Bare Metal Stents Versus Drug Eluting Stents: Where Do We Stand in 2015?

The evolution and revolution of drug coated balloons in coronary angioplasty: An up-to-date review of literature data

European Society of Cardiology (ESC) guidelines gave class I A indication for use of DCB in in-stent restenosis. However, no indication exists for the usage of DCB in de novo lesions. Although the current generation DES offer excellent results, as we embark more complex lesions such as calcified lesion and chronic total occlusion, restenosis and stent thrombosis are higher and tend to increase within the years. There is increasing desire to leave nothing behind to abolish the risk of restenosis and stent thrombosis and hence the absorbable scaffolds were introduced, but with disappointing results. In addition, they take several years to be absorbed. Drug coated balloons offer an alternative to stents with no permanent implant of metal or polymer. They are already in use in in Europe and Asia and they have been approved for the first time in the United States for clinical trials specifically for restenotic lesions. There is emerging data in de novo lesions which have shown that DCB are noninferior and in some studies maybe even superior to current generation DES especially in small vessels. In this article, we provide a comprehensive review of the literature on this expanding technology focussing on the evidence in both re-stenotic and de novo lesions.

Individualizing Medicinal Therapy Post Heart Stent Implantation: Tailoring for Patient Factors

The field of cardiovascular medicine is undergoing a transformative shift towards personalized medicinal therapy, particularly in the context of post stent implantation. This narrative review explores the significance, challenges, and future directions of individualized treatment strategies for patients with coronary stents. The review highlights the pivotal role of personalized approaches in optimizing treatment efficacy and minimizing adverse events. Real-world clinical studies and trials underscore the importance of tailoring antiplatelet therapy based on platelet function testing, genetic testing, and risk scoring. These studies reveal that personalized medicinal treatment improves clinical outcomes by balancing preventing thrombotic events and mitigating bleeding risks. Challenges, including cost, test availability, patient adherence, and ethical considerations, are discussed in depth, shedding light on the complexities of implementing personalized approaches. Technological advancements, including omics data integration, artificial intelligence, and big data analytics, shape the future of personalized medicinal therapy. These tools enable precise pharmacogenomic selection of medications and the development of integrated risk-scoring systems. Patient engagement and education are also central, with empowered patients and remote monitoring contributing to collaborative decision-making. In conclusion, the narrative review underscores that personalized medicinal therapy post stent implantation holds immense promise for revolutionizing cardiovascular care. By embracing a comprehensive approach that considers genetics, clinical factors, and patient preferences, healthcare providers can optimize treatment outcomes and improve patient quality of life. The evolving landscape of personalized medicine offers a glimpse into a future where tailored treatment strategies become the cornerstone of precision cardiovascular care.

Characterizing the Mechanical Performance of a Bare-Metal Stent with an Auxetic Cell Geometry

This study develops and characterizes the distinctive mechanical features of a stainless-steel metal stent with a tailored structure. A high-precision femtosecond laser was used to micromachine a stent with re-entrant hexagonal (auxetic) cell geometry. We then characterized its mechanical behavior under various mechanical loadings using in vitro experiments and through finite element analysis. The stent properties, such as the higher capability of the stent to bear upon bending, exceptional advantage at elevated levels of twisting angles, and proper buckling, all ensured a preserved opening to maintain the blood flow. The outcomes of this preliminary study present a potential design for a stent with improved physiologically relevant mechanical conditions such as longitudinal contraction, radial strength, and migration of the stent.

Engineering biomaterials to prevent post-operative infection and fibrosis

Implantable biomaterials are essential surgical devices, extending and improving the quality of life of millions of people globally. Advances in materials science, manufacturing, and in our understanding of the biological response to medical device implantation over several decades have resulted in improved safety and functionality of biomaterials. However, post-operative infection and immune responses remain significant challenges that interfere with biomaterial functionality and host healing processes. The objectives of this review is to provide an overview of the biology of post-operative infection and the physiological response to implanted biomaterials and to discuss emerging strategies utilizing local drug delivery and surface modification to improve the long-term safety and efficacy of biomaterials.

Cytocompatibility Evaluation of a Novel Series of PEG-Functionalized Lactide-Caprolactone Copolymer Biomaterials for Cardiovascular Applications

Although the use of bioresorbable materials in stent production is thought to improve long-term safety compared to their durable counterparts, a recent FDA report on the 2-year follow-up of the first FDA-approved bioresorbable vascular stent showed an increased occurrence of major adverse cardiac events and thrombosis in comparison to the metallic control. In order to overcome the issues of first generation bioresorbable polymers, a series of polyethylene glycol-functionalized poly-L-lactide-co-ε-caprolactone copolymers with varying lactide-to-caprolactone content is developed using a novel one-step PEG-functionalization and copolymerization strategy. This approach represents a new facile way toward surface enhancement for cellular interaction, which is shown by screening these materials regarding their cyto- and hemocompatibility in terms of cytotoxicity, hemolysis, platelet adhesion, leucocyte activation and endothelial cell adhesion. By varying the lactide-to-caprolactone polymer composition, it is possible to gradually affect endothelial and platelet adhesion which allows fine-tuning of the biological response based on polymer chemistry. All polymers developed were non-cytotoxic, had acceptable leucocyte activation levels and presented non-hemolytic (<2% hemolysis rate) behavior except for PLCL-PEG 55:45 which presented hemolysis rate of 2.5% ± 0.5. Water contact angles were reduced in the polymers containing PEG functionalization (PLLA-PEG: 69.8° ± 2.3, PCL-PEG: 61.2° ± 7.5) versus those without (PLLA: 79.5° ± 3.2, PCL: 76.4° ± 10.2) while the materials PCL-PEG550, PLCL-PEG550 90:10 and PLCL-PEG550 70:30 demonstrated best endothelial cell adhesion. PLLA-PEG550 and PLCL-PEG550 70:30 presented as best candidates for cardiovascular implant use from a cytocompatibility perspective across the spectrum of testing completed. Altogether, these polymers are excellent innovative materials suited for an application in stent manufacture due to the ease in translation of this one-step synthesis strategy to device production and their excellent in vitro cyto- and hemocompatibility.

Gefitinib-coated balloon inhibits the excessive hyperplasia of intima after vascular injuries through PI3K/AKT pathway

OBJECTIVE

To explore the effect of gefitinib-coated balloon suppressive action on the excessive hyperplasia of intima after balloon injury of common carotid artery in rats and on the PI3K/AKT signal pathway.

METHODS

MTT method and the expression of Bcl-2 and Caspase-3 proteins were detected in vitro; Adult SD rats were randomly split into 5 groups, namely sham group, model group, low-dosage gefitinib-coated balloon group, high-dosage gefitinib-coated balloon group, and paclitaxel-coated balloon group. The intimal proliferation of arteries, PCNA, P-AKT and PI3K protein expression, the cell apoptosis, expression of MMP9, TGFβ and IL6 mRNA were measured by hematoxylin and eosin (H&E) staining, immunohistochemistry, TUNEL staining, and RT-qPCR.

RESULTS

At the same time and concentration, Gefitinib suppressed the proliferation of smooth muscle cell more significantly than paclitaxel. Bcl-2 and Caspase-3 in vascular smooth muscle and endothelial cells (VSMC, EC) were significantly down-regulated and up-regulated after the cells were treated with gefitinib and paclitaxel. In gefitinib- and paclitaxel-coated balloon groups, significant up-regulations were found in the area of lumen. Furthermore, the expression of PCNA suggested that all coated balloons could suppress the excessive proliferation of smooth muscle cells in the hyperplastic intima compared with the control group. In gefitinib- and paclitaxel-coated balloon group, the expression of PI3K/AKT was significantly down-regulated. The use of drug-coated balloons mitigated the cell apoptosis in TUNEL. The expressions of MMP9, TGFβ and IL6 mRNA in the model group were obviously up-regulated; and they were obviously down-regulated in the high-dose gefitinib-coated balloon group compared with the model group.

CONCLUSIONS

Gefitinib-coated balloons were able to suppress the excessive proliferation in the common carotid arterial intima of rats more effectively than the paclitaxel-coated ones. The underlying mechanism may cover the PI3K/AKT signal pathway.

Biocompatible Polymer Materials with Antimicrobial Properties for Preparation of Stents

Biodegradable polymers are promising materials for use in medical applications such as stents. Their properties are comparable to commercially available resistant metal and polymeric stents, which have several major problems, such as stent migration and stent clogging due to microbial biofilm. Consequently, conventional stents have to be removed operatively from the patient's body, which presents a number of complications and can also endanger the patient's life. Biodegradable stents disintegrate into basic substances that decompose in the human body, and no surgery is required. This review focuses on the specific use of stents in the human body, the problems of microbial biofilm, and possibilities of preventing microbial growth by modifying polymers with antimicrobial agents.

Comparison of drug eluting stents (DESs) and bare metal stents (BMSs) with STEMI: who received BMS in the era of 2nd generation DES?

BACKGROUND

The aim of this study was to analyze the indications for using bare metal stents (BMSs) in hospitalizations with ST segment elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI).

METHODS

The study cohorts were identified from the National Inpatient Sample database from 2010-2014 using appropriate, International Classification of Diseases, 9^th Revision, Clinical Modification, diagnostic and procedural codes.

RESULTS

A total of 123,487 hospitalizations were identified for this study. Drug eluting stent (DES) use demonstrated lower in-hospital mortality (5.8% vs. 3.3%, P = < 0.01) and other in-hospital outcomes, thus resulting in lower hospitalization stay. Higher age, black race, greater comorbidity burden, inferior wall myocardial infarction, and the use of mechanical circulatory devices were all associated with BMS use.

CONCLUSION

DES was the preferred standard of care in the era of 2nd generation DES; however, BMSs were used in hospitalizations with high-risk procedures and multiple risk factors.

Gender difference with the use of percutaneous left ventricular assist device in patients undergoing complex high-risk percutaneous coronary intervention: From pVAD Working Group

Background:

The interventional treatment of complex high-risk indicated patients is technically difficult and can result in poor outcomes. Thus, percutaneous left ventricular assist devices are being increasingly used to provide hemodynamic support. No data is available comparing male and female for Complex High-risk Indicated Patients treated with percutaneous left ventricular assist devices. Our goal was to evaluate in-hospital as well as short term outcomes comparing males and females.

Methods:

There were 160 complex high-risk indicated patients with percutaneous left ventricular assist device use who were not in cardiogenic shock. A total of 132 male and 28 female patients were included. Ejection fraction below 35% with one additional criterion such as use of atherectomy device or treatment on unprotected left main disease or multi-vessel disease were our inclusion criteria. An Impella 2.5 or Impella CP (Abiomed Inc.) device was used as a left ventricular support device.

Results:

There was no difference in in-hospital mortality between the genders after performing a propensity score matched analysis (8.3% vs. 12.5%, p=0.54). Secondary outcomes of myocardial infarction, cardiogenic shock, congestive heart failure, dysrhythmia, major adverse cardiac events and composite of all complications were higher in males. Furthermore, 30-day survival was similar in males and females (88.9% vs. 87.5%, p=0.31). In addition, worse complications rates and survival were noted in patients with incomplete revascularization compared with those patients with complete revascularization in both gender.

Conclusion:

This study demonstrated no gender difference in clinical outcomes when using percutaneous left ventricular assist device support for the treatment of complex high-risk indicated patients. Overall, males had higher secondary outcomes compared with females with no difference in in-hospital mortality or 30-day survival rates.

Coronary Artery Bypass Grafting and Percutaneous Coronary Intervention after Kawasaki Disease: The Pediatric Canadian Series

Coronary artery (CA) aneurysms are serious complications of Kawasaki disease (KD) responsible for ischemic events. Percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) are reported with limited data on indications and comparative efficacy. Retrospective multicenter comparison of CA intervention following KD is performed in this study. Twenty two cases were available from 5 centers, of whom 11 underwent CABG, 10 PCI and 1 systemic thrombolysis. Age at intervention (8.3 ± 3.9 vs 11.3 ± 4.9 years, p = 0.14) and interval from diagnosis (5.6 ± 4.1 vs 6.5 ± 4.7 years, p = 0.64) were similar between CABG and PCI. Interventions were based on angiography in 15 patients or cardiac event in 7, with no difference between CABG and PCI (p = 0.24). Patients with CABG were more likely to undergo multivessel intervention (73 vs 10 %, p = 0.006). None of the patients needed reintervention after CABG, compared to 6 after PCI and 1 after systemic thrombolysis (p = 0.004). Signs of ischemia on stress testing or MIBI were present in 15 patients before intervention and persisted in 9 patients following last intervention, in a significantly higher proportion after CABG than PCI (80 vs 17 %, p = 0.01). In this series, CABG, which mostly involved multivessel intervention, was superior to PCI. Nevertheless, larger-scale studies may help define patient selection criteria for a beneficial PCI approach.