Biodegradable polymer drug-eluting stents versus second-generation drug-eluting stents in patients with and without diabetes mellitus:a single center study

Objective It remains undetermined whether biodegradable polymer drug-eluting stents(BP-DES)are superior to second generation drugeluting stents(G2-DES)in patients with and without diabetes mellitus(DM).The study aims to evaluate the efficacy and safety of G2-DES and BP-DES in patients with and without DM in a high-volume cardiovascular center in China.

Prolonged dual antiplatelet therapy after drug-eluting stent implantation improves long-term prognosis for acute coronary syndrome:five-year results from a large cohort study

BACKGROUND:To investigate the most appropriate dual antiplatelet therapy(DAPT)duration for patients with acute coronary syndrome(ACS)after drug-eluting stent(DES)implantation in the largest cardiovascular center of China.METHODS:We enrolled 5,187 consecutive patients with ACS who received DES from January to December 2013.Patients were divided into four groups based on DAPT duration:standard DAPT group(11-13 months,n=1,568)and prolonged DAPT groups(13-18 months[n=308],18-24 months[n=2,125],and>24 months[n=1,186]).Baseline characteristics and 5-year clinical outcomes were recorded.RESULTS:Baseline characteristics were similar across the four groups.Among the four groups,those with prolonged DAPT(18-24 months)had the lowest incidence of major adverse cardiovascular and cerebrovascular events(MACCEs)(14.1%vs.11.7%vs.9.6%vs.24.2%,P<0.001),all-cause death(4.8%vs.3.9%vs.2.1%vs.2.6%,P<0.001),cardiac death(3.1%vs.2.6%vs.1.4%vs.1.9%,P=0.004),and myocardial infarction(MI)(3.8%vs.4.2%vs.2.5%vs.5.8%,P<0.001).The incidence of bleeding was not different among the four groups(9.9%vs.9.4%vs.11.0%vs.9.4%,P=0.449).Cox multivariable analysis showed that prolonged DAPT(18-24 months)was an independent protective factor for MACCEs(hazard ratio[HR]0.802,95%confidence interval[CI]0.729-0.882,P<0.001),all-cause death(HR 0.660,95%CI 0.547-0.795,P<0.001),cardiac death(HR 0.663,95%CI 0.526-0.835,P<0.001),MI(HR 0.796,95%CI 0.662-0.957,P=0.015),and target vessel revascularization(HR 0.867,95%CI 0.755-0.996,P=0.044).Subgroup analysis for high bleeding risk showed that prolonged DAPT remained an independent protective factor for all-cause death and MACCEs.CONCLUSION:For patients with ACS after DES,appropriately prolonging the DAPT duration may be associated with a reduced risk of adverse ischemic events without increasing the bleeding risk.

Understanding the corrosion of Mg alloys in in vitro urinary tract conditions: A step forward towards a biodegradable metallic ureteral stent

Ureteral stents play a fundamental role in modern time urology. However, following the deployment, stent-related symptoms are frequent and affect patient health and quality of life. Using biodegradable metals as ureteral stent materials have emerged as a promising strategy, mainly due to the improved radial force and slower degradation rate expected. Therefore, this study aimed to characterize different biodegradable metals in urinary tract environment to understand their propensity for future utilization as base materials for ureteral stents. The corrosion of 5 Mg alloys - AZ31, Mg-1Zn, Mg-1Y, pure Mg, and Mg-4Ag - under simulated urinary tract conditions was accessed. The corrosion layer of the different alloys presented common elements, such as Mg(OH)_(2), MgO, and phosphate-containing products, but slight variations in their chemical compositions were detected. The corrosion rate of the different metals varied, which was expected given the differences in the corrosion layers. On top of this, the findings of this study highlighted the significant differences in the samples' corrosion and corrosion layers when in stagnant and flowing conditions. With the results of this study, we concluded that Mg-1Zn and Mg-4Ag presented a higher propensity for localized corrosion, probably due to a less protective corrosion layer;Mg-4Ag corroded faster than all the other four alloys,and Mg-1Y stood out due to its distinct corrosion pattern, that showed to be more homogeneous than all the other four samples, making this one more attractive for the future studies on biodegradable metals.

Rational design, synthesis and prospect of biodegradable magnesium alloy vascular stents

Biodegradable magnesium(Mg) alloys are expected to be promising materials for cardiovascular stents(CVS), which can avoid the longterm clinical problems of current CVS, such as in-stent restenosis, late stent thrombosis, etc. Mg alloy stents exhibit superior biocompatibility and tunable biodegradability, compared with conventional permanent metallic stents. However, the poor formability and non-uniform corrosion of Mg alloy stents hinder their clinical application of CVS. This review focuses on the development of Mg alloys for CVS in recent years.According to the results of bibliometric analysis, we analyzed different biodegradable Mg alloy systems. Moreover, the structural design strategies for Mg alloy stents that can reduce the stress concentration, as well as the surface modification methods to control the corrosion behavior and biological performance of Mg alloy stents are also highlighted. At last, this review systematically discussed the potential directions and challenges of biodegradable magnesium stents(BMgS) in cardiovascular fields.

Real-world five-year outcomes of FlexyRap®cobalt-chromium rapamycin-eluting stents with biodegradable polymer in patients with de-novo coronary artery disease

BACKGROUND The use of biodegradable polymer drug-eluting stents(BP-DES)has been proven to minimize restenosis and stent thrombosis.The current post-marketing monitoring was observed at the 5-year clinical outcomes of individuals who had been treated with FlexyRap®DES in the real world.AIM To assess the safety and effectiveness of FlexyRap®DES at the 5-year follow-up in real-world settings.METHODS Findings from a retrospective,multi-center,observational,post-market clinical follow-up study of patients treated with FlexyRap®DES for de novo coronary artery disease(CAD)were reported.During the 12-mo follow-up,the primary endpoint was target lesion failure,which was defined as the composite of cardiovascular death, target vessel myocardial infarction(TV-MI), and clinically driven target lesion revascularization.RESULTS The data of 500 patients received with FlexyRap®DES was obtained at the completion of the surveillance timeline of 5-year.After the implantation of FlexyRap®DES,the device success rate was 100%.Adverse events that led to major bleeding,permanent disability,or death were not experienced in the patients.The major adverse cardiac event rate at 12-mo,3-year,and 5-year follow-up was 1(0.2%),0(0%),and 1(0.2%)respectively with 0(0%)cardiovascular death,2(0.4%)TV-MI,and 0(0%)TLR compositely.Furthermore,late stent thrombosis was found in 2(0.4%)patients at the follow-up of 12-mo,very late stent thrombosis was observed in 2 patients(0.4%)at 3-year follow-up.CONCLUSION FlexyRap®DES was proved to be safe and efficacious in real-world patients with de novo CAD,indicating a lowered rate of cardiac events and stent thrombosis at 5-year follow-up.

Meta-analysis of outcomes from drug-eluting stent implantation in infrapopliteal arteries

BACKGROUND Percutaneous drug-eluting stent implantation(DESI)is an emerging and promising treatment modality for infrapopliteal artery diseases(IPADs).This systematic review and meta-analysis summarizes and quantitatively analyzes the outcomes of DESI in IPADs considering the hazard ratio(HR),which is a more accurate and appropriate outcome measure than the more commonly used relative risk and odds ratio.AIM To explore the superiority of drug-eluting stents(DESs)vs traditional treatment modalities for IPADs.METHODS The following postoperative indicators were the outcomes of interest:All-cause death(ACD)-free survival,major amputation(MA)-free survival,target lesion revascularization(TLR)-free survival,adverse event(AE)-free survival,and primary patency(PP)survival.The outcome measures were then compared according to their respective HRs with 95%confidence intervals(CIs).The participants were human IPAD patients who underwent treatments for infrapopliteal lesions.DESI was set as the intervention arm,and traditional percutaneous transluminal angioplasty(PTA)with or without bare metal stent implantation(BMSI)was set as the control arm.A systematic search in the Excerpta Medica Database(Embase),PubMed,Web of Science,and Cochrane Library was performed on November 29,2022.All controlled studies published in English with sufficient data on outcomes of interest for extraction or conversion were included.When studies did not directly report the HRs but gave a corresponding survival curve,we utilized Engauge Digitizer software and standard formulas to convert the information and derive HRs.Then,meta-analyses were conducted using a random-effects model.RESULTS Five randomized controlled trials and three cohort studies involving 2639 participants were included.The ACDfree and MA-free survival HR values for DESI were not statistically significant from those of the control treatment(P>0.05);however,the HR values for TLR-free,AE-free,and PP-survival differed significantly[2.65(95%CI:1.56-4.50),1.57(95%CI:1.23-2.01),and 5.67(95%CI:3.56-9.03),respectively].CONCLUSION Compared with traditional treatment modalities(i.e.,PTA with or without BMSI),DESI for IPADs is superior in avoiding TLR and AEs and maintaining PP but shows no superiority or inferiority in avoiding ACD and MA.

Biodegradable stents in gastrointestinal endoscopy

Biodegradable stents(BDSs)are an attractive option to avoid ongoing dilation or surgery in patients with benign stenoses of the small and large intestines.The experience with the currently the only BDS for endoscopic placement,made of Poly-dioxanone,have shown promising results.However some aspects should be improved as are the fact that BDSs lose their radial force over time due to the degradable material,and that can cause stent-induced mucosal or parenchymal injury.This complication rate and modest clinical efficacy has to be carefully considered in individual patients prior to placement of BDSs.Otherwise,the price of these stents therefore it is nowadays an important limitation.

Advantages and disadvantages of biodegradable platforms in drug eluting stents

Coronary angioplasty with drug-eluting stent(DES)implantation is currently the most common stent procedure worldwide.Since the introduction of DES,coronary restenosis as well as the incidence of target vessel and target lesion revascularization have been significantly reduced.However,the incidence of very late stent thrombosis beyond the first year after stent deployment has more commonly been linked to DES than to baremetal stent(BMS)implantation.Several factors have been associated with very late stent thrombosis after DES implantation,such as delayed healing,inflammation,stent mal-apposition and endothelial dysfunction. Some of these adverse events were associated with the presence of durable polymers,which were essential to allow the elution of the immunosuppressive drug in the first DES designs.The introduction of erodable polymers in DES technology has provided the potential to complete the degradation of the polymer simultaneously or immediately after the release of the immunosuppressive drug,after which a BMS remains in place.Several DES designs with biodegradable(BIO)polymers have been introduced in preclinical and clinical studies, including randomized trials.In this review,we analyze the clinical results from 6 observational and randomized studies with BIO polymers and discuss advantages and disadvantages of this new technology.

Silicone-covered biodegradable magnesium stent for treating benign esophageal stricture in a rabbit model

BACKGROUND Stent insertion can effective alleviate the symptoms of benign esophageal strictures(BES).Magnesium alloy stents are a good candidate because of biological safety,but show a poor corrosion resistance and a quick loss of mechanical support in vivo.AIM To test the therapeutic and adverse effects of a silicone-covered magnesium alloy biodegradable esophageal stent.METHODS Fifteen rabbits underwent silicone-covered biodegradable magnesium stent insertion into the benign esophageal stricture under fluoroscopic guidance(stent group).The wall reconstruction and tissue reaction of stenotic esophagus in the stent group were compared with those of six esophageal stricture models(control group).Esophagography was performed at 1,2,and 3 weeks.Four,six,and five rabbits in the stent group and two rabbits in the control groups were euthanized,respectively,at each time point for histological examination.RESULTS All stent insertions were well tolerated.The esophageal diameters at immediately,1,2 and 3 wk were 9.8±0.3 mm,9.7±0.7 mm,9.4±0.8 mm,and 9.2±0.5 mm,respectively(vs 4.9±0.3 mm before stent insertion;P<0.05).Magnesium stents migrated in eight rabbits[one at 1 wk(1/15),three at 2 wk(3/11),and four at 3 wk(4/5)].Esophageal wall remodeling(thinner epithelial and smooth muscle layers)was found significantly thinner in the stent group than in the control group(P<0.05).Esophageal injury and collagen deposition following stent insertion were similar and did not differ compared to rabbits with esophageal stricture and normal rabbits(P>0.05).CONCLUSION Esophageal silicone-covered biodegradable magnesium stent insertion is feasible for BES without causing severe injury or tissue reaction.Our study suggests that insertion of silicone-covered magnesium esophageal stent is a promising approach for treating BES.

Drug-eluting fully covered self-expanding metal stent for dissolution of bile duct stones in vitro

BACKGROUND The treatment of difficult common bile duct stones(CBDS)remains a big challenge around the world.Biliary stenting is a widely accepted rescue method in patients with failed stone extraction under endoscopic retrograde cholangiopancreatography.Fully covered self-expanding metal stent(FCSEMS)has gained increasing attention in the management of difficult CBDS.AIM To manufacture a drug-eluting FCSEMS,which can achieve controlled release of stone-dissolving agents and speed up the dissolution of CBDS.METHODS Customized covered nitinol stents were adopted.Sodium cholate(SC)and disodium ethylene diamine tetraacetic acid(EDTA disodium,EDTA for short)were used as stone-dissolving agents.Three different types of drug-eluting stents were manufactured by dip coating(Stent I),coaxial electrospinning(Stent II),and dip coating combined with electrospinning(Stent III),respectively.The drugrelease behavior and stone-dissolving efficacy of these stents were evaluated in vitro to sort out the best manufacturing method.And the selected stonedissolving stents were further put into porcine CBD to evaluate their biosecurity.RESULTS Stent I and Stent II had obvious burst release of drugs in the first 5 d while Stent III presented controlled and sustainable drug release for 30 d.In still buffer,the final stone mass-loss rate of each group was 5.19%±0.69%for naked FCSEMS,20.37%±2.13%for Stent I,24.57%±1.45%for Stent II,and 33.72%±0.67%for Stent III.In flowing bile,the final stone mass-loss rate of each group was 5.87%±0.25%for naked FCSEMS,6.36%±0.48%for Stent I,6.38%±0.37%for Stent II,and 8.15%±0.27%for Stent III.Stent III caused the most stone mass-loss no matter in still buffer or in flowing bile,which was significantly higher than those of other groups(P<0.05).In vivo,Stent III made no difference from naked FCSEMS in serological analysis(P>0.05)and histopathological examination(P>0.05).CONCLUSION The novel SC and EDTA-eluting FCSEMS is efficient in diminishing CBDS in vitro.When conventional endoscopic techniques fail to remove difficult CBDS,SC and EDTA-eluting FCSEMS implantation may be considered a promising alternative.

Effect of nonionic surfactants in release media on accelerated in-vitro release profile of sirolimus eluting stents with biodegradable polymeric coating

It is a well-known fact that sirolimus(SRL) undergoes degradation process via hydrolysis in aqueous media, leading to incorrect assessment of drug amount and thus release characteristics of formulations.The main objective of the present study was to evaluate the effect of nonionic surfactants in media on invitro release profiles for sirolimus eluting stents(SES) coated with biodegradable polymeric matrix.Phosphate buffer and acetate buffer incorporating nonionic surfactants with varying concentrations were examined for adequate solubility and stability(by RP-HPLC). Good sink condition was achieved in phosphate buffer(at pH 4.0) with 1.0% Tween 20, 1.0% Brij 35% and 0.5% Brij 58. Hydrodynamic size(by DLS) and the micelle-water partition coefficient(P) with standard free energy of solubilization(ΔGs°) of drug were evaluated to get some understanding about the solubilization phenomena. About 80% of drug release during the period of 48 h was achieved in optimized drug release media which was 1.0% Tween20 in phosphate buffer pH 4.0. The obtained accelerated SRL release profile in optimized medium correlated well with the real time in-vitro release in phosphate buffer(pH 7.4). Surface morphology changes(by SEM), changes in gravimetric weights and molecular weight change(by GPC) were examined before and after drug release to understand the drug release mechanism which explains that the polymer did not undergo degradation during the drug release.

Effect of Media on the in vitro Degradation of Biodegradable Ureteral Stent

The biodegradable ureteral stent should retain their supporting properties for defined period and then gradually degrade to small particles with the flow of urine. The mechanism and process of the stent's degradation should be investigated and understood well due to its direct impact on the stents' usage. An enhanced braidbased degradable ureteral stent composed of poly-glycolic acid(PGA) and the copolymer of lactic and glycolic acid(PGLA) was evaluated in vitro in this study with four kinds of degradable media:human urine(HU,pH = 7. 4),artificial urine(AU,pH = 5. 8),and phosphate buffer solutions( PBS,pH = 5. 8 and 7. 4) so as to compare the effects of media on the degradation of stents. The mechanical properties and morphology were observed at different degradaing time intervals of 0,7,14,21,28,and 35 d. The in vitro degradation behaviors of stents in four kinds of media were extremely different. The degradation rate of stents in HU was the highest. The impact of media's pH to the degradation is not obvious while the components in the media contribute much to the difference.

Ureteral stent technology:Drug-eluting stents and stent coatings

Ureteral stents are commonly used following urological procedures to maintain ureteral patency.However,alongside the benefits of the device,indwelling stents frequently cause significant patient discomfort(pain,urgency,frequency)and can become encrusted and infected.The importance of these sequelae is that they are not only bothersome to the patient but can lead to significant morbidity,urinary retention,ureteral damage,recurrent infections,pyelonephritis and sepsis.When these problems occur,stent removal or replacement alongside antibiotic,analgesic and/or other symptom-modifying therapies are essential to successfully treat the patient.In an attempt to prevent such morbidity,numerous approaches have been investigated over the past several decades to modify the stent itself,thereby affecting changes locally within the urinary tract without significant systemic therapy.These strategies include changes to device design,polymeric composition,drug-elution and surface coatings.Of these,drug-elution and surface coatings are the most studied and display the most promise for advancing ureteral stent use and efficacy.This article reviews these two strategies in detail to determine their clinical potential and guide future research in the area.

Drug-eluting balloons versus new generation drug-eluting stents for the management of in-stent restenosis: an updated meta-analysis of randomized studies

Background New-generation drug-eluting stents (DES) was more effective in the treatment of in-stent restenosis (ISR) compared with the first-generation DES. Drug-eluting balloons (DEB) and new-generation DES had been available strategies in treatment of bare-metal stents/DES ISR (BMS/DES-ISR). Six new randomized trials have recently examined the angiographic outcomes and one-year clinical outcomes of DEB and new generation DES in BMS/DES-ISR. However, the optimal management for BMS/DES-ISR lesions remains controversial. Methods We searched the randomized clinical trials evaluating the angiographic outcomes and one-year clinical outcomes of DEB and new-generation DES in patients with BMS/DES-ISR. The primary endpoints were the angiographic outcomes, including the minimal luminal diameter (MLD), diameter stenosis %(DS%), late lumen loss (LLL), and binary restenosis (BR). Results A total of six randomized clinical trials with 1177 BMS/DES-ISR patients were included in our meta-analysis. For angiographic outcomes, there were significantly less MLD and more DS% with DEB compared to new-generation DES (MLD: MD =?0.18, 95% CI:?0.31– ?0.04, P < 0.001;DS%: MD = 5.68, 95% CI: 1.00–10.37, P < 0.001). Moreover, for one-year clinical outcomes, DEB was associated with a significant increase risk in target lesion revascularization (TLR)(RR = 2.93, 95% CI: 1.50–5.72, P = 0.002). However, DEB was associated with higher risks of major adverse cardiac event, target vessel revascularization, TLR, BR, and more DS% only in DES-ISR group. Conclusions DEB and new-generation DES have the similar clinical efficacy for the treatment of BMS-ISR. However, DES showed more MLD, less DS%, and a decreased risk of TLR for the treatment of DES-ISR.

Six-month results of a biodegradable polymer and rapamycin-coating stent for coronary artery disease

Objective To assess the safety and efficacy of a novel biodegradable polymer and rapamycin-coating stent, the EXCEL stent, in the treatment of coronary artery disease (CAD), as compared with the CypherTM stent. Methods In this prospective, non-randomized study, 60 consecutive patients with symptomatic CAD received either an EXCEL stent (n=32), or a CypherTM stent(n=28),according to their respective treatment intention. Follow-up angiography was performed at a mean of 180±40 days. The primary endpoint of the study was the occurrence of a major adverse cardiac event (MACE), including death, myocardial infarction, or target-vessel revascularization during the 6 months after stenting. The secondary end points included the in-stent late luminal loss (LLL), percentage of in-stent stenosis of the luminal diameter, and the rate of restenosis (luminal narrowing of 50 percent or more) at 6 months. Results There were no significant differences between the two groups in baseline characteristics, including the distribution of target vessel and lesion types. During the follow up period of 6 months, there were no occurrences of MACE in either group. Twenty-seven patients(84%) in the EXCEL group and 10 (36 %) in the CypherTM group underwent quantitative coronary angiography at 6 months. For these patients, no restenosis occurred, and there were no differences in the in-stent stenosis of the luminal diameter (5.98±5.52% vs 5.21 ±6.3%,P＞0.05) and the LLL (-0.02±0.09 mm vs -0.01±0.07 mm, P＞0.05). Conclusions Compared with the CypherTM stent, the EXCEL Stent with biodegradable polymer and rapamycin-coating showed similar efficacy in the prevention of neointimal proliferation, restenosis, and associated clinical events in CAD patients.

Biodegradable stent or balloon dilatation for benign oesophageal stricture: Pilot randomised controlled trial

AIM:To undertake a randomised pilot study comparing biodegradable stents and endoscopic dilatation in patients with strictures.METHODS:This British multi-site study recruitedseventeen symptomatic adult patients with refractory strictures.Patients were randomisedus in gamulticentre,blinded assessor design,comparing a biodegradable stent(BS)with endoscopic dilatation(ED).The primary endpoint was the average dysphagia score during the first 6 mo.Secondary endpoints included repeat endoscopic procedures,quality of life,and adverse events.Secondary analysis included follow-up to 12 mo.Sensitivity analyses explored alternative estimation methods for dysphagia and multiple imputation of missing values.Nonparametric tests were used.RESULTS:Although both groups improved,the average dysphagia scores for patients receiving stents were higher after 6 mo:BS-ED 1.17(95%CI:0.63-1.78)P=0.029.The finding was robust under different estimation methods.Use of additional endoscopic procedures and quality of life(QALY)estimates were similar for BS and ED patients at 6 and12 mo.Concomitant use of gastrointestinal prescribed medication was greater in the stent group(BS 5.1,ED 2.0 prescriptions;P<0.001),as were related adverse events(BS 1.4,ED 0.0 events;P=0.024).Groups were comparable at baseline and findings were statistically significant but numbers were small due to under-recruitment.The oesophageal tract has somatic sensitivity and the process of the stent dissolving,possibly unevenly,might promote discomfort or reflux.CONCLUSION:Stenting was associated with greater dysphgia,co-medication and adverse events.Rigorously conducted and adequately powered trials are needed before widespread adoption of this technology.

Domestic versus imported drug-eluting stents for the treatment of patients with acute coronary syndrome

BACKGROUND:The application of coronary stents,especially drug-eluting stents(DESs),has made percutaneous coronary intervention(PCI) one of important therapeutic methods for CHD. DES has reduced the in-stent restenosis to 5%–9% and signifi cantly improved the long-term prognosis of patients with CHD. The study aimed to investigate the long-term eff icacy and safety of domestic drugeluting stents(DESs) in patients with acute coronary syndrome(ACS).METHODS:All patients with ACS who had undergone successful percutaneous coronary intervention(PCI) in the First Aff iliated Hospital of Zhengzhou University from July 2009 to December 2010 were included in this study. Patients were excluded from the study if they were implanted with bare metal stents or different stents(domestic and imported DESs) simultaneously. The included patients were divided into two groups according to different stents implanted:domestic DESs and imported DESs.RESULTS:In the 1 683 patients of this study,1 558(92.6%) patients were followed up successfully for an average of(29.1±5.9) months. 130(8.3%) patients had major adverse cardiovascular events(MACEs),including cardiac death in 32(2.1%) patients,recurrent myocardial infarction in 16(1%),and revascularization in 94(6%). The rates of cardiac death,recurrent myocardial infarction,revascularization,in-stent restenosis,stent thrombosis and other MACEs were not signif icantly different between the two groups(all P>0.05). Multivarite logistic regression revealed that diabetes mellitus(OR=1.75,95%CI:1.09–2.82,P=0.021),vascular numbers of PCI(OR=2.16,95%CI:1.22–3.83,P=0.09) and PCI with left main lesion(OR=9.47,95%CI:2.96–30.26,P=0.01) were independent prognostic factors of MACEs. The Kaplan-Meier method revealed that there was no significant difference in cumulative survival rates and survival rates free from clinical events between the two groups(all P>0.05).CONCLUSIONS:The incidences of clinical events and cumulative survival rates are not statistically different between domestic DESs and imported DESs. Domestic DES is effective and safe in the treatment of patients with ACS.

Five-year clinical outcomes of first-generation versus second-generation drug-eluting stents following coronary chronic total occlusion intervention

Background There are limited data comparing long-term clinical outcomes between first-generation (1G) and second-generation (2G) drug-eluting stents (DESs) in patients who underwent successful percutaneous coronary intervention (PCI) for coronary chronic total occlusion (CTO) lesion. Methods A total of 840 consecutive patients who underwent PCI with DESs for CTO lesion from January 2004 to November 2015 were enrolled. Finally, a total of 324 eligible CTO patients received 1G-DES (Paclitaxel-eluting stent or Sirolimus-eluting stent, n = 157) or 2G-DES (Zotarolimus-eluting stent or Everolimus-eluting stent, n = 167) were enrolled. The clinical endpoint was the occurrence of major adverse cardiac events (MACE) defined as all-cause death, recurrent myocardial infarction (re-MI), total repeat revascularization [target lesion revascularization (TLR), target vessel revascularization (TVR), and non-TVR]. We investigated the 5-year major clinical outcomes between 1G-DES and 2G-DES in patient who underwent successful CTO PCI. Results After propensity score matched (PSM) analysis, two well-balanced groups (111 pairs, n = 222, C-statistic = 0.718) were generated. Up to the 5-year follow-up period, the cumulative incidence of all-cause death, re-MI, TLR, TVR and non-TVR were not significantly different between the two groups. Finally, MACE was also similar between the two groups (HR = 1.557, 95% CI: 0.820–2.959, P = 0.176) after PSM. Conclusions In this study, 2G-DES was not associated with reduced long-term MACE compared with 1G-DES following successful CTO revascularization up to five years.

Structural Design and Numerical Analysis of a Novel Biodegradable Zinc Alloy Stent

Biodegradable zinc alloy stents are a prospective solution for complications caused by the incompatibility between artery and permanent stents.However,insufficient scaffolding has limited the clinical application of biodegradable zinc alloy stents.Therefore,in this study,a new stent concept was designed to improve the scaffolding.The mechanical performances of the new and a traditional design stent were investigated and compared using finite element analysis(FEA).The new and traditional design stent were expanded to the intended radial displacement of 0.24 mm under the expansion pressure of 0.58 MPa and 0.45 MPa,respectively.Then,a pressure load of 0.35 MPa was exerted on the outer surfaces of the two stents to compress them.The results showed that the radial recoiling ratio were 45.3%and 83.3%for the new and the traditional stent,respectively.The simulations demonstrate that the biodegradable zinc alloy stent offers enhanced support because of the new structural design.This study implies that biodegradable zinc alloy stent can be a new competitive intervention device for the future clinical cardiovascular application.

Duration of dual antiplatelet treatment in the era of next generation drug-eluting stents

Current percutaneous coronary intervention guidelines recommend dual antiplatelets(aspirin 100 mg + clopidogrel 75 mg daily) for at least 12 mo following drugeluting stent(DES) implantation if patients are not at high risk of bleeding.Several reports have tried to shorten the dual antiplatelet therapy to 3-6 mo,especially following next-generation DES implantation,for cost-effectiveness.However,the clinical results are inconsistent and the data regarding next-generation DESs limited.In this report,recently published important pivotal reports regarding the optimal duration of dual antiplatelets following DES implantation are summarized.