Evolution of drug-eluting coronary stents: a back-and-forth journey from the bench-to-bedside

Antiplatelet Therapy for Elderly Patients with Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention

The elderly represent an increasing proportion of patients presenting with acute coronary syndrome (ACS). Various data have shown that the benefits of percutaneous coronary revascularization are maintained in elderly patients presenting with ACS. Conversely, the management of antiplatelet therapy remains challenging and controversial, because older patients are usually at a high risk of both ischemia and bleeding. Moreover, the recommended ischemic and bleeding risk scores in patients with ACS were developed from studies with a low representation of older patients. New antiplatelet strategies have been developed, but their evidence in elderly patients is limited because they are usually underrepresented in randomized clinical trials due to their clinical complexity. The aim of this review is to summarize the different factors associated with increased ischemic and/or bleeding risk and the scientific evidence about the different antiplatelet strategies in elderly patients presenting with ACS and undergoing percutaneous coronary revascularization.

One-month DAPT after biodegradable-polymer everolimus-eluting stent implantation in patients at high-bleeding risk: an individual patient data pooled analysis of the SENIOR and POEM trials

Aims

Dual antiplatelet therapy (DAPT) can be shortened up to 1 month in high-bleeding risk (HBR) patients receiving a contemporary biodegradable-polymer sirolimus-eluting stent. We aimed to summarize the evidence on a similar DAPT regimen after biodegradable-polymer everolimus-eluting stent (EES) implantation in patients at HBR.

Methods and results

We pooled the individual participant data from the available trials evaluating this strategy, namely, the SENIOR and the POEM trials. Inclusion criteria were ≥1 biodegradable-polymer EES implantation and ≤1-month duration of DAPT. The primary endpoint was the 1-year composite of cardiovascular death, myocardial infarction, or stroke. Major bleeding was defined as Bleeding Academic Research Consortium (BARC) type 3-5 bleeding. Landmark analyses were performed at 1 month, the time point for intended DAPT interruption. We included 766 participants (age 77.5 ± 8.2 years, women 31.9%), 323 from the SENIOR and 443 from the POEM trial. The primary endpoint occurred in 45 participants (6.0%; 95% confidence interval [CI], 4.3-7.7%) through 1 year of follow-up, with 21 (2.8%; 95% CI, 1.6-3.9%) events during the first month and 24 (3.4%; 95% CI, 2.0-4.7%) thereafter. The incidences of cardiovascular death, myocardial infarction, and stroke were 2.2% (95% CI, 0.36-2.50%), 3.1% (95% CI, 1.8-4.3%), and 1.2% (95% CI, 0.4-2.0%), respectively. BARC type 3-5 bleeding ocuurred in 1.1% (95% CI, 0.3-1.8%) at 1 month and 2.9% (95% CI, 1.6-4.1%) at 1 year.

Conclusion

HBR patients receiving biodegradable-polymer EES had few ischemic and bleeding events when given 1 month of DAPT. One-month DAPT after biodegradable-polymer EES implantation seems safe in patients at HBR.

3D printing technology and its revolutionary role in stent implementation in cardiovascular disease

Cardiovascular disease (CVD), exemplified by coronary artery disease (CAD), is a global health concern, escalating in prevalence and burden. The etiology of CAD is intricate, involving different risk factors. CVD remains a significant cause of mortality, driving the need for innovative interventions like percutaneous coronary intervention and vascular stents. These stents aim to minimize restenosis, thrombosis, and neointimal hyperplasia while providing mechanical support. Notably, the challenges of achieving ideal stent characteristics persist. An emerging avenue to address this involves enhancing the mechanical performance of polymeric bioresorbable stents using additive manufacturing techniques And Three-dimensional (3D) printing, encompassing various manufacturing technologies, has transcended its initial concept to become a tangible reality in the medical field. The technology's evolution presents a significant opportunity for pharmaceutical and medical industries, enabling the creation of targeted drugs and swift production of medical implants. It revolutionizes medical procedures, transforming the strategies of doctors and surgeons. Patient-specific 3D-printed anatomical models are now pivotal in precision medicine and personalized treatment approaches. Despite its ongoing development, additive manufacturing in healthcare is already integrated into various medical applications, offering substantial benefits to a sector under pressure for performance and cost reduction. In this review primarily emphasizes stent technology, different types of stents, highlighting its application with some potential complications. Here we also address their benefits, potential issues, effectiveness, indications, and contraindications. In future it can potentially reduce complications and help in improving patients' outcomes. 3DP technology offers the promise to customize solutions for complex CVD conditions and help or fostering a new era of precision medicine in cardiology.

Performance of drug-coated balloons in coronary and below-the-knee arteries: Anatomical, physiological and pathological considerations

Below-the-knee (infrapopliteal) atherosclerotic disease, which presents as chronic limb-threatening ischemia (CLTI) in nearly 50% of patients, represents a treatment challenge when it comes to the endovascular intervention arm of management. Due to reduced tissue perfusion, patients usually experience pain at rest and atrophic changes correlated to the extent of the compromised perfusion. Unfortunately, the prognosis remains unsatisfactory with 30% of patients requiring major amputation and a mortality rate of 25% within 1 year. To date, randomized multicentre trials of endovascular intervention have shown that drug-eluting stents (DES) increase patency rate and lower target lesion revascularization rate compared to plain balloon angioplasty and bare-metal stents. The majority of these trials recruited patients with focal infrapopliteal lesions, while most patients requiring endovascular intervention have complex and diffuse atherosclerotic disease. Moreover, due to the nature of the infrapopliteal arteries, the use of long DES is limited. Following recent results of drug-coated balloons (DCBs) in the treatment of femoropopliteal and coronary arteries, it was hoped that similar effective results would be achieved in the infrapopliteal arteries. In reality, multicentre trials have failed to support the proposed hypothesis and no advantage was found in using DCBs in comparison to plain balloon angioplasty. This review aims to explore anatomical, physiological and pathological differences between lesions of the infrapopliteal and coronary arteries to explain the differences in outcome when using DCBs.

Nitric Oxide Releasing Nanomaterials for Cardiovascular Applications

A central paradigm of cardiovascular homeostasis is that impaired nitric oxide (NO) bioavailability results in a wide array of cardiovascular dysfunction including incompetent endothelium-dependent vasodilatation, thrombosis, vascular inflammation, and proliferation of the intima. Over the course of more than a century, NO donating formulations such as organic nitrates and nitrites have remained a cornerstone of treatment for patients with cardiovascular diseases. These donors primarily produce NO in the circulation and are not targeted to specific (sub)cellular sites of action. However, safe, and therapeutic levels of NO require delivery of the right amount to a precise location at the right time. To achieve these aims, several recent strategies aimed at therapeutically generating or releasing NO in living systems have shown that polymeric and inorganic (silica, gold) nanoparticles and nanoscale metal-organic frameworks could either generate NO endogenously by the catalytic decomposition of endogenous NO substrates or can store and release therapeutically relevant amounts of NO gas. NO-releasing nanomaterials have been developed for vascular implants (such as stents and grafts) to target atherosclerosis, hypertension, myocardial ischemia-reperfusion injury, and cardiac tissue engineering. In this review, we discuss the advances in design and development of novel NO-releasing nanomaterials for cardiovascular therapeutics and critically examine the therapeutic potential of these nanoplatforms to modulate cellular metabolism, to regulate vascular tone, inhibit platelet aggregation, and limit proliferation of vascular smooth muscle with minimal toxic effects.

Angiotensin Receptor-Neprilysin Inhibition in Patients With STEMI vs NSTEMI

BACKGROUND

Patients who sustain an acute myocardial infarction (AMI), including ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI), remain at high risk for heart failure (HF), coronary events, and death. Angiotensin-converting enzyme inhibitors have been shown to significantly decrease the risk for cardiovascular events in both STEMI and NSTEMI patients.

OBJECTIVES

The objectives were to determine whether angiotensin-receptor blockade and neprilysin inhibition with sacubitril/valsartan, compared with ramipril, has impact on reducing cardiovascular events according to the type of AMI.

METHODS

The PARADISE-MI (Prospective ARNI versus ACE inhibitor trial to DetermIne Superiority in reducing heart failure Events after Myocardial Infarction) trial enrolled patients with AMI complicated by left ventricular dysfunction and/or pulmonary congestion and at least 1 risk-enhancing factor. Patients were randomized to either sacubitril/valsartan or ramipril. The primary endpoint was death from cardiovascular causes or incident HF. In this prespecified analysis, we stratified patients according to AMI type.

RESULTS

Of 5,661 enrolled patients, 4,291 (75.8%) had STEMI. These patients were younger and had fewer comorbidities and cardiovascular risk factors than NSTEMI patients. After adjustment for potential confounders, the risk for the primary outcome was marginally higher in NSTEMI vs STEMI patients (adjusted HR: 1.19; 95% CI: 1.00-1.41), with borderline statistical significance (P = 0.05). The primary composite outcome occurred at similar rates in patients randomized to sacubitril/valsartan vs ramipril in STEMI (10% vs 12%; HR: 0.87; 95% CI: 0.73-1.04; P = 0.13) and NSTEMI patients (17% vs 17%; HR: 0.97; 95% CI: 0.75-1.25; P = 0.80; P interaction = 0.53).

CONCLUSIONS

Compared with ramipril, sacubitril/valsartan did not significantly decrease the risk for cardiovascular death and HF in patients with AMI complicated by left ventricular dysfunction, irrespective of the type of AMI. (Prospective ARNI vs ACE Inhibitor Trial to Determine Superiority in Reducing Heart Failure Events After MI; NCT02924727).

Drug-eluting stents for coronary artery disease in the perspective of bibliometric analysis

Drug-eluting stents (DES) play a crucial role in treating coronary artery disease (CAD) by preventing restenosis. These stents are coated with drug carriers that release antiproliferative drugs within the vessel. Over the past two decades, DES have been employed in clinical practice using various materials, polymers, and drug types. Despite optimizations in their design and materials to enhance biocompatibility and antithrombotic properties, evaluating their long-term efficacy and safety necessitates improved clinical follow-up and monitoring. To delineate future research directions, this study employs a bibliometric analysis approach. We comprehensively surveyed two decades' worth of literature on DES for CAD using the Web of Science Core Collection (WOSCC). Out of 5,778 articles, we meticulously screened them based on predefined inclusion and exclusion criteria. Subsequently, we conducted an in-depth analysis encompassing annual publication trends, authorship affiliations, journal affiliations, keywords, and more. Employing tools such as Excel 2021, CiteSpace 6.2R3, VOSviewer 1.6.19, and Pajek 5.17, we harnessed bibliometric methods to derive insights from this corpus. Analysis of annual publication data indicates a recent stabilisation or even a downward trend in research output in this area. The United States emerged as the leading contributor, with Columbia University and CRF at the forefront in both publication output and citation impact. The most cited document pertained to standardized definitions for clinical endpoints in coronary stent trials. Our author analysis identifies Patrick W. Serruys as the most prolific contributor, underscoring a dynamic exchange of knowledge within the field.Moreover, the dual chart overlay illustrates a close interrelation between journals in the "Medicine," "Medical," and "Clinical" domains and those in "Health," "Nursing," and "Medicine." Frequently recurring keywords in this research landscape include DES coronary artery disease, percutaneous coronary intervention, implantation, and restenosis. This study presents a comprehensive panorama encompassing countries, research institutions, journals, keyword distributions, and contributions within the realm of DES therapy for CAD. By highlighting keywords exhibiting recent surges in frequency, we elucidate current research hotspots and frontiers, thereby furnishing novel insights to guide future researchers in this evolving field.

Randomized Secondary Prevention Trials in Participants With Symptomatic Intracranial Atherosclerotic Stenosis

Intracranial atherosclerotic stenosis is a prevalent cause of ischemic stroke worldwide. Its association with silent cerebral infarcts and its contribution to cognitive impairment and dementia emphasize the critical need for disease prevention and effective management strategies. Despite extensive research on secondary stroke prevention treatment over the past several decades, intracranial atherosclerotic stenosis continues to exhibit a notably higher recurrent stroke rate compared with other causes. This review focuses on randomized secondary prevention trials involving antithrombotic therapy, endovascular treatment, open surgical therapy, and remote ischemic conditioning. It aims to provide an insightful overview of the major findings from each trial and their implications for future research efforts.

A Study of PLA Thin Film on SS 316L Coronary Stents Using a Dip Coating Technique

The dip coating process is one of the recognized techniques used to generate polymeric coatings on stents in an easy and low-cost way. However, there is a lack of information about the influence of the process parameters of this technique on complex geometries such as stents. This paper studies the dip coating process parameters used to provide a uniform coating of PLA with a 4-10 µm thickness. A stainless-steel tube (AISI 316L) was laser-cut, electropolished, and dip-coated in a polylactic acid (PLA) solution whilst changing the process parameters. The samples were characterized to examine the coating's uniformity, thickness, surface roughness, weight, and chemical composition. FTIR and Raman investigations indicated the presence of PLA on the stent's surface, the chemical stability of PLA during the coating process, and the absence of residual chloroform in the coatings. Additionally, the water contact angle was measured to determine the hydrophilicity of the coating. Our results indicate that, when using entry and withdrawal speeds of 500 mm min-1 and a 15 s immersion time, a uniform coating thickness was achieved throughout the tube and in the stent with an average thickness of 7.8 µm.

Shaping the Future of Cardiovascular Disease by 3D Printing Applications in Stent Technology and its Clinical Outcomes

Cardiovascular disease (CVD) is a leading cause of death worldwide. In recent years, 3D printing technology has ushered in a new era of innovation in cardiovascular medicine. 3D printing in CVD management encompasses various aspects, from patient-specific models and preoperative planning to customized medical devices and novel therapeutic approaches. In-stent technology, 3D printing has revolutionized the design and fabrication of intravascular stents, offering tailored solutions for complex anatomies and individualized patient needs. The advantages of 3D-printed stents, such as improved biocompatibility, enhanced mechanical properties, and reduced risk of in-stent restenosis. Moreover, the clinical trials and case studies that shed light on the potential of 3D printing technology to improve patient outcomes and revolutionize the field has been comprehensively discussed. Furthermore, regulatory considerations, and challenges in implementing 3D-printed stents in clinical practice are also addressed, underscoring the need for standardization and quality assurance to ensure patient safety and device reliability. This review highlights a comprehensive resource for clinicians, researchers, and policymakers seeking to harness the full potential of 3D printing technology in the fight against CVD.

Preliminary Investigation on Efficacy and Safety of Substance P-Coated Stent for Promoting Re-Endothelialization: A Porcine Coronary Artery Restenosis Model

BACKGROUND

Current polymer-based drug-eluting stents (DESs) have fundamental issues about inflammation and delayed re-endothelializaton of the vessel wall. Substance-P (SP), which plays an important role in inflammation and endothelial cells, has not yet been applied to coronary stents. Therefore, this study compares poly lactic-co-glycolic acid (PLGA)-based everolimus-eluting stents (PLGA-EESs) versus 2-methacryloyloxyethyl phosphorylcholine (MPC)-based SP-eluting stents (MPC-SPs) in in-vitro and in-vivo models.

METHODS

The morphology of the stent surface and peptide/drug release kinetics from stents were evaluated. The in-vitro proliferative effect of SP released from MPC-SP is evaluated using human umbilical vein endothelial cell. Finally, the safety and efficacy of the stent are evaluated after inserting it into a pig's coronary artery.

RESULTS

Similar to PLGA-EES, MPC-SP had a uniform surface morphology with very thin coating layer thickness (2.074 μm). MPC-SP showed sustained drug release of SP for over 2 weeks. Endothelial cell proliferation was significantly increased in groups treated with SP (n = 3) compared with the control (n = 3) and those with everolimus (n = 3) (SP: 118.9 ± 7.61% vs. everolimus: 64.3 ± 12.37% vs. the control: 100 ± 6.64%, p < 0.05). In the animal study, the percent stenosis was higher in MPC-SP group (n = 7) compared to PLGA-EES group (n = 7) (MPC-SP: 28.6 ± 10.7% vs. PLGA-EES: 16.7 ± 6.3%, p < 0.05). MPC-SP group showed, however, lower inflammation (MPC-SP: 0.3 ± 0.26 vs. PLGA-EES: 1.2 ± 0.48, p < 0.05) and fibrin deposition (MPC-SP: 1.0 ± 0.73 vs. PLGA-EES: 1.5 ± 0.59, p < 0.05) around the stent strut. MPC-SP showed more increased expression of cluster of differentiation 31, suggesting enhanced re-endothelialization.

CONCLUSION

Compared to PLGA-EES, MPC-SP demonstrated more decreased inflammation of the vascular wall and enhanced re-endothelialization and stent coverage. Hence, MPC-SP has the potential therapeutic benefits for the treatment of coronary artery disease by solving limitations of currently available DESs.

Clinically Driven Revascularization in High-Risk Patients Treated With Ticagrelor Monotherapy After PCI: Insights from the Randomized TWILIGHT Trial

Repeat coronary revascularization is a common adverse event after successful percutaneous coronary intervention. This analysis aimed to assess the effects of ticagrelor monotherapy on repeat clinically driven revascularization (CDR). In the TWILIGHT (Ticagrelor With Aspirin or Alone in High-Risk Patients after Coronary Intervention) trial, after 3 months of ticagrelor plus aspirin, high-risk patients were maintained on ticagrelor and randomly allocated to aspirin or placebo for 1 year. The primary end point of this analysis was CDR within 12 months after randomization. The key secondary end points were major adverse cardiovascular and cerebrovascular events (MACCEs), a composite of all-cause death, myocardial infarction, stroke, or CDR, and net adverse clinical events (NACEs), including the individual components of MACCEs and clinically relevant bleeding. The analysis was performed in the per-protocol population. CDR occurred in 473 of 7,039 patients and was associated with a significantly higher risk of subsequent all-cause death, myocardial infarction, or stroke (adjusted hazard ratios [HRs] 2.92, 95% confidence interval [CI] 1.82 to 4.67). Ticagrelor monotherapy was associated with a similar 12-month risk of CDR (7.1% vs 6.6%; HR 1.09, 95% CI 0.90 to 1.30, p = 0.363) and MACCEs (8.9% vs 8.6%; HR 1.04, 95% CI 0.89 to 1.22, p = 0.619), and a lower risk of NACEs (12.2% vs 14.6%; HR 0.83 95% CI 0.73 to 0.94, p = 0.004) than ticagrelor plus aspirin. In conclusion, among high-risk patients who underwent percutaneous coronary intervention, ticagrelor monotherapy after 3 months of ticagrelor-based dual antiplatelet therapy was associated with a similar risk of CDR and MACCEs and a decrease of NACEs (TWILIGHT: NCT02270242).

One-Month Dual Antiplatelet Therapy in Patients With Chronic and Acute Coronary Syndromes Treated With Bioresorbable Polymer Everolimus-Eluting Stents

There is a paucity of data regarding the safety of a 1-month dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) in patients at high bleeding risk (HBR) presenting with acute coronary syndromes (ACS). We aimed to compare the clinical outcomes of patients at HBR with chronic coronary syndrome (CCS) or ACS treated with PCI using bioresorbable polymer everolimus-eluting stent (BP-EES) followed by 1-month DAPT. Patients at HBR who underwent PCI with BP-EES were prospectively enrolled in 10 Italian centers. All patients were treated with 1-month DAPT. In case of need for anticoagulation, patients received an oral anticoagulant in addition to a P2Y12 inhibitor for 1 month, followed by oral anticoagulation only after that. The primary end point was a composite of cardiac death, myocardial infarction, or definite/probable stent thrombosis at 12 months. Overall, 263 patients (59.4%) with CCS and 180 patients (40.6%) with ACS were enrolled. No significant difference was evident between patients with CCS and ACS for the primary end point (4.3% vs 5.6%, respectively, p = 0.497) and for each isolated component. The risk for Bleeding Academic Research Consortium (BARC) type 1 to 5 or type 3 to 5 bleedings was also similar between patients with CCS and ACS (4.3% vs 5.2%, p = 0.677, and 1.6% vs 2.9%, p = 0.351, respectively). In conclusion, among HBR patients with ACS who underwent PCI with BP-EES, a 1-month DAPT strategy is associated with a similar risk of ischemic and bleeding events compared with those with CCS.

Mass Spectrometry Imaging of Biomaterials

The science related to biomaterials and tissue engineering accounts for a growing part of our knowledge. Surface modifications of biomaterials, their performance in vitro, and the interaction between them and surrounding tissues are gaining more and more attention. It is because we are interested in finding sophisticated materials that help us to treat or mitigate different disorders. Therefore, efficient methods for surface analysis are needed. Several methods are routinely applied to characterize the physical and chemical properties of the biomaterial surface. Mass Spectrometry Imaging (MSI) techniques are able to measure the information about molecular composition simultaneously from biomaterial and adjacent tissue. That is why it can answer the questions connected with biomaterial characteristics and their biological influence. Moreover, this kind of analysis does not demand any antibodies or dyes that may influence the studied items. It means that we can correlate surface chemistry with a biological response without any modification that could distort the image. In our review, we presented examples of biomaterials analyzed by MSI techniques to indicate the utility of SIMS, MALDI, and DESI-three major ones in the field of biomaterials applications. Examples include biomaterials used to treat vascular system diseases, bone implants with the effects of implanted material on adjacent tissues, nanofibers and membranes monitored by mass spectrometry-related techniques, analyses of drug-eluting long-acting parenteral (LAPs) implants and microspheres where MSI serves as a quality control system.

Research on the Current Application Status of Magnesium Metal Stents in Human Luminal Cavities

The human body comprises various tubular structures that have essential functions in different bodily systems. These structures are responsible for transporting food, liquids, waste, and other substances throughout the body. However, factors such as inflammation, tumors, stones, infections, or the accumulation of substances can lead to the narrowing or blockage of these tubular structures, which can impair the normal function of the corresponding organs or tissues. To address luminal obstructions, stenting is a commonly used treatment. However, to minimize complications associated with the long-term implantation of permanent stents, there is an increasing demand for biodegradable stents (BDS). Magnesium (Mg) metal is an exceptional choice for creating BDS due to its degradability, good mechanical properties, and biocompatibility. Currently, the Magmaris® coronary stents and UNITY-BTM biliary stent have obtained Conformité Européene (CE) certification. Moreover, there are several other types of stents undergoing research and development as well as clinical trials. In this review, we discuss the required degradation cycle and the specific properties (anti-inflammatory effect, antibacterial effect, etc.) of BDS in different lumen areas based on the biocompatibility and degradability of currently available magnesium-based scaffolds. We also offer potential insights into the future development of BDS.

Biolimus-eluting vs. other limus-eluting stents in NSTE-ACS: A pooled analysis of GLASSY and TWILIGHT

BACKGROUND

Biodegradable polymer biolimus-eluting stents (BP-BES) may be associated with better outcomes in patients with acute coronary syndromes (ACS) undergoing percutaneous coronary intervention (PCI) compared to other current-generation limus-eluting stents (LES).

AIMS

To compare BP-BES with other current-generation LES in ACS patients undergoing PCI.

METHODS

We pooled individual data of Non-ST-segment elevation (NSTE)-ACS patients from two large randomized controlled trials (GLASSY and TWILIGHT). The BP-BES groups consisted mostly of GLASSY patients, while the control group (other current-generation LES) included exclusively TWILIGHT patients. The primary outcome was major adverse cardiovascular events (MACE), including cardiovascular death, myocardial infarction, or stent thrombosis; the key secondary outcome was target-vessel failure (TVF). To account for trial design differences, outcomes were assessed at 3 months (short-term) and between 3 and 12 months (long-term) after PCI and subsequently pooled to estimate the 12-month hazards.

RESULTS

Of 7107 and 6053 NSTE-ACS patients included in the short- and long-term analysis, 32.7% and 36.5% received a BP-BES, respectively. Risk of MACE associated with BP-BES versus other LES was similar at short-term (1.1% vs 1.3%, adjusted HR 0.86, 95%CI 0.53-1.38), lower at long-term (1.7% vs 3.1%, adjusted HR 0.49, 95%CI 0.34-0.72), and lower in the entire 12-month period (pooled adjusted HR 0.61, 95%CI 0.45-0.82). The cumulative 12-month risk of TVF was reduced with BP-BES (adjusted HR 0.52, 95%CI 0.38-0.70).

CONCLUSION

BP-BES was associated with lower 12-month risks of MACE and TVF compared to other current generation LES among NSTE-ACS patients treated with abbreviated or standard ticagrelor-based DAPT. These non-randomized findings are hypothesis-generating.

CONDENSED ABSTRACT

Differences in clinical outcomes may exist between biodegradable polymer biolimus-eluting stents (BP-BES) and other current-generation limus-eluting stent (LES) in patients with acute coronary syndrome (ACS). We pooled individual data of about 7000 Non-ST-segment elevation ACS patients undergoing PCI and treated with ticagrelor with or without aspirin from two large randomized controlled trials (GLASSY and TWILIGHT). BP-BES patients derived very largely from GLASSY and other LES patients from TWILIGHT. In this population, BP-BES compared to other current generation LES, were associated with a lower 12-month risk of major adverse cardiovascular events and target-vessel failure.

Artificial Lungs for Lung Failure in the Era of COVID-19 Pandemic: Contemporary Review

In patients with severe acute respiratory distress syndrome caused by coronavirus 2019 (COVID-19), mortality remains high despite optimal medical management. Extracorporeal membrane oxygenation (ECMO) has been widely used to support such patients. ECMO is not a perfect solution; however, there are several limitations and serious complications associated with ECMO use. Moreover, the overall short-term mortality rate of patients with COVID-19 supported by ECMO is high (~30%). Some patients who survive severe acute respiratory distress syndrome have chronic lung failure requiring oxygen supplementation, long-term mechanical ventilation, or ECMO support. Although lung transplant remains the most effective treatment for patients with end-stage lung failure from COVID-19, optimal patient selection and transplant timing for patients with COVID-19-related lung failure are not clear. Access to an artificial lung (AL) that can be used for long-term support as a bridge to transplant, bridge to recovery, or even destination therapy will become increasingly important. In this review, we discuss why the COVID-19 pandemic may drive progress in AL technology, challenges to AL implementation, and how some of these challenges might be overcome.

Faster smooth muscle cell coverage in ultrathin-strut drug-eluting stent leads to earlier re-endothelialization

Background: The ultrathin-strut drug-eluting stent (DES) has shown better clinical results than thin- or thick-strut DES. We investigated if re-endothelialization was different among three types of DES: ultrathin-strut abluminal polymer-coated sirolimus-eluting stent (SES), thin-strut circumferential polymer-coated everolimus-eluting stent (EES), and thick-strut polymer-free biolimus-eluting stent (BES) to gain insight into the effect of stent design on promoting vascular healing. Methods: After implanting three types of DES in the coronary arteries of minipigs, we performed optical coherence tomography (OCT) at weeks 2, 4, and 12 (n = 4, each). Afterward, we harvested the coronary arteries and performed immunofluorescence for endothelial cells (ECs), smooth muscle cells (SMCs), and nuclei. We obtained 3D stack images of the vessel wall and reconstructed the en face view of the inner lumen. We compared re-endothelialization and associated factors among the different types of stents at different time points. Results: SES showed significantly faster and denser re-endothelialization than EES and BES at weeks 2 and 12. Especially in week 2, SES elicited the fastest SMC coverage and greater neointimal cross-sectional area (CSA) compared to EES and BES. A strong correlation between re-endothelialization and SMC coverage was observed in week 2. However, the three stents did not show any difference at weeks 4 and 12 in SMC coverage and neointimal CSA. At weeks 2 and 4, SMC layer morphology showed a significant difference between stents. A sparse SMC layer was associated with denser re-endothelialization and was significantly higher in SES. Unlike the sparse SMC layer, the dense SMC layer did not promote re-endothelialization during the study period. Conclusion: Re-endothelialization after stent implantation was related to SMC coverage and SMC layer differentiation, which were faster in SES. Further investigation is needed to characterize the differences among the SMCs and explore methods for increasing the sparse SMC layer in order to improve stent design and enhance safety and efficacy.

A technology evaluation of the Onyx Frontier drug-eluting stent

INTRODUCTION

Onyx FrontierTM represents the latest iteration within the family of zotarolimus-eluting stents (ZES), designed for the treatment of coronary artery disease. Approval by the Food and Drug Administration was granted in May 2022, and Conformité Européenne marking followed in August 2022.

AREAS COVERED

We hereby review the principal design features of Onyx Frontier, highlighting differences and similarities with other currently available drug-eluting stents. In addition, we focus on the refinements of this newest platform as compared with previous ZES versions, including the attributes yielding its exceptional crossing profile and deliverability. The clinical implications related to both its newest and inherited characteristics will be discussed.

EXPERT OPINION

The nuances of the latest Onyx Frontier, together with the continuous refinement previously witnessed throughout the development of ZES, lead to a latest generation device ideal for a diverse spectrum of clinical and anatomical scenarios. In particular, its peculiarities will be of benefit in the settings often offered by a progressively aging population, such as high bleeding risk patients and complex coronary lesions.

Is There an Advantage of Ultrathin-Strut Drug-Eluting Stents over Second- and Third-Generation Drug-Eluting Stents?

In patients undergoing percutaneous coronary intervention, the second-generation drug-eluting stents (DES) are considered the gold standard of care for revascularization. By reducing neointimal hyperplasia, drug-eluting coronary stents decrease the need for repeat revascularizations compared with conventional coronary stents without an antiproliferative drug coating. It is important to note that early-generation DESs were associated with an increased risk of very late stent thrombosis, most likely due to delayed endothelialization or a delayed hypersensitivity reaction to the polymer. Studies have shown a lower risk of very late stent thrombosis with developing second-generation DESs with biocompatible and biodegradable polymers or without polymers altogether. In addition, research has indicated that thinner struts are associated with a reduced risk of intrastent restenosis and angiographic and clinical results. A DES with ultrathin struts (strut thickness of 70 µm) is more flexible, facilitates better tracking, and is more crossable than a conventional second-generation DES. The question is whether ultrathin eluting drug stents suit all kinds of lesions. Several authors have reported that improved coverage with less thrombus protrusion reduced the risk of distal embolization in patients with ST-elevation myocardial infarction (STEMI). Others have described that an ultrathin stent might recoil due to low radial strength. This could lead to residual stenosis and repeated revascularization of the artery. In CTO patients, the ultrathin stent failed to prove non-inferiority regarding in-segment late lumen loss and showed statistically higher rates of restenosis. Ultrathin-strut DESs with biodegradable polymers have limitations when treating calcified (or ostial) lesions and CTOs. However, they also possess certain advantages regarding deliverability (tight stenosis, tortuous lesions, high angulation, etc.), ease of use in bifurcation lesions, better endothelialization and vascular healing, and reducing stent thrombosis risk. In light of this, ultrathin-strut stents present a promising alternative to existing DESs of the second and third generation. The aims of the study are to compare ultrathin eluting stents with second- and third-generation conventional stents regarding procedural performance and outcomes based on different lesion types and specific populations.

P2Y12 Inhibitor Monotherapy or Dual Antiplatelet Therapy After Complex Percutaneous Coronary Interventions

BACKGROUND

It remains unclear whether P2Y₁₂ inhibitor monotherapy preserves ischemic protection while limiting bleeding risk compared with dual antiplatelet therapy (DAPT) after complex percutaneous coronary intervention (PCI).

OBJECTIVES

We sought to assess the effects of P2Y₁₂ inhibitor monotherapy after 1-month to 3-month DAPT vs standard DAPT in relation to PCI complexity.

METHODS

We pooled patient-level data from randomized controlled trials comparing P2Y₁₂ inhibitor monotherapy and standard DAPT on centrally adjudicated outcomes after coronary revascularization. Complex PCI was defined as any of 6 criteria: 3 vessels treated, ≥3 stents implanted, ≥3 lesions treated, bifurcation with 2 stents implanted, total stent length >60 mm, or chronic total occlusion. The primary efficacy endpoint was all-cause mortality, myocardial infarction, and stroke. The key safety endpoint was Bleeding Academic Research Consortium (BARC) 3 or 5 bleeding.

RESULTS

Of 22,941 patients undergoing PCI from 5 trials, 4,685 (20.4%) with complex PCI had higher rates of ischemic events. The primary efficacy endpoint was similar between P2Y₁₂ inhibitor monotherapy and DAPT among patients with complex PCI (HR: 0.87; 95% CI: 0.64-1.19) and noncomplex PCI (HR: 0.91; 95% CI: 0.76-1.09; P_interaction = 0.770). The treatment effect was consistent across all the components of the complex PCI definition. Compared with DAPT, P2Y₁₂ inhibitor monotherapy consistently reduced BARC 3 or 5 bleeding in complex PCI (HR: 0.51; 95% CI: 0.31-0.84) and noncomplex PCI patients (HR: 0.49; 95% CI: 0.37-0.64; P_interaction = 0.920).

CONCLUSIONS

P2Y₁₂ inhibitor monotherapy after 1-month to 3-month DAPT was associated with similar rates of fatal and ischemic events and lower risk of major bleeding compared with standard DAPT, irrespective of PCI complexity. (PROSPERO [P2Y12 Inhibitor Monotherapy Versus Standard Dual Antiplatelet Therapy After Coronary Revascularization: Individual Patient Data Meta-Analysis of Randomized Trials]; CRD42020176853).

Drug-Eluting Stents: Technical and Clinical Progress

Drug-eluting stents (DES) demonstrated superior efficacy when compared to bare metal stents and plain-old balloon angioplasty and are nowadays used in almost all percutaneous revascularization procedures. The design of the stent platforms is constantly improving to maximize its efficacy and safety. Constant development of DES includes adoption of new materials used for scaffold production, new design types, improved overexpansion abilities, new polymers coating and, finally, improved antiproliferative agents. Especially nowadays, with the immense number of available DES platforms, it is crucial to understand how different aspects of stents impact the effect of their implantation, as subtle differences between various stent platforms could impact the most important issue-clinical outcomes. This review discusses the current status of coronary stents and the impact of stent material, strut design and coating techniques on cardiovascular outcomes.

Stent Thrombosis and Restenosis with Contemporary Drug-Eluting Stents: Predictors and Current Evidence

Iterations in stent technologies, advances in pharmacotherapy, and awareness of the implications of implantation techniques have markedly reduced the risk of stent failure, both in the form of stent thrombosis (ST) and in-stent restenosis (ISR). However, given the number of percutaneous coronary interventions (PCI) performed worldwide every year, ST and ISR, albeit occurring at a fairly low rate, represent a public health problem even with contemporary DES platforms. The understanding of mechanisms and risk factors for these two PCI complications has been of fundamental importance for the parallel evolution of stent technologies. Risk factors associated with ST and ISR are usually divided into patient-, lesion-, device- and procedure-related. A number of studies have shown how certain risk factors are related to early (1 month) versus late/very late ST (between 1 month and 1 year and >1 year, respectively). However, more research is required to conclusively show the role of time-dependence of risk factors also in the incidence of ISR (early [1 year] or late [>1 year]). A thorough risk assessment is required due to the complex etiology of ST and ISR. The most effective strategy to treat ST and ISR is still to prevent them; hence, it is crucial to identify patient-, lesion-, device- and procedure-related predictors.

The mega COMBO collaboration: An individual patient data pooled analysis of patients undergoing PCI with COMBO stent

BACKGROUND

COMBO (OrbusNeich Medical, Hong Kong) is a dual-therapy coronary stent featuring sirolimus as antiproliferative drug and an anti-CD34+ antibody coating to attract endothelial progenitor cells favoring rapid stent re-endothelization. The Mega COMBO collaboration aimed to evaluate the performance of the COMBO stent in a large contemporary cohort of patients undergoing percutaneous coronary intervention (PCI).

METHODS

Patient-level data of subjects undergoing PCI with the COMBO stent from the REMEDEE-Trial, REMEDEE-OCT, HARMONEE, REDUCE, SORT OUT X, REMEDEE-Registry and MASCOT studies were pooled together. The primary endpoint was 1-year target lesion failure (TLF), a composite of cardiovascular death, target vessel myocardial infarction (TV-MI) or clinically driven target lesion revascularization (CD-TLR). Secondary outcomes were the individual components of the primary endpoint and stent thrombosis (ST). Endpoints were evaluated against performance goals based on the EAPCI (the European Association of Percutaneous Coronary Intervention) recommendations for new drug-eluting stents.

RESULTS

A total of 6753 patients (mean age 63.7 ± 11.4 years, 23% women) were included. At 1-year follow-up, TLF occurred in 303 (4.6%) patients. The rates of cardiovascular death, TV-MI, and CD-TLR were 1.3%, 1.8%, and 2.5%, respectively. The rate of definite/probable ST was 0.73%, early ST (<1 month) was 0.48%, while late ST (1-12 months) was 0.26%. The performance goals were met for all of the evaluated endpoints.

CONCLUSIONS

This large patient-level pooled analysis provides a comprehensive outline of the performance of the dual-therapy COMBO stent. The low rates of primary and secondary endpoints suggest that this stent technology may be a good alternative to other contemporary drug eluting coronary stent platforms.