Stent Platforms Research Articles

A multi-center retrospective analysis of causative anatomical and procedural factors and clinical outcomes of longitudinal coronary stent deformation

Background and purpose: Longitudinal stent deformation (LSD) is a recently reported complication of percutaneous coronary intervention, but causative factors and associated clinical outcomes remain unknown. The purpose of this study is to have insight into procedural and anatomical factors that predispose to this complication and associated clinical outcomes. Methods and results: Twenty three cases of longitudinal coronary stent deformation were identified in 22 patients from March 2010 to August 2012 representing 0.56% of cases and affected 0.42% of stents deployed. The lesion in which LSD was identified were complex (lesion type B2/C 61.9%; B1 38.1%; A 0%) and most frequently occurred following attempts to pass secondary devices such as IVUS catheter (42.9%) and adjunctive balloon catheter (33.3%) through a previously deployed stent. Of the 23 deformed stents, the most common affected stent platform was the Element platform (56.5%) followed by the Driver platform (26.1%), and the Multi-link platform (17.3%). In 4 cases of complete stent apposition confirmed by previous IVUS study, LSD had been occurred in 12-month follow-up angiographic study. Proximal segment of left anterior descending artery (LAD) (26.1%) and left main ostium and trunk (21.7%) were the most prevalent site of LSD. Of the twenty three cases, re-stenting and/or re-ballooning were required in sixteen and major adverse cardiac event (MACE) did not occurred except one non-cardiac death. ![Figure][1] Conclusions: Longitudinal stent deformation can occur especially by secondary devices during PCI. Although seen in several different coronary segments and with several different stent platforms, in our study it was more commonly observed in proximal LAD and with the Element platform. [1]: pending:yes

Clinical and biomechanical behavior of a platinum-cromium stent platform in a large all-comers single centre PCI population: insights from the Novara-PROMETEUS registry

Aims: Recent reports have described cases of longitudinal deformation in new generation thin-strut coronary stents and biomechanical analyses have suggested increased susceptibility for such a complication for the novel platinum chromium (PtCr) Elements™ coronary stent platform. The present study assesses the incidence of longitudinal stent deformation for PtCr stents in a large single centre all-comers population. Methods and results: Quantitative angiographic analysis (QCA) of 337 PtCr stents deployed in 253 consecutive all-comers patients treated in our Laboratory from January 2011 to August 2012 was performed. QCA: nominal stent length ratio (QCA:NSLR) was considered as surrogate estimate of longitudinal stent deformation. The risk profile of the studied population was high, with 265 lesion (75.3%) classified as ACC/AHA type B2/C. QCA:NSLR averaged 0.95±0.04 in the whole population. The small post-deployment reduction of stent length had no clinical relevance, with only 3 cases (0.9%) of trivial geographical miss which did not required further interventions. Plaque prolapsed, usually small and focal, through the stent struts was observed in 19 cases (5.6%). No case of typical concertina effect was observed, while in 3 cases (0.9%) a large prolapsed plaque mimicked longitudinal stent deformation. Minor grades of stent deformation were more common and correlated with tortuous and calcified lesions, as expression of great stent conformability. Actually blinded a posteriori re-examination of the angiograms corresponding to the 20 lowest and highest ratios did not identify any cases of severe stent deformation. Logistic regression analysis identified a significant correlation between the need for predilation and lower QCA:NSLR values, while postdilation independently predicted higher QCA:NSLRs. Conclusions: Systematic QCA analysis of a large single centre population of all-comer PCI patients treated with PtCr stents failed to detect clinically relevant longitudinal stent deformations. Need for predilation was associated with a reduced stent length ratio, even if this did not substantially influenced PCI outcomes. Conversely postdilation was associated with QCA stent measures closest to nominal. (Clinicaltrials.gov ID: [NCT01759719][1]) [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT01759719&atom=%2Fehj%2F34%2Fsuppl_1%2FP3017.atom

GW24-e1275 Improved Biocompatibility of Poly (D, L-Lactide -Co-Glycolide) and Poly-L-lactic Acid Blended with Amorphous Calcium Phosphate in Rat Aortas and Rabbit Iliac Arteries

ObjectivesPolyesters are the major polymers used in coating or making biodegradable stent, but with issues of inflammation response and insufficient radial strength. We hypothesise blending Poly (D, L-Lactide-Co-Glycolide (PLGA) and...

First-in-human evaluation of the novel BioMime sirolimus-eluting coronary stent with bioabsorbable polymer for the treatment of single de novo lesions located in native coronary vessels - results from the meriT-1 trial

We report the initial human evaluation of the novel BioMimeTM sirolimus-eluting stent (SES) (Meril Life Sciences Pvt. Ltd., Gujarat, India) with an ultra-thin stent platform (65 μm) and a biodegradable polymer for the treatment of de novo coronary lesions. The meriT-1 trial was a prospective, non-randomised, single-arm, single-centre, first-in-human evaluation of the safety, feasibility and performance of the BioMime SES. Lesion criteria included non-occlusive stenosis ≤ 19 mm in length located in native coronary vessels. Clinical follow-up (FU) was performed at 1, 8 and 12 months; all patients were assigned for angiographic FU at eight months. A total of 30 patients (30 lesions) were enrolled between March 2009 and February 2010. Mean age was 49.9 years, 30% were diabetics, and 36.7% had previous myocardial infarction (MI). Baseline median [25%, 75% interquartile range] lesion length, reference diameter and % diameter stenosis were 15.51 mm [12.74, 20.27], 2.94 mm [2.71, 3.34], and 80.5% [67.0%, 90.7%], respectively. Overall, there was one stent implanted per lesion and procedural success was 100%. At eight-month angiographic FU (26/30), median in-stent late lumen loss was 0.15 mm [0.09, 0.33]; also, there were no cases of binary restenosis within the treated segment. Clinical FU at 12 months (100%) demonstrated absence of MACE (cardiac death, MI and target lesion revascularisation) and stent thrombosis (ST). The novel BioMime SES demonstrated excellent performance in single coronary lesions including high procedural success and efficacy, as demonstrated by the relatively low late lumen loss (a surrogate of neointimal hyperplasia) at eight-month angiographic FU. Overall, there were no safety concerns in this preliminary evaluation including absence of MACE or ST up to 12 months.

Coronary drug‐eluting stents: From design optimization to newer strategies

Compared with early bare-metal stents, drug-eluting stents (DESs) are more effective in treating coronary artery diseases, especially in inhibiting restenosis. However, in-stent restenosis still clinically occurs at a non-negligible rate. More importantly, delayed endothelialization, inflammation, and hypersensitivity trigger subacute or late adverse events, particularly stent thrombosis, and thereby raise more concerns over the long-term safety of DESs. These problems are mostly associated with the permanent polymeric materials, non-optimal therapeutic drugs, and/or metallic stent platforms used in current DES design. It is critically important to further improve and optimize DES design and apply newer strategies for developing next generation DES. These new generation DESs should maintain their clinical efficacy and meanwhile eliminate the long-term safety concerns. In this review article, the current information on the optimization of DES design was critically reviewed based on DES's basic components, namely, stent platform, restenotic drug, and polymer coating. The available strategies for designing next-generation DESs were also summarized, ranging from degradable polymer DESs, to polymer-free DESs, to fully biodegradable DESs.

Therapies Targeting Inflammation After Stent Implantation

Since the introduction of coronary vessel scaffold by metallic stent, percutaneous coronary intervention has become widely performed all over the world. Although drug-eluting stent technology has further decrease the incidence of in-stent restenosis, there still remaining issues related to stent implantation. Vessel inflammation is one of the causes that may be related to stent restenosis as well as stent thrombosis. Therefore, systemic therapies targeting inflammation emerged as adjunctive pharmacological intervention to improve outcome. Statins, corticosteroids, antiplatelets, and immunosuppresive or anti-cancer drugs are reported to favorably impact outcome after bare-metal stent implantation. In type 2 diabetic patients, pioglitazone may be the most promising drug that can lower neointimal proliferation and, as a result, lower incidence of restenosis and target lesion revascularization. On the other hand, several new stent platforms that might decrease inflammatory response after drug-eluting stent implantation have been introduced. Because durable polymer used in the first generation drug-eluting stents are recognized to be responsible for unfavorable vessel response, biocompatible or bioabsorbable polymer has been introduce and already used clinically. Furthermore, polymer-free drug-eluting stent and bioresorbable scaffold are under investigation. Although vessel inflammation may be reduced by using these new drug-eluting stents or scaffold, long-term impact needs to be investigated further.

Polymer coatings on drug-eluting stents: Samson’s hair and Achilles’ heel?

Drug-eluting stents (DES) minimise the risk of in-stent restenosis by means of controlled, local delivery of antiproliferative drugs from a thin layer of coating applied to a rigid stent backbone. In this respect, polymer coatings have proven largely indispensable for the control of drug release kinetics and the optimisation of DES efficacy. Investigation of polymer-free stent platforms has typically yielded comparatively lower levels of neointimal suppression by virtue of rapid drug dissociation in the initial hours and days after stent implantation 1 . Indeed, all of the currently available FDA-approved DES devices control drug release by use of durable polymer coatings 2,3

New Drug-eluting Stents: Polymer-free, Biodegradable Polymers or Bioabsorbable Scaffolds?

The advent of stents in interventional cardiology has contributed to excellent initial angiographic outcomes in all lesions, avoiding acute or subacute vessel occlusion and significantly reducing angiographic and clinical restenosis. Perhaps paradoxically, stents have been found to induce greater neointimal proliferation than balloon angioplasty. In fact, the best results are based on the virtual elimination of early elastic recoil and dissection (which guarantees an excellent immediate result) and avoidance of late remodeling of the coronary wall. Increased neointimal growth resulting from injury to the vascular wall by the metal stent is therefore ‘‘accommodated’’ and a larger coronary lumen is guaranteed in the long-term. The drug-eluting stents (DES) introduced more than a decade ago have inspired a new revolution in our specialty, drastically reducing neointimal hyperplasia and the need for reintervention. The unprecedented results obtained with DES have allowed us to offer percutaneous revascularization to patients with increasingly unfavorable clinical and anatomic characteristics. Some patients treated with DES do experience restenosis, but this problem is rare. The initial enthusiasm generated by DES has, however, been somewhat dampened by confirmation that these devices do not reduce the risk of stent thrombosis. In fact, they simply delay onset, whereby the risk of very late thrombosis (after the first year) could be higher than that with conventional stents. While this complication occurs only in exceptional circumstances, it has significant clinical implications. The international scientific community responded unanimously to this issue, initially with recommendations of concern and caution, and subsequently by the promotion of new research efforts. The optimization and duration of antiplatelet therapy were critically reviewed and the development of new DES was stimulated. Stent thrombosis is a multifactorial phenomenon. It is known that mechanical problems in the metal stent platform (underexpansion, incomplete apposition, deformation, or even rupture) and adverse drug reactions (initially only sirolimus

Newly available and recent advances in drug-eluting stents

The introduction of drug-eluting stents has revolutionized the treatment of coronary artery disease. First-generation stents, however, were associated with relatively high revascularization rates and the risk of stent thrombosis. This has led to a worldwide search for improvements in stent technology that will reduce adverse cardiac events following stent implantation while providing optimal treatment. Here, the authors discuss recent advances in stent technology from improvements in stent platform and stent polymer to newer mechanisms of drug delivery and the incorporation of proendothelizing agents. The authors also introduce some of the newly available stents and discuss the evidence associated with their use in clinical practice.

PCV42 - Hospital budget impact of readmission penalties and bundled payments: Potential impact of coronary stent platforms

PCV42 - Hospital budget impact of readmission penalties and bundled payments: Potential impact of coronary stent platforms

Coronary stents: historical development, current status and future directions

Coronary angioplasty with stenting has revolutionized the treatment of coronary artery disease. This article describes the history of coronary angioplasty and stenting, reviews the contemporary stents and recommendations and highlights the on-going work and potential future directions. This review examined the data on coronary stents available in PubMed. Coronary artery stenting is the treatment of choice for patients requiring coronary angioplasty. Stents, and particularly drug-eluting stents, reduce the risk of restenosis, but may be associated with the hazard of late stent thrombosis. Dual anti-platelet treatment is recommended for patients receiving coronary stents. The selection of stents for various lesions and patients and the duration of anti-platelet therapy remain debated areas. There are on-going preclinical and clinical studies to develop better stent platforms, more biocompatible polymers, novel anti-proliferative and anti-platelet drugs, pro-healing stents and bioresorbable scaffolds.

Clinical applications of a new enhanced stent imaging technology

Enhanced Stent Imaging (ESI) refers to a rapidly evolving class of imaging tools that seek to provide enhanced visualization of coronary stent architecture with minimal disruption to the catheterization laboratory workflow. Various ESI stent platforms are available, all of which utilize a brief cine acquisition of a deflated balloon within a stent to generate a motion-corrected, enhanced image of the stent. The enhanced image permits detailed assessment of stent architecture, integrity, and positioning relative to other stents. We present two illustrative cases of percutaneous coronary intervention utilizing a new ESI platform. The relevant literature is briefly reviewed.

COMPARISON OF IN VIVO LONGITUDINAL STRENGTH AND CONFORMABILITY FOLLOWING STENT IMPLANTATION IN RABBIT ILIAC ARTERY

Recently, longitudinal coronary stent deformation has been highlighted and some bench tests have demonstrated difference in longitudinal strength among the stent platforms, however, this has not been investigated in an in vivo setting. This is of interest because there may be a trade–off between

Carotid Artery Stenting Update

Stroke is the third leading cause of death and the most common cause of long-term disability in the USA. Approximately 25% of strokes are due to carotid artery disease. The mechanisms of stroke include thrombotic occlusion, thrombus embolism, atheroembolism and dissection or subintimal hematoma. Today, endarterectomy is the standard of care for management of significant carotid artery disease. The SAPPHIRE trial has proved the noninferiority of carotid artery stenting versus carotid endarterectomy in 'high-risk' patients, which led to the US FDA approval of carotid stent for high-risk patients. The CREST trial is the largest randomized trial comparing stenting versus endarterectomy and showed no significant difference in death, stroke or myocardial infarction. Over the last 15 years, the accumulation of experience, the improvement of stent platforms and embolic protection devices, and the strong demand from patients for a less invasive alternative to carotid endarterectomy has made carotid artery stenting an equally efficient and safe procedure for the prevention of stroke.

Circulation: Cardiovascular Interventions Editors’ Picks

<i>Circulation: Cardiovascular Interventions</i> Editors’ Picks

Risk-treatment paradox in women with symptomatic coronary artery disease

The implementation of evidence-based treatment including diagnostic and therapeutic invasive procedures has resulted in a reduction in the mortality attributable to coronary artery disease (CAD) despite the fact that patients at high risk are less likely to have access to it. Women in particular are up to 30 % less likely to receive percutaneous coronary intervention (PCI) following presentation with an acute coronary syndrome than men. This risk-treatment paradox for women is partially related to their older age, greater likelihood of comorbidities, and later presentation after symptom onset with more frequent atypical symptoms as well as to the higher proportion of symptomatic women having nonobstructive CAD. In addition, during the first decade of the PCI era, a poorer short-term survival after revascularization in women was reported while similar or better long-term outcomes than men was consistently observed. The subtly different spectrum of biological factors predisposing to high risk, frequent vascular complications, and high incidence of bleeding events, mostly related to the antithrombotic drugs over dosage, explain the early hazard seen in women. Newer antithrombotic regimens and the modern coronary stent platforms have contributed to drastic improvement of outcomes, particularly in high-risk subsets of patients including women. However, still more evidence from randomized trials with a representative proportion of women is required both to fully categorize CAD in women and to determine the most appropriate approach to therapy. Furthermore, physicians must continue to work to better identify high-risk patients and to tailor the evidence-based therapy to individual risk independent of patient’s sex.

CRT-8 Final Results of the Deliver Study - The Impact of the New Resolute Integrity Stent Platform in a Real-world Population With 7740 Patients

The Resolute Integrity zotarolimus-eluting stent utilizes novel continuous sinusoid technology (CST). With CST, a single cobalt alloy wire is formed into a repeating sinusoidal pattern, wrapped helically and fused to improve conformability, provide greater flexibility and ease of delivery without

Feasibility of Polymer/Drug Coating on Absorbable and Permanent Stent Platforms - Technological Challenges

Article Feasibility of Polymer/Drug Coating on Absorbable and Permanent Stent Platforms - Technological Challenges was published on September 7, 2013 in the journal Biomedical Engineering / Biomedizinische Technik (volume 58, issue SI-1-Track-O).

The resolute™ integrity zotarolimus-eluting stent in coronary artery disease: a review.

The introduction of first-generation drug-eluting stents (DES) was a major advance in the percutaneous treatment of coronary artery disease, with DES significantly reducing the incidence of restenosis and major adverse coronary events compared with bare metal stents. Next-generation DES now utilizes lower profiles, thinner struts, and other technological advances to help extend their safety and efficacy. Importantly, studies of next-generation devices have now gone beyond controlled clinical trials with selected populations to registries and studies with all-comer populations, where more diverse and complex sets of patients and lesions have been managed. Thus, a large body of evidence and comparative data about the safety and efficacy of these devices has accumulated. The Resolute™ zotarolimus-eluting stent (R-ZES; Medtronic Inc., Santa Rosa, CA, USA) is a next-generation DES that uses a novel biocompatible polymer on a cobalt alloy stent platform to extend the duration of drug elution and improve the stent’s efficacy. The Integrity™ platform (Medtronic, Inc., Santa Rosa, CA, USA) used in the most recent iteration of the R-ZES stent further enhances the flexibility and deliverability of the stent in complex lesions by incorporation of a continuous sinusoidal design. In the following review, the clinical data is critically examined for the R-ZES and discuss its performance using comparative data currently available for next-generation DES. It is concluded that R-ZES use in complex patients and lesions is associated with durable efficacy and safety and represents another generational improvement in DES technology, which undoubtedly will enhance patient outcomes postpercutaneous coronary interventional.

Advances in Coronary Stent Technology - Active Drug-Loaded Stent Surfaces for Prevention of Restenosis and Improvement of Biocompatibility

Beyond their originally sole mechanical function, current drug-eluting stents (DES) implement the concept of local drug delivery for the re-opening of stenotic arterial vessels, and for prevention of in-stent restenosis as one of the major limitations of conventional bare metal stents (BMS). Current DES consist of a permanent metallic stent platform and an active agent being released from a drug-incorporated polymer coating or a porous stent surface. Although DES have impressively demonstrated their capability of reducing in-stent restenosis, their safety remains under debate due to potential risks, such as delayed healing, late thrombosis and hypersensitivity demanding further development. Current advancements in the stent design address the stent platform, the pharmacologically active substance and/or the drug carrier. For instance, novel biocompatible absorbable stent platforms and drug carriers are developed and novel drugs with a differential effect on vascular endothelial and smooth muscle cells, providing efficient inhibition of muscle cells without altering the endothelial cell function, are identified. Moreover, biofunctionalization of the stent's surface with capture molecules for endothelial progenitor cells are under investigation in order to achieve an in situ endothelialization of the implant. In this context, this review paper discusses the current advances in coronary stent technology with a special focus on novel stent platforms, drugs and stent coatings for the prevention of restenosis and improvement of biocompatibility.