A pooled analysis of data comparing sirolimus-eluting stents with bare-metal stents

Randomized Comparison of Novel Low-Dose Sirolimus-Eluting Biodegradable Polymer Stent vs Second-Generation DES: TARGET-IV NA Trial

BACKGROUND

Drug-eluting stents (DESs) with controlled antiproliferative drug release reduce restenosis risk, but durable polymers can delay healing and inhibit reendothelialization. The Firehawk biodegradable polymer sirolimus-eluting stent (BP-SES) has a fully biodegradable sirolimus-containing polymer coating localized to recessed abluminal grooves on the stent surface and delivers roughly one-third the drug dose of other DESs.

OBJECTIVES

We report the primary results of the TARGET-IV NA (Firehawk Rapamycin Target Eluting Coronary Stent North American Trial) randomized controlled trial comparing clinical outcomes with BP-SES vs currently used second-generation DESs.

METHODS

The TARGET-IV NA study was a prospective, multicenter, single-blind, 1:1 randomized noninferiority trial comparing the BP-SES with control in North America and Europe among patients undergoing percutaneous coronary intervention for chronic or acute coronary syndromes. The primary endpoint was target lesion failure (TLF) at 12 months (composite of cardiac death, target vessel-related myocardial infarction, or ischemia-driven target lesion revascularization). The primary analysis (intention-to-treat) tested noninferiority of BP-SES vs control using an absolute margin of 3.85% and 1-sided α of 0.025. Noninferiority-powered secondary endpoints were tested in an optical coherence tomography substudy (endpoint: mean neointimal hyperplasia thickness) and an angiography substudy (endpoint: in-stent late lumen loss).

RESULTS

A total of 1,720 patients (mean age 66 years; 74% male) with 2,159 lesions were randomly allocated to receive either BP-SES (860 patients, 1,057 lesions) or control second-generation DES (860 patients, 1,084 lesions). A total of 61% of patients presented with stable coronary disease, 32% had unstable angina, and 7% had non-ST-segment elevation myocardial infarction (NSTEMI) or recent ST-segment elevation myocardial infarction. The rate of TLF with BP-SES was noninferior to control at 12 months (3.4% vs 3.3%, absolute risk difference 0.13%, upper bound 97.5% CI: 2.03, Pnoninferiority < 0.0001). Cardiac death, myocardial infarction, and stent thrombosis rates were similar between groups. Angiographic follow-up was available in 104 patients (97.2% of those enrolled in the angiographic substudy) and 128 (94.1%) lesions. At 13 months, the powered secondary endpoint of mean in-stent late lumen loss was 0.149 ± 0.263 mm for BP-SES and 0.327 ± 0.463 mm for control (least squares mean difference: -0.178; 90% CI: -0.2943 to -0.0632; Pnoninferiority < 0.0001). The optical coherence tomography substudy included 37 patients (42 lesions) with no difference in mean neointimal hyperplasia thickness between groups at 13 months (Pnoninferiority = 0.01).

CONCLUSIONS

The biodegradable polymer sirolimus-eluting stent was noninferior to currently used second-generation DES with regard to TLF at 1 year. (Firehawk® Rapamycin Target Eluting Coronary Stent North American Trial; NCT04562532).

Long-term outcomes following ultrathin vs thin-strut drug-eluting stents for percutaneous coronary intervention: an updated systematic review and meta-analysis of randomized control trials

OBJECTIVES

Current thin-strut 2nd generation drug eluting stents (DES) are considered as optimal standard of care for revascularization of coronary artery disease (CAD) patients undergoing percutaneous coronary intervention (PCI). Ultrathin (≤ 70 μm strut thickness) strut DES have recently been shown to reduce target lesion failure (TLF) compared to thin-strut DES. Therefore, in order to assess the validity of improved outcomes associated with ultrathin-strut DES, we conducted an updated meta-analysis that includes recently published follow-ups of previously conducted randomized controlled trials (RCTs).

METHODS

MEDLINE and Scopus were queried from their inception to May 2024 to identify studies comparing outcomes between ultrathin and current thin-strut 2nd generation DES groups. A random-effects meta-analysis was conducted to derive risk ratios (RR) from dichotomous data. The primary endpoint was long-term TLF defined as a composite of cardiac death, target vessel myocardial infarction (TV-MI) and clinically driven target lesion revascularization (CD-TLR). The secondary outcome was target-vessel failure (TVF) defined as a composite of cardiac death, TV-MI and clinically driven target-vessel revascularization (CD-TVR).

RESULTS

A total of 17 RCTs (n=22141) with a mean follow-up of 34 months were included. The risk of TLF was significantly lowered in the ultrathin DES group in comparison to thin-strut DES. A significant decrease was also noted in rates of TVF, CD-TLR and CD-TVR in the ultrathin DES vs thin-strut DES group.

CONCLUSION

The results of our analysis demonstrate a significantly reduced risk of TLF in the ultrathin DES group in comparison with thin-strut DES. Ultrathin DES was also associated with a significantly decreased risk of TVF, CD-TLR and CD-TVR.

Targeted therapy with a localised abluminal groove, low-dose sirolimus-eluting, biodegradable-polymer coronary stent - five-year results of the TARGET All Comers randomised clinical trial

BACKGROUND

In the prospective, multicentre, randomised TARGET All Comers study, percutaneous coronary intervention (PCI) with the FIREHAWK biodegradable-polymer sirolimus-eluting stent (BP-SES) was non-inferior to the durable-polymer everolimus-eluting stent (DP-EES) for the primary endpoint of target lesion failure (TLF) at 12 months.

AIMS

We aimed to report the final study outcomes at 5 years.

METHODS

Patients referred for PCI were randomised to receive either a BP-SES or DP-EES in a 1:1 ratio in 10 European countries. Randomisation was stratified by centre and ST-elevation myocardial infarction (STEMI) presentation, and clinical follow-up extended to 5 years. The primary endpoint was TLF (composite of cardiac death, target vessel myocardial infarction [MI], or ischaemia-driven target lesion revascularisation). Secondary endpoints included patient-oriented composite events (POCE; composite of all-cause death, all MI, or any revascularisation and its components).

RESULTS

From December 2015 to October 2016, 1,653 patients were randomly assigned to the BP-SES or DP-EES groups, of which 93.8% completed 5-year clinical follow-up or were deceased. At 5 years, TLF occurred in 17.1% of the BP-SES group and in 16.3% of the DP-EES group (p=0.68). POCE occurred in 34.0% of the BP-SES group and 32.7% of the DP-EES group (p=0.58). Revascularisation was the most common POCE, occurring in 19.3% of patients receiving BP-SES and 19.2% receiving DP-EES, of which less than one-third was ischaemia-driven target lesion-related. In the landmark analysis, there were no differences in the rates of TLF and POCE between groups from 1 to 5 years, and these results were consistent across all subgroups.

CONCLUSIONS

In an all-comers population requiring stent implantation for myocardial ischaemia, the BP-SES was non-inferior to the DP-EES for the primary endpoint of TLF at 12 months, and results were sustained at 5 years, confirming the long-term safety and efficacy of the FIREHAWK BP-SES.

Evaluation of coronary stents: A review of types, materials, processing techniques, design, and problems

In the world, one of the leading causes of death is coronary artery disease (CAD). There are several ways to treat this disease, and stenting is currently the most appropriate way in many cases. Nowadays, the use of stents has rapidly increased, and they have been introduced in various models, with different geometries and materials. To select the most appropriate stent required, it is necessary to have an analysis of the mechanical behavior of various types of stents. The purpose of this article is to provide a complete overview of advanced research in the field of stents and to discuss and conclude important studies on different topics in the field of stents. In this review, we introduce the types of coronary stents, materials, stent processing technique, stent design, classification of stents based on the mechanism of expansion, and problems and complications of stents. In this article, by reviewing the biomechanical studies conducted in this field and collecting and classifying their results, a useful set of information has been presented to continue research in the direction of designing and manufacturing more efficient stents, although the clinical-engineering field still needs to continue research to optimize the design and construction. The optimum design of stents in the future is possible by simulation and using numerical methods and adequate knowledge of stent and artery biomechanics.

Drug-Eluting Stent Restenosis: Modern Approach to a Classic Challenge

In-stent restenosis (ISR) is a recognized complication following percutaneous coronary intervention in which the luminal diameter is narrowed through neointimal hyperplasia and vessel remodeling. Although rates of ISR have decreased in most recent years owing to newer generation drug-eluting stents, thinner struts, and better intravascular imaging modalities, ISR remains a prevalent dilemma that proves to be challenging to manage. Several factors have been proposed to contribute to ISR formation, including mechanical stent characteristics, technical factors during the coronary intervention, and biological aspects of drug-eluting stents. Presentation of ISR can range from asymptomatic to late myocardial infarction and could be difficult to differentiate from acute thrombus formation. No definite guidelines are present on the management of ISR. In this review, we will discuss the mechanisms underlying ISR and provide insight into patient-related and procedural risk factors contributing to ISR, in addition to highlighting common treatment approaches utilized in the management of ISR.

Coronary Stenting: Reflections on a 35-Year Journey

Stenting was introduced as a therapy for coronary artery disease 35 years ago, and is currently the most commonly performed minimally invasive procedure globally. Percutaneous coronary revascularization, initially with plain old balloon angioplasty and later with stenting, has dramatically affected the outcomes of acute myocardial infarction and acute coronary syndromes. Coronary stenting is probably the most intensively studied therapy in medicine on the basis of the number of randomized clinical trials for a broad range of indications. Continuous improvements in stent materials, design, and coatings concurrent with procedural innovations have truly been awe-inspiring. The story of stenting is replete with high points and some low points, such as the initial experience with stent thrombosis and restenosis, and the more recent disappointment with bioabsorbable scaffolds. History has shown rapid growth of stent use with expansion of indications followed by contraction of some uses in response to clinical trial evidence in support of bypass surgery or medical therapy. In this review we trace the constantly evolving story of the coronary stent from the earliest experience until the present time. Undoubtedly, future iterations of stent design and materials will continue to move the stent story forward.

Intracoronary brachytherapy for the treatment of recurrent drug-eluting stent in-stent restenosis: A systematic review and meta-analysis

BACKGROUND

We performed a meta-analysis on observational studies since randomized control trials are not available. We studied intracoronary brachytherapy (ICBT) and recurrent drug eluting stent in-stent restenosis (DES-ISR) to evaluate the procedural success, target lesion revascularization (TLR), incidence of myocardial infarction (MI) and all-cause mortality at 2 years follow-up.

AIM

To perform meta-analysis for patients undergoing ICBT for recurrent DES-ISR.

METHODS

We performed a systematic search of the PubMed/MEDLINE, Cochrane and DARE databases to identify relevant articles. Studies were excluded if intra-coronary brachytherapy was used as a treatment modality for initial ISR and studies with bare metal stents. We used a random-effect model with DerSimonian & Laird method to calculate summary estimates. Heterogeneity was assessed using I² statistics.

RESULTS

A total of 6 observational studies were included in the final analysis. Procedural angiographic success following intra-coronary brachytherapy was 99.8%. Incidence of MI at 1-year was 2% and 4.1% at 2-years, respectively. The incidence of TLR 14.1% at 1-year and 22.7% at 2-years, respectively. All-cause mortality at 1- and 2-year follow-up was 3% and 7.5%, respectively.

CONCLUSION

Given the observational nature of the studies included in the analysis, heterogeneity was significantly higher for outcomes. While there are no randomized controlled trials or definitive guidelines available for recurrent ISR associated with DES, this analysis suggests that brachytherapy might be the alternative approach for recurrent DES-ISR. Randomized controlled trials are required to confirm results from this study.

Novel Supreme Drug-Eluting Stents With Early Synchronized Antiproliferative Drug Delivery to Inhibit Smooth Muscle Cell Proliferation After Drug-Eluting Stents Implantation in Coronary Artery Disease: Results of the PIONEER III Randomized Clinical Trial

BACKGROUND

Accelerated endothelial healing after targeted antiproliferative drug delivery may limit the long-term inflammatory response of drug-eluting stents (DESs). The novel Supreme DES is designed to synchronize early drug delivery within 4 to 6 weeks of implantation, leaving behind a prohealing permanent base layer. Whether the Supreme DES is safe and effective in the short term and can improve long-term clinical outcomes is not known.

METHODS

In an international, 2:1 randomized, single-blind trial, we compared treatment with Supreme DES to durable polymer everolimus-eluting stents (DP-EES) in patients with acute and chronic coronary syndromes. The primary end point was target lesion failure-a composite of cardiac death, target vessel myocardial infarction, or clinically driven target lesion revascularization. The trial was designed to demonstrate noninferiority (margin of 3.58%) of the Supreme DES at 12 months compared with DP-EES (URL: https://www.clinicaltrials.gov; Unique identifier: NCT03168776).

RESULTS

From October 2017 to July 2019, a total of 1629 patients were randomly assigned (2:1) to the Supreme DES (N=1086) or DP-EES (N=543). At 12 months, target lesion failure occurred in 57 of 1057 patients (5.4%) in the Supreme DES group and in 27 of 532 patients (5.1%) in the DP-EES group (absolute risk difference, 0.32% [95% CI, -1.87 to 2.5]; P_{noninferiority}=0.002]. There were no significant differences in rates of device success, clinically driven target lesion revascularization, or stent thrombosis at 12 months, and the safety composite of cardiovascular death and target vessel myocardial infarction was 3.5% versus 4.6% (hazard ratio, 0.76 [95% CI, 0.46-1.25]) with Supreme DES compared with DP-EES, although rates of combined clinically and non-clinically driven target lesion revascularization at 12 months were higher with Supreme DES.

CONCLUSIONS

Among patients with acute and chronic coronary syndromes undergoing percutaneous coronary intervention, the Supreme DES proved to be noninferior to the standard DP-EES. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03168776.

Second generation drug-eluting stents: a focus on safety and efficacy of current devices

Introduction: Percutaneous coronary intervention (PCI) represents the most frequent procedure performed in medicine. Second generation drug eluting stents (DES) have been developed to reduce the rates of late and very late complications of first generation DES.Areas covered: To improve long-term efficacy and safety of patients undergoing PCI, second generation DES have been developed with novel stent platforms, biocompatible durable and biodegradable polymers and newer antiproliferative agents. In this review we provide an overview of second generation DES and their clinical trials, discussing safety and effectiveness of these devices, and outlining clinical indication for use.Expert commentary: Numerous clinical trials have demonstrated the safety and efficacy of second generation DES over the last decade. These devices represent the gold standard treatment in stable and acute coronary syndromes.

10-Year Follow-Up of Patients With Everolimus-Eluting Versus Bare-Metal Stents After ST-Segment Elevation Myocardial Infarction

BACKGROUND

Outcomes data for a durable-polymer everolimus-eluting stent (EES) at extended long-term follow-up in patients with ST-segment elevation myocardial infarction (STEMI) are unknown.

OBJECTIVES

The aim of this study was to assess the 10-year outcomes of patients enrolled in the EXAMINATION (A Clinical Evaluation of Everolimus Eluting Coronary Stents in the Treatment of Patients With ST-Segment Elevation Myocardial Infarction) trial.

METHODS

The EXAMINATION-EXTEND (10-Years Follow-Up of the EXAMINATION Trial) study is an investigator-driven 10-year follow-up of the EXAMINATION trial, which randomly assigned 1,498 patients with STEMI in a 1:1 ratio to receive either EES (n = 751) or bare-metal stents (n = 747). The primary endpoint was a patient-oriented composite endpoint of all-cause death, any myocardial infarction, or any revascularization. Secondary endpoints included a device-oriented composite endpoint of cardiac death, target vessel myocardial infarction, or target lesion revascularization; the individual components of the combined endpoints; and stent thrombosis.

RESULTS

Complete 10-year clinical follow-up was obtained in 94.5% of the EES group and 95.9% of the bare-metal stent group. Rates of the patient-oriented composite endpoint and device-oriented composite endpoint were significantly reduced in the EES group (32.4% vs. 38.0% [hazard ratio: 0.81; 95% confidence interval: 0.68 to 0.96; p = 0.013] and 13.6% vs. 18.4% [hazard ratio: 0.72; 95% confidence interval: 0.55 to 0.93; p = 0.012], respectively), driven mainly by target lesion revascularization (5.7% vs. 8.8%; p = 0.018). The rate of definite stent thrombosis was similar in both groups (2.2% vs. 2.5%; p = 0.590). No differences were found between the groups in terms of target lesion revascularization (1.4% vs. 1.3%; p = 0.963) and definite or probable stent thrombosis (0.6% vs. 0.4%; p = 0.703) between 5 and 10 years.

CONCLUSIONS

At 10-year follow-up, EES demonstrated confirmed superiority in combined patient- and device-oriented composite endpoints compared with bare-metal stents in patients with STEMI requiring primary percutaneous coronary intervention. Between 5- and 10-year follow-up, a low incidence of adverse cardiovascular events related to device failure was found in both groups. (10-Years Follow-Up of the EXAMINATION Trial; NCT04462315).

Treatment of Patients With Recurrent Coronary In-stent Restenosis With Failed Intravascular Brachytherapy

Intravascular brachytherapy (VBT) is an effective and safe treatment option for recurrent drug-eluting stent (DES) in-stent restenosis (ISR). However, the optimal therapy for patients with failed VBT is not well-defined. In this study, we sought to evaluate the optimal treatment strategy for patients after a failed VBT. Patients with recurrent ISR after an initial unsuccessful VBT were identified from our percutaneous coronary intervention database. Patients were divided into 2 cohorts (standard treatment with DES or balloon angioplasty versus repeat VBT). Baseline characteristics and clinical outcomes during follow-up were extracted. A total of 279 patients underwent PCI after an initial unsuccessful VBT at our institution. Of those, 215 (77%) patients underwent standard treatment with balloon angioplasty with or without DES, and 64 (33%) underwent balloon angioplasty followed by repeat VBT. The mean age of the cohort was 64±11 years. Overall, 71% were men, 47% had diabetes, and 22% had heart failure. The majority (64%) presented with unstable angina. The groups had similar baseline characteristics. The rate of major adverse cardiovascular events (defined as all-cause mortality, myocardial infarction, or target vessel revascularization) was significantly lower in the repeat VBT group at 1 year (31% vs 14%, p = 0.03), 2 years (51% vs 31%, p = 0.03), and 3 years (57% vs 41%, p = 0.08). Target lesion revascularization and target vessel revascularization were consistently lower in the repeat VBT group at all follow-up intervals than in the standard treatment group. Treatment of recalcitrant ISR following an initial failed VBT is associated with a high MACE rate at 3-year follow-up. Repeat VBT is safe and effective and should be considered as the preferred strategy.

Comparison of Endothelial Dysfunction in Coronary Arteries with Bare Metal and 2nd-Generation Drug-Eluting Stents

Aims: Previous studies suggested that implantation with a 1st-generation DES was associated with coronary endothelial dysfunction, which was associated with Rho-kinase activation. Second-generation drug-eluting stents (DESs) may preserve coronary endothelial function in stented coronary arteries; however, because of methodological limitations, further study is needed to clarify the association between 2 ^nd -generation DESs and coronary endothelial dysfunction.

Methods: We retrospectively analysed the CuVIC trial database, where we identified 112 patients who underwent coronary stenting in the left coronary arteries with either a bare metal stent (BMS, n =53) or 2 ^nd -generation DES ( n =59). We compared vasomotions of target vessels with stents and non-target vessels without stents. Furthermore, we measured the Rho-kinase activation detected in mononucleocytes from aortic and coronary sinus blood.

Results: ACh-induced vasoconstrictive responses of target vessels were not enhanced with a 2 ^nd -generation DES (45±21% vs. 44±20%, P =0.56, paired t -test), but significantly enhanced in the coronary arteries with a BMS (50±18% vs. 42±20%, P =0.002). Rho-kinase activation did not differ between patients with a BMS and 2 ^nd -generation DES. In the target vessels with a BMS, large late lumen loss and acute coronary syndrome (ACS) at the index percutaneous coronary intervention (PCI) were associated with ACh-induced enhanced coronary vasoconstrictive responses.

Conclusions: Evaluation of ACh-induced vasomotion of target vessels comparing with non-target vessels revealed that 2 ^nd -generation DESs were not associated with coronary endothelial dysfunction in target vessels, nor activation of Rho-kinase in the coronary sinus blood 6-8 months after stenting.

Computer Simulation of Platelet Adhesion around Stent Struts in the Presence and Absence of Tissue Defects around Them

Aim

To predict platelet accumulation around stent struts in the presence or absence of tissue defects around them.

Methods

Computer simulations were performed using virtual platelets implementing the function of the three membrane proteins: glycoprotein (GP) Ibα, GPIIb/IIIa, and GPVI. These platelets were perfused around the stent struts implanted into the vessel wall in the presence or absence of tissue defects around them using within the simulation platform. The number of platelets that adhered around stent struts was calculated by solving the blood flow using Navier-Stokes equation along with the adhesion of membrane protein modeled within the platform.

Results

Platelet accumulation around stent struts occurred mostly at the downstream region of the stent strut array. The majority of platelets adhered at the downstream of the first bend regardless of the tissue defect status. Platelet adhesion around stent struts occurred more rapidly in the presence of tissue defects.

Conclusion

Computer simulation using virtual platelets suggested a higher rate of platelet adhesion in the presence of tissue defects around stent struts.

Potential Effects of Nonadherent on Adherent Human Umbilical Venous Endothelial Cells in Cell Culture

The adherence and shear-resistance of human umbilical venous endothelial cells (HUVEC) on polymers is determined in vitro in order to qualify cardiovascular implant materials. In these tests, variable fractions of HUVEC do not adhere to the material but remain suspended in the culture medium. Nonadherent HUVEC usually stop growing, rapidly lose their viability and can release mediators able to influence the growth and function of the adherent HUVEC. The aim of this study was the investigation of the time dependent behaviour of HUVEC under controlled nonadherent conditions, in order to gain insights into potential influences of these cells on their surrounding environment in particular adherent HUVEC in the context of in vitro biofunctionality assessment of cardiovascular implant materials. Data from adherent or nonadherent HUVEC growing on polystyrene-based cell adhesive tissue culture plates (TCP) or nonadhesive low attachment plates (LAP) allow to calculate the number of mediators released into the culture medium either from adherent or nonadherent cells. Thus, the source of the inflammatory mediators can be identified. For nonadherent HUVEC, a time-dependent aggregation without further proliferation was observed. The rate of apoptotic/dead HUVEC progressively increased over 90% within two days. Concomitant with distinct blebbing and loss of membrane integrity over time, augmented releases of prostacyclin (PGI2, up to 2.91 ± 0.62 fg/cell) and platelet-derived growth factor BB (PDGF-BB, up to 1.46 ± 0.42 fg/cell) were detected. The study revealed that nonadherent, dying HUVEC released mediators, which can influence the surrounding microenvironment and thereby the results of in vitro biofunctionality assessment of cardiovascular implant materials. Neglecting nonadherent HUVEC bears the risk for under- or overestimation of the materials endothelialization potential, which could lead to the loss of relevant candidates or to uncertainty with regard to their suitability for cardiac applications. One approach to minimize the influence from nonadherent endothelial cells could be their removal shortly after observing initial cell adhesion. However, this would require an individual adaptation of the study design, depending on the properties of the biomaterial used.

Atherosclerosis and Nanomedicine Potential: Current Advances and Future Opportunities

Atherosclerosis is the leading inducement of cardiovascular diseases, which ranks the first cause of global deaths. It is an arterial disease associated with dyslipidemia and changes in the composition of the vascular wall. Besides invasive surgical strategy, the current conservative clinical treatment for atherosclerosis falls into two categories, lipid regulating-based therapy and antiinflammatory therapy. However, the existing strategies based on conventional drug delivery systems have shown limited efficacy against disease development and plenty of side effects. Nanomedicine has great potential in the development of targeted therapy, controlled drug delivery and release, the design of novel specific drugs and diagnostic modalities, and biocompatible scaffolds with multifunctional characteristics, which has led to an evolution in the diagnosis and treatment of atherosclerosis. This paper will focus on the latest nanomedicine strategies for atherosclerosis diagnosis and treatment as well as discussing the potential therapeutic targets during atherosclerosis progress, which could form the basis of development of novel nanoplatform against atherosclerosis.

Durable polymer everolimus-eluting stents: history, current status and future prospects

INTRODUCTION

Coronary percutaneous interventions have evolved from plain old balloon angioplasty (POBA) to stent implantation, which itself evolved from bare-metal stents (BMS) to the new biodegradable stents which try to restore endothelial function. Currently, the most commonly used stent is the everolimus-eluting stent.

AREAS COVERED

This review will cover the current status of durable polymer everolimus-eluting stent, its history, and future perspectives. Nowadays, the everolimus-eluting stent is the most used device in the acute and chronic settings due to its safety and efficacy.

EXPERT OPINION

Durable polymer everolimus-eluting stent, supported by much evidence, has demonstrated its efficacy and safety, not only in de novo artery lesions, but in multiples scenarios, such as the acute setting and diabetic population, becoming one of the most polyvalent stents available. Nowadays, research is focused on the reduction of antiplatelet treatment duration. Similar rates of stent thrombosis with short dual antiplatelet treatment regimens of 1 to 3 months compared to pronged treatment have been observed. However, specific studies should be performed to evaluate this possibility.

Evaluation of the safety and efficacy of the Cobra PzF NanoCoated coronary stent in routine, consecutive, prospective, and high-risk patients: The e-Cobra study

BACKGROUND

The Cobra PzF coronary stent is cobalt chromium with flat thin struts, nano-coated with Polyzene-F that enhance rapid reendothelialization and reduce the risk of stent thrombosis and restenosis. It is designed to overcome shortfalls of BMS and DES in patients requiring short DAPT duration.

AIMS

To report procedural and 1-year clinical outcomes following Cobra PzF stent implantation in routine practice PCI.

METHODS

e-Cobra registry is a multicenter prospective study to evaluate Cobra PzF stent in routine practice in patients deemed appropriate for short DAPT after PCI. The primary endpoint was MACE rate at 12 months (Cardiac death, MI, TLR). The secondary endpoint was definite stent thrombosis at 12 months.

RESULTS

Among 940 patients (72% men, 72.8 ± 13.4 years) with multiple co-morbidities, 47% had acute coronary syndromes, and 62% were defined as high bleeding risk. A total of 1,229 lesions were treated with 1,314 stents. 36% of patients had lesion type B2 or C classification. Angiographic success was achieved in all cases. One-year follow-up was available for 97% of patients. The primary endpoint occurred in 9.0% of patients, including cardiac death 3.7%, MI 4.8%, and TLR 4.3%. Definite stent thrombosis occurred in six out of 915 (0.7%).

CONCLUSION

The Cobra PzF stent was safe and effective in routine practice patients and seems feasible in situations when short DAPT or Mono Antiplatelet Therapy (MAPT) is needed. One-year follow-up was associated with satisfactory clinical outcomes and validate previously reported data.

Northwell intracoronary brachytherapy for the treatment of recurrent drug eluting stent in-stent restenosis (NITDI study group)

OBJECTIVE

The purpose of this study is to report on safety, short-term and long-term clinical efficacy following intracoronary brachytherapy (ICBT) for restenosis (ISR) in patients with drug eluting stents (DES).

BACKGROUND

ICBT is an effective treatment for ISR of bare metal stents (BMS) but its utilization has waned due to the advent of DES. ISR following DES occurs at a frequency of 8% or greater.

METHOD

A retrospective analysis was performed on patients treated on an institutional review board (IRB) approved protocol using ICBT for DES ISR between January 2011 and October 2016. All patients were followed for 24 months for procedural complications, mortality, clinical ISR/target lesion revascularization (TLR) and stroke.

RESULTS

A total of 290 patients were identified with a mean age of 66.6 years. All of them had high rates of typical coronary artery disease risk factors. Our primary outcome, composite of in-hospital mortality, myocardial infarction (MI), safety outcomes and procedural failure was noted in 1(0.3%) patient who had a MI. No other secondary outcome was noted in-hospital. At 1-year follow up, 12.4% patients had ISR, 1.7% patients died, and 1 (0.3%) had ischemic stroke. At 2-year, 14.7% had ISR, and total 6 (2.1%) patients had MI.

CONCLUSION

ICBT demonstrates excellent technical success rates for treatment, safety, and reasonable efficacy over 2-years to be free from recurrent clinical ISR. This study represents the largest ICBT data for DES ISR to date among very complex lesion subsets, however, more prospective data will be needed to determine the optimal patient for treatment.

Time Course of Reendothelialization with Polyzene-F Nanocoated Cobra PzF™ Coronary Stent on Rabbit Iliac Arteries

PURPOSE

Evaluation of reendothelialization with a new thin struts cobalt chromium alloy stent coated with a nano-layer of Polyzene™-F (PzF) in a rabbit iliac artery model.

METHODS

Fifteen stented external rabbit iliac arteries were harvested at Day 7 for electron microscopy analysis following Cobra PzF stents implantation to assess reendothelialization and compare to historical data. Ten additional rabbits were used to assess time course of reendothelialization at 3 and 5 days.

RESULTS

At Day 7, almost complete coverage of endothelial cells was observed with a coverage of 99.54 ± 0.25% of the stented area. No thrombus area was noted. At Day 3, more than half of examined pieces was reendothelialized and reached 78.30 ± 3.7% at Day 5 (p < .01 between each group). All stents were well expanded against the arterial wall and no struts were mal-apposed.

CONCLUSIONS

Reendothelialization was rapid and complete at Day 7. This is the fastest reendothelization process after stenting in this model. No stent occlusion was observed.

MAPT (Mono Antiplatelet Therapy) as Regular Regimen After COBRA PzF™ NanoCoated Coronary Stent (NCS) Implantation

AIMS

To report procedural and 1-year outcomes following COBRA PzF NCS implantation in a routine daily setting with high bleeding risk (HBR) patients treated with clopidogrel as mono antiplatelet therapy (MAPT).

METHODS

This is a prospective, consecutive, observational study in HBR patients who underwent PCI with COBRA PzF NCS and treated with clopidogrel alone at discharge. The primary endpoint was definite stent thrombosis at one month. The secondary endpoint was MACE (Cardiac Death, myocardial infarction (MI), target lesion revascularization (TLR)) at 12 months.

RESULTS

From October 2015 to December 2018, 77 patients with 120 lesions were enrolled and treated. Mean age was 78.7 ± 8.89 years, 58.5% men and 18.2% had ACS. Patients included had a minimum of 2.0 inclusion LEADERS FREE criteria. Angiographic success was achieved in all cases. The primary endpoint occurred in 0%, no stent thrombosis was occurred. MACE at 12-months (available for 52 patients) was 3.8% including cardiac death 0%, MI 0% and TLR 3.8%. No severe bleeding events (BARC3-5) or stroke or late stent thrombosis were noted.

CONCLUSION

Clopidogrel as MAPT after COBRA PzF NCS implantation in HBR patients is feasible and an attractive option. One-year follow-up was associated with excellent clinical outcomes and should be confirmed with large randomised study.

CONDENSED ABSTRACT

This is prospective registry of high bleeding risk patients treated with the COBRA PzF NCS and MAPT at discharge. The primary end point demonstrated no stent thrombosis. The rate of major cardiac adverse events (a composite of cardiovascular death, myocardial infarction and target lesion revascularisation) at 1 year was 3.8%. No severe bleeding events, stroke or late stent thrombosis were noted. One-year follow-up was associated with good clinical outcomes and compared favorably with current devices.

Optical coherence tomography substudy of a prospective multicentre randomised post-market trial to assess the safety and effectiveness of the Firehawk cobalt-chromium coronary stent (rapamycin target-eluting) system for the treatment of atherosclerotic lesions: TARGET All Comers

AIMS

Durable polymer drug-eluting stents (DP-DES) may contribute to persistent inflammation, delayed endothelial healing and subsequent late DES thrombosis. The aim of this optical coherence tomography (OCT) substudy was to compare healing and neointimal coverage of a novel bioabsorbable polymer sirolimus-eluting stent (Firehawk®) (BP-DES) versus the DP-DES (XIENCE) at 90 days in an all-comers patient population.

METHODS AND RESULTS

The TARGET All Comers study is a prospective multicentre randomised post-market trial of 1,656 patients randomised 1:1 to Firehawk or XIENCE at 21 centres in 10 European countries. The TARGET OCT substudy enrolled 36 consecutive patients with 52 lesions at six centres proficient in OCT. Follow-up OCT was performed at three months or prior to revascularisation when occurring before the three-month window. The substudy was designed for non-inferiority of the primary endpoint of neointimal thickness. At follow-up, the mean neointimal thickness by OCT (52 lesions: Firehawk, n=24; XIENCE, n=28), was not significantly different between groups (Firehawk 75.5 μm vs. XIENCE V 82.3 μm) meeting the primary endpoint of non-inferiority (pnoninferiority<0.001). The percentage of stent strut coverage was high in both groups (strut level: 99.9±0.3% vs. 100±0.1%, p=0.26), and the proportion of malapposed struts (1.0±1.6% vs. 1.2±2.0%, p=0.51) was low in both groups.

CONCLUSIONS

Based on OCT, the Firehawk BP-DES has a similar healing response three months after implantation compared to the DP-DES, with near complete strut coverage, moderate neointima formation and minimal strut malapposition.

Integrated Stent Delivery System: A Next Generation of Stent Delivery and Drug-Eluting Stent

The SLENDER Integrated Delivery System (IDS™) is an 'all-in-one' fixed-wire coronary stenting device designed for direct stenting, precluding the need for conventional guidewires and predilatation balloons. It achieves ultra-low profiles (crossing profiles as low as 0.029″/0.737 mm), enabling the downsizing of catheters to facilitate transradial intervention in a large subsets of patients. The IDS represents the first advance in coronary stent delivery since the introduction of rapid-exchange stent delivery systems >20 years ago. SLENDER IDS has demonstrated non-inferiority compared with commercial DES, excellent long-term safety and a potentially more efficient approach to PCI where patient comfort is enhanced, procedures are streamlined, and resource consumption is reduced. This paper will summarize the novel features of this new stent delivery system and the early clinical data demonstrating safety and efficacy.

Effect of working environment and procedural strategies on mechanical performance of bioresorbable vascular scaffolds

Polymeric bioresorbable scaffolds (BRS), at their early stages of invention, were considered as a promising revolution in interventional cardiology. However, they failed dramatically compared to metal stents showing substantially higher incidence of device failure and clinical events, especially thrombosis. One problem is that use of paradigms inherited from metal stents ignores dependency of polymer material properties on working environment and manufacturing/deployment steps. Unlike metals, polymeric material characterization experiments cannot be considered identical under dry and submerged conditions at varying rates of operation. We demonstrated different material behaviors associated with variable testing environment and parameters. We, then, have employed extracted material models, which are verified by computational methods, to assess the performance of a full-scale BRS in different working condition and under varying procedural strategies. Our results confirm the accepted notion that slower rate of crimping and inflation can potentially reduce stress concentrations and thus reduce localized damages. However, we reveal that using a universal set of material properties derived from a benchtop experiment conducted regardless of working environment and procedural variability may lead to a significant error in estimation of stress-induced damages and overestimation of benefits procedural updates might offer. We conclude that, for polymeric devices, microstructural damages and localized loss of structural integrity should complement former macroscopic performance-assessment measures (fracture and recoil). Though, to precisely capture localized stress concentration and microstructural damages, context-related testing environment and clinically-relevant procedural scenarios should be devised in preliminary experiments of polymeric resorbable devices to enhance their efficacy and avoid unpredicted clinical events. STATEMENT OF SIGNIFICANCE: Bioresorbable scaffolds (BRS) with the hope to become the next cardiovascular interventional revolution failed in comparison to metal stents. When BRS were characterized using methods for metal stents, designers were misled to seek problem sources at erroneous timeframe and use inefficient indicators, and thus no signal of concern emerged. We demonstrated fundamental flaws associated with applying a universal set of material properties to study device performances in different phases of manufacturing/implantation, and these may be responsible for failure in predicting performance in first-generation BRS. We introduced new criterion for the assessment of structural integrity and device efficacy in next-generation BRS, and indeed all devices using polymeric materials which evolve with the environment they reside in.

Targeted therapy with a localised abluminal groove, low-dose sirolimus-eluting, biodegradable polymer coronary stent (TARGET All Comers): a multicentre, open-label, randomised non-inferiority trial

BACKGROUND

The FIREHAWK is a drug-eluting stent with a fully biodegradable sirolimus-containing polymer coating localised to recessed abluminal grooves on the stent surface. We investigated clinical outcomes with this targeted, low-dose, biodegradable polymer, sirolimus-eluting stent compared with XIENCE durable polymer, everolimus-eluting stents in an all-comers population.

METHODS

The TARGET All Comers study was a prospective, multicentre, open-label randomised non-inferiority trial done at 21 centres in ten European countries. Patients with symptomatic or asymptomatic coronary artery disease and objective evidence of myocardial ischaemia who qualified for percutaneous coronary intervention were randomised 1:1 to undergo implantation of a FIREHAWK or XIENCE. Randomisation was web-based, with random block allocation and stratification by centre and ST elevation myocardial infarction. Outcome assessors were masked to treatment allocation, but treating physicians and patients were not. The primary endpoint was target lesion failure at 12 months, a composite of cardiac death, target vessel myocardial infarction, or ischaemia-driven target lesion revascularisation. The control event rate for XIENCE was assumed to be 7%, the non-inferiority margin was 3.5%, and the primary analysis was in the intention-to-treat population, censoring patients who did not have either an event before 365 days or contact beyond 365 days. Late lumen loss was the primary endpoint of an angiographic substudy designed to investigate the non-inferiority of the FIREHAWK compared with the XIENCE stent. This trial is registered with ClinicalTrials.gov, number NCT02520180.

FINDINGS

From Dec 17, 2015, to Oct 14, 2016, 1653 patients were randomly assigned to implantation of the FIREHAWK (n=823) or XIENCE (n=830). 65 patients in the FIREHAWK group and 66 in the XIENCE group had insufficient follow-up data and were excluded from the analyses. At 12 months, target lesion failure occurred in 46 (6·1%) of 758 patients in the FIREHAWK group and in 45 (5·9%) of 764 patients in the XIENCE group (difference 0·2%, 90% CI -1·9 to 2·2, p_{non-inferiority}=0·004, 95% CI -2·2 to 2·6, p_superiority=0·88). There were no differences in ischaemia-driven revascularisation or stent thrombosis rates at 12 months. 176 patients were included in the angiographic substudy, in which in-stent late lumen loss was 0·17 mm (SD 0·48) in the FIREHAWK group and 0·11 mm (0·52) in the XIENCE group (p=0·48), with an absolute difference of 0·05 mm (95% CI -0·09 to 0·18, p_{non-inferiority}=0·024).

INTERPRETATION

In a broad all-comers population of patients requiring stent implantation for myocardial ischaemia, the FIREHAWK was non-inferior to the XIENCE as assessed with the primary endpoint of target lesion failure at 12 months and in-stent late lumen loss at 13 months. The FIREHAWK is a safe and effective alternative stent to treat patients with ischaemic coronary artery disease in clinical practice.

FUNDING

Shanghai Microport Medical.

In vitro and in vivo evaluation of a novel polymer-free everolimus-eluting stent by nitrogen-doped titanium dioxide film deposition

Inflammation and thrombosis are linked to the use of polymer-based drug-eluting stents (DES). The aim of this study was to develop a polymer-free everolimus (EVL)-eluting stent using nitrogen-doped titanium dioxide (N-TiO₂) and verify its efficacy by in vitro and in vivo assessment in a porcine coronary model. Various analytical approaches such as scanning electron microscopy and atomic force microscopy, electron spectroscopy, Fourier transform infrared spectrometry and contact angle measurement were employed for the characterization. As a part of biocompatibility assessment, platelet adhesion and smooth muscle cell (SMC) proliferation were examined. Bare metal stent (BMS), N-TiO₂ stent, everolimus-eluting N-TiO₂ (N-TiO₂-EVL) stent, and commercialized EVL-eluting stent (EES) were randomly placed in forty coronary arteries in twenty pigs. After four weeks of implantation, the stents were subjected to histological and quantitative analysis. The N-TiO₂ film used in this study was well coated without any cracks or peeling. Surface hydrophilicity (88.8% of angle decrement) could be associated with the decrease in surface roughness post N-TiO₂ deposition (37.0%). The platelet adhesion on the N-TiO₂ surfaces was less than that on the BMS surface. The proliferation of SMC was suppressed in the N-TiO₂-EVL group (30.2%) but not in the BMS group. In the animal study, the percent area restenosis was significantly decreased in the N-TiO₂-EVL group compared to that in the BMS group. The results (BMS; 47.0 ± 11.00%, N-TiO₂-EVL; 31.7 ± 10.50%, and EES; 29.1 ± 11.21%, n = 10, p < 0.05) were almost at par with those of the commercialized EVL-eluting stent. The introduction of N-TiO₂ deposition during fabrication of polymer-free DES may be an efficient accessorial process for preventing in-stent restenosis and thrombosis.

Prevention of in-stent restenosis with endothelial progenitor cell (EPC) capture stent placement combined with regional EPC transplantation: An atherosclerotic rabbit model

BACKGROUND

Even with drug-eluting stents, the risk of in-stent restenosis (ISR) remains high. The goal of this study was to investigate the use of an endothelial progenitor cell (EPC) capture stent plus regional EPC transplantation to reduce the ISR rate.

METHODS

Endothelial progenitor cell capture stents were fabricated using fibrin gel and anti-CD34 plus anti-VEGFR-2 dual antibodies. Twenty male New Zealand white rabbits established as an atherosclerotic model were randomly divided into two groups: group 1 (n = 10), in which EPC capture stents were deployed into the right iliac artery; and group 2 (n = 10), in which sirolimus-eluting stents were placed. In both groups, EPCs were transplanted into target vessels beyond the stents, with outflow blocked. Radiologic-pathologic correlation outcomes were reviewed after 2 months.

RESULTS

The technical success rate of EPC capture stent placement plus EPC transplantation was 100%. The ISR rate in group 1 was lower than in group 2 (1/10 vs. 4/10; p > 0.05). Minimal luminal diameters were larger in group 1 than in group 2 (computed tomographic angiography, 1.85 ± 0.15 mm vs. 1.50 ± 0.20 mm; duplex ultrasound, 1.90 ± 0.10 mm vs. 1.70 ± 0.30 mm; p > 0.05). Transplanted EPCs were tracked positively only in group 1. Pathologic analysis demonstrated neointimal hyperplasia thickness of 0.21 ± 0.09 mm in group 1 vs. 0.11 ± 0.07 mm in group 2 (p < 0.05).

CONCLUSION

Endothelial progenitor cell capture stent placement plus local EPC transplant decreases the ISR rate through thrombosis reduction rather than through neointimal hyperplasia inhibition.

Strain-induced accelerated asymmetric spatial degradation of polymeric vascular scaffolds

Polymer-based bioresorbable scaffolds (BRS) seek to eliminate long-term complications of metal stents. However, current BRS designs bear substantially higher incidence of clinical failures, especially thrombosis, compared with metal stents. Research strategies inherited from metal stents fail to consider polymer microstructures and dynamics--issues critical to BRS. Using Raman spectroscopy, we demonstrate microstructural heterogeneities within polymeric scaffolds arising from integrated strain during fabrication and implantation. Stress generated from crimping and inflation causes loss of structural integrity even before chemical degradation, and the induced differences in crystallinity and polymer alignment across scaffolds lead to faster degradation in scaffold cores than on the surface, which further enlarge localized deformation. We postulate that these structural irregularities and asymmetric material degradation present a response to strain and thereby clinical performance different from metal stents. Unlike metal stents which stay patent and intact until catastrophic fracture, BRS exhibit loss of structural integrity almost immediately upon crimping and expansion. Irregularities in microstructure amplify these effects and can have profound clinical implications. Therefore, polymer microstructure should be considered in earliest design stages of resorbable devices, and fabrication processes must be well-designed with microscopic perspective.

Histopathological comparison of biodegradable polymer and permanent polymer based sirolimus eluting stents in a porcine model of coronary stent implantation

Biodegradable stent coatings were recently introduced as a potential solution to overcome sustained inflammatory responses observed with permanent polymer-based drug-eluting stents. In a preliminary study, selected biodegradable or permanent polymer-based sirolimus-eluting stent (SES) formulations were screened for effectiveness in comparison to bare metal stents (BMS) at 28 days. Subsequently, the most favourable SES formulation was compared to commercially available SES (CypherTM) at 28,90 and 180 days to investigate the histopathologic response as well as tissue, blood and organ pharmacokinetics. Overlapping SES implantation was conducted to evaluate vascular healing at 28 days in this particular setting. SES with biodegradable poly (L-lactide) polymer (PLLA) or poly(lactide-co-glycolide) showed the most favourable outcome with regards to reductions in neointimal area in comparison to BMS at 28 days. The PLLA SES showed a similar reduction in neointimal area compared to CypherTM at 28 days, with significant greater reductions at 90 and 180 days (1.7 ± 0.7 mm2 vs. 3.1 ± 1.5 mm2, p=0.03 and 1.8 ± 1.2 mm2 vs. 3.0 ± 1.5 mm2, p=0.01, respectively). Sirolimus vascular tissue concentrations were detectable up to 90 days following implantation. Overlapping stented segments showed favourable histopathologic results with respect to fibrin deposition and endothelialisation at 28 days. In conclusion, the use of PLLA as drugeluting matrix resulted in mild inflammatory responses in the presence of effective sirolimus tissue concentrations. The greater efficacy observed at long-term follow-up in PLLA SES compared to CypherTM may be a multifactorial result of stent design, polymer biocompatibility and improved release kinetics.

Evaluation and efficacy of long length Pronova XR Bioabsorbable Polymer stent in the treatment of long coronary lesions

Aim

The study aims an observational registry of the long and extra-long length (>33 mm) Pronova XR stents in patients with long coronary lesions (>30 mm) in a prospective real world study.

Methods and results

Current study was conducted at Ruby Hall Clinic Pune, between July 2012 and July 2013 including 30 patients who underwent PTCA using long and extra-long Pronova XR stents. Among the stents used, one stent - 33 mm, 2 stents - 38 mm, 5 stents - 43 mm and 25 stents were of 48 mm in length. In particular average stent length for the study was 46.03 mm and the average stent diameter was 3.09 ± 0.41 mm.

For this study coronary angioplasty was performed using femoral approach and standard practice. Lesions were predilated using undersized balloons and study stent was deployed at pressure 7–26 atm. (12.8 ± 3.2 atm.) The successful delivery of stent at the intended lesion with visual residual stenosis less than 50% was defined as Procedural success. Follow up studies were conducted for all the patients at 30 days, 3 months and 6 months intervals. The predefined QCA parameters were calculated using Sanders Data System QCA plus software (Palo Alto, CA, USA).

No procedural complication was observed during the whole study. 100% successful stent placement was achieved in all patients. Six months clinical follow-up was available for all patients. No adverse events (Acute closure, angina, REPCI, MI, death, sub acute stent thrombosis) or hospitalization was reported for any of the patients except one. The Quantative Coronary Core Lab analysis post 6 months showed well-flowing stent with average late lumen loss 0.10 mm ±0.26.

Conclusion

In patients with long coronary lesions and very long length stent implantation series, Pronova XR showed excellent in 6 months results. This is for the first time reported that use of long length Pronova XR stents has shown so low restenosis rate and absent of mortality in six month period. These results offer a new opportunity to single long length stenting.

Evaluation of the Svelte Medical systems SLENDER IDS Sirolimus-eluting coronary stent-on-a-wire integrated delivery system for the treatment of coronary artery disease

INTRODUCTION

The SLENDER Integrated Delivery System (IDS™) is an 'all-in-one' fixed-wire coronary stenting device designed for direct stenting, precluding the need for conventional guidewires and predilatation balloons. It achieves ultra-low profiles (crossing profiles as low as 0.031" / 0.79), enabling the downsizing of catheters to facilitate TRI across wider subsets of patients. Areas covered: This paper aims to evaluate the SLENDER IDS for the treatment of coronary artery disease. Expert commentary: The system represents the first advance in coronary stent delivery since the introduction of rapid-exchange stent delivery systems more than 20 years ago. SLENDER IDS has demonstrated non-inferiority compared with commercial DES, excellent long-term safety and a potentially more efficient approach to PCI where patient comfort is enhanced, procedures are streamlined and resource consumption is reduced.

A biaxial strain-based expansion mechanism for auxetic stent deployment

BACKGROUND

Auxetics, a special class of materials, tend to expand both in the radial and longitudinal directions when a unidirectional tensile force is applied. Recently, studies have come up with new designs for auxetic vascular and nonvascular stents which are deployed with commercial balloon catheters. There are some inherent limitations associated with a unidirectional application of expansion force in the effective deployment of stents. This work proposed a solution to some of these limitations through the use of a biaxial mode of a predetermined strain-based expansion mechanism.

METHOD

The design incorporated a pressure-activated crank-slider mechanism. Fabrication of a prototype for experimental verification was carried out through milling and high-speed lathe machining. The testing of the device employed the use of auxetic stents, fabricated from a biocompatible polymer. A finite element study is presented to extrapolate experimental results to a broader range of operation and working conditions.

RESULTS AND CONCLUSIONS

The expansion mechanism is similar in operation to the opening of an umbrella. The length of the connected auxetic stent increases when internal hydraulic pressure is applied. The degree of linear expansion in 1 direction influences the expansion of auxetic stent in the lateral direction. As the device exerts pressure longitudinally, a larger amount of the force is distributed on the unit cells/hinges which ultimately results in an increased expansion of the stent.

Safety and Efficacy of New Biodegradable Polymer-based Sirolimus-Eluting Stents in a Preclinical Model

INTRODUCTION AND OBJECTIVES

New drug-eluting stents (DES) designed to overcome the limitations of existing devices should initially be tested in preclinical studies. Our objective was to analyze the safety and efficacy of new biodegradable polymer-based DES compared with bare-metal stents (BMS) and commercially available DES in a model of normal porcine coronary arteries.

METHODS

We randomly implanted 101 stents (BMS and biodegradable polymer-based sirolimus-eluting stents: 3 test stent iterations [BD1, BD2, and BD3], Orsiro, Biomime and Biomatrix) in the coronary arteries of 34 domestic pigs. Angiographic and histomorphometric studies were conducted 1 month (n = 83) and 3 months (n = 18) later.

RESULTS

The stents were implanted at a stent/artery ratio of 1.31 ± 0.21, with no significant differences between groups. At 1 month, the new test stents (BD1, BD2 and BD3) showed less late loss and angiographic restenosis, as well as lower histologic restenosis and neointimal area (P < .0005), than the BMS. There were no differences in endothelialization, vascular injury, or inflammation between the new test stents and BMS, although the new stents showed higher fibrin deposition (P = .0006). At 3 months, all these differences disappeared, except for a lower neointimal area with the new BD1 stent (P = .027). No differences at any time point were observed between the new test stents and commercially available controls.

CONCLUSIONS

In this preclinical model, the new biodegradable polymer-based DES studied showed less restenosis than BMS and no significant differences in safety or efficacy vs commercially available DES.

ST-Segment Elevation Myocardial Infarction with Acute Stent Thrombosis Presenting as Intractable Hiccups: An Unusual Case

Patient: Male, 51

Final Diagnosis: ST-segment elevation myocardial infarction with acute stent thrombosis

Symptoms: Chest pain • hiccups

Medication: —

Clinical Procedure: —

Specialty: Cardiology

First and second generation DESs reduce diabetes adverse effect on mortality and re-intervention in multivessel coronary disease: 9-Year analysis

BACKGROUND/PURPOSE

Diabetes portends an increased risk of adverse early and late outcomes in patients undergoing PCI. In this study, we aimed to investigate if the adverse effect of diabetes mellitus (DM) on early and late PCI outcomes is reduced with drug-eluting (DES) compared to bare-metal (BMS) stents.

METHODS/MATERIALS

We reviewed the Mount Sinai Beth Israel Hospital first PCI experience for multivessel coronary artery disease (CAD, 1998-2009). Patients were excluded if they had single-vessel CAD, emergency, no stent, prior bypass graft or myocardial infarction <24h. Diabetes-effect was derived from 9-year all-cause mortality and re-intervention risk-adjusted hazard ratios [AHR (95% confidence intervals)] for DES (N=2679; 48% three-vessel; 39% DM) and BMS (N=2651; 40% three-vessel; 33% DM) and then stratified based on stent (DES/BMS) and vessel disease (two/three).

RESULTS

Diabetes-effect on mortality was lower for DES (AHR_DM/NoDM=1.41 [1.14-1.74]) versus BMS (AHR_DM/NoDM=1.71 [1.50-2.01]), but this was predominantly driven by two-vessel patients. This diabetes effect was similar for first (DES1: AHR_DM/NoDM=1.43 [1.14-1.79]) and second (DES2: AHR_DM/NoDM=1.53 [0.77-3.07]) generation DES. Re-intervention comparisons were similarly increased by diabetes in all sub-cohorts.

CONCLUSIONS

Our analysis of a large real-world PCI series indicates that diabetes is associated with worse 9-year mortality irrespective of stent type, albeit this is mitigated to varying degrees with DES, particularly in DES2 and in case of 2-vessel disease. A complementary stent-effect analysis confirmed DES-to-BMS and DES2-to-DES1 superiority in both diabetics and non-diabetics.

Efficacy and safety of a biodegradable polymer Cobalt-Chromium sirolimus-eluting stent (EXCROSSAL) in treating de novo coronary artery disease: A pooled analysis of the CREDIT II and CREDIT III trials

BACKGROUND

The safety and efficacy of the second-generation biodegradable polymer Cobalt-Chromium sirolimus-eluting stent (EXCEL2) in daily clinical practice remains unknown. Additionally, to meet the China Food and Drug Administration requirements, we conducted an objective performance criterion study from the CREDIT II and CREDIT III trials.

METHODS

CREDIT II was a randomized trial comparing the EXCEL2 versus EXCEL stent in patients with up to 2 de novo coronary lesions. CREDIT III was a prospective, single-arm study evaluating the efficacy and safety of EXCEL2 in broad types of de novo coronary artery lesions. This pooled analysis included patients in the CREDIT III and EXCEL2 arm of the CREDIT II trial. The primary outcome was 12-month target lesion failure (TLF), a composite of cardiac death, target vessel myocardial infarction (TV-MI), and clinical indicated target lesion revascularization (CI-TLR). The patient-oriented composite endpoint (PoCE) of all-cause death, all MI, or any revascularization was also analyzed.

RESULTS

A total of 833 patients were included, consisting of 625 in the CREDIT III trial and 208 in the EXCEL2 arm of the CREDIT II trial. Twelve-month TLF occurred in 6.1% patients, cardiac death in 0.4%, TV-MI in 5%, and CI-TLR in 1.1%. Additionally, 64 (7.7%) PoCE and 3 probable late stent thromboses (0.4%) were recorded.

CONCLUSION

EXCEL2 stent met the objective performance criterion on efficacy and safety with a low level of 12-month TLF as well as stent thrombosis when treating patients with de novo coronary lesions. © 2017 Wiley Periodicals, Inc.

Impact of stent diameter and length on in-stent restenosis after DES vs BMS implantation in patients needing large coronary stents-A clinical and health-economic evaluation

AIMS

The British National Institute of Clinical Excellence (NICE) guidelines recommend to use drug-eluting stents (DES) instead of bare-metal stents (BMS) only in lesions >15 mm in length or in vessels <3 mm in diameter. We analyzed the impact of stent length and stent diameter on in-stent restenosis (ISR) in the BASKET-PROVE study population and evaluated the cost-effectiveness of DES compared to BMS.

METHODS/RESULTS

The BASKET-PROVE trial compared DES vs BMS in large coronary arteries (≥3 mm). We calculated incremental cost-effectiveness ratios (ICERs) and cost-effectiveness acceptability curves with regard to quality-adjusted life years (QALYs) gained and target lesion revascularizations (TLRs) avoided. A total of 2278 patients were included in the analysis. A total of 74 ISR in 63 patients were observed. In-stent restenosis was significantly more frequent in segments treated with a BMS compared to segments treated with a DES (5.4% vs 0.76%; P<.001). The benefit of a DES compared to a BMS regarding ISR was consistent among the subgroups of stent length >15 mm and ≤15 mm, respectively. With the use of DES in short lesions, there was only a minimal gain of 0.005 in QALYs. At a threshold of 10 000 CHF per TLR avoided, DES had a high probability of being cost-effective.

CONCLUSION

In the BASKET-PROVE study population, the strongest predictor of ISR is the use of a BMS, even in patients in need of stents ≥3.0 mm and ≤15 mm lesion length and DES were cost-effective. This should prompt the NICE to reevaluate its recommendation to use DES instead of BMS only in vessels <3.0 mm and lesions >15 mm length.

Comparison of Clinical Outcomes in Patients Undergoing Coronary Intervention with Drug-Eluting Stents or Bare-Metal Stents: A Nationwide Population Study

BACKGROUND

The aim of this propensity score-matched cohort study was to investigate the prognostic impacts of drug-eluting stents (DES) and bare-metal stents (BMS) in patients undergoing percutaneous coronary intervention (PCI).

METHODS

We conducted a retrospective cohort study based on the National Health Insurance program. Patients who had undergone coronary stenting between Jan. 2007 and Dec. 2008 were recruited and monitored until the end of 2010. Subjects with either BMS or DES were matched 2:1 by propensity score, which adjusted for age, sex, stent number and Charlson comorbidity index (CCI). The Kaplan-Meier method and Cox regression models were used for prognostic analyses.

RESULTS

Among a total of 966 patients with a mean age of 66 years, 644 subjects had BMS and 322 subjects had DES. The incidence of myocardial infarction (MI) and death were significantly lower in the DES group as compared with the BMS group for the three-year follow-up duration. With adjustments for age, sex, premium-based monthly salary, levels of hospital care, stent number, CCI, medications, and acute coronary syndrome presentation in the index hospitalization, use of DES rather than BMS was associated with reduced adverse coronary events (hazard ratio and 95% confidence interval: 0.55, 0.38-0.81 in the whole population, and 0.44, 0.26-0.73 in the subgroup patients with stable coronary artery disease).

CONCLUSIONS

Implantation of DES was related to better outcomes than for BMS, in terms of reducing MI and mortality after PCI. The survival benefit for patients with DES was even greater in patients with stable coronary artery disease.

Three-month evaluation of strut healing using a novel optical coherence tomography analytical method following bioresorbable polymer everolimus-eluting stent implantation in humans: the TIMELESS study

AIMS

Bioresorbable polymer drug-eluting stent technologies have been considered to have the potential to enhance vascular healing by reducing polymer exposure to the vessel wall, potentially allowing the earlier discontinuation of dual antiplatelet therapy. At present, the early vascular healing response to this type of technologies is still unclear.

PATIENTS AND METHODS

The TIMELESS study is a multicenter, prospective, single-arm study that enrolled real-world patients undergoing percutaneous coronary intervention. All patients underwent Synergy stent implantation, which consists of a platinum-chromium platform coated with an ultra-thin abluminal bioabsorbable poly-D,L-lactide-co-glycolide polymer-eluting everolimus.

RESULTS

A total of 37 patients were included in the study. The majority of the patients underwent percutaneous coronary intervention because of acute coronary syndromes. At 3 months, angiographic follow-up showed a percentage diameter of stenosis of 8.1±7.5% and an angiographic late loss of 0.03±0.24 mm. In all analyzed struts, less than 1% of struts were definitely uncovered or covered with fibrin, 12.5% (5.0-18.5%) showed evidence of partial coverage, and the remaining (∼85%) were fully covered. No stent thrombosis was observed up to 12 months of clinical follow-up.

CONCLUSION

In a real-world population, the implantation of a bioresorbable polymer drug-eluting stent resulted in almost complete strut coverage throughout the entire stent length at 3 months. The clinical implications for antiplatelet therapy and outcomes should be investigated further.