Modern Stents: Where Are We Going?

Impact of the number of modifiable risk factors on clinical outcomes after percutaneous coronary intervention: An analysis from the e-Ultimaster registry

Aims

A substantial proportion of the patients undergoing percutaneous coronary intervention (PCI) have none of the of standard modifiable cardiovascular risk factors (SMuRFs): hypertension, diabetes, hypercholesterolaemia and smoking. The aim of this analysis was to compare clinical outcomes after PCI according to the number of SMuRFs.

Methods

Patients with an indication for a PCI were stratified based upon the number of SMuRFs: 0, 1, 2 or 3-4. The primary outcome was target lesion failure (TLF), a composite of cardiac death, target vessel-related myocardial infarction or clinically driven target lesion revascularization at 1-year. Inverse weighted propensity score (IWPS) adjustment was performed to adjust for differences in baseline characteristics.

Results

The prevalence of SMuRFs was: 0 SMuRF 16.4 %; 1 SMuRF 27.8 %; 2 SMuRFs 34.7 % and 3-4 SMuRFs 21.1 %. Patients without SMuRFs were younger, more likely to be male and had less complex coronary artery disease. The incidence of TLF increased with the number of SMuRFs: 2.65 %, 2.75 %, 3.23 %, and 4.24 %, Ptrend < 0.001. The relative risk (RR) for a TLF was 60 % higher (95 % confidence interval 1.32-1.93, p < 0.01) for patients with 3-4 SMuRFs compared to patients without SMuRFs. The trend remained (Ptrend < 0.01) after IWPS with TLF rates of 2.88 %, 2.64 %, 2.88 % and 3.65 %. The RR for a TLF was 27 % higher (95 % CI 1.05-1.53, p < 0.01).

Conclusion

The incidence of clinical events at 1-year increased with the number of SMuRFs. While patients without SMuRFs have a relatively favourable risk profile, more research is needed to optimize therapeutic management in the majority of patients.

Coatings for Cardiovascular Stents-An Up-to-Date Review

Cardiovascular diseases (CVDs) increasingly burden health systems and patients worldwide, necessitating the improved awareness of current treatment possibilities and the development of more efficient therapeutic strategies. When plaque deposits narrow the arteries, the standard of care implies the insertion of a stent at the lesion site. The most promising development in cardiovascular stents has been the release of medications from these stents. However, the use of drug-eluting stents (DESs) is still challenged by in-stent restenosis occurrence. DESs' long-term clinical success depends on several parameters, including the degradability of the polymers, drug release profiles, stent platforms, coating polymers, and the metals and their alloys that are employed as metal frames in the stents. Thus, it is critical to investigate new approaches to optimize the most suitable DESs to solve problems with the inflammatory response, delayed endothelialization, and sub-acute stent thrombosis. As certain advancements have been reported in the literature, this review aims to present the latest updates in the coatings field for cardiovascular stents. Specifically, there are described various organic (e.g., synthetic and natural polymer-based coatings, stents coated directly with drugs, and coatings containing endothelial cells) and inorganic (e.g., metallic and nonmetallic materials) stent coating options, aiming to create an updated framework that would serve as an inception point for future research.

4-Methylumbelliferone-Functionalized Polyphosphazene and Its Assembly into Biocompatible Fluorinated Nanocoatings with Selective Antiproliferative Activity

Advanced multifunctional biomaterials are increasingly relying on clinically dictated patterns of selectivity against various biological targets. Integration of these frequently conflicting features into a single material surface may be best achieved by combining various complementary methodologies. Herein, a drug with a broad spectrum of activity, i.e., 4-methylumbelliferone (4-MU), is synthetically multimerized into water-soluble anionic macromolecules with the polyphosphazene backbone. The polymer structure, composition, and solution behavior are studied by ¹H and ³¹P NMR spectroscopy, size-exclusion chromatography, dynamic light scattering, and UV and fluorescence spectrophotometry. To take advantage of the clinically proven hemocompatibility of fluorophosphazene surfaces, the drug-bearing macromolecule was then nanoassembled onto the surface of selected substrates in an aqueous solution with fluorinated polyphosphazene of the opposite charge using the layer-by-layer (LbL) technique. Nanostructured 4-MU-functionalized fluoro-coatings exhibited a strong antiproliferative effect on vascular smooth muscle cells (VSMCs) and fibroblasts with no cytotoxicity against endothelial cells. This selectivity pattern potentially provides the opportunity for highly desirable fast tissue healing while preventing the overgrowth of VSMCs and fibrosis. Taken together with the established in vitro hemocompatibility and anticoagulant activity, 4-MU-functionalized fluoro-coatings demonstrate potential for applications as restenosis-resistant coronary stents and artificial joints.

Impact of Multisite artery disease on Clinical Outcomes After Percutaneous Coronary Intervention: An Analysis from the e-Ultimaster Registry

BACKGROUND

multisite artery disease is considered a 'malignant' type of atherosclerotic disease associated with an increased cardiovascular risk, but the impact of multisite artery disease on clinical outcomes after percutaneous coronary intervention (PCI) is unknown.

METHODS

Patients enrolled in the large, prospective e-Ultimaster study were grouped into 1) those without known prior vascular disease; 2) those with known single-territory vascular disease 3) those with known 2-3 territories (i.e, coronary, cerebrovascular, or peripheral) vascular disease (multisite artery disease). The primary outcome was coronary target lesion failure (TLF) defined as the composite of cardiac death, target vessel-related myocardial infarction, and clinically driven target lesion revascularization at 1-year. Inverse propensity score weighted (IPSW) analysis was performed to address differences in baseline patient and lesion characteristics.

RESULTS

Of the 37,198 patients included in the study, 62.3% had no prior known vascular disease, 32.6% had single-territory vascular disease, and 5.1% multisite artery disease. Patients with known vascular disease were older and were more likely to be men and to have more co-morbidities. After IPSW, the TLF rate incrementally increased with the number of diseased vascular beds (3.16%, 4.44% and 6.42% for no, single- and multisite artery disease, p<0.01 for all comparisons). This was also true for all cause death (2.22%, 3.28% and 5.29%, p<0.01 for all comparisons) and cardiac mortality (1.26%, 1.91% and 3.62%, p≤0.01 for all comparisons).

CONCLUSIONS

Patients with previously known vascular disease experienced an increased risk for adverse cardiovascular events and mortality post percutaneous coronary intervention. This risk is highest among patients with multisite artery disease.Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02188355.

Safety and Efficacy of Ultra Short-Duration Dual Antiplatelet Therapy After Percutaneous Coronary Interventions: A Meta analysis of Randomized Controlled Trials

INTRODUCTION

Dual antiplatelet therapy (DAPT) is required after percutaneous coronary intervention (PCI) to reduce stent thrombosis, but DAPT increases bleeding risks. The optimal duration of DAPT that provides the maximum protective ischemic effect along with the minimum bleeding risk is unclear. This is the first meta-analysis comparing outcomes for 1-month versus longer DAPT strategies following PCI.

METHODS

We searched PubMed, Cochrane, and ClinicalTrials.gov databases (from inception to October 2021) for randomized controlled trials (RCTs) that compared 1-month duration versus > 1-month duration of DAPT following PCI. We used a random-effects model to calculate risk ratio (RR) with 95% confidence interval (CI). The co-primary outcomes for study selection were all-cause mortality, major bleeding, and stent thrombosis. Secondary outcomes included myocardial infarction (MI), cardiovascular mortality, ischemic stroke and target vessel revascularization.

RESULTS

A total of five RCTs were included [n=29,355; 1-month DAPT(n=14,662) vs > 1-month DAPT (n=14,693)]. There was no statistically significant difference between the two groups in terms of all-cause mortality (RR 0.89; 95% CI 0.78-1.03; p = 0.12) and stent thrombosis (RR 1.07; 95% CI 0.80-1.43; p = 0.65). Similarly, there were no significant differences in MI, cardiovascular mortality, ischemic stroke, and target vessel revascularization. The rate of major bleeding was significantly lower in the group treated with DAPT for 1-month (RR 0.74; 95% CI 0.56-0.99, p = 0.04).

CONCLUSION

There is no difference in all-cause mortality, cardiovascular mortality, MI, stent thrombosis, ischemic stroke and target vessel revascularization with 1-month of DAPT following PCI with contemporary drug eluting stents compared to longer DAPT duration.

Applying Principles of Regenerative Medicine to Vascular Stent Development

Stents are a widely-used device to treat a variety of cardiovascular diseases. The purpose of this review is to explore the application of regenerative medicine principles into current and future stent designs. This review will cover regeneration-relevant approaches emerging in the current research landscape of stent technology. Regenerative stent technologies include surface engineering of stents with cell secretomes, cell-capture coatings, mimics of endothelial products, surface topography, endothelial growth factors or cell-adhesive peptides, as well as design of bioresorable materials for temporary stent support. These technologies are comparatively analyzed in terms of their regenerative effects, therapeutic effects and challenges faced; their benefits and risks are weighed up for suggestions about future stent developments. This review highlights two unique regenerative features of stent technologies: selective regeneration, which is to selectively grow endothelial cells on a stent but inhibit the proliferation and migration of smooth muscle cells, and stent-assisted regeneration of ischemic tissue injury.

Cardiovascular Stents: A Review of Past, Current, and Emerging Devices

One of the leading causes of morbidity and mortality worldwide is coronary artery disease, a condition characterized by the narrowing of the artery due to plaque deposits. The standard of care for treating this disease is the introduction of a stent at the lesion site. This life-saving tubular device ensures vessel support, keeping the blood-flow path open so that the cardiac muscle receives its vital nutrients and oxygen supply. Several generations of stents have been iteratively developed towards improving patient outcomes and diminishing adverse side effects following the implanting procedure. Moving from bare-metal stents to drug-eluting stents, and recently reaching bioresorbable stents, this research field is under continuous development. To keep up with how stent technology has advanced in the past few decades, this paper reviews the evolution of these devices, focusing on how they can be further optimized towards creating an ideal vascular scaffold.

Targeting the epigenome in in-stent restenosis: from mechanisms to therapy

Coronary artery disease (CAD) is one of the most common causes of death worldwide. The introduction of percutaneous revascularization has revolutionized the therapy of patients with CAD. Despite the advent of drug-eluting stents, restenosis remains the main challenge in treating patients with CAD. In-stent restenosis (ISR) indicates the reduction in lumen diameter after percutaneous coronary intervention, in which the vessel's lumen re-narrowing is attributed to the aberrant proliferation and migration of vascular smooth muscle cells (VSMCs) and dysregulation of endothelial cells (ECs). Increasing evidence has demonstrated that epigenetics is involved in the occurrence and progression of ISR. In this review, we provide the latest and comprehensive analysis of three separate but related epigenetic mechanisms regulating ISR, namely, DNA methylation, histone modification, and non-coding RNAs. Initially, we discuss the mechanism of restenosis. Furthermore, we discuss the biological mechanism underlying the diverse epigenetic modifications modulating gene expression and functions of VSMCs, as well as ECs in ISR. Finally, we discuss potential therapeutic targets of the small molecule inhibitors of cardiovascular epigenetic factors. A more detailed understanding of epigenetic regulation is essential for elucidating this complex biological process, which will assist in developing and improving ISR therapy.