB [Providing Regional Observations to Study Predictors of Events in the Coronary Tree II Combined with a Randomized, Controlled, Intervention Trial]; NCT02171065). [ABSTRACT FROM AUTHOR]

The impact of endothelial shear stress (ESS) on vessel remodeling in vessels implanted with bioresorbable scaffold (BRS) as compared to metallic drug-eluting stent (DES) remains elusive. The aim of this study was to determine whether the relationship between ESS and remodeling patterns differs in BRS from those seen in metallic DES at 3-year follow-up. In the ABSORB II randomized trial, lesions were investigated by serial coronary angiography and intravascular ultrasound (IVUS). Three-dimensional reconstructions of coronary arteries post-procedure and at 3 years were performed. ESS was quantified using non-Newtonian steady flow simulation. IVUS cross-sections in device segment were matched using identical landmarks. Paired ESS calculations post-procedure and at 3 years were feasible in 57 lesions in 56 patients. Post-procedure, median ESS at frame level was higher in BRS than in DES, with marginal statistical significance (0.97 ± 0.48 vs. 0.75 ± 0.39 Pa, p = 0.063). In the BRS arm, vessel area and lumen area showed larger increases in the highest tercile of median ESS post-procedure as compared to the lowest tercile. In contrast, in DES, no significant relationship between median ESS post-procedure and remodeling was observed. In multivariate analysis, smaller vessel area, larger lumen area, higher plaque burden post-procedure, and higher median ESS post-procedure were independently associated with expansive remodeling in matched frames. Only in BRS, younger age was an additional significant predictor of expansive remodeling. In a subset of lesions with large plaque burden, shear stress could be associated with expansive remodeling and late lumen enlargement in BRS, while ESS had no impact on vessel dimension in metallic DES. Image 1 • Computational fluid dynamics study can predict vessel behavior in instrumented vessel segments. • Polymeric scaffold has the capability of modifying the vessel dimensions according to the current shear stress. • High endothelial shear stress has impact on expansive remodeling in bioresorbable scaffold implanted vessel segments. • Higher plaque burden post-implantation is associated with expansive vessel remodeling. [ABSTRACT FROM AUTHOR]