Differential Response of Delayed Healing and Persistent Inflammation at Sites of Overlapping Sirolimus- or Paclitaxel-Eluting Stents

Recent Advances in the Treatment of Coronary In-Stent Restenosis

In-stent restenosis (ISR) remains the predominant cause of stent failure and the most common indication for repeat revascularization. Despite technological advances in stent design, ISR continues to pose significant challenges, contributing to increased morbidity and mortality among patients undergoing percutaneous coronary interventions. In the last decade, intravascular imaging has emerged as an important method for identifying the mechanisms behind ISR and guiding its treatment. Treatment options for ISR have expanded to include balloon angioplasty, cutting or scoring balloons, intravascular lithotripsy, atheroablative devices, drug-eluting stents, drug-coated balloons, surgical revascularization, and intravascular brachytherapy. The aim of the current review is to describe the classification and mechanisms of ISR, provide a comprehensive and updated overview of the evidence supporting different treatment strategies, suggest a management algorithm, and present insights into future developments in the field.

A Prospective, Randomized Trial of Bioresorbable Polymer Drug-Eluting Stents versus Fully Bioresorbable Scaffolds in Patients Undergoing Coronary Stenting

Background: The performance of an everolimus-eluting bioresorbable scaffold (BRS) was inferior to an everolimus-eluting metallic drug-eluting stent (DES) with permanent polymer, mainly due the mechanical features of BRS technology. The performance of BRS as compared to metallic DES with bioresorbable polymers remains unstudied. Methods: This prospective, randomized, multicenter, clinical trial enrolled patients who underwent coronary stenting for de novo coronary lesions. Patients were randomly assigned to bioresorbable polymer everolimus-eluting stents (BP-EES) or everolimus-eluting BRS. The primary endpoint was percentage diameter stenosis (in-device) at 6- to 8-month angiographic surveillance. The main secondary endpoint was the device-oriented composite endpoint (DOCE) of cardiac death/target vessel-myocardial infarction/target lesion revascularization assessed after 12 months and 5 years. Results: The trial was prematurely terminated after the enrollment of 117 of 230 patients (BP-EES, n = 60; BRS, n = 57) due to safety issues associated with BRS technology. The primary endpoint of in-device diameter stenosis at angiographic surveillance was 12.5 ± 7.7% with BP-EES versus 19.3 ± 16.5% with BRS (p = 0.01). The DOCE occurred in 5.0% in the BP-EES group versus 12.3% of patients in the BRS group (hazard ratio [HR] 2.48, 95% confidence interval [CI] 0.64-9.58, p = 0.19) after 12 months and in 11.7% in the BP-EES group versus 26.4% of patients in the BRS group (HR 2.38, 95% CI 0.97-5.84, p = 0.06) after 5 years. Conclusions: BP-EES showed superior mid-term angiographic performance compared with BRS. Clinical event rates did not differ significantly between the groups up to 5 years of follow-up. These results should be interpreted with caution in view of the premature discontinuation of the study.

Dynamic investigation of zein-based degradable and hemocompatible coatings for drug-eluting stents: a microfluidic approach

Biodegradable stent coatings have shown great potential in terms of delivering drugs to a damaged vessel wall, and their release profiles are key elements governing the overall performance of drug-eluting stents (DESs). However, release and degradation kinetics are usually not tested under simulated physiological conditions or in dynamic environments, both essential aspects in the design of novel DESs. To bridge this gap, fused silica-based microfluidic systems, with either round or square channel cross-sections, were designed to mimic the microenvironment of a stented vessel. In particular, we fabricated and characterized microfluidic chips based on customizable channels, which were spray-coated with a naturally-derived, rutin-loaded zein solution, to perform a comprehensive study under flow conditions. Dynamic assays after 6 hours showed how the degradation of the zein matrix was affected by the cross-sectional conformation (∼69% vs. ∼61%, square and round channel, respectively) and the simulated blood fluid components (∼55%, round channel with a more viscous solution). The released amount of rutin was ∼81% vs. ∼77% and ∼78% vs. ∼74% from the square and round channels, using the less and more viscous blood-simulated fluids, respectively. Fitting the drug release data to Korsmeyer-Peppas and first-order mathematical models provided further insight into the mechanism of rutin release and coating behavior under flowing conditions. More importantly, whole blood tests with our newly developed microfluidic platforms confirmed the hemocompatibility of our zein-based coating. In detail, in-flow and static studies on the blood cell behavior showed a significant reduction of platelet adhesion (∼73%) and activation (∼93%) compared to the stainless-steel substrate, confirming the benefits of using such naturally-derived coatings to avoid clogging. Overall, our microfluidic designs can provide a key practical tool for assessing polymer degradation and drug release from degradable matrices under flowing conditions, thus aiding future studies on the development of hemocompatible, controlled-release coatings for DESs.

Paclitaxel exerts antiplatelet and antithrombotic activities: Additional benefit from use of paclitaxel-coated balloons and -eluting stents in coronary revascularization and prevention of in-stent restenosis

INTRODUCTION

Paclitaxel is a microtubule-stabilizing drug used to treat several types of cancer, including ovarian and breast cancer. Because of its antiproliferative effect on vascular smooth muscle cells, balloons and stents are coated with paclitaxel for use in coronary revascularization and prevention of in-stent restenosis (ISR). However, mechanisms underlying ISR are complicated. Platelet activation is one of the major causes of ISR after percutaneous coronary intervention. Although the antiplatelet activity of paclitaxel was noted in rabbit platelets, the effect of paclitaxel on platelets remains unclear. This study investigated whether paclitaxel exhibits antiplatelet activity in human platelets.

METHODS AND RESULTS

Paclitaxel inhibited platelet aggregation induced by collagen but not that induced by thrombin, arachidonic acid, or U46619, suggesting that paclitaxel is more sensitive to the inhibition of collagen-induced platelet activation. Moreover, paclitaxel blocked collagen receptor glycoprotein (GP) VI downstream signaling molecules, including Lyn, Fyn, PLCγ2, PKC, Akt, and MAPKs. However, paclitaxel did not directly bind to GPVI and cause GPVI shedding, as detected by surface plasmon resonance and flow cytometry, respectively, indicating that paclitaxel may interfere with GPVI downstream signaling molecules, such as Lyn and Fyn. Paclitaxel also prevented granule release and GPIIbIIIa activation induced by collagen and low convulxin doses. Moreover, paclitaxel attenuated pulmonary thrombosis and delayed platelet thrombus formation in mesenteric microvessels without significantly affecting hemostasis.

CONCLUSION

Paclitaxel exerts antiplatelet and antithrombotic effects. Thus, paclitaxel may provide additional benefits beyond its antiproliferative effect when used in drug-coated balloons and drug-eluting stents for coronary revascularization and prevention of ISR.

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

BACKGROUND

Diffuse coronary artery disease (CAD) is a prognostic factor after percutaneous coronary intervention (PCI) and requires multiple overlapping stent implantations.

HYPOTHESIS

We investigated the impact of ultra-long 48 mm drug-eluting stent (DES) on procedural and clinical outcomes in real-world practice.

METHODS

Patients who underwent DES implantation for a lesion length of >40 mm were selected from a prospective registry between 2019 and 2021. Patients treated with one or more ultra-long 48 mm DES were in the ultra-long DES group (n = 221). The others comprised the conventional DES group (n = 428). Procedural and clinical outcomes were compared after propensity score matching (PSM). The primary endpoint was a device-oriented composite outcome (DOCO) consisting of cardiac death, target vessel-related myocardial infarction, and target lesion revascularization at 1-year follow-up.

RESULTS

After PSM, 158 matched pairs of patients showed no differences in the baseline clinical and angiographic characteristics. The stent delivery failure rate, the use of guide-extension catheter or anchor balloon technique, and the procedural success rate were similar for both groups. Approximately two-thirds of lesions could be treated with one DES in the ultra-long DES group. At 1-year follow-up, the DOCO was similar for both groups (2.5% vs. 0.6%, p = .168).

CONCLUSIONS

In daily clinical practice, ultra-long DES implantation is as safe and effective as multiple overlapping conventional DES implants in treating diffuse long CAD. However, ultra-long DES can reduce the number of stents. (Trial Registration: ClinicalTrials.gov Identifier: NCT02038127).

The Effects of Sirolimus and Magnesium on Primary Human Coronary Endothelial Cells: An In Vitro Study

Drug eluting magnesium (Mg) bioresorbable scaffolds represent a novel paradigm in percutaneous coronary intervention because Mg-based alloys are biocompatible, have adequate mechanical properties and can be resorbed without adverse events. Importantly, Mg is fundamental in many biological processes, mitigates the inflammatory response and is beneficial for the endothelium. Sirolimus is widely used as an antiproliferative agent in drug eluting stents to inhibit the proliferation of smooth muscle cells, thus reducing the occurrence of stent restenosis. Little is known about the potential interplay between sirolimus and Mg in cultured human coronary artery endothelial cells (hCAEC). Therefore, the cells were treated with sirolimus in the presence of different concentrations of extracellular Mg. Cell viability, migration, barrier function, adhesivity and nitric oxide synthesis were assessed. Sirolimus impairs the viability of subconfluent, but not of confluent cells independently from the concentration of Mg in the culture medium. In confluent cells, sirolimus inhibits migration, while it cooperates with Mg in exerting an anti-inflammatory action that might have a role in preventing restenosis and thrombosis.

Assessment of Nit-Occlud atrial septal defect occluder device healing process using micro-computed tomography imaging

After percutaneous implantation of a cardiac occluder, a complex healing process leads to the device coverage within several months. An incomplete device coverage increases the risk of device related complications such as thrombosis or endocarditis. We aimed to assess the device coverage process of atrial septal defect (ASD) occluders in a chronic sheep model using micro-computed tomography (micro-CT). After percutaneous creation of an ASD, 8 ewes were implanted with a 16-mm Nit-Occlud ASD-R occluder (PFM medical, Cologne, Germany) and were followed for 1 month (N = 3) and 3 months (N = 5). After heart explant, the device coverage was assessed using micro-CT (resolution of 41.7 μm) and was compared to histological analysis. The micro-CT image reconstruction was performed in 2D and 3D allowing measurement of the coverage thickness and surface for each device. Macroscopic assessment of devices showed that the coverage was complete for the left-side disk in all cases. Yet incomplete coverage of the right-side disk was observed in 5 of the 8 cases. 2D and 3D micro-CT analysis allowed an accurate evaluation of device coverage of each disk and was overall well correlated to histology sections. Surface calculation from micro-CT images of the 8 cases showed that the median surface of coverage was 93±8% for the left-side disk and 55±31% for the right-side disk. The assessment of tissue reactions, including endothelialisation, after implantation of an ASD occluder can rely on in vitro micro-CT analysis. The translation to clinical practice is challenging but the potential for individual follow-up is shown, to avoid thrombotic or infective complications.

Neointimal characteristic changes following drug-coated balloons in lesions with repeated revascularization

BACKGROUND

Since their emergence, drug-coated balloons (DCBs) have been used widely to treat in-stent lesions with coronary artery disease (CAD). However, despite their superior efficacy to balloon angioplasty, how DCBs affect neointimal characteristics is poorly understood.

OBJECTIVES

We aimed to assess the neointimal characteristic changes following DCB treatment.

METHODS

Using optical frequency domain imaging (OFDI), we serially observed the in-stent lesion site just after and 1 year after DCB angioplasty in 12 lesions of 11 patients with repeated revascularization. Neoatherosclerosis was defined as lipid-laden neointima with or without calcification in the stented lesion. Progression or regression of neoatherosclerosis, newly formed neointimal calcification, newly formed uncovered strut and newly formed evagination were assessed. Tiny tissue protrusion was also recorded as mushroom-like protrusion.

RESULTS

Underlying stents were first-generation (n = 5) or newer (n = 7) drug-eluting stents (DESs) with implantation durations ranging from 1 to 15 years (median 8 years). Surprisingly, two-thirds of the lesions (67%, 8 of 12) showed progression of neoatherosclerosis, while a quarter of lesions (25%, 3 of 12) showed regression of neoatherosclerosis. The maximal lipid arc increased from 122° to 174°. Newly formed neointimal calcification was observed in 2 of 12 lesions (16%). Newly formed uncovered struts (33%; 4 of 12) and newly formed evaginations (33%; 4 of 12) were not rare. Mushroom-like protrusion was found in a quarter of lesions (25%; 3 of 12).

CONCLUSION

Our study demonstrated that a considerable number of lesions showed varied neointimal characteristic changes in a small number of patients. Further studies in a larger population are needed to understand the clinical impact of these findings.

Provisional or 2-Stent Technique for Bifurcation Lesions in the Second-Generation Drug-Eluting Stent Era

Background

For bifurcating coronary lesions, a provisional stent technique is recommended compared with a routine 2-stent strategy. However, much of these data are from trials involving first-generation drug-eluting stents (DES) or bare-metal stents where the risk of restenosis with the 2-stent technique is higher. We investigated the efficacy of various 2-stent techniques versus a provisional stent technique for bifurcation lesions with newer-generation DES.

Methods

PubMed and Embase were searched through May 2022 for randomized control trials investigating bifurcation percutaneous coronary intervention techniques using newer-generation DES, and a meta-analysis was conducted. The primary end point was major adverse cardiovascular events (MACE) at the longest reported follow-up time.

Results

Our study identified 13 randomized control trials including 4041 patients. Compared with the provisional technique, 2-stent techniques significantly decreased MACE (hazard ratio [HR], 0.76; 95% CI, 0.59-0.97; P = .03), target vessel myocardial infarction (HR, 0.38; 95% CI, 0.20-0.71; P = .002), and target vessel revascularization (HR, 0.66; 95% CI, 0.47-0.93; P = .02). There were no significant differences in all-cause mortality (HR, 0.94; 95% CI, 0.62-1.45; P = .79), cardiovascular mortality (HR, 0.82; 95% CI, 0.49-1.38; P = .45), myocardial infarction (HR, 1.00; 95% CI, 0.73-1.37; P = .99), and stent thrombosis (HR, 0.86; 95% CI, 0.52-1.44; P = .58). Of the 2-stent techniques, the double kissing crush technique significantly decreased MACE and target lesion revascularization than other 2-stent techniques.

Conclusions

In this era of newer-generation DES, a 2-stent approach, especially the double kissing crush technique, is superior to a provisional stenting technique for a bifurcation lesion, with a significant reduction in MACE, target vessel myocardial infarction, and revascularization.

Safety and efficacy of 48 mm Xience Xpedition everolimus-eluting stent for the treatment of long coronary lesions

INTRODUCTION

Long drug-eluting stents may limit the issue of overlapping multiple stents when treating long coronary lesions.

AIM

The aim of the study was to assess the safety and efficacy of the 48 mm Xience Xpedition everolimus-eluting stent (48mm-EES) for the treatment of long coronary lesions, in an all-comer population.

METHODS

Patients receiving at least one 48mm-EES were prospectively included from March 2014 to December 2018. The primary endpoint was target lesion failure (TLF), defined as a composite of cardiac death, target vessel myocardial infarction, and clinically driven target lesion revascularization (TLR) at 1 year. The main secondary endpoint was the patient-oriented composite endpoint (POCE) defined as a composite of death, stroke, myocardial infarction, and reintervention.

RESULTS

A total of 268 patients with 276 long coronary lesions, including 94 chronic total occlusions (CTO), were successfully treated using at least one 48mm-EES. The total stent length per lesion was 66 ± 22 mm. A single 48mm-EES was suitable to successfully treat the target lesion in 48% of cases (60% for non-CTO lesions). One-year follow-up rate was 96.3%. TLF occurred in 13 patients (5.3%), mainly driven by TLR (4.1%). Two cardiac death occurred (0.7%). POCE occurred in 30 patients (11.6%) mainly driven by repeat revascularization (9.7%). Definite stent thrombosis was observed in two patients (0.7%). No difference was observed in one-year outcomes between single 48mm-EES and multiple stents implantation as well as between CTO and non-CTO lesions.

CONCLUSION

The 48mm-EES is safe and effective to treat long coronary lesions, including CTOs, and provides attractive cost-effectiveness by limiting multiple stenting.

The Mechanisms of Restenosis and Relevance to Next Generation Stent Design

Stents are lifesaving mechanical devices that re-establish essential blood flow to the coronary circulation after significant vessel occlusion due to coronary vessel disease or thrombolytic blockade. Improvements in stent surface engineering over the last 20 years have seen significant reductions in complications arising due to restenosis and thrombosis. However, under certain conditions such as diabetes mellitus (DM), the incidence of stent-mediated complications remains 2–4-fold higher than seen in non-diabetic patients. The stents with the largest market share are designed to target the mechanisms behind neointimal hyperplasia (NIH) through anti-proliferative drugs that prevent the formation of a neointima by halting the cell cycle of vascular smooth muscle cells (VSMCs). Thrombosis is treated through dual anti-platelet therapy (DAPT), which is the continual use of aspirin and a P2Y₁₂ inhibitor for 6–12 months. While the most common stents currently in use are reasonably effective at treating these complications, there is still significant room for improvement. Recently, inflammation and redox stress have been identified as major contributing factors that increase the risk of stent-related complications following percutaneous coronary intervention (PCI). The aim of this review is to examine the mechanisms behind inflammation and redox stress through the lens of PCI and its complications and to establish whether tailored targeting of these key mechanistic pathways offers improved outcomes for patients, particularly those where stent placement remains vulnerable to complications. In summary, our review highlights the most recent and promising research being undertaken in understanding the mechanisms of redox biology and inflammation in the context of stent design. We emphasize the benefits of a targeted mechanistic approach to decrease all-cause mortality, even in patients with diabetes.

Optical coherence tomographic insights of very late stent thrombosis of a second-generation drug-eluting stent: a case report

Background

Very-very late stent thrombosis (VVLST) occurring more than 5 years after implantation of drug-eluting stent (DES) is extremely rare, being restricted to few case reports. Mainly described with first-generation stents, this life-threatening complication has not been described with later-generation stents. We describe the first case of VVLST occurring 3309 days (>9 years) after implantation of second-generation DES.

Case summary

A 62-year-old man presented with the acute coronary syndrome. He has a history of percutaneous coronary intervention (PCI) to the right coronary artery using the three second-generation DES more than 9 years ago. Coronary angiogram revealed in-stent restenosis (ISR) with doubtful angiographic thrombus. Optical coherence tomography (OCT) confirmed the diagnosis of stent thrombosis (STh) localized to the stent overlap zone with underlying ISR. Patient underwent OCT-guided PCI with DES implantation and was discharged on dual antiplatelet therapy including ticagrelor. He is doing well on follow-up at 6 months.

Discussion

Stent thrombosis can occur in second-generation stents nearly a decade after implant. Stent overlap segment is more prone to neo-atheroma formation and vulnerable plaque leading to STh. In addition to confirming the diagnosis, OCT provides exciting insights into the underlying mechanism. This has implications for long-term antiplatelet therapy in patients implanted with multiple stents.

Preclinical Evaluation of a Novel Polymer-free Everolimus-eluting Stent in a Mid-term Porcine Coronary Restenosis Model

BACKGROUND

Titanium dioxide films exhibit good biocompatibility and may be effective as drug-binding matrices for drug-eluting stents. We conducted a mid-term evaluation of a novel polymer-free everolimus-eluting stent using nitrogen-doped titanium dioxide film deposition (TIGEREVOLUTION^®) in comparison with a commercial durable polymer everolimus-eluting stent (XIENCE Alpine^®) in a porcine coronary restenosis model.

METHODS

Twenty-eight coronary arteries from 14 mini-pigs were randomly allocated to TIGEREVOLUTION^® stent and XIENCE Alpine^® stent groups. The stents were implanted in the coronary artery at a 1.1-1.2:1 stent-to-artery ratio. Eleven stented coronary arteries in each group were finally analyzed using coronary angiography, optical coherence tomography, and histopathologic evaluation 6 months after stenting.

RESULTS

Quantitative coronary analysis showed no significant differences in the pre-procedural, post-procedural, and 6-month lumen diameters between the groups. In the volumetric analysis of optical coherence tomography at 6 months, no significant differences were observed in stent volume, lumen volume, and percent area stenosis between the groups. There were no significant differences in injury score, inflammation score, or fibrin score between the groups, although the fibrin score was zero in the TIGEREVOLUTION^® stent group (0 vs. 0.07 ± 0.11, P = 0.180).

CONCLUSION

Preclinical evaluation, including optical coherence tomographic findings 6 months after stenting, demonstrated that the TIGEREVOLUTION^® stent exhibited efficacy and safety comparable with the XIENCE Alpine^® stent, supporting the need for further clinical studies on the TIGEREVOLUTION^® stent.

Nano-crush technique in narrow angle (<70˚) bifurcation - bench test, computed tomographic reconstruction, fluid dynamics, and clinical outcomes

BACKGROUND

Bifurcation stenting techniques are still refining and under testing. Nano-crush is a novel technique which allow minimum protrusion of side branch struts at the ostium. To demonstrate the efficacy of Nano-crush technique in narrow-angle bifurcation (<70˚) using bench test model, 3D reconstruction of the stent structure, computational fluid dynamics study and a clinical follow-up.

METHODS

This was a retrospective observational single-centre study which included 40 patients who underwent angioplasty using Nano-crush technique for de-novo complex coronary bifurcation lesions with narrow bifurcation angle(<70˚) between April-2016 to March-2019. The in-vitro bench test and computational fluid dynamics analysis were performed using a bifurcation model designed. The clinical primary endpoint was major adverse cardiac events (MACE), defined as a composite of cardiac death, myocardial infarction, and target lesion revascularization (TLR) at one-year angiographic follow-up.

RESULTS

The reconstructed results of in-vitro bench test showed minimum length of stent struts moving away from the rounded side branch ostium. The mean age of patients was 62.8 ± 7.98 years (32 male) and presented 100% procedural success. The mean bifurcation angle was 47.3˚ ± 9.2˚. The MACE was reported in 4 (10%) patients which included 1 (2.5%) death and 3 (7.5%) TLR at the mean follow-up of 35.54 ± 12.31 months. No significant correlation between occurrence of MACE and gender, age, comorbidities and bifurcation angle was reported.

CONCLUSIONS

The Nano-crush technique demonstrated least metal load around carina and abnormal flow dynamics in narrow angle (<70˚) bifurcation lesions and also reported favorable long-term clinical outcomes.

[Morphological and Molecular-Biological Changes in the Coronary Arteries after Stenting]

This review addresses morphological changes in coronary arteries following stenting, which result from damage to the vascular wall. These changes include 1) formation of a thrombus in the site of intimal injury; 2) inflammation; 3) proliferation and migration of smooth muscle cells; 4) formation of extracellular matrix. Each of these pathological processes has specific morpho-biological features. The review shows the role of von Willebrand factor in development of early thrombosis after intimal injury, which provokes activation of the inflammatory response followed by proliferation of smooth muscle cell that synthetize the extracellular matrix. These cellular and intercellular changes are based on overexpression of TGF-β1 protein, which facilitates modulation of various types of smooth muscle cells, including contractile and secretory ones. Issues of fine regulation of cellular and intercellular interactions by apoptosis, activation of mTOR signaling molecules, and microRNA are still understudied. Dynamic changes in drug-coated stents during development of neoatherosclerosis and late thrombosis remain not elucidated. Current reports show that initial mechanisms triggering pathological regenerative and hyperplastic processes that result in coronary restenosis in the area of implanted stents may form early (first hours or days) after stenting. Most studies were performed on experimental rather than on autopsy material, which does not allow fully unbiased interpretation of obtained data. Studying dynamics of morphological and molecular changes in coronary arteries after stenting, including on autopsy material, will allow one to express an opinion on the risk of postoperative thrombosis and restenosis.

Drug-Coated Balloon for Arteriovenous Access Stenosis in Hemodialysis Patients

Hemodialysis access stenosis is a pervasive problem that occurs due to the physiology of the high-flow circuit. Stenosis occurs due to endothelial and smooth muscle injuries that result in neointimal hyperplasia. Percutaneous transluminal angioplasty is the standard treatment for dialysis access-induced stenosis. Unfortunately, it is also associated with vessel wall trauma, which causes further intimal hyperplasia and restenosis. Data from randomized controlled trials (RCTs) and systematic reviews of the use of drug-coated balloons (DCBs) for dialysis access stenosis have been controversial. While several single-center trials or RCTs have reported safe and effective use of DCBs, conflicting results still exist. Furthermore, paclitaxel is known to be associated with an increased mortality risk. Herein, we review the current evidence on the role of DCBs in the treatment of dialysis access stenosis.

Evolution of antithrombotic therapy in patients undergoing percutaneous coronary intervention: a 40-year journey

Since its introduction in 1977, percutaneous coronary intervention has become one of the most commonly performed therapeutic procedures worldwide. Such widespread diffusion, however, would have not been possible without a concomitant evolution of the pharmacotherapies associated with this intervention. Antithrombotic agents are fundamental throughout the management of patients undergoing coronary stent implantation, starting from the procedure itself to the long-term prevention of cardiovascular events. The last 40 years of interventional cardiology have seen remarkable improvements in both drug therapies and device technologies, which largely reflected a progressive understanding of the pathophysiological mechanisms of coronary artery disease, as well as procedure- and device-related adverse events. The purpose of this article is to provide an overview of the important milestones in antithrombotic pharmacology that have shaped clinical practice of today while also providing insights into knowledge gaps and future directions.

Heparin-Tagged PLA-PEG Copolymer-Encapsulated Biochanin A-Loaded (Mg/Al) LDH Nanoparticles Recommended for Non-Thrombogenic and Anti-Proliferative Stent Coating

Drug-eluting stents have been widely implanted to prevent neointimal hyperplasia associated with bare metal stents. Conventional polymers and anti-proliferative drugs suffer from stent thrombosis due to the non-selective nature of the drugs and hypersensitivity to polymer degradation products. Alternatively, various herbal anti-proliferative agents are sought, of which biochanin A (an isoflavone phytoestrogen) was known to have anti-proliferative and vasculoprotective action. PLA-PEG diblock copolymer was tagged with heparin, whose degradation releases heparin locally and prevents thrombosis. To get a controlled drug release, biochanin A was loaded in layered double hydroxide nanoparticles (LDH), which are further encapsulated in a heparin-tagged PLA-PEG copolymer. LDH nanoparticles are synthesized by a co-precipitation process; in situ as well as ex situ loading of biochanin A were done. PLA-PEG-heparin copolymer was synthesized by esterification reaction, and the drug-loaded nanoparticles are coated. The formulation was characterized by FTIR, XRD, DSC, DLS, and TEM. In vitro drug release studies, protein adhesion, wettability, hemocompatibility, and degradation studies were performed. The drug release was modeled by mathematical models to further emphasize the mechanism of drug release. The developed drug-eluting stent coating is non-thrombogenic, and it offers close to zero-order release for 40 days, with complete polymer degradation in 14 weeks.

Percutaneous Intervention in Diffuse Coronary Disease: Overlapping Versus Single Very Long Stent Technique. Results From the OVERLONG Registry

BACKGROUND

Both stent length and stent overlap are associated with worse outcomes in the percutaneous treatment of diffuse coronary artery disease (dCAD). However, evidence comparing these issues is scarce. We aimed to compare the results between the use of single very long stent (VLS) and ≥2 overlapping stents (OS) in the treatment of dCAD.

METHODS

Seven hundred twenty-four consecutive lesions were included: 275 treated with a single VLS (≥40 mm) and 449 with ≥2 OS. Procedural characteristics were assessed, and survival analysis was performed to compare the incidence of major adverse cardiovascular events (MACE; composite of cardiovascular death, nonfatal myocardial infarction, target lesion revascularization [TLR], or stent thrombosis) during a median follow-up of 31 months.

RESULTS

Procedures with VLS required less contrast volume (268 ± 122 vs 302 ± 113 cm3; P < .01), fluoroscopy time (16 ± 8 vs 21 ± 16 minutes; P < .01), and procedure duration (37 ± 18 vs 47 ± 27 minutes; P < .01) than the OS procedures. The VLS group showed lower incidence of MACE (4.4% vs 10.7%; P < .01), driven mainly by lower TLR rate (1.1% vs 4.7%; P < .01). The use of OS was an independent predictor of MACE.

CONCLUSIONS

In this study, the use of VLS for the treatment of dCAD was associated with better outcomes compared to OS.

Perfusion Balloon for the Treatment of Very Late Stent Thrombosis

A method to manage ST-segment elevated myocardial infarction (STEMI) caused by very late stent thrombosis (VLST) has yet to be established. In this case series, we present several cases of STEMI caused by VLST, which were successfully revascularized using a perfusion balloon. Since the perfusion balloon (Ryusei: Kaneka Medix Corporation, Osaka, Japan) has the unique advantage of maintaining blood flow during balloon inflation, we can keep dilating the target lesion for more than several minutes. Extended inflation might work to prevent acute recoil, and to achieve optimal expansion without an additional stent. Our case series may provide a reasonable option for the treatment of VLST.

Inflammation as a determinant of healing response after coronary stent implantation

Cardiovascular disease remains the leading cause of death and morbidity worldwide. Inflammation plays an important role in the development of atherosclerosis and is associated with adverse clinical outcomes in patients after percutaneous coronary interventions. Data on stent elements that lead to excessive inflammatory response, proper identification of high-risk patients, prevention and treatment targeting residual inflammatory risk are limited. This review aims to present the role of inflammation in the context of evolving stent technologies and appraise the potential imaging modalities in detection of inflammatory response and anti-inflammatory therapies.

Pseudoaneurysm Development after Drug-Eluting Balloon (DEB) Angioplasty of a Venous Femoropopliteal Bypass Graft

Endovascular recanalization of occluded venous femoropopliteal bypass grafts is widely used because of easy access. This case report describes pseudoaneurysm developing 4 weeks after endovascular recanalization of an occluded in situ venous femoropopliteal graft. The patient was treated for a popliteal aneurysm with a venous femoropopliteal bypass graft, which subsequently occluded. Four weeks after DEB PTA, the occluded graft developed 3 pseudoaneurysms. Impaired vessel wall healing after intraluminal paclitaxel administration could have contributed to this. This case adds a perspective to the choice of treatment of occluded venous femoropopliteal bypass grafts.

Overlapping Drug-Eluting Stent Is Associated with Increased Definite Stent Thrombosis and Revascularization: Results from 15,561 Patients in the AUTHENTIC Study

PURPOSE

This study was to analyze the incidence of definite stent thrombosis (ST) after the implantation of drug-eluting stents (DESs) and cutoff value of overlapping length for predicting definite ST. An overlapping stent is associated with a high rate of clinical events after DES implantation compared with a non-overlapping stent. However, the rates of definite ST and clinical outcomes from a large patient population remain underreported.

METHODS

A total of 15,561 patients with 24,183 lesions who underwent DES implantation from January 2005 to February 2017 were retrospectively included in 5 tertiary hospitals in China. The main endpoint was the incidence of definite ST after procedures.

RESULTS

With a median of 1932 (IQR = 1194-2929) days, clinical follow-up was available in 7484 patients in the overlap group and in 8077 patients in the non-overlap group. The rates of definite ST were 3.1% in the overlap group and 1.2% in the non-overlap group (HR: 2.67 (95% CI: 2.11-3.38), p < 0.001). Of the 24,183 treated lesions, the incidences of definite ST were 2.4% in the overlap group and 0.9% in the non-overlap group (HR: 2.96 (95% CI: 2.38-3.69), p < 0.001). Stent overlap was associated with a higher rate of target lesion revascularization (TLR) (9.4%) compared with stent non-overlap (6.4%, p < 0.001). The length of overlapping stent ≥ 2.93 mm strongly correlated with definite ST.

CONCLUSION

The present study shows that overlapping DES increases definite ST and revascularization in patients during long-term follow-up. In addition, the longer overlapping zone was associated with worse clinical outcomes.

Flexible endoscopic micro-optical coherence tomography for three-dimensional imaging of the arterial microstructure

Micro-optical coherence tomography (µOCT) is a novel imaging approach enabling visualization of the microstructures of biological tissues at a cellular or sub-cellular level. However, it has been challenging to develop a miniaturized flexible endoscopic µOCT probe allowing helical luminal scanning. In this study, we built a flexible endoscopic µOCT probe with an outer diameter of 1.2 mm, which acquires three-dimensional images of the arterial microstructures via helical scanning with an axial and lateral resolutions of 1.83 µm and 3.38 µm in air, respectively. Furthermore, the depth of focus of the µOCT imaging probe was extended two-fold using a binary phase spatial filter. We demonstrated that the present endoscopic µOCT could image cellular level features of a rabbit artery with high-risk atheroma and a bioresorbable scaffold-implanted swine coronary artery. This highly-translatable endoscopic µOCT will be a useful tool for investigating coronary artery disease and stent biology.

Vascular autophagy in health and disease

Homeostasis is maintained within organisms through the physiological recycling process of autophagy, a catabolic process that is intricately involved in the mobilization of nutrients during starvation, recycling of cellular cargo, as well as initiation of cellular death pathways. Specific to the cardiovascular system, autophagy responds to both chemical (e.g. free radicals) and mechanical stressors (e.g. shear stress). It is imperative to note that autophagy is not a static process, and measurement of autophagic flux provides a more comprehensive investigation into the role of autophagy. The overarching themes emerging from decades of autophagy research are that basal levels of autophagic flux are critical, physiological stressors may increase or decrease autophagic flux, and more importantly, aberrant deviations from basal autophagy may elicit detrimental effects. Autophagy has predominantly been examined within cardiac or vascular smooth muscle tissue within the context of disease development and progression. Autophagic flux within the endothelium holds an important role in maintaining vascular function, demonstrated by the necessary role for intact autophagic flux for shear-induced release of nitric oxide however the underlying mechanisms have yet to be elucidated. Within this review, we theorize that autophagy itself does not solely control vascular homeostasis, rather, it works in concert with mitochondria, telomerase, and lipids to maintain physiological function. The primary emphasis of this review is on the role of autophagy within the human vasculature, and the integrative effects with physiological processes and diseases as they relate to the vascular structure and function.

Clinical Prognosis Associated With the Use of Overlapping Stents With Homogenous Versus Heterogeneous Pharmacological Characteristics for the Treatment of Diffuse Coronary Artery Disease

BACKGROUND

The clinical impact of percutaneous coronary intervention (PCI) and implantation of overlapping stents (OS) using platforms with the same versus different pharmacological characteristics is unknown. Our objective was to compare the outcomes of PCI with OS according to their pharmacological characteristics.

METHODS

In this observational single-center registry, we included all PCI performed from April 2014 to December 2018 in which overlapping drug-eluting stents were implanted. Two groups were created according to whether the stents release the same drug [homogeneous: (HO)] or different [heterogeneous: (HE)]. The primary endpoint was the need for target lesion revascularization (TLR). Clinical assessment was performed after the procedure, bianually and at the end of follow-up (June 2019).

RESULTS

381 lesions with OS (HO: 209; HE: 172) were included (75.1% male, 66.7 ± 11.6 years). Clinical presentation was stable coronary artery disease in 49.9%. Syntax score was 23.7 ± 13.3. The number of OS implanted was 2.2 ± 0.5 and the total stent length was 59.5 ± 20.1 mm (HE: 61.5 ± 21.6 vs. HO: 57.8 ± 18.8 mm; p < 0.01). After a median follow-up of 21 months, the HE group showed a lower TLR rate than the HO group (HE:2.3% vs HO:7.2%; p = 0.03). The rates of cardiac death (p = 0.44), myocardial infarction (p = 0.36) and stent thrombosis (p = 0.85) were similar between groups. In the multivariate analysis, the OS with homogeneous-drug devices was an independent predictor of a higher rate of TLR.

CONCLUSIONS

PCI using OS with homogeneous pharmacological characteristics was associated with a higher rate of TLR in comparison with the implantation of OS with heterogeneous pharmacological characteristics.

Clinical considerations and recommendations for OCT-guided carotid artery stenting

Introduction: Optical Coherence Tomography (OCT) is an intravascular imaging providing high-resolution images of morphological features of arterial wall. Nowadays, OCT is an accepted intravascular modality to study coronary arteries, stent implantation, and vessel injury. In the last decade, an increasing interest have been focused on the application of OCT in carotid arteries.Areas covered: Literature evidence in the application of OCT in carotid arteries still remains debated. So far, OCT has been used as a research tool, aiming to evaluate atherosclerotic plaques' features and stents' behavior after implantation. This paper is intended to summarize clinical evidences and practices in the use of OCT in carotid arteries district and during CAS procedures. Literature review was completed via Pubmed search using Keywords.Expert opinion: CAS is a safe and effective procedure when performed by trained physicians with a tailored approach. In this scenario, ambiguous pictures at ultrasound, angiography, and IVUS might be clarified using OCT.By providing unprecedented microstructural information on atherosclerotic plaques, OCT may identify the features of vulnerable carotid plaque and, by identifying possible defects after stent implantation as malapposition and plaque prolapse, it may help the tailoring approach to CAS.

Impact of ultra-long sirolimus-eluting stents on coronary artery lesions: one-year results of real-world FLEX-LONG Study

BACKGROUND

The FLEX-LONG study assessed the safety and clinical outcomes of ultra-long (44 mm/48 mm) biodegradable polymer-coated Supraflex (Sahajanand Medical Technology Pvt. Ltd., Surat, India) sirolimus-eluting stents (SES) in real-world patients with complex, long coronary artery lesions.

METHODS

It was an investigator-initiated, retrospective, non-randomized, observational and single-center study, which evaluated one-year results of 141 patients who had undergone implantation of at least one ultra-long (44 mm/48 mm) Supraflex SES. The incidence of major adverse cardiac events (MACE), a composite of cardiac death, myocardial infarction (MI) and target lesion revascularization (TLR), at one-year follow-up was considered as primary outcome. Stent thrombosis was analyzed as a safety outcome.

RESULTS

The mean age of the study population was 56.2±9.6 years and 78.0% (110/141) patients were male. The study analyzed high risk patients, including 62 (44.0%) hypertensive and 60 (42.6%) diabetic patients. Total 147 target lesions were treated, including 25 (17.0%) total occlusions. Total 51 (34.7%) and 96 (65.3%) Supraflex SES of 44 mm and 48 mm were implanted, respectively. Average stent length and diameter were 46.6±1.9 mm and 3.4±0.2 mm, respectively. One-year follow-up was obtained in 100% of patients. There was one probable stent thrombosis after three weeks. At one-year follow-up, 99.3% of patients remained event free.

CONCLUSIONS

The results of the FLEX-LONG study support the use of ultra-long (44 mm/48 mm) Supraflex SES, in the treatment of high-risk real-world patients. The stent appeared to be safe and effective at one-year with low clinical events in complex, long coronary artery lesions.

Preclinical Evaluation of a Novel Sirolimus-Eluting Iron Bioresorbable Coronary Scaffold in Porcine Coronary Artery at 6 Months

OBJECTIVES

The aim of this study was to investigate the operability, 6-month efficacy, and safety of the novel sirolimus-eluting iron bioresorbable coronary scaffold (IBS) system compared with a cobalt-chromium everolimus-eluting stent (EES) (XIENCE Prime stent) in porcine coronary arteries.

BACKGROUND

Bioresorbable scaffolds have been considered the fourth revolution in percutaneous coronary intervention. However, the first-generation bioresorbable scaffold showed suboptimal results.

METHODS

Forty-eight IBS and 48 EES were randomly implanted into nonatherosclerotic swine. The operability, efficacy, and safety of the IBS and EES were evaluated using coronary angiography, optical coherence tomography, micro-computed tomography, scanning electron microscopy, and histopathologic evaluation at 7, 14, 28, 90, and 180 days after implantation.

RESULTS

The operability of the ultrathin IBS (∼70 μm) was comparable with that of the EES, except for its visibility. There was no statistically significant difference in area stenosis between the IBS and EES from 28 to 180 days. The IBS maintained its integrity up to 90 days without corrosion, while corrosion was observed in a few struts in 2 of 10 IBS at 180 days. The percentage of endothelialization of IBS was higher than that of XIENCE Prime stents within 14 days after implantation. The fibrin score was higher in the IBS group at 28 days but comparable with the EES group at 90 and 180 days. No scaffold or stent thrombosis was seen in either group. No abnormal histopathologic changes in scaffolded or stented vessel segments and 5 main remote organs were observed in either group.

CONCLUSIONS

Preclinical results suggest that the novel IBS has comparable operability, mid-term efficacy, and safety with the EES, and its corrosion profile in porcine coronary arteries is reasonable, which could support initial clinical study of the IBS.

Decreased mean perfusion pressure as an independent predictor of acute kidney injury after cardiac surgery

Acute kidney injury after cardiac surgery (AKICS) is common. Previous studies examining the role that mean arterial pressure (MAP) during cardiopulmonary bypass (CPB) may have on AKICS have not taken into account how baseline central venous pressure (CVP) and mean perfusion pressure (MPP) (i.e. MAP − CVP) can influence its evolution. To assess whether the change in MPP to the kidneys (i.e. delta MPP or DMPP) during CPB compared to baseline is an independent predictor of AKICS. After ethical approval, a retrospective observational study was performed on all patients undergoing CPB between October 2013 and June 2015 at a university-affiliated hospital. Known risk factors for the development of AKICS were recorded, as were the MPP values at baseline and during CPB. From this, statistical modelling was performed to identify predictors of postoperative AKICS. 664 patients were identified. Analysis was performed on 513 patients after exclusion. On logistic regression, significant and independent predictors of AKICS included: d20DMPP (cumulative duration of MPP values during CPB that were 20% below baseline and exceeded three consecutive minutes) (P = 0.010); baseline CVP; age; pre-operative creatinine level; and left ventricular (LV) dysfunction (ejection fraction (EF) < 45%). On alternative modelling, the cumulative number of MPP values during CPB that were 10% below baseline was also independently associated with AKICS (P = 0.003). Modelling without taking into account CVP also supported this association. The duration of differences in perfusion pressure to the kidneys during CPB compared to baseline is an independent predictor of AKICS.

Effect of resveratrol combined with atorvastatin on re-endothelialization after drug-eluting stents implantation and the underlying mechanism

AIMS

To explore whether the combination of atorvastatins and resveratrol is superior to each individual drug alone regarding re-endothelialization after drug-eluting stents (DESs) implantation.

MATERIALS AND METHODS

Ninety-four rabbits were randomized into control, atorvastatin, resveratrol, and combined medication groups. Abdominal aorta injury was induced via ballooning, followed by DES implantation. Neointimal formation and re-endothelialization after stent implantation were assessed via optical coherence tomography and scanning electron microscopy. The effects of resveratrol and atorvastatin on bone marrow-derived mesenchymal derived stem cells (BMSCs) were assessed.

KEY FINDINGS

Compared with the findings in the resveratrol and atorvastatin groups, the neointimal area and mean neointimal thickness were greater in the combined medication group, which also exhibited improved re-endothelialization. Compared with the effects of monotherapy, combined treatment further protected BMSCs against rapamycin-induced apoptosis and improved cell migration. Combined medication significantly upregulated Akt, p-Akt, eNOS, p-eNOS, and CXCR4 expression in BMSCs compared with the effects of monotherapy, and these effects were abolished by the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002.

SIGNIFICANCE

The combination of atorvastatin and resveratrol has the potential of accelerating re-endothelialization after stent implantation, reducing the risk of thrombosis and improving the safety of DESs.

Comparison of Morphological Patterns Between In-Stent Restenosis Lesions of Overlapping and Non-Overlapping Second- and Third-Generation Stents Using Optical Frequency Domain Imaging

PURPOSE

To analyze the difference in morphological patterns between in-stent restenosis (ISR) lesions of overlapping segments and ISR lesions of non-overlapping segments with second- and third-generation drug-eluting stents (DESs) using optical frequency domain imaging (OFDI).

METHODS

We analyzed 23 consecutive ISR lesions after second- or third-generation DES implantation using OFDI.

RESULTS

A total of 18 men and 5 women (median age, 68.0 years; interquartile range, 51.0-74.0 years) were included in the analysis. Fourteen and nine patients underwent second- and third-generation DES implantation, respectively. The median ISR detection timepoint was 10.0 months after implantation (interquartile range, 9.0-34.0 months). In 9 out of 23 lesions, ISR was found in the stent overlap area (overlapping segment group); the remaining 14 cases were categorized as the non-overlapping segment group. In OFDI analysis, homogeneous, layered, and heterogeneous patterns were found in 22%, 55%, and 22%, respectively, of lesions in the overlapping segment group and 14%, 50%, and 35%, respectively, of lesions in the non-overlapping segment group. There was no difference in the distribution of restenotic tissue structure patterns between the groups (p = .756).

CONCLUSIONS

Morphological assessments of ISR tissue using OFDI showed no difference between the overlapping and non-overlapping segment groups with second and third-generation DESs in this hypothesis generating study.

Randomised comparison of provisional side branch stenting versus a two-stent strategy for treatment of true coronary bifurcation lesions involving a large side branch: the Nordic-Baltic Bifurcation Study IV

Background

It is still uncertain whether coronary bifurcations with lesions involving a large side branch (SB) should be treated by stenting the main vessel and provisional stenting of the SB (simple) or by routine two-stent techniques (complex). We aimed to compare clinical outcome after treatment of lesions in large bifurcations by simple or complex stent implantation.

Methods

The study was a randomised, superiority trial. Enrolment required a SB≥2.75 mm, ≥50% diameter stenosis in both vessels, and allowed SB lesion length up to 15 mm. The primary endpoint was a composite of cardiac death, non-procedural myocardial infarction and target lesion revascularisation at 6 months. Two-year clinical follow-up was included in this primary reporting due to lower than expected event rates.

Results

A total of 450 patients were assigned to simple stenting (n=221) or complex stenting (n=229) in 14 Nordic and Baltic centres. Two-year follow-up was available in 218 (98.6%) and 228 (99.5%) patients, respectively. The primary endpoint of major adverse cardiac events (MACE) at 6 months was 5.5% vs 2.2% (risk differences 3.2%, 95% CI -0.2 to 6.8, p=0.07) and at 2 years 12.9% vs 8.4% (HR 0.63, 95% CI 0.35 to 1.13, p=0.12) after simple versus complex treatment. In the subgroup treated by newer generation drug-eluting stents, MACE was 12.0% vs 5.6% (HR 0.45, 95% CI 0.17 to 1.17, p=0.10) after simple versus complex treatment.

Conclusion

In the treatment of bifurcation lesions involving a large SB with ostial stenosis, routine two-stent techniques did not improve outcome significantly compared with treatment by the simpler main vessel stenting technique after 2 years.

Trial registration number

NCT01496638.

The Orsiro Ultrathin, Bioresorbable-Polymer Sirolimus-Eluting Stent: A Review of Current Evidence

Advances in stent design and the development of bioresorbable polymers have allowed the development of novel stent technologies such as the Orsiro bioresorbable-polymer sirolimus eluting stent (BP-SES). Over several noninferiority trials, the BP-SES has demonstrated itself to be a safe and effective therapy for obstructive coronary artery disease. This article reviews the current evidence of the efficacy of the BP-SES and examines its performance in high-risk populations, such as patients presenting with ST-segment myocardial infarction, chronic total occlusions, diabetes, and small vessel disease.

Assessment of the healing process after percutaneous implantation of a cardiovascular device: a systematic review

The healing process, occurring after intra-cardiac and intra-vascular device implantation, starts with fibrin condensation and attraction of inflammatory cells, followed by the formation of fibrous tissue that slowly covers the device. The duration of this process is variable and may be incomplete, which can lead to thrombus formation, dislodgement of the device or stenosis. To better understand this process and the neotissue formation, animal models were developed: small (rats and rabbits) and large (sheep, pigs, dogs and baboons) animal models for intra-vascular device implantation; sheep and pigs for intra-cardiac device implantation. After intra-vascular and intra-cardiac device implantation in these animal models, in vitro techniques, i.e. histology, which is the gold standard and scanning electron microscopy, were used to assess the device coverage, characterize the cell constitution and detect complications such as thrombosis. In humans, optical coherence tomography and intra-vascular ultrasounds are both invasive modalities used after stent implantation to assess the structure of the vessels, atheroma plaque and complications. Non-invasive techniques (computed tomography and magnetic resonance imaging) are in development in humans and animal models for tissue characterization (fibrosis), device remodeling evaluation and device implantation complications (thrombosis and stenosis). This review aims to (1) present the experimental models used to study this process on cardiac devices; (2) focus on the in vitro techniques and invasive modalities used currently in humans for intra-vascular and intra-cardiac devices and (3) assess the future developments of non-invasive techniques in animal models and humans for intra-cardiac devices.

Comparison of drug-eluting balloon with repeat drug-eluting stent for recurrent drug-eluting stent in-stent restenosis

OBJECTIVE

Approximately, 10-20% of patients with drug eluting stent (DES) in-stent restenosis (ISR) will develop recurrent ISR; yet, the optimal management of recurrent DES-ISR is unknown. We sought to compare the outcomes of recurrent DES-ISR treated with drug eluting balloons (DEB) to those with repeated implantation of new-generation DES.

METHODS

A total of 172 patients with recurrent DES-ISR were enrolled and stratified into two cohorts: the repeated DES implantation (Re-DES) group and the DEB group. The primary endpoint was the 1-year incidence of major adverse cardiovascular events (MACE).

RESULTS

Ninety-three patients treated with DEB and 79 patients with Re-DES implantation were analyzed. Both groups had comparable baseline characteristics. Lesser residual stenosis was achieved in the Re-DES group (11.3 ± 3.2% vs. 22.4 ± 4.3%; P = 0.00) than in the DEB group. However, the incidence of MACE and target lesion revascularization (TLR) were less in the DEB group (17.2% vs. 32.9%; P = 0.02 and 15.1% vs. 27.8%; P = 0.04, respectively). For the ≥3 metal-layered DES-ISR subgroup, DEB drastically reduced the incidences of MACE and TLR compared with Re-DES (20.0% vs. 57.9%; P = 0.02 and 16.0% vs. 47.4%; P = 0.04, respectively). Survival analysis demonstrated that MACE-free survival was significantly higher in the DEB group compared with the Re-DES group, whether the metal layers were ≥3 or 2. Multivariate analysis revealed that the risk factors of MACE were diabetes mellitus, ≥3 metal-layered DES ISR, and repeat DES deployment.

CONCLUSIONS

For recurrent DES-ISR, DEB may improve clinical outcomes compared with Re-DES implantation, especially for ≥3 metal-layered DES-ISR.

Provisional Stenting Using the Zilver PTX Drug-Eluting Stent After Drug-Coated Balloon Angioplasty: Initial Experience From the Double Drug Dose "3D" Study

Purpose: To explore the provisional use of a drug-eluting stent (DES) after suboptimal drug-coated balloon (DCB) angioplasty in complex, calcified femoropopliteal lesions. Materials and Methods: A prospective, single-center, investigator-initiated pilot study enrolled 15 patients (mean age 71.3 years; 9 men) with symptomatic stenosis (n=6) or occlusion (n=9) of the native superficial femoral and/or proximal popliteal arteries who experienced suboptimal DCB dilation despite postdilation. Lesion characteristics were evaluated with computed tomography angiography and duplex ultrasound confirmed by intravascular ultrasound. Follow-up included clinical and imaging evaluations as well as blood tests to monitor inflammatory markers. Endpoints included systemic inflammation, acute/chronic thrombosis, aneurysm formation, and mortality. Results: Provisional stenting was required for residual stenosis >50% in 4 cases and flow-limiting dissection in 11. Provisional spot stenting was done using the Zilver PTX DES. Clinical improvement was observed in all cases. After 24-month follow-up all patients were alive and in good clinical condition. One- and 2-year primary patency rates were 93.3% and 92.9%, respectively; secondary patency was 100%. Restenosis required reintervention in 2 cases. No local or systemic complications or toxicity were observed due to the use of a double dose of paclitaxel. No significant increase in any inflammation marker was observed in the perioperative period, and no aneurysm formation was seen over 24 months of follow-up. Conclusion: Combined DCB plus DES therapy seems to be safe and correlated with high primary patency following suboptimal angioplasty. Larger studies are required to confirm the safety and efficacy of this approach.

Polymer-Free vs. Polymer-Coated Drug-Eluting Stents for the Treatment of Coronary Artery Disease: A Meta-Analysis of 16 Randomized Trials

BACKGROUND

Polymer-coating represents one of components of drug-eluting stents (DES) to have experienced a more intensive technological evolution. Polymer-free DES (PF-DES) have offered promising angiographic results, with earlier complete re-endothelization, potentially reducing the thrombotic risk and offering the option of a shorter antiplatelet therapy. However, contrasting prognostic data have been reported so far with PF-DES. Therefore, the aim of the present study was to perform a comprehensive updated meta-analysis of randomized trials (RCT) comparing the impact of PF-DES vs polymer- coated DES (PC-DES) on clinical outcome.

METHODS

Literature and main scientific session abstracts were searched for RCTs comparing PF-DES vs PC-DES for the treatment of CAD. The primary efficacy endpoint was mortality, secondary endpoints were cardiovascular death, myocardial infarction, target lesion revascularization (TLR) and stent thrombosis.

RESULTS

We included 16 randomized clinical trials, with a total of 15,689 patients, including 50.6% randomized to PF-DES. At a median follow-up of 24 months, PF-DES were associated to a significant reduction in mortality as compared to PC-DES (0.82 [0.68, 0.99], p = .03, I2 = 0%; phet = 0.93). However, no significant benefit was observed in terms of cardiovascular death or major ischemic endpoints (respectively CV death: OR [95% CI] = 0.92 [0.71, 1.18] p = .50, I2 = 0.50; phet = 0.84; MI: OR [95% CI] = 1.08 [0.90, 1.29], p = .42; I2 = 0%, phet = 0.98; TLR: OR [95% CI] = 1.02 [0.78, 1.32], p = .91; I2 = 0.63 phet = 0.0003; ST: OR [95% CI] = 0.98 [0.87, 1.10], p = .72; I2 = 0% phet = 0.64). By meta-regression analysis, the mortality benefits of PF-DES were not conditioned by the rate of diabetes mellitus or acute coronary syndromes.

CONCLUSIONS

Based on the current meta-analysis, PF-DES are associated to a significant reduction in mortality as compared to PC-DES, but not in the occurrence of major ischemic events. Future larger studies are certainly needed to further investigate and confirm our findings, especially in particular subsets of patients, such as those with high bleeding risk or acute myocardial infarction.

Feasibility of Implanting 50-60 mm-Tapered Drug Eluting Stents in Chronic Total Occlusions

BACKGROUND

Percutaneous coronary intervention (PCI) of chronic total occlusions (CTO) usually involves multiple overlapping stents implantation to cover long coronary segments. A higher rate of restenosis has been described with stent overlapping. Recently, new long tapered stents emerged as a potential tool for treating long coronary lesions. Feasibility of using these new devices for the CTO PCI has not been described. The aim of this work was to describe our initial experience with 50 and 60 mm-long tapered sirolimus-eluting stents (SES) in CTO PCI.

METHODS

We included 54 consecutive patients who underwent a CTO PCI and in whom an attempt to implant a 50 or 60 mm-long tapered SES was performed. Baseline clinical, angiographic, and procedural characteristics were recorded.

RESULTS

The median (IQR) age was 64 (58-73) years, and 45 (83.3%) patients were male. The tapered SES 50 and 60 mm-long was successfully implanted in 51 (94.4%) patients. In three patients, a 60 mm-long stent could not be implanted, and two or three overlapped shorter drug-eluting stents were deployed instead. An average of 1.4 ± 0.6 stents per patient was implanted. A single stent was deployed in 32 (59.3%) patients. During a median follow-up of 330 (149-551) days, repeat PCI in the target vessel was performed in two patients.

CONCLUSIONS

The use of the new BioMime Morph™ tapered SES for the treatment of CTO appears to be feasible in a high proportion of procedures. Further studies confirming the feasibility of this approach and its potential clinical advantages are needed.

Hybrid-stenting with metallic and bioresorbable drug-eluting stents 2-year clinical outcomes in KUM ABSORB registry

AIM AND OBJECTIVE

We sought to investigate and compare outcomes 2 years after Hybrid-stenting with bioresorbable vascular scaffolds (BVS) and contemporary metallic drug-eluting stents (DES) within the same coronary lesion versus BVS alone.

METHODS

Between 11/2012 and 7/2015 at our institution, 134 (33.2%) were treated with Hybrid-stenting for complex or long coronary lesions, 270 patients were treated by BVS alone. The primary outcome of interest was target lesion failure (TLF) at 2-years of follow-up.

RESULTS

Patients treated by Hybrid-stenting were more frequently men (80% vs. 70%, p = 0.04) had extensive multivessel disease (84% vs. 71%, p < 0.01) including more complex (89% vs. 52%, p < 0.01) and longer lesions (28.9 mm vs 16.4 ± mm, p < 0.01) resulting in longer treated segments (47.3 mm vs 21.5 mm, p < 0.01) and more residual in-segment stenosis (12.3% vs 8.5%, p < 0.01) compared to BVS alone patients. At 2 years, cumulative incidence of TLF was 9.7% of Hybrid-stenting patients and 11.5% of BVS alone patients (p = 0.62), myocardial infarction (3.0% vs 4.1%, p = 0.59) and mortality (1.5% vs 4.1%, p = 0.17), respectively. Target lesion revascularization occurred in 9 Hybrid-stenting patients (2 located in DES) and in 20 BVS alone patients, cumulative incidence 6.7% vs. 7.4% (p = 0.80). Chronic kidney disease and residual in-segment stenosis >30% were identified as independent predictors of TLF at 2-years.

CONCLUSION

Despite differences in clinical and angiographic profile, Hybrid-stenting performed similar to BVS alone at 2 years after percutaneous coronary intervention.

Endothelial Function: A Short Guide for the Interventional Cardiologist

An impaired function of the coronary endothelium is an important determinant of all stages of atherosclerosis, from initiation, to mediation of functional phenomena—such as spasm and plaque erosion, to atherothrombotic complications. Endothelial function is modified by therapies, including stent implantation. Finally, endothelial function changes over time, in response to physical stimuli and pharmocotherapies, and its assessment might provide information on how individual patients respond to specific therapies. In this review, we describe the role of the endothelium in the continuum of coronary atherosclerosis, from the perspective of the interventional cardiologist. In the first part, we review the current knowledge of the role of endothelial (dys)function on atherosclerotic plaque progression/instabilization and on the mechanisms of ischemia, in the absence of coronary artery stenosis. In the second part of this review, we describe the impact of coronary artery stenting on endothelial function, platelet aggregation, and inflammation.