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

Innovations in Intracoronary Imaging: Present Clinical Practices and Future Outlooks

Engaging intracoronary imaging (IC) techniques such as intravascular ultrasound or optical coherence tomography enables the precise description of vessel architecture. These imaging modalities have well-established roles in providing guidance and optimizing percutaneous coronary intervention (PCI) outcomes. Furthermore, IC is increasingly recognized for its diagnostic capabilities, as it has the unique capacity to reveal vessel wall characteristics that may not be apparent through angiography alone. This manuscript thoroughly reviews the contemporary landscape of IC in clinical practice. Focused on current methodologies, the review explores the utility and advancements in IC techniques. Emphasizing their role in clarifying coronary pathophysiology, guiding PCI, and optimizing patient outcomes, the manuscript critically evaluates the strengths and limitations of each modality. Additionally, the integration of IC into routine clinical workflows and its impact on decision-making processes are discussed. By synthesizing the latest evidence, this review provides valuable insights for clinicians, researchers, and healthcare professionals involved in the dynamic field of interventional cardiology.

Outcomes of Drug-Eluting Balloons for In-Stent Restenosis: Large Cohort Analysis and Single-Center Clinical Experience

BACKGROUND

The use of drug-eluting balloons (DEBs) remains clinically relevant in the contemporary era of drug-eluting stent percutaneous coronary interventions (DES-PCI), especially in the setting of in-stent restenosis (ISR). Our goal was to assess the outcomes of ISR patients in a large prospective registry.

METHODS

A total of 2329 consecutive patients with ISR-PCI (675 using DEB and 1654 with DES) were treated in our medical centre from 2010 to 2021. Clinical end points included mortality and major adverse cardiac events (MACE) at 1 year. Clinical outcomes were adjusted for multiple confounders.

RESULTS

Mean ages (65.9 ± 11.0 vs 66.1 ± 10.5; P = 0.73) and percentages of female patients (16.6% vs 18.2%; P = 0.353) were similar between both ISR groups. Patients treated with DEB for ISR suffered more from diabetes, hypertension, and previous myocardial infarction (P < 0.01 for all) and presented more frequently with acute coronary syndrome (40.0% vs 34.4%; P = 0.01) compared with patients treated with DES for ISR. One-year MACE was significantly higher in the DEB ISR-PCI group (23.4% vs 19.6%; P = 0.002) compared to the DES ISR-PCI group, but no significant differences in mortality were observed at 1 year between the groups. After adjustment for multiple confounders, DEB ISR-PCI was not associated with increased MACE at 1 year (P = 0.55).

CONCLUSIONS

In our large experience, patients treated with DEB for ISR-PCI have higher baseline risk and sustained increased MACE rates compared with DES ISR-PCI patients. After adjustment for confounding variables, clinical outcomes are similar between the groups at 1 year after PCI.

Structural and temporal dynamics analysis of zinc-based biomaterials: History, research hotspots and emerging trends

Objectives

To examine the 16-year developmental history, research hotspots, and emerging trends of zinc-based biodegradable metallic materials from the perspective of structural and temporal dynamics.

Methods

The literature on zinc-based biodegradable metallic materials in WoSCC was searched. Historical characteristics, the evolution of active topics and development trends in the field of zinc-based biodegradable metallic materials were analyzed using the bibliometric tools CiteSpace and HistCite.

Results

Over the past 16 years, the field of zinc-based biodegradable metal materials has remained in a hotspot stage, with extensive scientific collaboration. In addition, there are 45 subject categories and 51 keywords in different research periods, and 80 papers experience citation bursts. Keyword clustering anchored 3 emerging research subfields, namely, #1 plastic deformation #4 additive manufacturing #5 surface modification. The keyword alluvial map shows that the longest-lasting research concepts in the field are mechanical property, microstructure, corrosion behavior, etc., and emerging keywords are additive manufacturing, surface modification, dynamic recrystallization, etc. The most recent research on reference clustering has six subfields. Namely, #0 microstructure, #2 sem, #3 additive manufacturing, #4 laser powder bed fusion, #5 implant, and #7 Zn-1Mg.

Conclusion

The results of the bibliometric study provide the current status and trends of research on zinc-based biodegradable metallic materials, which can help researchers identify hot spots and explore new research directions in the field.

Residence time in complex left main bifurcation disease after stenting

BACKGROUND

Data regarding the mean resident time (RT) after left main (LM) bifurcation stenting are scant. In the present study we performed a patient-specific computational fluid dynamic (CFD) analysis to investigate the different post-stenting mean RT values in LM patients treated with single-or double stenting techniques.

METHODS

Patients were identified after reviewing the local Optical Coherence Tomography (OCT) scans database. Overall, 27 patients (mean age 65.5 ± 12.4, 21 males) [10 patients treated with provisional cross-over stenting, 7 with the double kissing crush (DK crush) and 10 with the nano-inverted T (NIT) technique, respectively] with isolated and significant LM bifurcation disease were analyzed.

RESULTS

After LM bifurcation stenting, the NIT showed a higher averages WSS values at all bifurcation sites compared to DK crush and provisional cross-over stenting. Moreover, the mean RT resulted lower after NIT compared to provisional or DK crush. During the diastolic phase, the average RT of the entire LM bifurcation was 0.46 s, 0.38 s and 0.33 s after using the provisional stenting, DK crush and NIT, respectively. Moreover, the average RT in the LM bifurcation decreased by 17.1 % using the DK crush and by 28.2 % using the NIT compared to the Provisional.

CONCLUSION

The present OCT-derived CFD analysis revealed that, in patients with complex bifurcation LM disease, the provisional approach resulted in lower WSS values, while double stenting techniques, especially the NIT technique, resulted in a marked reduction of average RT compared to the provisional approach.

CONDENSED ABSTRACT

In the present study we performed a patient-specific Optical coherence tomography (OCT)-based computational fluid dynamic (CFD) analysis to investigate the different post-stenting mean RT values in 27 patients treated with provisional cross-over stenting, DK crush and Nano-inverted-T (NIT) stenting. The NIT showed a higher averages WSS values at all bifurcation sites compared to DK crush and Provisional. The mean RT resulted lower in NIT compared to Provisional or DK crush. During the entire diastolic phase, the average RT of the entire LM bifurcation was 0.46 s, 0.38 s and 0.33 s after using the provisional stenting, DK crush and NIT, respectively. Moreover, the average RT in the entire LM bifurcation decreased by 17.1 % using the DK crush and by 28.2 % using the NIT compared to the Provisional.

A New Frontier for Drug-Coated Balloons: Treatment of "De Novo" Stenosis in Large Vessel Coronary Artery Disease

Background: Drug-coated balloons (DCB) are a well-established option for treating in-stent restenosis endorsed by European Guidelines on myocardial revascularization. However, in recent years, a strategy of "leaving nothing behind" with DCB in de novo coronary stenosis has emerged as an appealing approach. Methods: We performed a systematic review to evaluate the current literature on the use of drug-coated balloons in the treatment of de novo stenosis in large vessel disease. Results: Observational studies, as well as randomized studies, demonstrated the safety of DCB percutaneous coronary interventions (PCI) in large vessel disease. The rate of major adverse cardiac events is even lower compared to drug-eluting stents in stable coronary artery disease. Conclusions: DCB PCI is feasible in large vessel disease, and future large, randomized studies are ongoing to confirm these results.

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.

Future of Endovascular and Surgical Treatments of Atherosclerotic Intracranial Stenosis

Intracranial atherosclerotic disease and resultant intracranial stenosis is a global leading cause of stroke, and poses an ongoing treatment challenge. Among patients with intracranial stenosis, those with hemodynamic compromise are at high risk for recurrent stroke despite medical therapy and risk factor modification. Revascularization of the hypoperfused territory is the most plausible treatment strategy for these high-risk patients, yet surgical and endovascular therapies have not yet shown to be sufficiently safe and effective in randomized controlled trials. Advances in diagnostic and therapeutic technologies have led to a resurgence of interest in surgical and endovascular treatment strategies, with a growing body of evidence to support their further evaluation in the treatment of select patient populations. This review outlines the current and emerging endovascular and surgical treatments and highlights promising future management strategies.

Heart Failure-Related Outcomes in Patients with Left Ventricular Dysfunction Undergoing Percutaneous Chronic Total Occlusion Revascularization

Background

The presence of a chronic total occlusion (CTO) and severe left ventricular (LV) systolic dysfunction are known negative prognostic factors in patients with coronary artery disease. Several studies have examined the effect of CTO revascularization on mortality, symptoms, occurrence of myocardial infarction (MI), and cardiac function in patients with normal or reduced LV function. However, the effect of CTO revascularization on heart failure-related events in patients with LV dysfunction, such as heart failure hospitalization (HFH), the occurrence of atrial fibrillation (AF), and a worsening renal function (WRF), has not yet been evaluated. To assess the success rate and safety of CTO percutaneous coronary interventions (PCIs) in coronary patients with LV ejection fractions of ≤ 40% and evaluate the impact of successful CTO revascularization on HFH, occurrence of AF, and WRF.

Methods

Prospectively, data were collected from CTO PCIs performed at three referral centers and analyzed. From a total of 1435 CTO PCIs, 132 (9.2%) patients with a left ventricular ejection fraction (LVEF) of ≤ 40% were included in this analysis. The median follow-up duration was 23.18 months (interquartile range (IQR): 11.02-46.66 months).

Results

A successful CTO PCI was achieved in 109 of these patients, while the procedure was unsuccessful in 23 patients (82.5% procedural success rate). Overall, the intervention had an acceptable number of peri-procedural (or in-hospital) complications (9.1%). During the follow-up period, the rates of all-cause death, cardiovascular death, and non-fatal MI were not significantly different between the two groups. The rates of HFH were significantly lower in the successful PCI group, while WRF and AF did not differ between successful and unsuccessful PCI groups. Successful PCI and higher estimated glomerular filtration rate (eGFR) were independent predictors of a lower risk of HFH, while prior stroke and diabetes were independent predictors of a higher risk of HFH.

Conclusions

In patients with reduced LV systolic function (ejection fraction, EF ≤ 40%), CTO PCI is a safe and effective procedure and successful CTO PCI is independently associated with a lower risk of HFH during follow-up. Further expansion of this cohort is necessary to confirm these results.

A nightmare of clopidogrel resistance in a resource-limited setting: case report of subacute stent thrombosis

BACKGROUND

Stent thrombosis, a life-threatening complication of percutaneous coronary intervention (PCI) continues to occur despite effective antiplatelet regimens and improved stenting methods. Noncompliance with dual antiplatelet therapy is the most common etiology; however, in spite of timely and their optimum administration the rates of recurrent myocardial infarction (MI) and stent thrombosis remain high. Clopidogrel resistance is increasingly evoked with elevated risk of anterothrombotic events particularly in the setting of stent implantation. In this case report, we present a case of subacute stent thrombosis associated with clopidogrel resistance in a resource-constrained setting.

CASE PRESENTATION

A 60 year old man with a long standing history of hypertension presented with a 6-month history of progressive shortness of breath. Initial electrocardiogram (ECG) revealed T-wave inversion on lateral leads and echocardiogram revealed akinetic basal lateral wall and hypokinetic mid lateral wall with reduced systolic functions. An elective coronary angiography (CAG) revealed a 90% stenosis of mid left anterior descending (LAD) artery and an 80% stenosis on the proximal left circumflex artery. He underwent a successful PCI with a drug-eluting stent implantation to mid LAD. He was discharged in a stable state 48 h post revascularization with dual antiplatelet (clopidogrel and acetylsalicylic acid). Seven days later, he presented with a crushing substernal chest pain. Cardiac enzymes were elevated and ECG revealed anterior ST-elevation MI. An emergency CAG revealed a high thrombus burden with 100% occlusion of mid LAD. Following unsuccessful ballooning, intravenous and intracoronary thrombolysis with tenecteplase was given. A TIMI II flow was achieved and the patient was sent to the coronary care unit. However, 14 h later there was yet a new onset of severe chest pain. A 12-lead ECG previewed anterior ST-elevation MI and the cardiac enzymes were high. Urgent CAG revealed in-stent thrombotic total occlusion of mid LAD. A stent in stent was then implanted and TIMI III flow was restored. Clopidogrel resistance was suspected and the patient was transitioned to ticagrelol. There were no further ischemic events during the remainder of hospitalization and the patient was discharged in a hemodynamically stable state three days later. During follow-up after one and three months, he was fairly stable without any further cardiac events.

CONCLUSIONS

Owing to clopidogrel resistance, stent thrombosis in the setting of dual antiplatelet therapy compliance may occur. While in a situation of clopidogrel resistance newer and more potent antiplatelet drugs should be used, their availability and cost remains a significant barrier particularly in the developing world. Nonetheless, a high index of suspicion and timely revascularization is fundamental to restore patency of the thrombosed vessel and confer better risk-adjusted survival rates.

Matrix-Binding, N-Cadherin-Targeting Chimeric Peptide Inhibits Intimal Thickening but Not Endothelial Repair in Balloon-Injured Carotid Arteries

BACKGROUND

Treatment of occluded vessels can involve angioplasty, stenting, and bypass grafting, which can be limited by restenosis and thrombosis. Drug-eluting stents attenuate restenosis, but the current drugs used are cytotoxic, causing smooth muscle cell (SMC) and endothelial cell (EC) death that may lead to late thrombosis. N-cadherin is a junctional protein expressed by SMCs, which promotes directional SMC migration contributing to restenosis. We propose that engaging N-cadherin with mimetic peptides can act as a cell type-selective therapeutic strategy to inhibit polarization and directional migration of SMCs without negatively impacting ECs.

METHODS

We designed a novel N-cadherin-targeting chimeric peptide with a histidine-alanine-valine cadherin-binding motif, combined with a fibronectin-binding motif from Staphylococcus aureus. This peptide was tested in SMC and EC culture assays of migration, viability, and apoptosis. Rat carotid arteries were balloon injured and treated with the N-cadherin peptide.

RESULTS

Treating scratch-wounded SMCs with the N-cadherin-targeting peptide inhibited migration and reduced polarization of wound-edge cells. The peptide colocalized with fibronectin. Importantly, EC junction, permeability, or migration was not impacted by peptide treatment in vitro. We also demonstrated that the chimeric peptide persisted for 24 hours after transient delivery in the balloon-injured rat carotid artery. Treatment with the N-cadherin-targeting chimeric peptide reduced intimal thickening in balloon-injured rat carotid arteries at 1 and 2 weeks after injury. Reendothelialization of injured vessels after 2 weeks was unimpaired by peptide treatment.

CONCLUSIONS

These studies show that an N-cadherin-binding and fibronectin-binding chimeric peptide is effective in inhibiting SMC migration in vitro and in vivo and limiting neointimal hyperplasia after balloon angioplasty without affecting EC repair. These results establish the potential of an advantageous SMC-selective strategy for antirestenosis therapy.

Clinical Outcomes and Prognostic Factors in Complex, High-Risk Indicated Procedure (CHIP) and High-Bleeding-Risk (HBR) Patients Undergoing Percutaneous Coronary Intervention with Sirolimus-Eluting Stent Implantation: 4-Year Results

We aimed to characterize the performance and safety of percutaneous coronary intervention (PCI) in complex, high-risk indicated procedure (CHIP) and high-bleeding-risk (HBR) patients at a 4-year follow up. We included all consecutive patients who underwent PCI with the sirolimus-eluting coronary stent Alex Plus (Balton, Poland) between July 2015 and March 2016. We analyzed various baseline demographic and clinical characteristics, laboratory data, and clinical outcomes. We enrolled 232 patients in whom 282 stents were implanted, including 81 patients meeting the CHIP criteria and 76 patients meeting the HBR criteria. In the whole population, the mean age was 68 ± 11 years, and 23.7% were females. Most procedures were performed from radial access (83.2%) using a 6F guiding catheter (95.7%). The lesions were mostly predilated (61.6%), and postdilatation was performed in 37.9%. The device success was 99.6% (in one case, a second stent was required due to heavy calcifications). Additional stents were deployed in 39% of cases due to edge dissection (6.9%), side branch stenting (5.2%), or diffuse disease (26.9%). Myocardial infarction (MI) type 4a was revealed in 2.2% of cases. At 4 years, the MACE rates for the whole population and for CHIP and HBR patients were 23.3%, 29.6%, and 27.6%, respectively. CHIP patients had a higher risk of MACEs (29.6% vs. 19.9%, HR 1.69, p = 0.032) and cardiac death (11.1% vs. 4.6%, HR 2.50, p = 0.048). There were no differences for MI (7.4% vs. 6.6%, p = 0.826) and TLR (18.5% vs. 12.6%, p = 0.150). HBR patients were also characterized by a higher risk of MACEs (27.6% vs. 21.2%, HR 1.84, p = 0.049) and cardiac death (17.1% vs. 1.9%, HR 9.61, p < 0.001). There were no differences for MI (7.9% vs. 6.4%, p = 0.669) and TLR (11.8% vs. 16.0%, p = 0.991). PCI in CHIP and HBR patients is feasible with a low rate of periprocedural complications. Nevertheless, CHIP and HBR patients are at a high risk of future adverse events and require strict surveillance to improve outcomes.

Comparison of 7-Year, Real-World Clinical Outcomes between Drug-Coated Balloon Angioplasty versus Drug-Eluting Stent Implantation in Patients with Drug-Eluting Stent In-Stent Restenosis

There are no data available comparing the real-world, long-term clinical outcomes of drug-eluting balloon (DEB) angioplasty and drug-eluting stent (DES) implantation in DES in-stent restenosis (ISR) lesions. We aimed to compare the real-world, long-term data available between DEBs and DESs in DES-ISR lesions. We analyzed consecutive DES-ISR lesions (225 lesions from 205 patients; male: 66.3%; mean age: 62.4 years) treated with either DEB or DES. The primary endpoint was target lesion revascularization (TLR), and the primary safety endpoint was the lesion-oriented composite outcome (LOCO). The LOCO is composed of cardiac death, myocardial infarction, and target lesion thrombosis during follow-up. During the 7-year follow-up period, TLR did not differ significantly between the DEB (n = 108) and the DES groups (n = 117) (HR: 1.07; 95% CI: 0.59-1.93, p = 0.83). The LOCO was significantly lower in the DEB group compared to the DES group (HR: 0.40; 95% CI: 0.16-0.98, p = 0.04), which was mainly driven by the lower levels of myocardial infarction (HR: 0.24; 95% CI: 0.06-0.94, p = 0.04) and the absence of target lesion thrombosis in the DEB group (vs. DES group 6%, p = 0.02). Additionally, cardiac death was found to be similar between the DEB and DES groups (HR: 0.56; 95% CI: 0.18-1.75, p = 0.32). DEB angioplasty showed favorable safety with a similar efficacy to that of DES implantation in DES-ISR lesions during the long-term follow-up period.

Strategies for surface coatings of implantable cardiac medical devices

Cardiac medical devices (CMDs) are required when the patient's cardiac capacity or activity is compromised. To guarantee its correct functionality, the building materials in the development of CMDs must focus on several fundamental properties such as strength, stiffness, rigidity, corrosion resistance, etc. The challenge is more significant because CMDs are generally built with at least one metallic and one polymeric part. However, not only the properties of the materials need to be taken into consideration. The biocompatibility of the materials represents one of the major causes of the success of CMDs in the short and long term. Otherwise, the material will lead to several problems of hemocompatibility (e.g., protein adsorption, platelet aggregation, thrombus formation, bacterial infection, and finally, the rejection of the CMDs). To enhance the hemocompatibility of selected materials, surface modification represents a suitable solution. The surface modification involves the attachment of chemical compounds or bioactive compounds to the surface of the material. These coatings interact with the blood and avoid hemocompatibility and infection issues. This work reviews two main topics: 1) the materials employed in developing CMDs and their key characteristics, and 2) the surface modifications reported in the literature, clinical trials, and those that have reached the market. With the aim of providing to the research community, considerations regarding the choice of materials for CMDs, together with the advantages and disadvantages of the surface modifications and the limitations of the studies performed.