Recent Advances in Stent Technology: Do They Reduce Cardiovascular Events?

Recent advances in surface functionalization of cardiovascular stents

Cardiovascular diseases (CVD) are the leading global threat to human health. The clinical application of vascular stents improved the survival rates and quality of life for patients with cardiovascular diseases. However, despite the benefits stents bring to patients, there are still notable complications such as thrombosis and in-stent restenosis (ISR). Surface modification techniques represent an effective strategy to enhance the clinical efficacy of vascular stents and reduce complications. This paper reviews the development strategies of vascular stents based on surface functional coating technologies aimed at addressing the limitations in clinical application, including the inhibition of intimal hyperplasia, promotion of re-endothelialization. These strategies have improved endothelial repair and inhibited vascular remodeling, thereby promoting vascular healing post-stent implantation. However, the pathological microenvironment of target vessels and the lipid plaques are key pathological factors in the development of atherosclerosis (AS) and impaired vascular repair after percutaneous coronary intervention (PCI). Therefore, restoring normal physiological environment and removing the plaques are also treatment focuses after PCI for promoting vascular repair. Unfortunately, research in this area is limited. This paper reviews the advancements in vascular stents based on surface engineering technologies over the past decade, providing guidance for the development of stents.

Advancements in the Treatment of Atherosclerosis: From Conventional Therapies to Cutting-Edge Innovations

Atherosclerosis is a leading cause of morbidity and mortality worldwide, driven by a complex interplay of lipid dysregulation, inflammation, and vascular pathology. Despite advancements in understanding the multifactorial nature of atherosclerosis and improvements in clinical management, existing therapies often fall short in reversing the disease, focusing instead on symptom alleviation and risk reduction. This review highlights recent strides in identifying genetic markers, elucidating inflammatory pathways, and understanding environmental contributors to atherosclerosis. It also evaluates the efficacy and limitations of current pharmacological treatments, revascularization techniques, and the impact of these interventions on patient outcomes. Furthermore, we explore innovative therapeutic strategies, including the promising fields of nanomedicine, nucleic acid-based therapies, and immunomodulation, which offer potential for targeted and effective treatment modalities. However, integrating these advances into clinical practice is challenged by regulatory, economic, and logistical barriers. This review synthesizes the latest research and clinical advancements to provide a comprehensive roadmap for future therapeutic strategies and emphasize the critical need for innovative approaches to fundamentally change the course of atherosclerosis management.

Comparison of Efficacy and Safety Between Drug-Coated Balloons Versus Drug-Eluting Stents in the Treatment of De Novo Coronary Lesions in Large Vessels: A Study-Level Meta-Analysis of Randomized Control Trials

BACKGROUND

Drug-coated balloons (DCB) can be used as an alternative to drug-eluting stents (DES) in patients with de novo small vessel coronary artery disease. This study aims to assess the efficacy and safety of solely using DCB versus DES in percutaneous coronary intervention (PCI) for de novo coronary lesions in large vessels.

METHOD

A database search was conducted using PubMed, EMBASE, Cochrane Library, and http://Clinicaltrials.gov for trials comparing DCB only with DES in treating de novo coronary lesions in large vessels. Efficacy outcomes included coronary angiography (CAG), follow-up minimal lumen diameter (MLD), and late luminal loss (LLL). Safety outcomes included target lesion failure [TLF: cardiac death, myocardial infarction (MI), target lesion revascularization (TLR)] and their individual components.

RESULTS

We included seven randomized control trials (RCTs) with 816 patients, of which 422 and 394 patients were in the DCB and DES groups, respectively. MLD measured during the 6-12 months follow-up in the DCB group was statistically significantly smaller than in the DES group (MD -0.21, 95% CI -0.34 to -0.07, P = 0.003, I2 = 52%). LLL measured at 6-12 months follow-up was statistically significantly lower in the DCB group than in the DES group (MD -0.13, 95% CI -0.22 to -0.05, P = 0.003, I2 = 60%). TLF, cardiac death, MI, and TLR, were not statistically significantly different between the two groups.

CONCLUSION

Use of DCB was associated with less LLL at 6-12 months than DES and was not associated with any increase in adverse clinical events. This data suggests DCB are as effective in treating de novo coronary lesions in large vessels as DES.

"Synergistic anticoagulant and endothelial regeneration strategy" based on mussel-inspired phospholipid copolymer coating and bioactive zeolitic imidazolate frameworks-90 to maintain the patency of CoCr stent

Given the risks of poor patient compliance and bleeding associated with current dual antiplatelet therapies, it is urgent to develop the next generation of cardiovascular stents with anticoagulation and rapid endothelialization capabilities. Inspired by the prominent bioactivity and bioavailability of zeolitic imidazolate framework-90 (ZIF-90) in driving endothelial cell (EC) morphogenesis, this research proposes a "synergistic anticoagulant and endothelial regeneration strategy" depending on mussel-inspired phospholipid copolymer (MIPC) and ZIF-90. Depending on the copolymerization of the catechol with dopamine (Dopa) monomers, Dopa/MIPC coating was immobilized on the surface of CoCr via a one-pot process for resisting the initial thrombosis induced by platelets and fibrinogen. Meanwhile, ZIF-90 was loaded on the coating via coordination effect, aiming to accelerate the proliferation and migration of ECs. Compared with CoCr, the well-designed CoCr-Dopa/MIPC@ZIF-90 not only reduced fibrinogen adhesion by approximately 40 % and platelet adhesion by almost 55 %, but also promoted the proliferation and migration of ECs significantly in vitro. Furthermore, the blood flow velocity of CoCr-Dopa/MIPC@ZIF-90 stent was similar to natural aorta and ECs coverage on it was greatly strengthened after 30 days in a rat aorta vascular stent implantation model. Collectively, CoCr-Dopa/MIPC@ZIF-90 exhibited obvious superiority in reducing the formation of thrombus and promoting endothelial regeneration, which might meet the high requirement for the next generation of vascular stent.

3D-Printed Shape Memory Poly(alkylene terephthalate) Scaffolds as Cardiovascular Stents Revealing Enhanced Endothelialization

Cardiovascular diseases are the leading cause of death and current treatments such as stents still suffer from disadvantages. Balloon expansion causes damage to the arterial wall and limited and delayed endothelialization gives rise to restenosis and thrombosis. New more performing materials that circumvent these disadvantages are required to improve the success rate of interventions. To this end, the use of a novel polymer, poly(hexamethylene terephthalate), is investigated for this application. The synthesis to obtain polymers with high molar masses up to 126.5 kg mol-1 is optimized and a thorough chemical and thermal analysis is performed. The polymers are 3D-printed into personalized cardiovascular stents using the state-of-the-art solvent-cast direct-writing technique, the potential of these stents to expand using their shape memory behavior is established, and it is shown that the stents are more resistant to compression than the poly(l-lactide) benchmark. Furthermore, the polymer's hydrolytic stability is demonstrated in an accelerated degradation study of 6 months. Finally, the stents are subjected to an in vitro biological evaluation, revealing that the polymer is non-hemolytic and supports significant endothelialization after only 7 days, demonstrating the enormous potential of these polymers to serve cardiovascular applications.

Revascularization Modalities in Acute Coronary Syndrome: A Review of the Current State of Evidence

Acute coronary syndrome (ACS) stands as a leading global cause of mortality, underscoring the importance of effective prevention, early diagnosis, and timely intervention. While medications offer benefits to many patients, revascularization procedures such as coronary artery bypass grafting (CABG), percutaneous coronary intervention (PCI), and emerging hybrid approaches remain pivotal for ACS management. This review delves into the 2018 ESC/EACTS guidelines alongside an analysis of existing literature to shed light on the spectrum of revascularization methods. While both CABG and PCI demonstrate promising outcomes, the optimal choice between the two hinges on a comprehensive assessment of individual patient factors, anatomical complexity guided by advanced imaging, comorbidities, and age. The determination of whether to pursue culprit or total revascularization, as well as immediate or staged revascularization, is contingent upon various factors, including age, disease complexity, and clinical outcomes. This evidence-based decision-making process is orchestrated by a multidisciplinary heart team grounded in ongoing clinical evaluation. The primary objective of this review is to provide valuable insights into revascularization strategies and scrutinize the congruence of current guidelines with recent advancements in the field.

Sex Differences in Long-Term Outcomes in Patients With Chronic Coronary Syndrome After Percutaneous Coronary Intervention - Insights From a Japanese Real-World Database Using a Storage System

BACKGROUND

Several studies have reported some sex differences in patients with coronary artery diseases. However, the results regarding long-term outcomes in patients with chronic coronary syndrome (CCS) are inconsistent. Therefore, the present study investigated sex differences in long-term outcomes in patients with CCS after percutaneous coronary intervention (PCI).

METHODS AND RESULTS

This was a retrospective, multicenter cohort study. We enrolled patients with CCS who underwent PCI between April 2013 and March 2019 using the Clinical Deep Data Accumulation System (CLIDAS) database. The primary outcome was major adverse cardiovascular events (MACE), defined as a composite of cardiovascular death, non-fatal myocardial infarction, or hospitalization for heart failure. In all, 5,555 patients with CCS after PCI were included in the analysis (4,354 (78.4%) men, 1,201 (21.6%) women). The median follow-up duration was 917 days (interquartile range 312-1,508 days). The incidence of MACE was not significantly different between the 2 groups (hazard ratio [HR] 1.20; 95% confidential interval [CI] 0.97-1.47; log-rank P=0.087). After performing multivariable Cox regression analyses on 4 different models, there were still no differences in the incidence of MACE between women and men.

CONCLUSIONS

There were no significant sex differences in MACE in patients with CCS who underwent PCI and underwent multidisciplinary treatments.

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.

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.