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The objective of the study is to investigate the safety, feasibility, and degradation profile of a novel Mg alloy-based bioresorbable coronary scaffold (JFK-PRODUCT BRS) with thin struts (110 µm). Polymer- or Mg alloy-based BRSs have not replaced nondegradable metal stents because of the higher prevalence of scaffold thrombosis and restenosis in clinical practice; these poor clinical outcomes were due to inadequate scaffold designs, including thick struts (more than 150 µm) and their inappropriate degradation processes. Fourteen healthy pigs received 17 JFK-PRODUCT BRSs in the coronary arteries and were sacrificed at 1, 6, 12, 18, and 26 months after implantation. Angiography, optical coherence tomography, microfocus X-ray computed tomography (µCT), scanning electron microscopy with energy-dispersive X-ray spectrometry (SEM-EDX), and histopathological evaluation were performed. The JFK-PRODUCT had a median percent late recoil of 11.28% at 1 month. The µCT observation confirmed that scaffold discontinuity reached 64.8% at 12 months with increased scaffold inner area thereafter, suggesting artery positive remodeling. The inflammation was mild, peaked at 18 months, and decreased thereafter. The SEM-EDX analysis demonstrated gradual degradation of the scaffold with formation of inorganic deposits, presumed to be calcium phosphates. It also revealed the disappearance of calcium phosphates at 26 months, achieving almost complete replacement of the scaffold by biocomponents. The current study demonstrated the safety and feasibility of JFK-PRODUCT with a lower acute recoil rate despite its thin struts. The scaffolds were almost completely disappeared at 26 months after implantation.

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BACKGROUND: The acute coronary syndrome (ACS) continues to be a fundamental indication for revascularization by percutaneous coronary intervention (PCI). Drug-eluting stent (DES) implantation remains a part of contemporary practice but permanent caging of the vascular structure with the metallic stent structure may increase the rate of device-related adverse clinical events. As an alternative to classic metallic DESs, the bioresorbable scaffolds (BRSs) have emerged as a temporary vascular support technology. We evaluated the mid-term outcomes of two generations of bioresorbable scaffolds-Absorb (Abbott-Vascular, Chicago, IL, USA) and Magmaris (Biotronik, Germany)-in patients with non-ST-elevation ACS. METHODS: The study cohort consisted of 193 subjects after Magmaris implantation and 160 patients following Absorb implantation in large-vessel lesions. RESULTS: At 2 years, a significantly lower rate of a primary outcome (cardiac death, myocardial infarction, stent thrombosis) was observed with Magmaris (5.2% vs. 15%; p = 0.002). In addition, we observed a significantly lower rate of MI in the target vessel (2.6% vs. 9.4%; p = 0.009) and a lower rate of scaffold thrombosis (0% vs. 3.7%; p = 0.008). The TLF rate between the two groups was not significantly different. CONCLUSION: Magmaris demonstrated a good safety profile and more favorable clinical outcomes when compared to Absorb in patients with non-ST-elevation ACS.

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BACKGROUND: Acute coronary syndrome (ACS) as a clinical manifestation of coronary artery disease (CAD) remains a significant cause of mortality and morbidity, as reported worldwide annually. The second generation of drug-eluting stents (DES) is a gold standard in percutaneous interventions in ACS patients however, permanent caging of the vessel with metallic DES has some drawbacks. Bioresorbable vascular scaffolds (BRS) were designed as a temporal vessel-supporting technology allowing for anatomical and functional restoration. Nevertheless, following the initial encouraging reports, numerous concerns about the safety of BRS occurred. METHODS: In this study, a 1-year performance of 193 patients with magnesium BRS - Magmaris (Biotronik, Berlin, Germany) was evaluated in comparison to 160 patients with polymer BRS - Absorb (Abbott-Vascular, Chicago, USA) in the non-ST-segment elevation-ACS setting. RESULTS: The Magmaris, when compared to Absorb showed a significantly lower rate of primary endpoint (death from cardiac causes, myocardial infarction, stent thrombosis) as well as target lesion failure in 30-day and 1 year follow-up. In the Absorb group, a significantly higher rate of stent thrombosis was observed. CONCLUSIONS: Data from the present study suggests encouraging safety a profile and more favorable clinical outcomes of Magnesium BRS in comparison to the polymer Absorb - BRS.

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BACKGROUND: Research on the resorbable magnesium scaffolds (RMSs) has shown their safety and effectiveness in stable clinical conditions. It seems that this new therapeutic option could be promising for selected acute coronary syndrome (ACS) patients. AIMS: Our analysis aims to analyse the long-term performance of RMSs among ACS patients. METHODS: The study population consisted of consecutive ACS patients treated with the implantation of at least one RMS. The Magmaris ACS Registry was designed as a single-arm observational registry in the 'real-world' treatment practice setting. RESULTS: The study population consisted of 193 patients, predominantly male (78%), at a mean (SD) age of 64 (9) years and with the typical risk factors of ACS. Unstable angina (UA) was the indication for revascularisation in 32.1%, non-ST-segment myocardial infarction (NSTEMI) in 65.8% and ST-segment elevation myocardial infarction (STEMI) only in 2.1%. During the mean 24 months of follow-up, ten cases (5.2%) of target lesion failure (TLF) were diagnosed, of which five cases (2.6%) were clinically driven target lesion failure (CD-TLR), four cases (2.1%) of asymptomatic scaffold restenosis and one case (0.5%) of target vessel myocardial infarction (TV-MI). No cardiac deaths and 2 non-cardiac deaths (2.2%, both fatal strokes) were observed. No cases of scaffold thrombosis were observed during the median 24-month follow-up. CONCLUSIONS: The use of the RMSs in selected ACS patients is associated with procedural safety and promising early and long-term clinical efficacy and safety outcomes. Proper lesion selection is key to the long-term success of bioresorbable technology in this patient population.

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In this paper we are reporting an unexpected evolution after multiple Resorbable Magnesium Scaffolds (RMS) implantations in overlap.

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BACKGROUND: The resorbable magnesium scaffold (RMS) has demonstrated a good safety profile to treat de novo lesions. Nevertheless, bifurcation lesions involving a side branch (SB) >2.0 mm in diameter were excluded from these studies, and such lesions remain technically challenging due to concerns of scaffold deformation or fracture. We sought to evaluate different SB dilation strategies after provisional T-stenting strategy with RMS using silicon bifurcation phantoms. METHODS AND RESULTS: Three different strategies were compared: proximal optimization technique (POT)-side-rePOT (rePOT), kissing-balloon inflation (KBI), and mini kissing-balloon inflation (MKBI) strategies. Strut and connector fractures were evaluated by micro computed tomography and apposition by optical coherence tomography (OCT). Twelve Magmaris scaffolds (Biotronik) were successfully implanted (4 in each group). There was no difference in strut and connector fractures among the three techniques, as no fracture was visualized. OCT demonstrated that MKBI significantly decreased global malapposition following SB inflation as compared with rePOT or KBI strategies (95.3% vs 88.3% of perfectly apposed struts [P<.001] and 93.6% [P<.01], respectively, for MKBI vs rePOT and KBI). After step-by-step over-expansion of 6 RMS devices with 3.75 mm, 4.0 mm, and 4.5 mm NC balloons at 16 atm (ie, +1.5 mm from the initial 3.0 mm RMS), no strut or connector fracture could be visualized. CONCLUSION: Provisional single-stent technique with the Magmaris RMS on a bifurcation lesion is technically feasible with these three different strategies without scaffold fracture. MKBI strategy resulted in better apposition rates as compared with KBI or rePOT strategies. Nevertheless, Magmaris use in bifurcation lesions should not be advised before similar results are confirmed by in vivo studies.

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We present first-in-human treatment with bioabsorbable magnesium scaffolds for percutaneous coronary intervention in a patient with nickel allergy. We present images from angiography and optical coherence tomography at three months. We also review the current status of these novel devices.

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An ideal bone substituting material should be bone-mimicking in terms of mechanical properties, present a precisely controlled and fully interconnected porous structure, and degrade in the human body to allow for full regeneration of large bony defects. However, simultaneously satisfying all these three requirements has so far been highly challenging. Here we present topologically ordered porous magnesium (WE43) scaffolds based on the diamond unit cell that were fabricated by selective laser melting (SLM) and satisfy all the requirements. We studied the in vitro biodegradation behavior (up to 4 weeks), mechanical properties and biocompatibility of the developed scaffolds. The mechanical properties of the AM porous WE43 (E = 700-800 MPa) scaffolds were found to fall into the range of the values reported for trabecular bone even after 4 weeks of biodegradation. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), electrochemical tests and µCT revealed a unique biodegradation mechanism that started with uniform corrosion, followed by localized corrosion, particularly in the center of the scaffolds. Biocompatibility tests performed up to 72 h showed level 0 cytotoxicity (according to ISO 10993-5 and -12), except for one time point (i.e., 24 h). Intimate contact between cells (MG-63) and the scaffolds was also observed in SEM images. The study shows for the first time that AM of porous Mg may provide distinct possibilities to adjust biodegradation profile through topological design and open up unprecedented opportunities to develop multifunctional bone substituting materials that mimic bone properties and enable full regeneration of critical-size load-bearing bony defects. STATEMENT OF SIGNIFICANCE: The ideal biomaterials for bone tissue regeneration should be bone-mimicking in terms of mechanical properties, present a fully interconnected porous structure, and exhibit a specific biodegradation behavior to enable full regeneration of bony defects. Recent advances in additive manufacturing have resulted in biomaterials that satisfy the first two requirements but simultaneously satisfying the third requirement has proven challenging so far. Here we present additively manufactured porous magnesium structures that have the potential to satisfy all above-mentioned requirements. Even after 4 weeks of biodegradation, the mechanical properties of the porous structures were found to be within those reported for native bone. Moreover, our comprehensive electrochemical, mechanical, topological, and biological study revealed a unique biodegradation behavior and the limited cytotoxicity of the developed biomaterials.

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