Conventional Drug-eluting Stents Research Articles

Synchrotron microtomography reveals insights into the degradation kinetics of bio-degradable coronary magnesium scaffolds

Bioresorbable magnesium scaffolds are a promising future treatment option for coronary artery stenosis, especially for young adults. Due to the degradation of these scaffolds (<1 year), long-term device-related clinical events could be reduced compared to treatments with conventional drug eluting stents. First clinical trials indicate a return of vasomotion after one year, which may be associated with improved long-term clinical outcomes. However, even after decades of development, the degradation process, ideal degradation time and biological response in vivo are still not fully understood.The present study investigates the in vivo degradation of magnesium scaffolds in the coronary arteries of pigs influenced by different strut thicknesses and the presence of antiproliferative drugs. Due to high 3D image contrast of synchrotron-based micro-CT with phase contrast (SR-μCT), a qualitative and quantitative evaluation of the degradation morphology of magnesium scaffolds was obtained. For the segmentation of the μCT images a convolutional network architecture (U-net) was exploited, demonstrating the huge potential of merging high resolution SR-μCT with deep learning (DL) supported data analysis.In total, 30 scaffolds, made of the rare earth alloy Resoloy®, with different strut designs were implanted into the coronary arteries of 10 domestic pigs for 28 days using drug-coated or uncoated angioplasty balloons for post-dilatation. The degradation morphology was analyzed using scanning electron microscopy, energy dispersive x-ray spectroscopy and SR-μCT. The data from these methods were then related to data from angiography, optical coherence tomography and histology.A thinner strut size (95 vs. 130 μm) and the presence of paclitaxel indicated a slower degradation rate at 28 d in vivo, which positively influences the late lumen loss (0.5 and 0.6 mm vs. 1.0 and 1.1 mm) and recoil values (0 and 1.7% vs. 6.1 and 22%).

A prospective double-blinded randomized study on drug-eluting stent implantation into nitrate-induced maximally dilated vessels in patients with coronary artery disease

BackgroundPercutaneous coronary intervention (PCI) has been developed using drug-eluting stents (DES); however, stent implantation is associated with concerns of stent thrombosis and target vessel revascularization (TVR). The stent diameter is a critical factor in TVR and clinical events. The nitrate administration in coronary angiography can dilate the reference vessel diameter, enabling accurate vessel size measurement and optimal stent implantation support. This study was designed to evaluate the effect of stent implantation in the maximally dilated coronary artery in patients with coronary artery disease (CAD).MethodsThis prospective double-blinded randomized (1:1) study is designed to compare the efficacy and safety between DES implantation into the nitrate-induced maximally dilated vessels and conventional DES implantation in patients with CAD. A total of 400 patients who underwent PCI with a sirolimus-eluting stent will be enrolled. The primary endpoint is the mean diameter of the deployed stents. Secondary endpoints include cardiac death, myocardial infarction, stent thrombosis, or ischemia-driven TVR 1 year after the procedure.DiscussionThis study will be the first randomized controlled trial to evaluate the effect of DES implantation on nitrate-induced maximally dilated vessels in patients with CAD.Trial registrationThe trial was registered on 18 June 2021 as Effect of Ultimaster Stents Treated to the Most Dilated Coronary Vessels (ClinicalTrials.gov Identifier: NCT04931784).

Is There an Advantage of Ultrathin-Strut Drug-Eluting Stents over Second- and Third-Generation Drug-Eluting Stents?

In patients undergoing percutaneous coronary intervention, the second-generation drug-eluting stents (DES) are considered the gold standard of care for revascularization. By reducing neointimal hyperplasia, drug-eluting coronary stents decrease the need for repeat revascularizations compared with conventional coronary stents without an antiproliferative drug coating. It is important to note that early-generation DESs were associated with an increased risk of very late stent thrombosis, most likely due to delayed endothelialization or a delayed hypersensitivity reaction to the polymer. Studies have shown a lower risk of very late stent thrombosis with developing second-generation DESs with biocompatible and biodegradable polymers or without polymers altogether. In addition, research has indicated that thinner struts are associated with a reduced risk of intrastent restenosis and angiographic and clinical results. A DES with ultrathin struts (strut thickness of 70 µm) is more flexible, facilitates better tracking, and is more crossable than a conventional second-generation DES. The question is whether ultrathin eluting drug stents suit all kinds of lesions. Several authors have reported that improved coverage with less thrombus protrusion reduced the risk of distal embolization in patients with ST-elevation myocardial infarction (STEMI). Others have described that an ultrathin stent might recoil due to low radial strength. This could lead to residual stenosis and repeated revascularization of the artery. In CTO patients, the ultrathin stent failed to prove non-inferiority regarding in-segment late lumen loss and showed statistically higher rates of restenosis. Ultrathin-strut DESs with biodegradable polymers have limitations when treating calcified (or ostial) lesions and CTOs. However, they also possess certain advantages regarding deliverability (tight stenosis, tortuous lesions, high angulation, etc.), ease of use in bifurcation lesions, better endothelialization and vascular healing, and reducing stent thrombosis risk. In light of this, ultrathin-strut stents present a promising alternative to existing DESs of the second and third generation. The aims of the study are to compare ultrathin eluting stents with second- and third-generation conventional stents regarding procedural performance and outcomes based on different lesion types and specific populations.

Impact of the ultra-long 48 mm drug-eluting stent on procedural and clinical outcomes in patients with diffuse long coronary artery disease.

Diffuse coronary artery disease (CAD) is a prognostic factor after percutaneous coronary intervention (PCI) and requires multiple overlapping stent implantations. We investigated the impact of ultra-long 48 mm drug-eluting stent (DES) on procedural and clinical outcomes in real-world practice. Patients who underwent DES implantation for a lesion length of >40 mm were selected from a prospective registry between 2019 and 2021. Patients treated with one or more ultra-long 48 mm DES were in the ultra-long DES group (n = 221). The others comprised the conventional DES group (n = 428). Procedural and clinical outcomes were compared after propensity score matching (PSM). The primary endpoint was a device-oriented composite outcome (DOCO) consisting of cardiac death, target vessel-related myocardial infarction, and target lesion revascularization at 1-year follow-up. After PSM, 158 matched pairs of patients showed no differences in the baseline clinical and angiographic characteristics. The stent delivery failure rate, the use of guide-extension catheter or anchor balloon technique, and the procedural success rate were similar for both groups. Approximately two-thirds of lesions could be treated with one DES in the ultra-long DES group. At 1-year follow-up, the DOCO was similar for both groups (2.5% vs. 0.6%, p = .168). In daily clinical practice, ultra-long DES implantation is as safe and effective as multiple overlapping conventional DES implants in treating diffuse long CAD. However, ultra-long DES can reduce the number of stents. (Trial Registration: ClinicalTrials.gov Identifier: NCT02038127).

Bioresorbable vascular scaffolds versus conventional drug-eluting stents across time: a meta-analysis of randomised controlled trials

BackgroundBioresorbable vascular scaffolds (BVS) were designed to reduce the rate of late adverse events observed in conventional drug-eluting stents (DES) by dissolving once they have restored lasting patency.ObjectivesCompare the safety...

Magmaris Resorbable Magnesium Scaffold Versus Conventional Drug-Eluting Stent in ST-Segment Elevation Myocardial Infarction: 1-Year Results of a Propensity-Score-Matching Comparison

Magmaris® (Biotronik AG, Switzerland) is the first RMS and early experience has shown promising results in stable coronary artery disease. Acute coronary syndromes have been hypothesized as a potential target group for bioresorbable scaffolds, but the efficacy and safety of RMS has not been extensively studied in ST-segment elevation myocardial infarction (STEMI).BEST-MAG is a prospective multicenter trial designed to evaluate optical coherence tomography (OCT-)guided implantation of resorbable magnesium scaffold (RMS) in STEMI.Consecutive STEMI patients fulfilling inclusion/exclusion criteria were treated with RMS following a standardized OCT-based implantation technique including systematic pre- and post-dilatation, and baseline plus final OCT imaging. The primary endpoint was a device oriented composite endpoint (DOCE) including cardiac death, target vessel myocardial infarction (TV-MI) and target lesion revascularization (TLR) within 12 months. Clinical outcomes were compared after propensity score matching (PSM) to the results of the randomized controlled BIOSTEMI trial comparing biodegradable polymer sirolimus eluting (BP-SES) and durable polymer everolimus eluting stents (DP-EES) in STEMI.Between 15th February 2019 and 25th May 2020, 30 patients were included in 5 centers. Procedural success was achieved in all cases based on OCT control with final scaffold expansion of 82 ± 11%. At twelve-months, DOCE rate was 13.3% (n = 4), including 4 cases of TLR (13.3%) and one case of TV-MI (3.3%). No cardiac death occurred, and no scaffold thrombosis (ScT) was observed. Using PSM, DOCE rates in BP-SES and DP-EES groups were 10% and 6% respectively and TLR rates were 3.3% and 0.0%.In this study, OCT-guided RMS implantation in selected STEMI patients appeared feasible but was associated with numerically higher rates of TLR as compared with conventional drug-eluting stents, although the limited number of patients included in this analysis does not allow drawing statistically significant conclusions.

Polymer Coating Integrity, Thrombogenicity and Computational Fluid Dynamics Analysis of Provisional Stenting Technique in the Left Main Bifurcation Setting: Insights from an In-Vitro Model.

Currently, the provisional stenting technique is the gold standard in revascularization of lesions located in the left main (LM) bifurcation. The benefit of the routine kissing balloon technique (KBI) in bifurcation lesions is still debated, particularly following the single stent treatment. We compared the latest-generation drug-eluting stent (DES) with no side branch (SB) dilatation “keep it open” technique (KIO) vs. KBI technique vs. bifurcation dedicated drug-eluting stent (BD-DES) implantation. In vitro testing was performed under a static condition in bifurcation silicone vessel models. All the devices were implanted in accordance with the manufacturers’ recommendations. As a result, computational fluid dynamics (CFD) analysis demonstrated a statistically higher area of high shear rate in the KIO group when compared to KBI. Likewise, the maximal shear rate was higher in number in the KIO group. Floating strut count based on the OCT imaging was significantly higher in KIO than in KBI and BD-DES. Furthermore, according to OTC analysis, the thrombus area was numerically higher in both KIO and KBI than in the BD-DES. Scanning electron microscopy (SEM) analysis shows the highest degree of strut coating damage in the KBI group. This model demonstrated significant differences in CFD analysis at SB ostia with and without KBI optimization in the LM setting. The adoption of KBI was related to a meaningful reduction of flow disturbances in conventional DES and achieved results similar to BD-DES.

DynamX Bioadaptor, a Unique “Uncaging” Platform for Coronary Artery Revascularisation: Ongoing Clinical Results From the DynamX Hong Kong Registry

Drug-eluting stents (DES) are the current mainstay in treatment and have reduced major adverse cardiac events (MACE) in the first year after PCI. Beyond 1 year, a 2%–3% annualised event rate without plateau is observed. The DynamX™ Coronary Bioadaptor System is a 71 μm cobalt-chromium platform with a novel “uncaging” mechanism of circumferential rings, which maintains the axial links between the rings following uncaging. Conventional metallic DES “cage” the artery, inhibit positive adaptive remodelling and vasomotion, and cause geometric distortion. These factors likely contribute to the persistent increase in annual MACE rate. The DynamX Bioadaptor combines acute performance of contemporary DES and unique benefits of arterial “uncaging”, allowing positive adaptive remodelling and restoring compliance and geometry. In previously reported clinical trials results, the DynamX Bioadaptor has shown excellent clinical safety and lumen maintenance and Bioadaptor growth not seen with DES.

DynamX Bioadaptor, a Novel Uncaging Platform for Percutaneous Coronary Artery Revascularisation: 6 Month Clinical and Imaging Results

Compared with bare metal stents, drug-eluting stents (DES) reduce major adverse cardiac events (MACE) in the first year after PCI, but still have an ongoing 2%–3% annual event rate. The DynamX Coronary Bioadaptor is a 71 μm cobalt-chromium platform with a novel “uncaging” mechanism of circumferential rings, which maintains the axial links between the rings following uncaging. Unlike conventional metallic DES, this allows positive adaptive remodelling and restoration of vascular compliance and geometry, with potential long-term benefits.

Efficacy and Safety of Dual-Drug-Eluting Stents for de Novo Coronary Lesions in South Korea-The Effect Trial.

Background: Drug-eluting stents (DESs) are commonly used in percutaneous coronary intervention (PCI) procedures; however, complications including in-stent restenosis and stent thrombosis are significant challenges. The dual-DES is a stent that elutes two drugs to target various stages of the restenosis reaction. This study investigated the safety and efficacy of dual-DES in clinical practice. Methods: This study included 375 patients who underwent PCI with Cilotax™ or DXR™ dual-DESs at one of 13 centers in South Korea. The primary endpoint was target lesion failure (TLF) within 1 year. The secondary endpoints were cardiac death, myocardial infarction (MI), target lesion revascularization (TLR), and stent thrombosis. Results: The rates of TLF in dual-DESs (3.7%) were comparable to those reported in conventional DES. In addition, the DXR™ group had a significantly lower rate of TLF than the Cilotax™ group. In multivariate analysis, the DXR™ group had a lower risk of TLF (adjusted hazard ratio (HR) 0.30, 95% CI 0.09–0.92, p = 0.036) and MI (adjusted HR 0.16, 95% CI 0.03–0.82, p = 0.027) than the Cilotax™ group. Conclusion: Dual-DESs had similar clinical outcomes regarding efficacy and safety as conventional DES. Among the dual-DES, the DXR™ stent as a new generation dual-DES had more favorable clinical outcomes than the Cilotax™ stent.

Clinical Outcomes after Additional Dynamic Renal® Stent Implantation for Stent Recoil in Ostial Coronary Lesions.

Background: Interventional treatment of aorto-ostial coronary stenoses is limited by stent recoil and suboptimal angiographic results, leading to restenosis and frequent re-interventions. As a potential bail-out strategy for stent recoil, implantation of an additional stent to increase radial force has been reported. Thus, we sought to investigate clinical outcomes after additional implantation of a Dynamic Renal® stent (DRS), a non-coronary; bare-metal stent with very high radial force, in aorto-ostial coronary stenoses. Methods: Patients treated by implantation of DRSs for stent recoil in the ostial right coronary artery or the left main stem were identified from the hospital database. Baseline clinical and procedural characteristics were compared to patients who underwent re-intervention for in-stent-restenosis in similar segments by either implantation of conventional drug-eluting stents (DES) or paclitaxel-coated balloons (PCB). Clinical follow-ups were performed up to three years following re-intervention with the assessment of death, target lesion reintervention (TLR), and major adverse cardiac events (MACE) as a combination death, myocardial infarction and target vessel revascularization. Kaplan–Meier analyses were performed for event-free survival between the three groups. Results: Between 05/2013 and 07/2019, 28 patients underwent DRS implantation of aorto-ostial coronary lesions. In comparison with 49 patients with DES implantation and 29 patients undergoing PCB treatment, no relevant differences in baseline parameters were identified. Median follow-up was 714 days, with an available follow-up of >1 year after intervention in 82.1% of patients. In the entire study cohort at two years after re-intervention, the TLR rate was 16% (17 patients), the MACE rate 37% (39 patients), and all-cause mortality 9% (10 patients), with no significant differences between the three groups. Conclusions: DRS implantation for treating stent recoil of aorto-ostial coronary lesions resulted in a high rate of TLR, and was associated with similar risk for death and MACE compared to treatment of in-stent-restenosis with DES or PCB. Randomized, larger comparisons of contemporary DES in patients exclusively presenting with stent recoil are necessary to further define the efficacy and safety of this approach.

Comparison of overexpansion capabilities and thrombogenicity at the side branch ostia after implantation of four different drug eluting stents

Interventions in bifurcation lesions often requires aggressive overexpansion of stent diameter in the setting of long tapering vessel segment. Overhanging struts in front of the side branch (SB) ostium are thought to act as a focal point for thrombi formation and consequently possible stent thrombosis. This study aimed to evaluate the overexpansion capabilities and thrombogenicity at the SB ostia after implantation of four latest generation drug-eluting stents (DES) in an in-vitro bifurcation model. Four clinically available modern DES were utilized: one bifurcation dedicated DES (Bioss LIM C) and three conventional DES (Ultimaster, Xience Sierra, Biomime). All devices were implanted in bifurcation models with proximal optimization ensuring expansion before perfusing with porcine blood. Optical coherence tomography (OCT), immunofluorescence (IF) and scanning electron microscope analysis were done to determine thrombogenicity and polymer coating integrity at the over-expanded part of the stents. Computational fluid dynamics (CFD) was performed to study the flow disruption. OCT (p = 0.113) and IF analysis (p = 0.007) demonstrated lowest thrombus area at SB ostia in bifurcation dedicated DES with favorable biomechanical properties compared to conventional DES. The bifurcated DES also resulted in reduced area of high shear rate and maximum shear rate in the CFD analysis. This study demonstrated numerical differences in terms of mechanical properties and acute thrombogenicity at SB ostia between tested devices.

Feasibility, Safety, and Clinical Performance of Self-apposing Stents for Left Main Stenosis

Drug-eluting stents (DES) are the gold standard for percutaneous coronary interventions (PCI); however, technical and anatomical challenges need to be addressed to ensure optimal apposition and prevent late adverse events. Complex vessel anatomies, including ectatic or aneurysmatic vessels, or significant differences in diameter in left main stenosis of the coronary artery, are clinical indications in which current PCI techniques attempt to shape conventional DES to follow vessel anatomy, thus modifying the original stent scaffold and its properties. However, due to their design, balloon-expandable cobalt–chromium and cobalt–nickel DES have limitations regarding their expansion capacity, which can result in undersizing and malapposition. New stent scaffolds have recently been introduced into clinical practice to address these challenging anatomies, including a drug-eluting nitinol stent platform. The nature of the nitinol device allows conformability to the native vessel, covering complex anatomies without manual adaptation. In this article, the authors present the rationale and current data on self-apposing nitinol DES in left main stenosis, and suggest that the device may be safely and effectively used with comparable rates of adverse cardiovascular events, as seen with second-generation balloon-expandable DES.

BIOABSORBABLE SCAFFOLDS FOR PERCUTANEOUS CORONARY INTERVENTIONS IN PATIENTS WITH CORONARY ARTERY DISEASE: PROBLEMS AND FUTURE PERSPECTIVES

Highlights. Bioabsorbable vascular scaffolds for percutaneous coronary interventions in multivessel coronaryartery disease patients and concomitant type 2 diabetes mellitus may increase the effectiveness of endovascular treatment and improve the long-term prognosis. The review article discusses recent data and evidences on the efficacy and safety of various stent generations for treating patients with coronary artery disease. The main complications commonly occurred following the implantation of drug-eluting stents in the long-term period are summarized, suggesting the rationale for the use of the next generation bioabsorbable vascular scaffolds in routine clinical practice. Bioabsorbable vascular scaffolds for endovascular treatment of patients with coronary artery disease show comparable efficacy compared with conventional drug-eluting stents. Particular attention is paid to the technical approaches of bioabsorbable vascular scaffold implantation, the use of intavascular imaging to control the implantation, as well as the timing of dual antiplatelet therapy in the postoperative period. The final term of the first-generation scaffold absorption, dual antiplatelet therapy, the effectiveness of bioabsorbable vascular scaffold-treated distal lesions and safety in patients with type 2 diabetes are highlighted. Future perspectives of using the next generation bioabsorbable vascular scaffolds that may improve the efficiency of percutaneous coronary interventions are presented.

Thromboresistance and functional healing in the COBRA PzF stent versus competitor DES: implications for dual antiplatelet therapy.

The aim of this study was to investigate the COBRA PzF stent (C-PzF) with respect to thrombogenicity and healing versus conventional drug-eluting stents (DES) in dedicated preclinical models to evaluate their suitability for short-term dual antiplatelet therapy (DAPT). To examine acute thrombogenicity, the C-PzF durable polymer drug-eluting stent (DP-DES), and a bioabsorable polymer DES (BP-DES) were compared in a porcine arteriovenous shunt model and in a rabbit model to evaluate endothelial coverage at 14 days. Barrier function at 28 days in the rabbit was assessed in the former stents as well as in a polymer-free DES (PF-BES). The number of clots by scanning electron microscopy (SEM) was significantly less in the C-PzF and DP-EES versus the BP-EES. Endothelial coverage at 14 days was significantly greater in the C-PzF versus the DP-EES and BP-EES by CD31/PECAM-1 positive area in confocal microscopy (CM) (24.7% vs 11.9% vs 3.7%, respectively) and SEM (99.0% vs 29.6% vs 17.7%, respectively). Barrier protein expression by CM for p120/vascular-endothelial cadherin complex was significantly greater in the C-PzF versus the DP-EES, BP-EES, and PF-BES (82.6% vs 12.8% vs 14.4% vs 18.1%, respectively). The percentage of Evan's Blue positive area was least in the C-PzF versus all groups (22.0% vs 70.7% vs 66.4% vs 55.2%, respectively). The C-PzF demonstrated a unique combination of thrombogenicity and healing advantages compared to contemporary DES and may be uniquely suitable for very short-term DAPT.

Development of Dual Drug Eluting Cardiovascular Stent with Ultrathin Flexible Poly(l-lactide-co-caprolactone) Coating.

The pleiotropic effects of the atorvastatin-fenofibrate combination can be effectively harnessed for site-specific therapy to minimize stent-related complications. The present study aims to utilize the pleiotropic effects of these two drugs entrapped in a uniform and defect-free coating of poly(l-lactide-co-caprolactone) (PLCL) on a stainless steel stent to overcome stent-associated limitations. The stent coating parameters were optimized using ultrasonic spray coating technique to achieve a thin, smooth, and defect-free dual drug-loaded polymer coating on the stent. The dual drug-loaded polymer coated stent was characterized for surface morphology, thickness and coating integrity. In vitro drug release kinetics of the fabricated stent reveals a sustained release of both drugs for more than 60 days. Significant reduction of thrombus formation and adhesion of lipopolysaccharide-stimulated macrophages on the dual drug containing polymer-coated stent indicates that the drug combination possesses antithrombotic and anti-inflammatory effects. The combination did not adversely influence endothelialization but significantly retarded smooth muscle cell proliferation indicating its potential to overcome restenosis. No bacterial biofilm formation was observed on the stent due to the antibacterial activity of atorvastatin. A rat subcutaneous model was used to evaluate the biocompatibility of the coated stent and compared with the commercial stent. MicroCT, scanning electron microscopy, and morphometric analyses revealed that the coated stents exhibited excellent histocompatibility with no inflammatory response as evidenced from the cytokine levels measured 28 days postimplantation. Our data demonstrates for the first time that the combination of atorvastatin and fenofibrate can be successfully employed in cardiovascular stents to overcome the current limitations of conventional drug-eluting stents.

LONG-TERM AUSTRALIAN BIORESORBABLE SCAFFOLD OUTCOMES FOLLOWING WITHDRAWAL FROM MARKET: A REPORT FROM THE VICTORIAN CARDIAC OUTCOMES REGISTRY

Bioresorbable scaffolds (BRS) have emerged as a novel technology in interventional cardiology. However, recent trials demonstrate higher rates of scaffold thrombosis and device failure compared to conventional drug eluting stents. Limited Australian data on BRS outcomes are available. BRS

Sirolimus-eluting BiOSS LIM dedicated bifurcation stent in the treatment of unprotected distal left main stenosis.

Proximal optimization technique (POT) has been proposed to adapt the conventional drug-eluting stent (DES) with the fractal anatomy of the bifurcation. However, only few DES are labeled for post-expansion beyond 5.0 mm. Furthermore, recrossing in the side branch (SB) through the main vessel (MV) stent cells may be challenging. To compare the sirolimus-eluting, balloon-expandable dedicated bifurcation stent BiOSS LIM DES versus the second generation DES in the treatment of distal unprotected left main coronary arteries (ULMCAs) lesions. Forty-two consecutive patients with distal ULMCA lesions were treated with the BiOSS LIM (BiOSS LIM group) in our center. A matched-group of patients treated with second-generation DES was selected from our database (Control group). The primary endpoint was the procedural complication rate, including (a) SB occlusion, defined as intraprocedural TIMI flow grade <3 immediately after MV stenting; and/or (b) trouble in SB access, defined as the need of ≥2 guidewires or a failure to recross in the SB trough the MV stent cells. The need of POT in the two groups was also analyzed. The primary endpoint occurred in four (9.5%) patients in the BiOSS LIM group and in 13 (31%) in the Control group (p = 0.028; OR = 4.25; 95% confidence interval: 1.25-14.43). POT was performed more often in the Control group (71% vs. 35%; p = 0.004). Compared to conventional DES, the BiOSS LIM stent (1) facilitates SB recrossing and (2) fits well with the fractal anatomy of the left main bifurcation.

Biodegradable polymer material based smart stent: Wireless pressure sensor and 3D printed stent

In this paper, we present a 3D-printed biocompatible and biodegradable polymer stent with an integrated wireless pressure sensor, designed for advanced health monitoring applications. The Polycaprolactone (PCL) based polymer stent has a drug coating similar to conventional drug-eluting stents (DES) and a wireless pressure sensor that enables the real-time measurement of pressure inside the blood vessel. The wireless pressure sensor is made of poly(d-lactide) (PDLA), a biocompatible material that can be decomposed and absorbed together with the polymer stent in the body. The resonance frequency of the fabricated wireless pressure sensor (initially 148 MHz) decreases with blood pressure changes. Experimental results indicate that the sensitivity of the wireless pressure sensor (60 kHz/mmHg) shows a linear frequency shift within the pressure range of 0–220 mmHg.

Prospective, randomized trial of bioresorbable scaffolds vs. everolimus-eluting stents in patients undergoing coronary stenting for myocardial infarction: the Intracoronary Scaffold Assessment a Randomized evaluation of Absorb in Myocardial Infarction (ISAR-Absorb MI) trial.

Bioresorbable scaffolds (BRS) provide short-term coronary artery scaffolding and drug delivery. Although prior trials showed a higher rate of device failure compared with conventional drug-eluting stents (DES), only a single trial investigated patients undergoing percutaneous coronary intervention (PCI) for acute myocardial infarction (MI). We aimed to compare outcomes with BRS vs. DES in patients undergoing PCI for MI. We did a prospective, randomized, multicentre, non-inferiority, clinical trial of everolimus-eluting BRS vs. durable polymer everolimus-eluting stents (EES) in patients with acute MI. Patients were eligible for enrolment if they presented with ST-elevation MI, or non-ST-elevation MI with thrombosis visual at angiography and were randomly allocated to treatment with BRS or EES in 2:1 proportion. Angiographic follow-up was scheduled at 6-8 months and clinical follow-up was done at 12 months. The primary endpoint was percentage diameter stenosis in-segment at follow-up. A total of 262 patients were enrolled and were allocated to BRS (n = 173) or EES (n = 89). Angiographic follow-up was available for 213 (81.3%) patients. Mean diameter stenosis was 24.6 ± 12.2% with BRS vs. 27.3 ± 11.7% with EES (mean difference -2.7%, upper limit of one-sided 97.5% confidence limit 0.7%, pre-specified margin of non-inferiority 5%, Pnon-inferiority <0.001). The rate of the device-oriented composite of cardiac death/target vessel MI/target lesion revascularization [BRS: 12 (7.0%) vs. EES: 6 (6.7%), hazard ratio (HR) 1.04, 95% confidence interval (CI) 0.39-2.78] and definite/probable stent thrombosis [3 (1.7%) vs. 2 (2.3%), HR 0.76, 95% CI 0.13-4.56] were comparable in both groups. In patients undergoing PCI for acute MI BRS were non-inferior to EES for percentage diameter stenosis at angiographic follow-up. Rates of clinical events were comparable between the treatment groups, although the study was not powered to detect differences in clinical outcomes. The trial was registered at www.clinicaltrials.gov (NCT01942070).