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Background Over the last decade, drug-eluting stents (DES) have undergone substantial modifications with thinner struts and more biocompatible durable polymer (DP) or biodegradable polymer (BP). In DP-based DES, after drug elusion has been completed, DP remnants may trigger of local inflammatory vascular reactions and promote delayed healing, leading to accelerated neoatherosclerosis (NA). Thus, BPs have been developed to reduce the above-mentioned risks. Recently, poor strut coverage and in-stent NA are increasingly recognized the cause of late stent failure, but it is unclear whether BPs can reduce the incidence of NA and the poor stent coverage as compared to DPs. Objectives The purpose of this study was to compare the incidence of NA and the stent coverage using optical coherence tomography (OCT) between the DPs and the BPs. Methods Between July 2016 and April 2018, 127 consecutive patients with new-generation DES who underwent 8-month follow up OCT imaging were enrolled. Patients were divided into the two groups: DP group who had the new-generation durable polymer everolimus-eluting and zotarolimus-eluting stents and BP group who had the new-generation biodegradable polymer sirolimus-eluting and everolimus-eluting stents. We compared patient characteristics including hypertension, dyslipidemia and diabetes mellitus and 8-month follow up OCT findings including NA, uncovered struts and malapposed struts between the two groups. Results The DP group comprised 64 patients (50.4%. The incidence of NA, uncovered struts and malapposed struts were similar between the two groups (DPs vs BPs, 1.56% vs 7.94%, P=0.11; 7.80% vs 5.88%, P=0.16 and 2.76% vs 2.01%, P=0.43, respectively) (table). The other parameters were also similar between the two groups. Table 1 DP group (n=64) BP group (n=63) P value Hypertension 44 (68.8%) 50 (79.4%) 0.2251 Dyslipidemia 39 (60.9%) 37 (58.7%) 0.8573 Diabetes mellitus 25 (39.1%) 30 (47.6%) 0.3731 8 month OCT follow up findings Neoatherosclerosis 1 (1.6%) 5 (7.9%) 0.1147 Uncovered struts 7.8% (2.8–20.4) 5.9% (0.7–16.7) 0.1616 Malapposed struts 0.2% (0–2.8) 0% (0–2.8) 0.4392 Conclusions The new-generation DP based-DES may have similar effects on vascular response compared to the new-generation BP-based DES during 8-month follow-up period.

Background and introduction Diabetic patients are at high risk of adverse cardiovascular events after percutaneous coronary intervention (PCI) even with durable polymer drug-eluting stents. A biodegradable polymer everolimus-eluting stents (BP-EES) might improve clinical outcomes in patients with diabetes mellitus. Purpose This study aimed to compare the mid-term clinical outcomes between BP-EES and durable polymer everolimus-eluting stents (DP-EES) in diabetic patients. Methods We investigated consecutive 383 patients treated with BP-EES or DP-EES at our Heart Center between January and December 2016. Among these patients, 155 (40.5%) patients had diabetes mellitus. The primary endpoint was 3-year cumulative incidence of target lesion failure (TLF) defined as target vessel-related myocardial infarction (MI) and clinical-driven target lesion revascularization (TLR). Moreover, the incidence of definite stent thrombosis (ST) was also evaluated. Results After propensity score matching, 148 patients were divided into 2 groups (BP-EES; N=74, DP-EES; N=74). The 3-year cumulative incidences of TLF were significantly lower in BP-EES group than in DP-EES group (BP-EES vs. DP-EES; 1.4% vs. 11.4%, p=0.01). The incidence of cardiac death, target vessel-related MI, and definite ST were none in the both group. Figure 1 Conclusions In diabetic patients, the incidence of TLR within 3 years was significantly lower in BP-EES than in DP-EES. In PCI for diabetic patients, BP-EES might improve clinical outcomes compared to DP-EES.

Background The true benefit of biodegradable polymer drug-eluting stent (BP-DES) over second-generation durable polymer drug-eluting stent (DP-DES) expected to be represented during late period of follow-up after percutaneous coronary intervention (PCI), but prior meta-analysis only evaluated short-term outcomes. Purpose We aimed to compare the long-term clinical outcomes after PCI with BP-DES versus second-generation DP-DES by a meta-analysis of randomized controlled trials. Methods Randomized controlled trials comparing BP-DES with second-generation DP-DES implantations were searched through PubMed, MEDLINE, EMBASE, and Cochrane databases. All-cause death, cardiac death, myocardial infarction (MI), target vessel revascularization (TVR), target lesion revascularization (TLR), and definite/probable stent thrombosis (ST) were compared between the groups. In addition, a landmark analysis with the landmark set at 1-year and a subgroup analysis based on stent characteristics were performed. Results Fifteen trials that included a total of 21311 randomized patients with at least 2 years follow-up were analyzed. At a median follow-up of 4.2 years, no significant differences in the risks of all-cause death (odds ratio [OR] 1.03, 95% confidence interval [CI] 0.94–1.14), cardiac death (OR 1.03, 95% CI 0.88–1.20), MI (OR 0.90, 95% CI 0.79–1.01), TVR (OR 0.96, 95% CI 0.82–1.12), TLR (OR 0.97, 95% CI 0.85–1.11), and definite/probable ST (OR 0.84, 95% CI 0.67–1.05) were found between the groups. In the 1-year landmark analysis, the rates of all-cause death (OR 1.04, 95% CI 0.93–1.17), cardiac death (OR 1.11, 95% CI 0.92–1.36), MI (OR 0.94, 95% CI 0.79–1.13), TVR (OR 0.95, 95% CI 0.73–1.23), TLR (OR 1.00, 95% CI 0.80–1.24), and definite/probable ST (OR 0.94, 95% CI 0.67–1.31) were similar between the groups. There were comparable rates of any study endpoints between the groups regardless of stent platform (stainless steel vs. alloy), the polymer degradation period (6 months) or the drug release duration (6 months) of BP-DES, or the DAPT duration (≥6 months vs. ≥12 months). However, the use of BP-DES with sirolimus eluting (OR 0.82, 95% CI 0.70–0.97), circumferential drug distribution (OR 0.79, 95% CI 0.65–0.96), thin strut (defined as Clinical outcomes Conclusions In this meta-analysis, long-term clinical outcomes were equivalent between BP-DES and second-generation DP-DES implantations. However, among BP-DESs, the improved risks of MI in those with sirolimus eluting, circumferential drug distribution, thin strut, or ultrathin strut and decreased rates of TVR in those with circumferential drug distribution were noted.

Background Biodegradable polymer drug-eluting stent (BP-DES) has been developed to improve clinical outcomes after percutaneous coronary intervention (PCI) for patients presenting coronary artery disease (CAD). Although BP-DES showed non-inferior safety and efficacy to durable polymer DES (DP-DES) in several randomized clinical trials, hemodialysis (HD) patients, who have been well known as high risk population for adverse events, were excluded in the most of trials. Therefore, there are limited data comparing the clinical outcomes between BP-DES and DP-DES in HD patients with CAD after PCI. Purpose The purpose of this study was to investigate clinical outcomes in HD patients after BP-DES implantation compared with those after DP-DES implantation. Methods We retrospectively analyzed 234 HD patients (male 74%, mean age 71±10 years) undergoing PCI for 404 lesions with 472 DESs (71 patients for 138 lesions with 170 BP-DESs [91 Ultimaster and 79 Synergy] and 163 HD patients for 266 lesions with 302 DP-DESs [219 Xience, 53 Promus and 30 Resolute]) from 2011 to 2017. Two-year clinical outcomes were compared between BP-DES group and DP-DES group. The primary outcome measure was the incidence of target lesion revascularization (TLR), while the secondary outcome measures were the occurrence of cardiac death (CD), stent thrombosis (ST), myocardial infraction (MI), target vessel revascularization (TVR), non-TVR and major adverse cardiac event (MACE) defined as a composite of CD, MI, and TVR. Outcome measures were estimated by the Kaplan-Meier method and the differences between BP-DES group and DP-DES group were assessed by the log-rank test. We also conducted Cox's proportional hazard model to identify predictors for TLR occurrence. Results Baseline patient and lesion characteristics were similar between the two groups. The two-year incidence of TLR was not significantly different between BP-DES group and DP-DES group (14.1% vs. 22.2%, p=0.391). The two-year incidences of CD (17.3% vs. 17.5%, p=0.381), ST (0% vs. 3.9%, p=0.133), MI (4.2% vs. 5.8%, p=0.965), TVR (21.3% vs. 27.5%, p=0.586), non-TVR (26.1% vs. 31.3%, p=0.439) and MACE (41.1% vs. 42.6%, p=0.526) were also not different between the two groups. After multivariate analysis, diabetes mellitus (hazard ratio 1.97; 95% confidence interval 1.03–3.78, p=0.004) was independently associated with TLR occurrence in HD patients. Two-year clinical outcomes of HD patient Conclusions At two-year follow-up after PCI, BP-DES had comparable safety and efficacy profiles to DP-DES in HD patients presenting CAD. Acknowledgement/Funding None

Aiming to solve the contradiction between the workability and performance of pothole patching using cold mixtures, this paper proposed new patching materials based on the microcapsule technique and polymer reinforcement, namely cold mixtures with polymer modified asphalt and dense graded (DG) of aggregates (PADG) mixtures. Laboratory tests were conducted to compare the PADG mixtures with commonly used DG mixtures and open graded (OG) mixtures concerning workability, storability, cohesion, stability, and durability of each mixture. The results found that the PADG mixtures were satisfactory in their workability and storability and were as satisfactory as the OG mixtures. Meanwhile, stability and durability of the PADG mixtures was better than the DG mixtures and OG mixtures, i.e., the PADG mixtures showed stability in the conditions of the timeliness, low temperature, and immersion, as well as the freeze-thaw resistance and wear resistance in wet conditions. Therefore, it can be concluded that PADG mixtures are applicable in timely and durable pothole repairs in low temperatures and wet conditions.

Advances in coronary stent technology have revolutionised the treatment of coronary artery disease (CAD) in current clinical practice. Novel stent platforms, such as biodegradable polymer drug-eluting stents (BP-DES) and polymer-free drug-eluting stents (PF-DES), have been developed in recent years to improve on patient outcomes of preceding generations of devices. These new-generation drug-eluting stents (DES) utilise a biocompatible or bioresorbable polymer coating to theoretically eliminate the risk of very late stent thrombosis (ST) associated with the current gold standard durable polymer drug-eluting stents (DP-DES). The permanent polymer coating of DP-DES has been shown to induce a chronic inflammatory response in the vessel wall leading to ST. The performance of new-generation DES compared with DP-DES has not been well appraised in the literature. To summarise the latest clinical evidence, the present thesis included meta-analyses of randomised controlled trials (RCTs) comparing the safety and efficacy profiles of new-generation DES, namely BP-DES and PF-DES, with DP-DES. Subgroup analyses based on anti-proliferative drug, duration of dual antiplatelet therapy (DAPT), and length of follow-up were performed to ascertain if these variables might affect patient outcomes. Landmark analyses were also performed to evaluate late outcomes beyond 1 year. The overall rationale for the present thesis was to provide both qualitative and quantitative assessments of the clinical outcomes of new-generation DES to better inform the ongoing development of clinical practice guidelines for the use of coronary stents in patients with CAD. In summary, new-generation DES and DP-DES conferred equivocal safety and efficacy profiles, with comparable risks of definite or probable ST, myocardial infarction (MI), cardiac death, all-cause death, target lesion revascularisation (TLR), and target vessel revascularisation (TVR). The theoretical advantages of BP-DES and PF-DES over DP-DES were not realised in the meta-analyses. Further RCTs with greater length of follow-up and larger patient population are warranted to determine the purported benefits of these novel stent platforms.

Aims Despite similar efficacy and safety profile in pilot studies, bioresorbable polymer drug-eluting stents (BP-DES) could have potential benefit over latest generation durable polymer (DP)-DES by facilitating vessel healing, therefore reducing inflammation and neoatherosclerosis leading to enhanced clinical safety. Therefore, we sought to perform a meta-analysis of randomized clinical trials (RCTs) comparing the safety and efficacy of everolimus-eluting BP-DES (BP-EES) to second-generation DP-DES. Methods and results We conducted a systematic review and meta-analysis to examine the safety and efficacy of BP-EES in patients treated for coronary artery disease. We searched PubMed, Scopus, and the Cochrane Library through February 2018 for RCTs that included outcome data on BP-EES. We identified four eligible studies, which included a total of 4631 patients. Three studies reported a follow-up of one year and one study of five years. The BP-EES group, included 2315 patients and the DP-DES group included 2316 patients (1143 treated with DP-EES and 1173 treated with zotarolimus eluting DP-DES). Patient's characteristics were comparable between the two groups except for higher prevalence of prior MI in the DP-DES group (25.7 vs 22.5%, respectively, p = 0.001). Procedural characteristics were comparable among groups except for slightly longer lesions in the BP-EES group compared to the DP-DES group (mean 15.1 vs 14.9 mm, p = 0.04). No significant differences were observed for cardiac mortality (p = 0.72), occurrence of MI (p = 0.64), any TLR (p = 0.93), ST (p = 0.85) or major adverse cardiac events (p = 0.43). Conclusion Overall, based on the available data BP-EES had similar one-year outcomes to contemporary DP-DES. Whether these devices could enhance clinical safety remains to be evaluated at longer follow-up.

Background The choice of optimal drug‐eluting stent therapy for patients with diabetes mellitus ( DM ) undergoing percutaneous coronary intervention remains uncertain. We aimed to assess the long‐term clinical outcomes after percutaneous coronary intervention with biodegradable polymer sirolimus‐eluting stents ( BP ‐ SES ) versus durable polymer everolimus‐eluting stents ( DP ‐ EES ) in patients with DM . Methods and Results In a prespecified subgroup analysis of the BIOSCIENCE (Ultrathin Strut Biodegradable Polymer Sirolimus‐Eluting Stent Versus Durable Polymer Everolimus‐Eluting Stent for Percutaneous Coronary Revascularization) trial ( NCT 01443104), patients randomly assigned to ultrathin‐strut BP ‐ SES or thin‐strut DP ‐ EES were stratified according to diabetic status. The primary end point was target lesion failure, a composite of cardiac death, target vessel myocardial infarction, and clinically indicated target lesion revascularization, at 5 years. Among 2119 patients, 486 (22.9%) presented with DM . Compared with individuals without DM, patients with DM were older and had a greater baseline cardiac risk profile. In patients with DM, target lesion failure at 5 years occurred in 74 patients (cumulative incidence, 31.0%) treated with BP ‐ SES and 57 patients (25.8%) treated with DP ‐ EES (risk ratio, 1.23; 95% CI , 0.87–1.73 [ P =0.24]). In individuals without DM, target lesion failure at 5 years occurred in 124 patients (16.8%) treated with BP ‐ SES and 132 patients (16.8%) treated with DP ‐ EES (risk ratio, 0.98; 95% CI, 0.77–1.26 [ P =0.90; P for interaction=0.31]). Cumulative 5‐year incidence rates of cardiac death, target vessel myocardial infarction, clinically indicated target lesion revascularization, and definite stent thrombosis were similar among patients with DM treated with BP ‐ SES or DP ‐ EES . There was no interaction between diabetic status and treatment effect of BP ‐ SES versus DP ‐ EES . Conclusions In a prespecified subgroup analysis of the BIOSCIENCE trial, we found no difference in clinical outcomes throughout 5 years between patients with DM treated with ultrathin‐strut BP ‐ SES or thin‐strut DP ‐ EES . Clinical Trial Registration URL : https://www.clinicaltrials.gov/ . Unique identifier: NCT 01443104.

Background Despite improved long-term safety of biodegradable polymer (BP) drug-eluting stents (DES) compared to first-generation durable polymer (DP) DES, data on the safety and efficacy of BP-DES compared with second-generation (2G) DP-DES in patients with acute myocardial infarction (AMI) are limited. Hypothesis To evaluate the safety and efficacy of BP-DES compared with 2G-DP-DES in the higher stent thrombosis (ST) risk setting of AMI. Methods A total of 3359 AMI patients who received either BP-DES (n = 261) or 2G-DP-DES (n = 3098) were included from the Korea Acute Myocardial Infarction Registry (KAMIR). Differences in baseline clinical and angiographic characteristics were adjusted using a 1:5 propensity score matching analysis (n = 261 for BP-DES and n = 1305 for 2G-DP-DES). The primary outcome was the incidence of major adverse cardiac events (MACE) including all-cause death, recurrent myocardial infarction (re-MI), and target vessel revascularization (TVR). The rate of definite or probable ST was also investigated. Results In adjusted analysis, there was no significant difference between the 2 groups in baseline clinical and angiographic characteristics; 2-year MACE (10.7% and 9.9% in the BP-DES group and 2G-DP-DES group, respectively, P = 0.679); ST incidence (0.8% vs 0.9%, respectively, P = 1.0), and rates of all-cause death, re-MI, and TVR. By multivariate analysis, old age, diabetes mellitus, renal dysfunction, and left ventricular dysfunction were the independent predictors of MACE after BP-DES or 2G-DP-DES implantation. Conclusions BP-DES and 2G-DP-DES appear to have comparable 2-year safety and efficacy for the treatment of AMI. However, longer-term follow-up is needed.

Purpose The BIOFLOW-VI (Biotronik–Safety and Clinical Performance of the Drug Eluting Orsiro Stent in the Treatment of Subjects With De Novo Coronary Artery Lesions–VI) study evaluates the angiographic efficacy, clinical safety, and effectiveness of the ultrathin strut, biodegradable polymer sirolimus-eluting stent (BP-SES) compared with a durable polymer everolimus-eluting stent (DP-EES). This randomized controlled clinical trial was designed to enable approval of new drug-eluting stents in China. Methods A total of 440 eligible patients from 11 sites with up to 2 de novo native coronary artery lesions were randomly assigned to receive either BP-SES (n = 220) or DP-EES (n = 220) from July 2014 to September 2016 in this prospective, multicenter, noninferiority trial. Findings The primary end point of 9-month in-stent late lumen loss (LLL) was 0.05 (0.02) mm in the BP-SES group versus 0.07 (0.02) mm in the DP-EES group, with a mean difference of −0.02 mm (95% CI, −0.06 to 0.03; P = 0.44; Pnoninferiority Implications The randomized BIOFLOW-VI trial showed that BP-SES was noninferior to DP-EES with regard to the primary end point of 9-month in-stent LLL in a Chinese population. ClinicalTrials.gov Identifier: NCT02870985

Emerging clinical trial data in STEMI patients support using an ultra-thin strut biodegradable polymer sirolimus eluting stent (BP-SES), ‘Orsiro’, over contemporary second-generation durable polymer drug eluting stents (DP-DES) however the net clinical outcomes in all-comers is unknown. We

Long term outcomes of biodegradable polymer drug-eluting stents (BP-DES) compared to durable polymer drug-eluting stents (DP-DES), are not well described. A comprehensive search in clinicalTrials.gov, PubMed, EBSCO, Web of Science, google scholar and Ovid was performed for RCTs comparing BP-DES and

Newer-generation drug-eluting stents (DES) reduce mortality and late stent thrombosis compared with bare metal stents and early generation DES. Recent randomized controlled trials (RCT) showed reduction in target lesion revascularization with ultrathin biodegradable-polymer (BP) stents but similar

Purpose Patients with high bleeding risk (HBR) who undergo percutaneous coronary intervention also have an increased risk of ischemic events and represent an overall high-risk population. The coating of durable polymer drug-eluting stents (DP-DES) may induce inflammation and delay arterial healing, which might be reduced by novel biodegradable polymer DES (BP-DES). We aimed to evaluate the safety and efficacy of treating HBR patients with very thin-strut BP-DES versus thin-strut DP-DES. Methods Participants in BIO-RESORT (NCT01674803), an investigator-initiated multicenter, randomized all-comers trial, were treated with very thin-strut BP-DES (Synergy or Orsiro) or thin-strut DP-DES (Resolute Integrity). For the present analysis, patients were classified following HBR criteria based on previous trials. The primary endpoint was target vessel failure: a composite of cardiac death, target vessel-related myocardial infarction, or target vessel revascularization at 1 year. Results Of all 3514 patients, 1009 (28.7%) had HBR. HBR patients were older (p

Introduction To date the early strut coverage with the second-generation durable-polymer ONYX zotarolimus-eluting stent (O-ZES) is unknown. Aim Optical coherence tomography (OCT) assessed the strut coverage of O-ZES at thirty-day follow-up. Material and methods OCT was performed after implantation and at 1-month follow-up in 15 patients treated with O-ZES. Results Mean patient age was 67 ±7 years (73% males). The clinical presentation consisted of acute coronary syndromes (n = 13) and stable coronary disease (n = 2). Four (26%) patients had diabetes. OCT analysis was performed at baseline and 1-month follow-up in all stents. 378 cross-sections with 3582 struts were assessed at baseline and 3661 at follow-up. At follow-up, 88% struts were covered by tissue with a median thickness 37.91 μm (IQR: 22.32-64.15). Median in-stent area obstruction by neointima was 2.64% (IQR: 1.70-4.84). From the total stent covered area, 92.3% showed complete strut coverage. Homogeneous tissue was observed in 74% of cases. There were no differences in minimal lumen area (5.07 ±1.08 mm2 vs. 4.81 ±0.94 mm2, p = 0.125) or minimal stent area (4.95 ±1.22 mm2 vs. 4.92 ±0.99 mm2) at baseline and at follow-up. There were no differences in the rate of strut malapposition (4.3% vs. 5.7%, p = 0.417). For all stents, malapposition volume was 47.9 mm3 at baseline and 51.7 mm3 at follow-up, giving the late acquired stent malapposition volume of 3.8 mm3. Conclusions The second-generation durable polymer O-ZES showed favorable vessel healing at 30-day OCT follow-up.

Aims 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). Methods and results 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). Conclusions 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.

Background Polymer-free drug-eluting stents (PF-DES) were introduced with the aim of reducing the risk of stent thrombosis associated with durable polymer drug-eluting stents (DP-DES). The comparison of safety and efficacy profiles between these two stent platforms remains unclear. Materials and methods We conducted electronic database searches for randomized controlled trials (RCTs) comparing patients treated with either PF-DES or DP-DES. Outcomes included definite or probable stent thrombosis (ST), myocardial infarction (MI), cardiac death, all-cause death, target lesion revascularization (TLR), and target vessel revascularization (TVR). A random-effects model was used to derive risk ratios (RRs) with 95% confidence intervals (CIs). Subgroup analyses based on different variables were also performed. After screening a total of 1026 articles, the present meta-analysis included 13 RCTs comprising 8021 patients. Results No significant differences were found for the risks of definite or probable ST (RR, 0.94; 95% CI, 0.62–1.43; P = 0.77), MI (RR, 1.06; 95% CI, 0.85–1.33; P = 0.61), cardiac death (RR, 0.98; 95% CI, 0.80–1.21; P = 0.88), all-cause death (RR, 0.87; 95% CI, 0.76–1.00; P = 0.06), TLR (RR, 1.12; 95% CI, 0.94–1.33; P = 0.22), and TVR (RR, 1.18; 95% CI, 0.87–1.61; P = 0.29). Similarly, no significant differences were found for all outcomes regardless of anti-proliferative drug, except for an increased risk of TLR for polymer-free paclitaxel-eluting stents compared with DP-DES (RR, 2.32, 95% CI, 1.30–4.14; P = 0.005). Conclusions Our findings showed that PF-DES and DP-DES confer equivalent safety and efficacy profiles, with similar rates of stent thrombosis., Highlights • Polymer-free and durable polymer drug-eluting stents confer similar safety and efficacy profiles. • There were comparable rates of stent thrombosis between the two stent platforms. • Further trials with greater length of follow-up are warranted to assess long-term safety and efficacy outcomes.

Background: Biodegradable polymer sirolimus-eluting stents (BP-SESs) have been reported to be noninferior compared with durable polymer everolimus-eluting stents (DP-EES) in a randomized clinical trial. We sought to compare the efficacy and safety of an ultrathin strut BP-SES with a DP-EES in an all-comers population. Methods and Results: Among 7640 consecutive patients who underwent percutaneous coronary intervention between March 2011 and June 2015, 4638 patients were exclusively treated with BP-SES (N=1896; 3137 lesions) or DP-EES (N=2742; 4468 lesions). After propensity score matching within strata of clinical indications, the final study population consisted of 2902 matched patients (BP-SES 2406 lesions and DP-EES 2368 lesions). The primary device-oriented composite end point (DOCE) included cardiac death, target vessel myocardial infarction, and target lesion revascularization at 1 year. BP-SES (6.9%) was noninferior to DP-EES (8.0%) with respect to device-oriented composite end point (hazard ratio [HR], 0.85; 95% CI, 0.65–1.11; P for noninferiority P for superiority=0.24). No differences in cardiac death (BP-SES, 2.3% versus DP-EES, 3.0%; HR, 0.76; 95% CI, 0.49–1.20; P =0.25), myocardial infarction (BP-SES, 4.6% versus DP-EES, 4.6%; HR, 1.00; 95% CI, 0.71–1.40; P =0.99), or target lesion revascularization (BP-SES, 2.8% versus DP-EES, 2.5%; HR, 1.11; 95% CI, 0.71–1.74; P =0.65) were observed. The rate of periprocedural myocardial infarction was comparable between the 2 groups (2.1% versus 2.2%; HR, 0.97; 95% CI, 0.59–1.58; P =0.89). The rate of definite stent thrombosis was similarly low throughout 1 year (BP-SES, 0.8% versus DP-EES, 0.8%; HR, 1.00; 95% CI, 0.45–2.22; P =1.00). Conclusions: In a consecutively enrolled percutaneous coronary intervention population reflecting routine clinical practice, BP-SES was noninferior to DP-EES for device-oriented composite end point at 1 year. Clinical Trial Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02241291.

Background: Progress in the platforms for DES is aimed at improving safety and outcomes. Second-generation DESs have a biocompatible durable polymer (DP), in addition to bioabsorbable polymers (BP). The benefit of BP is to remove the polymer-triggered inflammatory stimulation associated with DP. There is evidence to suggest BP-DESs are non-inferior to the current generation DES at 12 months. The time course for polymer absorption varies between stents and may take from 4 to 15 months. Hence the potential benefits of BP-DES over DP-DES can only be tested over a longer period, to overcome the time taken for polymer absorption. Purpose: The purpose of the meta-analysis was to compare the safety and efficacy outcomes of BP-DES over a long-term follow-up. Methods: A thorough computer-based search using Ovid MEDLINE, EMBASE, Google Scholar, and PubMed databases was conducted up to 11 November 2017. We only included randomised studies (RCT) comparing clinical outcomes between the BP-DESs and DP-DESs. Only studies where data were available for a minimum of 5 years were included. Safety (Stent thrombosis (ST) and reinfarction) and efficacy (target lesion revascularization (TLR), cardiac mortality) were analysed. Results: The literature search yielded 445 citations. After going through the abstracts and full-texts of the articles we included 5 RCTs where 5-year follow-up data was available. The information about the included studies, stent platform, drug and type of polymer is provided in Table 1.There was no difference in the ST (OR 0.71, 95% CI 0.47 –1.09, I2 = 31%, P=0.12), reinfarction (OR 1.01, 95% CI 0.85 –1.21, I2 = 0%, P=0.89), cardiac mortality (OR 1.00, 95% CI 0.81 –1.23, I2 = 0%, P=0.98), all cause mortality (OR 0.95, 95% CI 0.80 –1.14, I2 = 21%, P=0.61) and TLR (OR 0.80, 95% CI 0.58–1.11, I2 = 68%, P=0.18). Furthermore, there was no difference in the very late ST (OR 0.49, 95% CI 0.19 –1.30, I2 = 56%, P=0.15).

Aims Biodegradable polymer drug‐eluting stents (BP‐DES) were developed in hopes of reducing the risk of stent thrombosis. The comparison of this new stent platform with second‐generation durable polymer drug‐eluting stents (DP‐DES) has not been well described. We, therefore, performed a meta‐analysis to evaluate the safety and efficacy profiles of BP‐DES versus second‐generation DP‐DES in patients with coronary artery disease. Methods and Results Electronic database searches were conducted, from their dates of inception to June 2018, to identify randomized controlled trials (RCTs) comparing patients with either BP‐DES or second‐generation DP‐DES. Risk estimates were expressed as risk ratios (RRs) with 95% confidence intervals (CIs). We also performed a landmark analysis beyond 1 year and sensitivity analyses based on different variables. A total of 24,406 patients from 19 RCTs were included in the present meta‐analysis. There were no significant differences between BP‐DES and second‐generation DP‐DES for the risks of definite or probable stent thrombosis (RR 0.88; 95% CI, 0.69–1.12; P = 0.29), myocardial infarction (RR 0.97; 95% CI, 0.86–1.09; P = 0.59), cardiac death (RR 1.08; 95% CI, 0.92–1.28; P = 0.34), all‐cause death (RR 1.02; 95% CI, 0.91–1.13; P = 0.77), target lesion revascularization (RR 1.05; 95% CI, 0.94–1.17; P = 0.38), and target vessel revascularization (RR 1.05; 95% CI, 0.95–1.16; P = 0.36). Similar outcomes were observed regardless of anti‐proliferative drug and duration of dual antiplatelet therapy (all P > 0.05). Conclusion Our findings demonstrate similar safety and efficacy profiles between BP‐DES and second‐generation BP‐DES, with comparable rates of stent thrombosis.

For the past years, a lot was said about the great potential of reuse of the fly ashes in the building materials industry. Fly ashes have gained recognition as a good addition to various concretes, including ordinary concrete, polymer cement concrete, and polymer concrete. Many research was conducted on the positive effect of fly ash on the technological and technical properties; however, most of them included tests performed after several days or weeks. Not much published data concerned tests conducted after a longer period of time, confirming the durability of polymer composites with fly ashes. The paper presents the results of compressive strength of polymer concretes with fly ashes tested after longer time. Composites with vinyl ester resin, standard sand, and fluidized fly ash were tested after 18 months, and composites with the same resin, river sand, and fluidized or siliceous fly ash were tested after 7 years. The results were compared with the results of the respective specimens tested after 14 days. Research results indicated that there was no reduction in compressive strength. Moreover, in all cases, a significant improvement of strength was noted. The research has demonstrated the usefulness of fly ash as a component for the production of durable polymer concrete.

Drug-eluting stents (DESs) have improved the outcomes of acute myocardial infarction patients (AMI) patients, however, the risk of late stent thrombosis with DES due to delayed healing of vessel wall is still considerable. The aim of this study was to compare the safety and efficacy of biodegradable

This editorial refers to ‘Everolimus-eluting bioresorbable stent vs. durable polymer everolimus-eluting metallic stent in patients with ST-segment elevation myocardial infarction: results of the randomized ABSORB ST-segment elevation myocardial infarction—TROFI II trial’[†][1], by M. Sabate et al ., on page 229. Bioresorbable stents (BRS) represent a disruptive technology with potential for improving long-term outcomes after percutaneous intervention.1 The principal advantage of BRS compared with conventional metallic stent technology is that the device is broken down by the body after its useful function has been served, potentially restoring normal vessel anatomy over the long term and ameliorating the risk of late adverse events in the treated arterial segment.2 Two such devices have received CE mark approval for use; both are based on polylactic acid stent backbones: the everolimus-eluting Absorb stent (Abbott Vascular, Abbott Park, IL, USA) in 2011 and the novolimus-eluting DESolve stent (Elixir Medical, Sunnyvale, CA, USA) in 2013. However, current approval processes leading to CE mark are based on conformity testing (i.e. performance as intended) and assessment of safety, and generally do not require comparative efficacy assessment against existing devices.3 In fact, BRS are generally more challenging to implant in comparison with metallic stents, and careful patient and lesion selection is crucial to ensuring good results with this technology.4 Moreover, clinical experience with these devices remains rather limited, and further comparative efficacy data are required before we can be sure of the place of these devices in day-to-day practice. Encouraging results have been reported with the Absorb BRS compared with conventional metallic drug-eluting stents (DES) in small randomized trials enrolling patients presenting with stable or unstable angina.5, … [1]: #fn-2

This paper reviews the current state of the art for coronary stent materials and surface coatings, with an emphasis on new technologies that followed on from first-generation bare metal and drug-eluting stents. These developments have been driven mainly by the need to improve long term outcomes, including late stent thrombosis. Biodegradable drug-eluting coatings aim to address the long term effects of residual durable polymer after drug elution; the SYNERGY, BioMatrix, and Nobori stents are all promising devices in this category, with minimal polymer through the use of abluminal coatings. Textured stent surfaces have been used to attached drug directly, without polymer; the Yukon Choice and BioFreedom stents have some promising data in this category, while a hydroxyapatite textured surface has had less success. The use of drug-filled reservoirs looked promising initially but the NEVO device has experienced both technical and commercial set-backs. However this approach may eventually make it to market if trials with the Drug-Filled Stent prove to be successful. Non-pharmacological coatings such as silicon carbide, carbon, and titanium-nitride-oxide are also proving to have potential to provide better performance than BMS, without some of the longer term issues associated with DES. In terms of biological coatings, the Genous stent which promotes attachment of endothelial progenitor cells has made good progress while gene-eluting stents still have some practical challenges to overcome. Perhaps the most advancement has been in the field of biodegradable stents. The BVS PLLA device is now seeing increasing clinical use in many complex indications while magnesium stents continue to make steady advancements.

Objective: Durable polymer sirolimus-eluting stents (DP-SES) are associated with a low risk of stent thrombosis; biodegradable polymer drug-eluting stents (BP-DES) were designed to reduce these risks. However, their benefits are still variable. Method: We undertook a meta-analysis of randomized trials identified by systematic searches of Medline, Embase, and the Cochrane Database. Results: Eleven studies (9,676 patients) with a mean follow-up of 22.6 months were included. Overall, compared with DP-SES, BP-DES significantly lowered the rate of definite or probable stent thrombosis (RR, 0.73; 95% CI, 0.55-0.97; p = 0.03; I2 = 0.0%) due to a decreased risk of very late stent thrombosis (RR, 0.26; 95% CI, 0.11-0.63; p = 0.00; I2 = 0.0%). However, BP-DES were associated with a comparable rate of early and late stent thrombosis. Meanwhile, BP-DES were associated with a broadly equivalent risk of target vessel revascularization (RR, 0.90; 95% CI, 0.78-1.03; p = 0.13; I2 = 0.0%), cardiac death (RR, 0.89; 95% CI, 0.72-1.09; p = 0.24; I2 = 0.0%), myocardial infarction (RR, 1.03; 95% CI, 0.84-1.26; p = 0.79; I2 = 0.0%), and major adverse cardiac events (MACE; RR, 0.91; 95% CI, 0.83-1.0; p = 0.08; I2 = 0.0%). Furthermore, angiographic data showed that in-stent and in-segment late luminal loss were similar between the two groups. Conclusions: Compared with DP-SES, BP-DES were associated with a lower rate of very late stent thrombosis and an equivalent risk of MACE. Larger randomized studies are needed to confirm this finding.

Among patients with acute ST-segment elevation myocardial infarction (STEMI), early-generation drug-eluting stents (DES) have been associated with a reduction in target-vessel revascularization compared with bare-metal stents after primary percutaneous coronary intervention. However, this early

Densely grafted polymer brushes prepared by surface-initiated polymerization (SIP) represent a versatile platform to engineer surface and interface properties. At high grafting densities, surface tethered polymer chains are forced into an extended chain conformation, which can impart these films with appealing materials properties such as low friction or efficient non-biofouling properties. The extended chain conformation of densely grafted polymer chains can also influence their chemical reactivity, in particular in close proximity to the polymer brush–substrate interface. This chapter provides an overview of recent efforts aiming at investigating detachment or degrafting of densely grafted hydrophilic polymer brushes from substrates upon exposure to aqueous media. The collective results from these reports suggest that swelling-induced stretching of such surface-attached polymers activates mechanochemical bonds near the brush–substrate interface and facilitates chain cleavage. Understanding the mechanochemistry of polymer brushes may provide novel opportunities to design robust, durable polymer brush films or, alternatively, systems that are designed to degraft on-demand.

Stent thrombosis and clinically driven restenosis are rare in the era of newer generation DES. The Synergy bioresorbable polymer DES appears to be comparable to other durable polymer and other bioabsorbable polymer DES in terms of safety and efficacy at 1-year post implantation. Further long-term study is needed to determine the specific role of the Synergy stent and other DES with bioabsorbable polymers.

Polymeric component is associated with the increased risk of delayed vessel healing and stent endothelialization. We aimed to clarify neointimal coverage within 1 month after implantation of the new-generation abluminal biodegradable polymer (BP) drug-eluting stent (DES) compared with the second-generation durable polymer (DP) everolimus-eluting stent (EES). Between November 2015 and October 2016, 32 BP-DES and 25 DP-EES were evaluated by optical frequency domain imaging (OFDI) within 1 month after the procedure. The average interval to follow-up OFDI was not significantly different between the groups (16.3 ± 7.7 days in BP-DES vs. 15.4 ± 7.4 days in DP-EES, P = 0.75). Neointimal coverage was significantly superior in BP-DES in both apposed and malapposed strut (apposed: 53.9% in BP-DES vs. 28.0% in DP-EES, P 0.001; malapposed: 22.9% in BP-DES vs. 7.5% in DP-EES, P = 0.001). When the follow-up period was divided into 2 and 2 weeks, neointimal coverage was also significantly superior in BP-DES ( 2 weeks: 47.7% in BP-DES vs. 19.2% in DP-EES, P 0.001; 2 weeks: 60.1% in BP-DES vs. 37.4% in DP-EES, P = 0.001). The new-generation BP-DES showed excellent early neointimal coverage compared with the second-generation DP-EES in both apposed and malapposed struts.

This study aimed to compare very late vascular response after stent implantation between everolimus-eluting stent (EES) with a thin, non-adhesive, durable, biocompatible fluorinated polymer and biolimus-eluting stent (BES) with a biodegradable polymer by optical coherence tomography (OCT).In the NOBORI-BES Versus XIENCE V/PROMUS-EES Trial (NEXT), a formal OCT substudy investigated 48 patients (27 EES-treated lesions in 23 patients and 28 BES-treated lesions in 25 patients) with 2-year (18-30 months) follow-up imaging at 18 centers. The percentage of uncovered strut by neointima was significantly lower in EES compared with BES (2.1±4.7% vs. 7.9±10.8%, p=0.013). The percentage of malapposed strut was not different between EES and BES (0.1±0.3% vs. 0.5±1.3%, p=0.138). The frequency of stent with evagination, which is identified as outward bulges in the luminal contour between struts, was significantly lower in EES compared with BES (22% vs. 86%, p0.001). The frequency of neoatherosclerosis was not different between EES and BES (11% vs. 11%, p=1.000).At 2 years after stent implantation, uncovered stent strut by neointima and evagination were less frequently observed in EES compared with BES. This OCT study suggests that the very late vascular response is different between EES and BES.

Aims The aim of this study was to evaluate the safety and efficacy profile of new-generation, SYNERGY everolimus-eluting stents (S-EES) as compared to XIENCE everolimus-eluting stents (X-EES) with a durable polymer coating in "complex patients". Methods and results We included 2,001 consecutive patients treated with S-EES (n=400) or X-EES (n=1,601) at two Italian centres between May 2013 and May 2015. We used propensity score matching to obtain two cohorts of patients with similar baseline risk profiles. Patients were stratified according to baseline complexity based on the EVOLVE II trial exclusion criteria. The primary outcome was major adverse cardiac events (MACE), defined as the composite of all-cause death, myocardial infarction (MI), and target lesion revascularisation (TLR), at one year. Among 391 matched pairs of patients treated with S-EES or X-EES, we identified 253 (63%) as complex. At one-year follow-up, among "complex" patients, MACE rates did not differ between the S-EES and X-EES groups (9.9% vs. 9.5%, p=0.830, HR 1.04, CI: 0.72-1.48). Similarly, death, MI, and TLR, stratified for complexity, were comparable between S-EES and X-EES treated patients at one year. Of note, no definite ST was observed in either the S-EES or the X-EES cohort. Conclusions New-generation S-EES with a bioresorbable polymer coating appear to be safe and effective irrespective of patient complexity as compared to X-EES.

Objectives The aim of this study was to investigate the hypothesis that a novel biodegradable polymer–coated, cobalt-chromium (CoCr), sirolimus-eluting stent (BP-SES) is noninferior in safety and efficacy outcomes compared with a durable polymer (DP)-SES. Background No randomized trials have the compared safety and efficacy of BP-SES versus DP-SES on similar CoCr platforms, thereby isolating the effect of the polymer type. Methods In this prospective, single-blind, randomized trial conducted at 32 Chinese sites, 2,737 patients eligible for coronary stenting were treated with BP- or DP-SES in a 2:1 ratio. The primary endpoint was 12-month target lesion failure (TLF), a composite of cardiac death, target vessel myocardial infarction, or clinically indicated target lesion revascularization. Secondary endpoints included TLF components, and definite/probable stent thrombosis. Results At 12 months, the difference in the primary endpoint of TLF between BP-SES (6.3%) and DP-SES (6.1%) groups was 0.25% (95% confidence interval: −1.67% to 2.17%, p for noninferiority = 0.0002), demonstrating noninferiority of BP-SES to DP-SES. Individual TLF components of cardiac death (0.7% vs. 0.6%, p = 0.62), target vessel myocardial infarction (3.6% vs. 4.3%, p = 0.39), and clinically indicated target lesion revascularization (2.6% vs. 2.2%, p = 0.50) were similar, as were low definite/probable stent thrombosis rates (0.4% vs. 0.6%, p = 0.55). Conclusions In this large-scale real-world trial, BP-SES was noninferior to DP-SES for 1-year TLF. (Evaluate Safety and Effectiveness of the Tivoli ® DES and the Firebird ® DES for Treatment of Coronary Revascularization; NCT01681381 )

Objective The long-term coronary arterial response of biodegradable polymer biolimus-eluting stents (BES) remains unclear. We sought to evaluate the coronary arterial response of biodegradable polymer BES at 5 years after stent implantation using optical coherence tomography (OCT) as compared with that of durable polymer sirolimus-eluting stents (SES) and bare-metal stents (BMS). Methods Five-year follow-up OCT was performed in 30 patients with 33 stents (10 with 12 BES; 10 with 11 SES; 10 with 10 BMS). Quantitative parameters and qualitative characteristics of the neointima were evaluated. A total of 5178 struts (BES, n = 2056; SES, n = 1410; BMS, n = 1712) were analyzed. Results Uncovered struts were found in 15 out of 2055 struts in the BES (weighted estimate 0.01%, 95% confidence intervals [CI]: 0.00–0.33%) and 54 out of 1410 struts in the SES (0.11%, 95% CI: 0.00–3.33%) (odds ratio [OR] 0.12, 95% CI: 0.01–1.95, p = 0.13). None of 1712 struts were uncovered in the BMS. Cross-sectional qualitative analysis of neointimal tissue showed that the frequency of lipid-laden neointima tended to be lower in the BES (2.26%, 95% CI: 0.38–12.3%) compared with the SES (9.90%, 95% CI: 4.37–20.9%; OR 0.21, 95% CI 0.03–1.16, p = 0.07), and was similar to the BMS (2.23%, 95% CI: 0.54–8.74%; OR 0.98, 95% CI 0.13–7.14, p = 0.98). Conclusions Biodegradable polymer BES shows a favorable coronary arterial response compared with SES, but different response with BMS at 5 years follow-up. The observed frequency of in-stent neoatherosclerosis within BES was similar to BMS and tended to be lower than SES.

Biodegradable polymer-based drug-eluting stents are thought to be safer than durable polymer-based stents. However, the long-term vascular response remains unclear. The aim of this study was to compare the biocompatibility of durable polymer-based sirolimus-eluting (SES) and everolimus-eluting (EES) stents with biodegradable polymer-based biolimus-eluting (BES) stents in a porcine coronary model. Stents were implanted in porcine coronaries. Acetylcholine challenge tests and optical coherence tomography (OCT) examination were performed at one month. Animals were sacrificed at three and six months (n=6 each), and the stents were analysed histologically. At one month, acetylcholine challenge tests revealed a trend towards greatest vasoconstriction in SES, less in BES, and least in EES, but the differences were not significant. OCT analysis demonstrated the highest incidence of uncovered struts in SES, followed by BES, while EES showed almost complete strut coverage (41.7±27.0%, 24.5±23.8%, 0.4±0.8%, respectively; p=0.004). Upon histological analysis at three months, SES showed a significantly higher inflammatory score than BES and EES (2.9±1.4, 0.8±0.9, 0.5±0.4, respectively; p=0.001), and this was maintained at six months (1.6±1.5, 0.3±0.3, 0.4±0.6, respectively; p=0.049). While SES showed an increased inflammatory reaction, EES and BES showed minimal inflammation. These results indicate that the late inflammatory reaction does not necessarily depend on degradability of the polymer, if the combination of the drug, metal, and polymer is biocompatible.

First-generation drug-eluting stents have raised concerns regarding the risk of late and very late stent thrombosis compared with bare metal stents and require prolonged dual antiplatelet therapy. Despite extensive investigations, the physiopathology of these late events remains incompletely understood. Aside from patient- and lesion-related risk factors, stent polymer has been cited as one of the potential causes. In fact, the persistence of durable polymer after complete drug release has been shown to be responsible for local hypersensitivity and inflammatory reactions. Third-generation drug-eluting stents with more biocompatible or biodegradable polymers have subsequently been developed to address this problem. In this article, we evaluate and discuss the concept and clinical results (safety and efficacy) of a third-generation drug-eluting stent with biodegradable polymer: the Nobori® stent.

Background:The aim of the present study was to compare vascular healing response between everolimus-eluting stent (EES) and biolimus-eluting stent (BES) using optical coherence tomography (OCT).Methods and Results:In the NOBORI Biolimus-Eluting Versus XIENCE V/PROMUS Everolimus-Eluting Stent Trial (NEXT), a formal OCT substudy investigated 91 patients (55 EES-treated lesions in 48 patients and 51 BES-treated lesions in 43 patients) with 8–12 months follow-up imaging at 18 centers. A total of 980 frames with 8,996 struts in EES and 907 frames with 8,745 struts in BES were analyzed. Mean neointima thickness in EES and BES was 105±82μm and 91±80μm, respectively (P

The use of biodegradable-polymer drug-eluting stents (BP-DES) has been associated with early endothelialization and improved vascular healing. The authors aim to study the real-world clinical outcome of patients who received BP-DES versus second-generation durable-polymer drug-eluting stents (DP-DES