Very Late Stent Thrombosis in Drug-Eluting Stents New Observations and Clinical Implications

Long-term outcomes following bioresorbable vascular scaffolds

INTRODUCTION

The higher scaffold thrombosis rates observed with the first-generation bioresorbable scaffolds (BRSs) compared to conventional drug-eluting stents were likely due in part to bioresorbable polymers having insufficient radial strength, necessitating larger strut profiles. Meta-analysis of the long-term outcomes from the first-generation Absorb bioresorbable vascular scaffold (BVS) showed that this period of excess risk ended at 3 years. Therefore, current attention has been focused on improving early outcomes by increasing the scaffold's tensile strength and reducing strut thickness.

AREAS COVERED

This review summaries the lessons learned from the first-generation BRS. It updates the long-term clinical outcomes of trials evaluating the ABSORB BVS and metallic alloy-based BRS. In addition, it reviews the next-generation BRSs manufactured in Asia.

EXPERT OPINION

Critical areas to improve the performance and safety of biodegradable scaffolds include further development in material science, surface modification, delivery systems, and long-term follow-up studies.

Nanotechnology in development of next generation of stent and related medical devices: Current and future aspects

Coronary stents have saved millions of lives in the last three decades by treating atherosclerosis especially, by preventing plaque protrusion and subsequent aneurysms. They attenuate the vascular SMC proliferation and promote reconstruction of the endothelial bed to ensure superior revascularization. With the evolution of modern stent types, nanotechnology has become an integral part of stent technology. Nanocoating and nanosurface fabrication on metallic and polymeric stents have improved their drug loading capacity as well as other mechanical, physico-chemical, and biological properties. Nanofeatures can mimic the natural nanofeatures of vascular tissue and control drug-delivery. This review will highlight the role of nanotechnology in addressing the challenges of coronary stents and the recent advancements in the field of related medical devices. Different generations of stents carrying nanoparticle-based formulations like liposomes, lipid-polymer hybrid NPs, polymeric micelles, and dendrimers are discussed highlighting their roles in local drug delivery and anti-restenotic properties. Drug nanoparticles like Paclitaxel embedded in metal stents are discussed as a feature of first-generation drug-eluting stents. Customized precision stents ensure safe delivery of nanoparticle-mediated genes or concerted transfer of gene, drug, and/or bioactive molecules like antibodies, gene mimics via nanofabricated stents. Nanotechnology can aid such therapies for drug delivery successfully due to its easy scale-up possibilities. However, limitations of this technology such as their potential cytotoxic effects associated with nanoparticle delivery that can trigger hypersensitivity reactions have also been discussed in this review. This article is categorized under: Implantable Materials and Surgical Technologies > Nanotechnology in Tissue Repair and Replacement Therapeutic Approaches and Drug Discovery > Nanomedicine for Cardiovascular Disease Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Long-term cardiovascular outcomes of biodegradable polymer drug eluting stents in patients with diabetes versus non-diabetes mellitus: a meta-analysis

BACKGROUND

Today, diabetes mellitus (DM) has become a worldwide concern. DM is a major risk factor for the development of cardiovascular diseases (CVD). Eligible patients with CVD are treated invasively by percutaneous coronary intervention (PCI) whereby a stent is implanted inside the coronary vessel with the particular lesion to allow sufficient blood flow. Newer scientific research have shown that even though associated with a lower rate of re-stenosis, first-generation drug eluting stents (DES) were associated with a higher rate of late stent thrombosis. Recently, newer stents, namely biodegradable polymer DES (BP-DES) have been developed to overcome the safety issues of earlier generation DES. In this analysis we aimed to systematically compare the long term (≥ 12 months) adverse cardiovascular outcomes observed in DM versus non-DM patients who were implanted with BP-DES.

METHODS

Cochrane central, MEDLINE (Subset PubMed), EMBASE, Web of Science, http://www.

CLINICALTRIALS

gov and Google scholar were searched for relevant publications involving BP-DES in patients with DM versus non-DM and their associated adverse cardiovascular outcomes. The mean follow-up time period ranged from 12 to 120 months. Data analysis was carried out with the latest version of the RevMan software (version 5.4). Based on the Mantel-Haenszel test, risk ratios (RR) with 95% confidence intervals (CI) were calculated and used to represent the results following analysis.

RESULTS

Seven (7) studies with a total number of 10,246 participants were included in this analysis. Stents which were implanted during PCI were BP-DES. Participants were enrolled from the year 2006 to 2013. Our current results showed that in patients who were implanted with BP-DES, the risks of major adverse cardiac events (RR: 1.30, 95% CI: 1.18-1.43; P = 0.00001), myocardial infarction (RR: 1.48, 95% CI: 1.14-1.93; P = 0.003), all-cause mortality (RR: 1.70, 95% CI: 1.29-2.23; P = 0.0002), cardiac death (RR: 1.93, 95% CI: 1.28-2.93; P = 0.002), target vessel revascularization (RR: 1.35, 95% CI: 1.03-1.77; P = 0.03), target lesion revascularization (RR: 1.28, 95% CI: 1.07-1.54; P = 0.007) and target lesion failure (RR: 1.79, 95% CI: 1.52-2.12; P = 0.00001) were significantly higher in the DM group. Definite and probable stent thrombosis (RR: 1.80, 95% CI: 1.28-2.55; P = 0.0009) were also significantly higher in the DM group.

CONCLUSIONS

Diabetes mellitus was an independent risk factor associated with long term adverse cardiovascular outcomes following PCI with BP-DES.

Clinical implications of inflammation in atheroma formation and novel therapies in cardiovascular diseases

Cardiovascular diseases (CVD) are the leading causes of death and disability in the world. Among all CVD, the most common is coronary artery disease (CAD). CAD results from the complications promoted by atherosclerosis, which is characterized by the accumulation of atherosclerotic plaques that limit and block the blood flow of the arteries involved in heart oxygenation. Atherosclerotic disease is usually treated by stents implantation and angioplasty, but these surgical interventions also favour thrombosis and restenosis which often lead to device failure. Hence, efficient and long-lasting therapeutic options that are easily accessible to patients are in high demand. Advanced technologies including nanotechnology or vascular tissue engineering may provide promising solutions for CVD. Moreover, advances in the understanding of the biological processes underlying atherosclerosis can lead to a significant improvement in the management of CVD and even to the development of novel efficient drugs. To note, over the last years, the observation that inflammation leads to atherosclerosis has gained interest providing a link between atheroma formation and oncogenesis. Here, we have focused on the description of the available therapy for atherosclerosis, including surgical treatment and experimental treatment, the mechanisms of atheroma formation, and possible novel therapeutic candidates such as the use of anti-inflammatory treatments to reduce CVD.

Evaluation of the safety and efficacy of a Polyzene-F nanocoated coronary stent system: A systematic review and single-arm meta-analysis

Background

A stent for patients with coronary heart disease (CHD) provides a requirement for a long-term antiplatelet therapy because of the high possibility of the development of stent thrombosis. It was against this background that both Cobra and Catania Polyzene-F (PzF) stents were designed to reduce the occurrence of stent thrombosis (ST). In this study, we review the safety and effectiveness of a PzF-nanocoated stent.

Methods

This systematic review with the title was registered in PROSPERO (No.398781). The inclusion criteria were including studies among patients with PzF-nanocoated coronary stents and reported target vessel failure (TVF) and ST as the outcomes, and the exclusion criteria were excluding reported patients who could not receive the adjunctive medical therapies or without the necessary endpoints. Reports about PzF-nanocoated stents were searched in PubMed, Embase, and Web of Science and other sources. Because of the existence of few reports and a lack of comparison groups, a single-arm meta-analysis was conducted in R software (v3.6.2), using a random-effects model with the generic inverse variance method. After a heterogeneity test, assessment of evidence quality was conducted by using GRADE software. A funnel plot Egger's test was performed to evaluate publication bias, and a sensitivity analysis was done to determine the robustness of the overall effects.

Results

Six studies of 1,768 subjects were included. The primary endpoint that pooled the TVF rate was 8.9% (95% CI 7.5%–10.2%), which comprised the pooled cardiac death (CD) rate (1.5%, 95% CI 0%–3%), myocardial infarction (MI) rate (2.7%, 95% CI 0.4%–5.1%), target vessel revascularization (TVR) (4.8%, 95% CI 2.4%–7.2%), or target lesion revascularization (TLR) (5.2%, 95% CI 4.2%–6.4%), while the secondary endpoint ST was 0.4% (95% CI 0.1%–0.9%). The funnel plots of TVF, CD, TVR, and TLR did not show any serious publication bias, and TVF, TVR, and TLR showed evidence of moderate quality in GRADE assessment. The sensitivity analysis showed that TVF, TLR, and ST exhibited good stability (I2 = 26.9%, 16.4%, and 35.5%, respectively), while the other endpoints showed moderate instability.

Conclusion

These data indicated that the PzF-nanocoated coronary stents of the Cobra and Catania systems demonstrated good safety and efficacy in clinical application. However, the sample size of patients included in the reports was relatively small, and this meta-analysis will be updated if more studies are published in the future.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42023398781

Relationship between atherogenic index of plasma and stent thrombosis in patients with acute coronary syndrome

OBJECTIVE

Stent thrombosis (ST) is an uncommon but serious complication in patients undergoing percutaneous coronary intervention (PCI). This study aimed to investigate the effect of atherogenic index of plasma (AIP) on ST.

METHODS

Among the 10,258 patients who underwent coronary angiography between January 2018 and December 2020, 239 patients who underwent PCI with the diagnosis of acute coronary syndrome (ACS) due to ST were included as the study group (ST group) and 459 patients who underwent percutaneous intervention for ACS and did not have any in-stent lesion as the control group (non-ST group). ST classification was done according to the Academic Research Consortium definition.

RESULTS

The mean age of the patients was 63.3±10.6 years (483 male, 69.2%). The groups were similar in terms of characteristic properties, comorbidities, and the drugs being used (p>0.05 for all). Drug eluting stents were used in 86.5% of the patients. In the ST group, the median time from stent implantation to thrombosis was 285 days. Mean AIP and the ratio of triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) were statistically significantly higher in the ST group than in the controls (p<0.001 and p=0.018, respectively), and a positive correlation was observed between time from stent implantation to thrombosis and AIP and TG/HDL-C (rS=0.229, p=0.010 and rS=0.222, p=0.010, respectively). Multivariate logistic regression analysis revealed that stent length, prior ST elevation myocardial infarction, TG/HDL-C, and AIP were independent predictors of ST.

CONCLUSION

AIP is an easy calculable biomarker, and the performance of AIP to predict ST is better than TG/HDL-C.

Very late stent thrombosis associated with COVID-19 infection: a case report and review of the literature

Coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2 has varied manifestation with multisystem involvement. Acute coronary syndrome in COVID-19 as a result of stent thrombosis is an uncommon entity and is often due to hypercoagulable state. A 40-year-old male was referred to us with acute onset chest pain. He also reported fever, sore throat and dry cough for six days which mandated testing for COVID-19 which turned out to be positive. He had a prior history of coronary artery disease with a drug eluting stent implanted two years back. An electrocardiogram was suggestive of acute anterior wall myocardial infarction while echocardiogram revealed hypokinesia of left anterior descending (LAD) artery territory. Coronary angiogram revealed non-occlusive thrombus in proximal LAD stent. A Thrombolysis in Myocardial Infarction (TIMI) III flow was restored following balloon angioplasty with a non-compliant balloon and use of glycoprotein (GP) IIb-IIIa receptor antagonist. A diagnosis of very late stent thrombosis subsequent to COVID-19 was made.

Current perspectives on bioresorbable scaffolds in coronary intervention and other fields

Introduction: The first-generation bioresorbable scaffolds (BRSs) had a large strut profile to compensate for the insufficient radial strength of bioresorbable polymer materials, resulting in higher scaffold thrombosis rates than conventional drug-eluting stents. To improve the clinical safety and efficacy, the new generation BRSs have been improved by optimal structure design, post-processing of bioresorbable polymer materials, or altering bioresorbable metallic alloys.Areas covered: This review summarizes the lessons learned from the first-generation BRS, updates the clinical outcomes of trials evaluating ABSORB bioresorbable vascular scaffold at long-term and bioresorbable metallic alloy-based devices, and examines recent outcomes of BRS treated in STEMI patients. This review also provides an overview of the current clinical data of seven BRSs manufactured in Asia, and of the BRSs extended application in other clinical arenas.Expert opinion: Drawbacks of the first-generation BRSs need to be addressed by the next generation of these stents with novel materials and technologies. Clinical research, including randomized controlled trials, are required to further evaluate BRSs application in coronary artery disease. The encouraging results of BRSs innovation applied in the peripheral arteries and gastrointestinal tracts support other potential clinical applications of BRS technology.

The Association Between S100A8/A9 and the Development of Very Late Stent Thrombosis in Patients With Acute Myocardial Infarction

Very late stent thrombosis (VLST) is a rare but serious complication following percutaneous coronary intervention (PCI). S100A8/A9 plays an important role in thrombosis through modulating the inflammatory response. This observational study aimed to reveal the association between S100A8/A9 and VLST. Continuous blood samples were collected from patients at both the time of index PCI for acute myocardial infarction (AMI) and the time of PCI for VLST (VLST group) or follow-up coronary angiography (AMI group). In all, 56 patients were selected in each group from a cohort of 8476 patients and other 112 individuals who underwent health checkups (normal control [NC] group) were selected as controls. Serum levels of S100A8/A9 and high sensitivity C-reactive protein (hs-CRP) were tested and compared. The mean level of S100A8/A9 was 3754.4 ± 1688.9 ng/mL during index PCI and increased to 5517.8 ± 2650.9 ng/mL at the time of VLST; in the AMI group, S100A8/A9 level was 2434.9 ± 1243.4 ng/mL during index PCI and decreased to 1568.2 ± 772.1 ng/mL during follow-up, similar to that detected in the NC group (1618.2 ± 641.4 ng/mL). Of note, S100A8/A9 levels showed significant increases during VLST when compared to its own levels during index PCI, which was different from the changes of hs-CRP. Higher serum levels of S100A8/A9 are associated with the development of VLST.