Late Coronary Stent Thrombosis

Nanoparticles as Drug Delivery Systems for the Targeted Treatment of Atherosclerosis

Atherosclerosis continues to be a leading cause of morbidity and mortality globally. The precise evaluation of the extent of an atherosclerotic plaque is essential for forecasting its likelihood of causing health concerns and tracking treatment outcomes. When compared to conventional methods used, nanoparticles offer clear benefits and excellent development opportunities for the detection and characterisation of susceptible atherosclerotic plaques. In this review, we analyse the recent advancements of nanoparticles as theranostics in the management of atherosclerosis, with an emphasis on applications in drug delivery. Furthermore, the main issues that must be resolved in order to advance clinical utility and future developments of NP research are discussed. It is anticipated that medical NPs will develop into complex and advanced next-generation nanobotics that can carry out a variety of functions in the bloodstream.

Factors associated with early, late, and very late stent thrombosis among patients with acute coronary syndrome undergoing coronary stent placement: analysis from the ATLAS ACS 2-TIMI 51 trial

Background

Stent thrombosis (ST) is an uncommon but serious complication of stent implantation. This study aimed to explore factors associated with early, late, and very late ST to help guide risk assessment and clinical decision-making on ST.

Methods

The analysis included patients who received stent placement for the index acute coronary syndrome (ACS). Cumulative incidence of ST was assessed at 30 days (early ST), 31-360 days (late ST), 361-720 days (very late ST), and up to 720 days. Cox proportional hazards models were used to assess associations between ST and various factors, including patient characteristics [i.e., age, sex, ACS presentation, history of hypertension, smoking, diabetes, prior myocardial infarction (MI), heart failure, prior ischemic stroke, and cancer], laboratory tests [i.e., positive cardiac biomarker, hemoglobin, platelet count, white blood cell (WBC) count], and treatment [i.e., drug-eluting stent (DES) vs. bare-metal stent (BMS) and anticoagulant with rivaroxaban vs. placebo].

Results

Among the 8,741 stented patients, 155 ST events (2.25%) occurred by Day 720. The cumulative incidences of early, late, and very late ST were 0.80%, 0.81%, and 0.77%, respectively. After multivariable adjustment, age ≥ 75 [hazard ratio (HR) = 2.13 (95% confidence interval, CI: 1.26-3.60)], a history of prior MI [HR = 1.81 (95% CI: 1.22-2.68)], low hemoglobin level [HR = 2.34 (95% CI: 1.59-3.44)], and high WBC count [HR = 1.58 (95% CI: 1.02-2.46)] were associated with a greater risk of overall ST, whereas DES [HR = 0.56 (95% CI: 0.38-0.83)] and rivaroxaban therapy [HR = 0.63 (95% CI: 0.44-0.88)] were associated with a lower risk of overall ST up to 720 days. Low hemoglobin level and high WBC count were associated with early ST (low hemoglobin: HR = 2.35 [95% CI: 1.34-4.12]; high WBC count: HR = 2.11 [95% CI: 1.17-3.81]). Low hemoglobin level and prior MI were associated with a greater risk of late ST (low hemoglobin: HR = 2.32 [95% CI: 1.26-4.27]; prior MI: HR = 2.98 [95% CI: 1.67-5.31]), whereas DES was associated with a lower risk of late ST [HR = 0.33 (95% CI: 0.16-0.67)]. Age ≥75 years was associated with very late ST.

Conclusion

The study identified positive and negative associations with early, late, and very late ST. These variables may be useful in constructing risk assessment models for ST.

Clinical Trial Registration

http://www.clinicaltrials.gov, identifier NCT00809965.

Advances in Fabrication Technologies for the Development of Next-Generation Cardiovascular Stents

Coronary artery disease is the most prevalent cardiovascular disease, claiming millions of lives annually around the world. The current treatment includes surgically inserting a tubular construct, called a stent, inside arteries to restore blood flow. However, due to lack of patient-specific design, the commercial products cannot be used with different vessel anatomies. In this review, we have summarized the drawbacks in existing commercial metal stents which face problems of restenosis and inflammatory responses, owing to the development of neointimal hyperplasia. Further, we have highlighted the fabrication of stents using biodegradable polymers, which can circumvent most of the existing limitations. In this regard, we elaborated on the utilization of new fabrication methodologies based on additive manufacturing such as three-dimensional printing to design patient-specific stents. Finally, we have discussed the functionalization of these stent surfaces with suitable bioactive molecules which can prove to enhance their properties in preventing thrombosis and better healing of injured blood vessel lining.

A randomized control trial to assess optical coherence tomography parameters of the Xlimus drug-eluting stent: the XLIMIT trial

Background

Third generation drug-eluting stents (DES) potentially offer better technical performance and reduced neointimal proliferation than previous generation DES. The XLIMIT non-inferiority trial evaluated the performance of the Xlimus (a novel sirolimus-eluting coronary stent system) in terms of endothelialization and tissue healing compared to the bioresorbable polymer Synergy DES.

Methods

A total of 177 patients undergoing percutaneous coronary intervention (PCI) were randomized in a 2:1 ratio (2 Xlimus: 1 Synergy). The primary endpoints, defined as the in-stent neointimal volume weighted by the sum of the lengths of the implanted stent (ISNV) and the in-stent neointimal percent volume obstruction (%VO) were evaluated at 6-9 months by means of optical coherence tomography (OCT). Additional OCT parameters as well as clinical endpoints were also collected.

Results

Most of the patients were males (77.4%), and the mean age was 64 years. One third of the population had stable angina/silent ischemia. A total of 300 stents (237 lesions) were analyzed: 198 (152 lesions) were in the Xlimus group, and 102 (85 lesions) in the Synergy group. The ISNV in the Xlimus group was 30.7 ± 24.5 mm3 while in the Synergy group it was 26.5 ± 26.7 mm3: the difference between the two means was 0.08 (-0, 04-0, 45), p = 0.018, thus meeting the non-inferiority hypothesis. The %VO was 16.3% ± 10.4% and 13.3% ± 10.8% in the Xlimus and Synergy groups, respectively: the difference between the two means was 3.0 (-0, 06-4, 2), (p = 0.01), thus meeting the non-inferiority hypothesis. No difference was found with respect to the secondary OCT endpoints as well as for clinical endpoints.

Conclusions

The study results confirm that the biological interaction of the Xlimus and Synergy DES with the coronary artery is comparable, and that translates in very reassuring OCT parameters at follow-up: as such, the Xlimus is non-inferior to the Synergy.

Clinical Trial Registration

ClinicalTrials.gov, identifier (NCT03745053).

An integrative review of nonobvious puzzles of cellular and molecular cardiooncology

Oncologic patients are subjected to four major treatment types: surgery, radiotherapy, chemotherapy, and immunotherapy. All nonsurgical forms of cancer management are known to potentially violate the structural and functional integrity of the cardiovascular system. The prevalence and severity of cardiotoxicity and vascular abnormalities led to the emergence of a clinical subdiscipline, called cardiooncology. This relatively new, but rapidly expanding area of knowledge, primarily focuses on clinical observations linking the adverse effects of cancer therapy with deteriorated quality of life of cancer survivors and their increased morbidity and mortality. Cellular and molecular determinants of these relations are far less understood, mainly because of several unsolved paths and contradicting findings in the literature. In this article, we provide a comprehensive view of the cellular and molecular etiology of cardiooncology. We pay particular attention to various intracellular processes that arise in cardiomyocytes, vascular endothelial cells, and smooth muscle cells treated in experimentally-controlled conditions in vitro and in vivo with ionizing radiation and drugs representing diverse modes of anti-cancer activity.

Percutaneous stent implantation for occluded central shunts in adults: A case report and review of current evidence

Background

Patients with cyanotic complex congenital heart defects (CHDs) commonly undergo palliation with interposition of systemic-to-pulmonary shunts (SPSs). These palliative shunts are rarely found in adults with CHDs and can be complicated with progressive obstruction or total occlusion during follow-up. The best treatment option for shunt re-permeabilization is challenging and case-oriented because most patients are high risk candidates for redo surgeries. We aimed to review the current evidence on percutaneous stent implantation to treat failed SPSs.

Methods

We performed a comprehensive literature review on percutaneous stent implantation to treat failed and occluded SPSs. We also reported the case of a 33-year-old man with cyanotic CHD and a occluded central aorto-pulmonary shunt, who was successfully treated with percutaneous balloon dilatation and subsequently stent implantation at our institution.

Result

We identified and included 31 articles reporting on 150 patients and 165 stent implantations in failed SPSs. The age of patients at the time of stent implantation ranged from 6 days to 47 years. The time between the surgical shunt creation and transcatheter intervention ranged from 1 day to 17 years. Overall, 161/165 (97.5%) stent implantations were successful. The most common clinical presentation was cyanosis and decreased atrial oxygen saturations and the indication for stent implantation was shunt obstruction and stenosis.

Conclusion

This review highlights the benefits of endovascular stenting to permeabilize failed SPSs in children and adults with complex CHD who are classified as poor candidates for re-surgical repair.

Beneficial effects of high-density lipoprotein (HDL) on stent biocompatibility and the potential value of HDL infusion therapy following percutaneous coronary intervention

Several epidemiological studies have shown a clear inverse relationship between serum levels of high-density lipoprotein cholesterol (HDL-C) and the risk of atherosclerotic cardiovascular disease (ASCVD), even at low-density lipoprotein cholesterol levels below 70 mg/dL. There is much evidence from basic and clinical studies that higher HDL-C levels are beneficial, whereas lower HDL-C levels are detrimental. Thus, HDL is widely recognized as an essential anti-atherogenic factor that plays a protective role against the development of ASCVD. Percutaneous coronary intervention is an increasingly common treatment choice to improve myocardial perfusion in patients with ASCVD. Although drug-eluting stents have substantially overcome the limitations of conventional bare-metal stents, there are still problems with stent biocompatibility, including delayed re-endothelialization and neoatherosclerosis, which cause stent thrombosis and in-stent restenosis. According to numerous studies, HDL not only protects against the development of atherosclerosis, but also has many anti-inflammatory and vasoprotective properties. Therefore, the use of HDL as a therapeutic target has been met with great interest. Although oral medications have not shown promise, the developed HDL infusions have been tested in clinical trials and have demonstrated viability and reproducibility in increasing the cholesterol efflux capacity and decreasing plasma markers of inflammation. The aim of the present study was to review the effect of HDL on stent biocompatibility in ASCVD patients following implantation and discuss a novel therapeutic direction of HDL infusion therapy that may be a promising candidate as an adjunctive therapy to improve stent biocompatibility following percutaneous coronary intervention.

Analysis of Functionalized Ferromagnetic Memory Alloys from the Perspective of Developing a Medical Vascular Implant

Durable biocompatible metal vascular implants are still one of the significant challenges of contemporary medicine. This work presents the preparation of ferromagnetic biomaterials with shape memory in metal strips based on FePd (30 at% Pd) that is either not doped or doped with Ga and Mn, coated with poly(benzofuran-co-arylacetic acid) or polyglutamic acid. The coating of the metal strips with polymers was achieved after the metal surface had been previously treated with open-air cold plasma. The final functionalization was performed to induce anti-thrombogenic/thrombolytic properties in the resulting materials. SEM-EDX microscopy and X-ray photoelectron microscopy (XPS) determined the morphology and composition of the metal strips covered with polymers. In vitro tests of standardized thromboplastin time (PTT) and prothrombin time (PT) were performed to evaluate the thrombogenicity of these biofunctionalized materials for future possible monitoring of the implant in patients.

Diabetes and restenosis

Restenosis, defined as the re-narrowing of an arterial lumen after revascularization, represents an increasingly important issue in clinical practice. Indeed, as the number of stent placements has risen to an estimate that exceeds 3 million annually worldwide, revascularization procedures have become much more common. Several investigators have demonstrated that vessels in patients with diabetes mellitus have an increased risk restenosis. Here we present a systematic overview of the effects of diabetes on in-stent restenosis. Current classification and updated epidemiology of restenosis are discussed, alongside the main mechanisms underlying the pathophysiology of this event. Then, we summarize the clinical presentation of restenosis, emphasizing the importance of glycemic control in diabetic patients. Indeed, in diabetic patients who underwent revascularization procedures a proper glycemic control remains imperative.

Stent-Based Gene Delivery for Coronary Disease

Percutaneous coronary interventions (PCI) are the mainstay for treatment of advanced coronary disease. A majority of PCI involve deployment of a stent in the affected vascular segment. This chapter introduces the concept of using stents as a platform for delivering gene therapies to the vasculature with the overarching aim of mitigating in-stent restenosis (ISR), late stent thrombosis (LST), and neoatherosclerosis (NA), a triad of delayed complications that reduce the overall success rate of PCI. The chapter provides a detailed methodology for coatless reversible attachment of adenoviral (Ad) and adeno-associated viral (AAV) vectors to the metal stent struts along with representative in vitro and in vivo results.

The feasibility of the flower stenting technique for ostial lesions of the common iliac artery

BACKGROUND AND AIMS

A balloon-expandable stent (BES) is generally used for ostial lesions of the common iliac artery (CIA) owing to the positional ease of stent adjustment. However, there are potential risks such as vessel dissection and perforation due to vessel overstretching during. In our hospital, we performed endovascular therapy (EVT) for CIA ostial lesions via a novel method named "the flower stenting method," using a self-expandable stent. This study aimed to analyze the efficacy and safety of this method.

METHODS

This study was single-center, retrospective, and observational. We enrolled 83 patients (91 limbs) who underwent EVT with SMART stent (Cordis, Miami, Florida) for CIA ostial lesions from 2007 to 2014. The primary endpoint was the rate of freedom from target lesion revascularization (TLR) in 5 years, and the secondary endpoint was the success rate of stent placement for the CIA ostium.

RESULTS

The average patient age was 72.3 ± 9.4 years, 71% of the patients were men, 19% were receiving hemodialysis, and 60% had diabetes. Additionally, 38% of the lesions were Trans-Atlantic Inter-Society Consensus C/D lesions, while 37% were chronic total occlusion lesions. The average lesion length was 36 ± 23 mm, and the average vessel diameter was 10.7 ± 1.4 mm. The rate of freedom from TLR was 97.3% at 5 years, and the success rate of only stent placement was 90.1%.

CONCLUSION

The flower stenting method leads to acceptable outcomes and is useful for accurate stent deployment.

Some Perspectives on Hypersensitivity to Coronary Stents

The development of coronary stents has represented a revolution in the treatment of coronary heart disease. Beyond their many advantages, stents also have their limitations and complications. Allergic reactions to coronary stents are more common than acknowledged. These stented patients are exposed to foreign substances inserted in direct contact with the coronary intima. Hypersensitivity to stent components and drugs prescribed after stent insertion together with any environmental exposure seem to contribute to these adverse reactions. Patients can present to the hospital with a wide range of symptoms and multiple complications, the most important ones being instent restenosis and stent thrombosis. Although not very common (and not always easy to identify), allergic reactions after coronary or peripheral stents should be taken into account. Careful selection of patients (for elective stent implantation) depending on the propensity to allergies, although hard to achieve, represents a key factor in reducing the number of these complications.

Clinical Impact of Irregular Protrusion Angle After Coronary Stenting at Culprit Lesions With ST-Elevation Myocardial Infarction - An Intravascular Optical Coherence Tomography Study

Background: A recent optical coherence tomography (OCT) registry showed that the presence of irregular protrusion (IP) after coronary stenting was a predictor of worse 1-year cardiovascular events. This study evaluated the clinical impact of OCT-detected IP after coronary stenting at ST-elevation myocardial infarction (STEMI) culprit lesions. Methods and Results: In all, 139 consecutive STEMI patients with OCT-detected IP after stenting were analyzed retrospectively. The maximum IP angles were measured and patients with IP were divided into 2 groups (large IP, maximum IP angle ≥180°; small IP, 0°<angle<180°). The primary endpoints were cardiac death, target vessel myocardial infarction, target lesion revascularization, and stent thrombosis at 1 year after the index percutaneous coronary intervention (PCI). Of STEMI patients with IP, 51.8% had large IP. The incidence of the primary endpoints higher was higher in the large than small IP group (12.5% vs. 1.5%, respectively; P=0.018). The occurrence of plaque rupture was an independent predictor of large IP (odds ratio 4.58; 95% confidential interval 1.86-11.27; P=0.001). Conclusions: Maximum IP angle ≥180° was an independent predictor of clinical events in STEMI patients with IP.

Evaluation of Dual Versus Triple Therapy by Landmark Analysis in the RE-DUAL PCI Trial

OBJECTIVES

The aim of this study was to explore the early versus late benefits and risks of dabigatran dual therapy versus warfarin triple therapy in the RE-DUAL PCI (Randomized Evaluation of Dual Antithrombotic Therapy With Dabigatran Versus Triple Therapy With Warfarin in Patients With Nonvalvular Atrial Fibrillation Undergoing Percutaneous Coronary Intervention) trial.

BACKGROUND

Patients with atrial fibrillation who undergo percutaneous coronary intervention are at increased risk for both bleeding and thrombotic events.

METHODS

A total of 2,725 patients with atrial fibrillation underwent percutaneous coronary intervention and were randomized to receive dabigatran 110 mg, or dabigatran 150 mg plus a P2Y₁₂ inhibitor (and no aspirin), or warfarin plus a P2Y₁₂ inhibitor plus aspirin. Landmark analysis was performed at 30 and 90 days.

RESULTS

There was a consistent and large reduction in major or clinically relevant nonmajor bleeding in patients randomized to dual therapy during the first 30 days (110 mg: hazard ratio [HR]: 0.45; 95% confidence interval [CI]: 0.31 to 0.66; p < 0.0001; 150 mg: HR: 0.46; 95% CI: 0.30 to 0.72; p = 0.0006) compared with warfarin triple therapy. There was early net clinical benefit in both dabigatran groups versus warfarin (110 mg: HR: 0.65; 95% CI: 0.47 to 0.88; p = 0.0062; 150 mg: HR: 0.54; 95% CI: 0.37 to 0.79; p = 0.0015), due to larger reductions in bleeding than increased thrombotic events for dabigatran 110 mg and bleeding reduction without increased thrombotic risk for dabigatran 150 mg dual therapy versus warfarin triple therapy. After the removal of aspirin in the warfarin group, bleeding remained lower with dabigatran 110 mg and was similar with dabigatran 150 mg versus warfarin.

CONCLUSIONS

In RE-DUAL PCI, in which patients in the dual-therapy arms were treated with aspirin for an average of only 1.6 days, there was early net clinical benefit with both doses of dabigatran dual therapy, without an increase in thrombotic events with dabigatran 150 mg. This could be helpful in the subset of patients with elevated risk for both bleeding and thrombotic events.

Pathological assessment of very late bare metal stent thrombosis in the left main coronary artery: a case report

Background

Late catch-up phenomenon following stent implantation is a well-known complication. However, no report has evaluated thrombosis after 9 years with multi-modality and pathological evaluation.

Case summary

A 71-year-old man with stable angina underwent elective percutaneous intervention of the left main coronary artery with implantation of a bare metal stent (BMS) 9 years ago. At the 9-year follow-up, coronary computed tomography (CCT) and coronary angiography (CAG) findings revealed a thrombus-like structure in the BMS slightly protruding into the sinus of Valsalva. Therefore, the previously prescribed double-antiplatelet therapy was replaced with an anticoagulant and clopidogrel, and a potent statin treatment was initiated. After the changes in drug treatment, follow-up examinations with CCT at 1 and 3 months suggested a decrease in the size of the thrombus; however, it appeared to increase after 6 months. Subsequently, the patient underwent surgical intervention. Pathological assessment of the explanted stent showed a proteoglycan-dominated extracellular matrix with few smooth muscle cells suggesting an organized thrombus.

Discussion

It should be emphasized that multiple factors might be responsible for very late stent thrombosis, such as peri-stent strut chronic inflammation involving proteoglycans, stent protrusion, and poorly controlled type 2 diabetes mellitus, possibly further inducing inflammatory cells.

Cardiovascular outcomes associated with Ultrathin bioresorbable polymer sirolimus eluting stents versus thin, durable polymer everolimus eluting stents following percutaneous coronary intervention in patients with type 2 diabetes mellitus: A meta-analysis of published studies

BACKGROUND

Percutaneous coronary intervention with the new generation drug eluting stents (DES) is 1 among the revascularization procedures required to treat patients with coronary artery disease (CAD). Since late stent thrombosis and silent myocardial infarction are highly associated with type 2 diabetes mellitus (T2DM), an analysis comparing the newer generation DES in this specific subgroup of patients would be scientifically relevant.In this analysis, we aimed to systematically compare the cardiovascular outcomes observed with the ultrathin bioresorbable polymer sirolimus eluting stents (SES) versus thin, durable polymer everolimus eluting stents (EES) following percutaneous coronary intervention in patients with T2DM.

METHODS

Through online databases, relevant studies comparing ultrathin bioresorbable polymer SES versus the durable polymer EES were carefully searched. The cardiovascular outcomes were assessed during a follow-up time period of 1 year and more than 1 year (1-5 years) respectively. This meta-analysis was carried out by the latest version of the RevMan software. Following analysis, the results were represented by odds ratios (OR) with 95% confidence intervals (CI).

RESULTS

A total number of 1967 patients with T2DM were included in this analysis. During a 1 year follow-up time period, target lesion failure (TLF) (OR: 0.59, 95% CI: 0.34-1.02; P = .06, target vessel revascularization (TVR) (OR: 0.97, 95% CI: 0.55-1.70; P = .91) and target lesion revascularization (TLR) (OR: 0.91, 95% CI: 0.44-1.87; P = .79) were similarly observed with ultrathin bioresorbable polymer SES versus the thin, durable polymer EES in these patients with T2DM. Other cardiovascular outcomes including myocardial infarction (MI), major adverse cardiac events, all-cause mortality (OR: 0.72, 95% CI: 0.37-1.40; P = .34), cardiac death and stent thrombosis (OR: 0.85, 95% CI: 0.45-1.62; P = .63) were also similarly observed with these 2 types of new stents. During a follow-up time period above 1 year (1-5 years), still no significant difference was observed in TLF, TVR, TLR, major adverse cardiac events, MI, all-cause mortality, cardiac death and stent thrombosis (OR: 0.62, 95% CI: 0.33-1.16; P = .14).

CONCLUSIONS

The ultrathin bioresorbable polymer SES were similar to the durable polymer EES in these patients with T2DM. These 2 types of new generation stents were comparable in terms of cardiovascular outcomes. Hence, they might be recommended in patients with T2DM. Upcoming trials should be able to confirm this hypothesis.

Use of Cangrelor in Cervical and Intracranial Stenting for the Treatment of Acute Ischemic Stroke: A "Real Life" Single-Center Experience

BACKGROUND AND PURPOSE

In cases of large-vessel-occlusion strokes due to an underlying tandem internal carotid artery occlusion or intracranial atherosclerotic disease, concomitant stent placement may be needed. Immediate platelet inhibition is necessary, but to date, a standardized approach for antiplatelet inhibition in acute settings is still missing. Here we report our single-center experience about the safety and efficacy of periprocedural administration of cangrelor in patients with acute ischemic stroke due to intracranial or cervical artery occlusion undergoing stent placement.

MATERIALS AND METHODS

We retrospectively evaluated all cases of acute ischemic stroke that needed acute stent implantation and were treated with periprocedural administration of cangrelor between January 2019 and April 2020 at our institution. All patients who needed either extracranial or intracranial artery stent placement (in either the anterior or posterior circulation) were included.

RESULTS

We evaluated 38 patients in whom cangrelor was administered IV periprocedurally. Their mean age was 64 years (range, 26-85 years), with 25/38 male subjects and 13/38 female patients. In 26 patients (68.4%), a tandem occlusion was present and was treated with carotid artery stent placement, while 12 patients (31.6%) required an intracranial stent implantation. In 4 subjects (10.5%), an intracerebral hemorrhage occurred after the procedure. All patients in the series were alive 1 week after the procedure.

CONCLUSIONS

Although larger, multicentric randomized studies are strongly warranted, our results support the hypothesis of a possible role of cangrelor as a valuable therapeutic option in the management of platelet inhibition in acute ischemic stroke procedures after intra- or extracranial stent placement.

Safety and Efficacy of Second-Generation Drug-Eluting Stents in Real-World Practice: Insights from the Multicenter Grand-DES Registry

Objective

In this study, we sought to compare the efficacy and safety of the Xience Prime/Xience V/Promus EES and Biomatrix/Biomatrix Flex/Nobori BES with resolute integrity/resolute ZES using the grand drug-eluting stent (Grand-DES) registry.

Background

Currently, new-generation drug-eluting stents (DESs) are used as the standard of care in patients undergoing percutaneous coronary intervention. No study has simultaneously compared everolimus-eluting stent (EES), biolimus-eluting stent (BES), and zotarolimus-eluting stent (ZES).

Methods

Stent-related composite outcomes (target lesion failure) and patient-related composite outcomes were compared in crude and propensity score-matched analysis.

Results

Of the 17,286 patients in the Grand-DES group, 5,137, 2,970, and 4,990 patients in the EES, BES, and ZES groups completed a three-year follow-up. In the propensity score-matched cohort, the stent-related outcome (EES vs. BES vs. ZES; 5.9% vs. 6.7% vs. 7.1%, P = 0.226) and patient-related outcomes (12.7% vs. 13.5% vs. 14.3%, P = 0.226) and patient-related outcomes (12.7% vs. 13.5% vs. 14.3%, P = 0.226) and patient-related outcomes (12.7% vs. 13.5% vs. 14.3%, P = 0.226) and patient-related outcomes (12.7% vs. 13.5% vs. 14.3%.

Conclusions

In this robust real-world registry with unrestricted use of EES, BES, and ZES, the three stent groups showed comparable safety and efficacy at the 3-year follow-up.

Acute Coronary Syndrome after 17 Years of Bare Metal Stent Implantation: "Very" Very Late Stent Thrombosis

Very late stent thrombosis (VLST) is a catastrophic and life-threatening complication after percutaneous coronary intervention which presents as an acute coronary syndrome with significantly high mortality and morbidity. VLST is a rare entity with drug-eluting stents and even rarer with bare metal stents. The exact pathophysiologic mechanism of VLST after BMS implantation is not known although various mechanisms have been proposed. Recently, in-stent neoatherosclerosis with intimal plaque rupture has been proposed as a potential mechanism of VLST after BMS. We report a rare case of VLST occurring 17 years after BMS implantation with angiographic and intravascular imaging evidence which provides insight into the mechanisms of VLST.

Acute and sub-acute stent thrombosis: Frequency, predictors and features in patients undergoing primary percutaneous intervention at a tertiary care cardiac centre

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Early stent thrombosis (ST) is relatively frequent in patients undergoing primary PCI.

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Diabetic and hypertensive patients are at an increased risk of ST.

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Presentation of patients in Killip Class III-IV is an independent predictor of early ST.

Objectives

To assess the frequency of early (acute and sub-acute) stent thrombosis (ST) after primary percutaneous coronary intervention (pPCI) and to identify its potential predictors.

Background

ST is a serious clinical event associated with a high mortality rate. A very limited data are available regarding the incidence rate of early ST after pPCI and its predictors, especially for Pakistani population.

Methods

Study included consecutive patients who underwent primary PCI. Telephonic follow-ups were made to obtain 30-days outcomes including ST, mortality, and re-occurrence of symptoms. ST was defined as per the standardized definition proposed by the Academic Research Consortium and classified as acute (during the procedure) and sub-acute (within 30 days).

Results

A total of 569 patients were included with 80.5% (485) male patients. The stent thrombosis (acute or sub-acute) was observed in 33 (5.8%) patients out of which 3 (9.1%) were definite ST while remaining 30 (90.9%) were probable ST. Patients who develop ST were predominantly male, hypertensive, diabetic, with reduced pre PCI LVEF (%) and Killip Class. A significantly higher in-hospital mortality rate was observed in patients with ST as compared to without ST, 36.4% (12/33) vs. 0.2% (1/536); p-value < 0.001 respectively. Killip Class (III-IV) was found to be the independent predictor of ST with an adjusted odds ratio of 5.2 [1.76–15.32].

Conclusions

Early stent thrombosis (ST) is relatively frequent in patients undergoing primary PCI. Diabetic and hypertensive patients are at an increased risk of ST and presentation of patients in Killip Class III-IV is an independent predictor of early ST.

Drug-eluting or bare-metal stents for percutaneous coronary intervention: a systematic review and individual patient data meta-analysis of randomised clinical trials

BACKGROUND

New-generation drug-eluting stents (DES) have mostly been investigated in head-to-head non-inferiority trials against early-generation DES and have typically shown similar efficacy and superior safety. How the safety profile of new-generation DES compares with that of bare-metal stents (BMS) is less clear.

METHODS

We did an individual patient data meta-analysis of randomised clinical trials to compare outcomes after implantation of new-generation DES or BMS among patients undergoing percutaneous coronary intervention. The primary outcome was the composite of cardiac death or myocardial infarction. Data were pooled in a one-stage random-effects meta-analysis and examined at maximum follow-up and a 1-year landmark. Risk estimates are reported as hazard ratios (HRs) with 95% CIs. This study is registered in PROSPERO, number CRD42017060520.

FINDINGS

We obtained individual data for 26 616 patients in 20 randomised trials. Mean follow-up was 3·2 (SD 1·8) years. The risk of the primary outcome was reduced in DES recipients compared with BMS recipients (HR 0·84, 95% CI 0·78-0·90, p<0·001) owing to a reduced risk of myocardial infarction (0·79, 0·71-0·88, p<0·001) and a possible slight but non-significant cardiac mortality benefit (0·89, 0·78-1·01, p=0·075). All-cause death was unaffected (HR with DES 0·96, 95% CI 0·88-1·05, p=0·358), but risk was lowered for definite stent thrombosis (0·63, 0·50-0·80, p<0·001) and target-vessel revascularisation (0·55, 0·50-0·60, p<0·001). We saw a time-dependent treatment effect, with DES being associated with lower risk of the primary outcome than BMS up to 1 year after placement. While the effect was maintained in the longer term, there was no further divergence from BMS after 1 year.

INTERPRETATION

The performance of new-generation DES in the first year after implantation means that BMS should no longer be considered the gold standard for safety. Further development of DES technology should target improvements in clinical outcomes beyond 1 year.

FUNDING

Bern University Hospital.

A prospective, multicenter, randomized OCT study of early neointimal condition at first and second months after BuMA Supreme stent versus XIENCE stent implantation in high-bleeding-risk coronary artery disease patients: study protocol for a randomized controlled trial

Background

Earlier vascular healing after drug-eluting stent (DES) implantation may reduce the incidence of late stent thrombosis and provide theoretical evidence to shorten dual antiplatelet therapy duration in patients with high bleeding risks. The BuMA supreme stent is a newly developed DES-coated with the sirolimus by using the international patent electronic grafted eG™ technology. Previous randomized trials showed that BuMA stents had better stent-strut coverage at 3-month follow-ups, which were evaluated by optical coherence tomography (OCT). However, there have been a limited number of studies that are directly evaluating the extent of neointima formation at the first and second months after stent implantation in high-bleeding-risk patients with coronary artery disease. This clinical trial is designed to demonstrate the non-inferiority of the BuMA supreme stent compared to the XIENCE stent in early neointimal formation.

Methods/design

This is a prospective, multicenter, randomized trial. Forty patients will be assigned into the first-month OCT group, and another 40 patients into the second-month OCT group. The patients in each cohort will be randomized again into two groups in a 1:1 ratio, either being implanted with the BuMA Supreme stent or the Xience V/Prime/Xpedition stent. The primary endpoint is stent-strut neointimal coverage rate (%) at the first and second months, respectively. Secondary endpoints include neointimal hyperplasia area/volume, neointimal hyperplasia thickness, stent-strut malapposition rate, late lumen loss (LLL), restenosis rate, device/lesion/clinical success rate, device-oriented composite endpoints at the first and second months, stent thrombosis and other serious adverse events and bleeding events at follow-up.

Discussion

The results will provide the first accurate imaging evidence on neointimal formation of the BuMA Supreme stent and the Xience stent at 1–2 months post PCI. The result should inspire further exploration and adjustment of DAPT treatments.

Trial registration

ClinicalTrials.gov, ID: NCT02747329. Registered on 21 April 2016. Last updated 17 May 2018.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3361-0) contains supplementary material, which is available to authorized users.

Evaluation of an in vitro coronary stent thrombosis model for preclinical assessment

Stent thrombosis remains an infrequent but significant complication following percutaneous coronary intervention. Preclinical models to rapidly screen and validate therapeutic compounds for efficacy are lacking. Herein, we describe a reproducible, high throughput and cost-effective method to evaluate candidate therapeutics and devices for either treatment or propensity to develop stent thrombosis in an in vitro bench-top model. Increasing degree of stent malapposition (0.00 mm, 0.10 mm, 0.25 mm and 0.50 mm) was associated with increasing thrombosis and luminal area occlusion (4.1 ± 0.5%, 6.3 ± 0.5%, 19.7 ± 4.5%, and 92.6 ± 7.4%, p < 0.0001, respectively). Differences in stent design in the form of bare-metal, drug-eluting, and bioresorbable vascular scaffolds demonstrated differences in stent thrombus burden (14.7 ± 3.8% vs. 20.5 ± 3.1% vs. 86.8 ± 5.3%, p < 0.01, respectively). Finally, thrombus burden was significantly reduced when healthy blood samples were incubated with Heparin, ASA/Ticagrelor (DAPT), and Heparin+DAPT compared to control (DMSO) at 4.1 ± 0.6%, 6.9 ± 1.7%, 4.5 ± 1.2%, and 12.1 ± 1.8%, respectively (p < 0.01). The reported model produces high throughput reproducible thrombosis results across a spectrum of antithrombotic agents, stent design, and degrees of apposition. Importantly, performance recapitulates clinical observations of antiplatelet/antithrombotic regimens as well as device and deployment characteristics. Accordingly, this model may serve as a screening tool for candidate therapies in preclinical evaluation.

Perioperative major adverse cardiac events in urgent femoral artery repair after coronary stenting are less common than previously reported

OBJECTIVE

Noncardiac surgery early after coronary stenting has been associated with a high rate of stent thrombosis and catastrophic outcomes. However, those outcomes were mostly seen when dual antiplatelet therapy (DAPT) was discontinued before surgery. This observational study sought to estimate the risk of major adverse cardiac events (MACEs) after femoral artery repair following recent stent-percutaneous coronary intervention under continued DAPT and to explore potential risk factors. We suspect that in this setting, the risk of MACEs is lower than previously reported.

METHODS

This retrospective cohort study included all consecutive patients who underwent femoral artery repair because of puncture site complications (bleeding or occlusion) within 28 days after coronary stenting at a tertiary referral center in Switzerland from 2005 to 2015. The primary end point consisted of the MACEs death, cardiac arrest, stent thrombosis, and myocardial infarction.

RESULTS

There were 12,960 patients who underwent coronary stenting. Seventy patients (0.5%) required repair of the femoral vessels, which was performed under continued DAPT in all cases. Eight patients (11.4%; 95% confidence interval [CI], 5.4-21.8) experienced a total of 17 MACEs within 30 days after surgery, including 5 deaths (7.1%; 95% CI, 2.7-16.6). Factors significantly associated with postoperative MACEs were cardiogenic shock on admission before coronary stenting (hazard ratio, 6.9; 95% CI, 1.8-29.6; P = .035) and limb ischemia as an indication for surgery compared with bleeding (hazard ratio, 10.5; 95% CI, 2.7-40.7; P = .008).

CONCLUSIONS

In our series, femoral artery repair under DAPT for access site complications early after stent-percutaneous coronary intervention is associated with only a modest MACE rate and therefore a much better outcome than previously reported.

Comparison of short-term clinical outcomes between Resolute Onyx zotarolimus-eluting stents and everolimus-eluting stent in patients with acute myocardial infarction: Results from the Korea Acute Myocardial infarction Registry (KAMIR)

BACKGROUND

There are few studies which compare the efficacy and safety of the Resolute Onyx zotarolimus-eluting stent (O-ZES) and everolimus-eluting stent (EES) in patients with acute myocardial infarction (AMI). Therefore, the present study aimed to compare clinical outcomes of O-ZES and EES in patients with AMI undergoing successful percutaneous coronary intervention (PCI).

METHODS

From January 2016 to December 2016, the Korea Acute Myocardial Infarction Registry (KAMIR) enrolled 3,364 consecutive patients. Among them, O-ZES was used in 402 patients and EES was used in 1,084 patients. The primary endpoint was target lesion failure (TLF), as defined by composite of cardiac death, target vessel myocardial infarction (TV-MI), and ischemic driven-target lesion revascularization (ID-TLR) at 6 month clinical follow-up.

RESULTS

At 6 months, the incidence of TLF was not significantly different between O-ZES and EES group (4.0% vs. 3.9%, adjusted hazard ratio [HR] 1.17, 95% confidential interval [CI] 0.58-2.35, p = 0.665). O-ZES also showed similar results of cardiac death (3.7% vs. 3.4%, adjusted HR 1.25, 95% CI 0.59-2.63, p = 0.560), TV-MI (0.2% vs. 0.6%, adjusted HR 0.56, 95% CI 0.07-4.85, p = 0.600), ID-TLR (0.0% vs. 0.3%, p = 0.524), and definite or probable stent thrombosis (0.2% vs. 0.3%, adjusted HR 0.63, 95% CI 0.06-6.41, p = 0.696) when compared with EES.

CONCLUSIONS

The present study shows that implantation of O-ZES or EES provided similar clinical outcomes with similar risk at 6-month of TLF and definite/probable ST in patients with AMI undergoing successful PCI.

Randomised trial of the comparison of drug-eluting stents in patients with diabetes: OCT DES trial

Background

To date, there have been limited comparisons performed between everolimus-eluting stents (EES) and zotarolimus-eluting stents (ZES) in patients with diabetes mellitus (DM). The objectives of this study was to assess the use of second-generation drug-eluting stents in patients with DM, using optical coherence tomography (OCT) to compare the level of stent coverage of Boston Scientific Promus Element EES compared with Medtronic Resolute Integrity ZES.(Clinicaltrials.gov number NCT02060357).

Methods

This is a single-centre randomised blinded trials assessing two commercially available stents in 60 patients with diabetes (ZES: n=30, EES: n=30). Patients underwent intracoronary assessment at 6 months with OCT assessing stent coverage, malapposition, neointimal thickness and percentage of in-stent restenosis (ISR).

Results

Of the 60 patients randomised, 46 patients underwent OCT analysis. There was no difference in baseline characteristics between the two groups. Both Promus Element and Resolute Integrity had low rates of uncovered struts at 6 months with no significant difference between the two groups (2.44% vs 1.24%, respectively; P=0.17). Rates of malapposition struts (3.9% vs 2.5%, P=0.25) and percentage of luminal loss did not differ between stent types. In addition, there was no significant difference in major adverse cardiovascular events (P=0.24) between the stent types.

Conclusions

This study is the first randomised trial to evaluate OCT at 6 months for ZES and EES in patients with diabetes. Both stents showed comparable strut coverage at 6 months, with no difference in ISR rates at 6 months.

Protective Layer Development for Enhancing Stability and Drug-Delivery Capabilities of DES Surface-Crystallized Coatings

Carrier-free drug-eluting stents (DES)-based crystalline coatings are gaining prominence because of their function, skipping many limitations and clinical complications of the currently marketed DES. However, their usage has been humbled by inflexibility of the crystalline coating and limited mechanical and physical properties. This study reports for the first time the development of a protective top coating for enhancing the merits and delivery capabilities of the crystalline coating. Flexible and water-soluble polysaccharide top coating was developed and applied onto rapamycin (RM) crystalline carpet. The top coating prevented crystalline coating delamination during stent crimping and expansion without affecting its release profile. Crystalline coating strata and its interfaces with the metallic substrate and top coating were fully studied and characterized. The crystalline top-coated stents showed significant physical, mechanical, and chemical stability enhancement with ∼2% RM degradation after 1 year under different storage conditions. Biocompatibility study of the top-coated stents implanted subcutaneously for 1 month into SD rats did not provoke any safety concerns. Incorporating RM into the top coating to develop a bioactive protective coating for multilayer release purposes was also investigated. The developed protective coating had wide applicability and may be further implemented for various drugs and implantable medical devices.

Recent advances to accelerate re-endothelialization for vascular stents

Cardiovascular diseases are considered as one of the serious diseases that leads to the death of millions of people all over the world. Stent implantation has been approved as an easy and promising way to treat cardiovascular diseases. However, in-stent restenosis and thrombosis remain serious problems after stent implantation. It was demonstrated in a large body of previously published literature that endothelium impairment represents a major factor for restenosis. This discovery became the driving force for many studies trying to achieve an optimized methodology for accelerated re-endothelialization to prevent restenosis. Thus, in this review, we summarize the different methodologies opted to achieve re-endothelialization, such as, but not limited to, manipulation of surface chemistry and surface topography.

Nitric Oxide Releasing Coronary Stent: A New Approach Using Layer-by-Layer Coating and Liposomal Encapsulation

The sustained or controlled release of nitric oxide (NO) can be the most promising approach for the suppression or prevention of restenosis and thrombosis caused by stent implantation. The aim of this study is to investigate the feasibility in the potential use of layer-by-layer (LBL) coating with a NO donor-containing liposomes to control the release rate of NO from a metallic stent. Microscopic observation and surface characterizations of LBL-modified stents demonstrate successful LBL coating with liposomes on a stent. Release profiles of NO show that the release rate is sustained up to 5 d. In vitro cell study demonstrates that NO release significantly enhances endothelial cell proliferation, whereas it markedly inhibits smooth muscle cell proliferation. Finally, in vivo study conducted with a porcine coronary injury model proves the therapeutic efficacy of the NO-releasing stents coated by liposomal LBL technique, supported by improved results in luminal healing, inflammation, and neointimal thickening except thrombo-resistant effect. As a result, all these results demonstrate that highly optimized release rate and therapeutic dose of NO can be achieved by LBL coating and liposomal encapsulation, followed by significantly efficacious outcome in vivo.

Clinical usefulness of red cell distribution width to angiographic severity and coronary stent thrombosis

Background

Red cell distribution width (RDW) is a quantitative measurement and shows heterogeneity of red blood cell size in peripheral blood. RDW has recently been associated with cardiovascular events and cardiovascular diseases, and it is a novel predictor of mortality. In this study, we aimed to evaluate the clinical usefulness of measuring RDW in patients with coronary stent thrombosis.

Patients and methods

We retrospectively reviewed 3,925 consecutive patients who presented with acute coronary syndrome and who underwent coronary angiography at the Siyami Ersek Hospital between May 2011 and December 2013. Of the 3,925 patients, 73 patients (55 males, mean age 59±11 years, 55 with ST elevated myocardial infarction) with stent thrombosis formed group 1. Another 54 consecutive patients who presented with acute coronary syndrome (without coronary stent thrombosis, 22 patients with ST elevated myocardial infarction, 44 males, mean age 54±2 years) and underwent percutaneous coronary intervention in May 2011 formed group 2. Data were collected from all groups for 2 years. The RDW values were calculated from patients 1 month later at follow-up. Syntax scores were calculated for all the patients. The patients were also divided as low syntax score group and moderate–high syntax score group.

Results

The patients in group 1 with stent thrombosis had significantly higher RDW level (13.85) than the patients in group 2 without stent thrombosis (12) (P<0.001). In addition, in all study patients, the moderate–high syntax score group had significantly higher RDW level (13.6) than the low syntax score group (12.9) (P=0.009). A positive correlation was determined between RDW and syntax scores (r=0.204).

Conclusion

RDW is a new marker of poor prognosis in coronary artery disease. Increased RDW level is correlated with angiographic severity of coronary artery disease, and RDW may be an important clinical marker of coronary stent thrombosis in patients undergoing coronary intervention.

Randomized evaluation of short-term dual antiplatelet therapy in patients with acute coronary syndrome treated with the COMBO dual therapy stent: rationale and design of the REDUCE trial

BACKGROUND

The optimal duration of dual antiplatelet therapy (DAPT) in acute coronary syndrome (ACS) patients treated with drug eluting stents (DES) is still under debate. Recent meta-analyses on ≤6months versus 12months DAPT suggest that bleeding rates can be reduced, without a higher rate of thrombotic complications. In particular, the COMBO dual therapy stent, being associated with early re-endothelialization, may allow for a reduction of the duration of DAPT without increasing the thrombotic risk, while reducing the risk of bleeding complications.

AIM

The aim of the REDUCE trial is to demonstrate the non-inferiority of a combined efficacy and safety endpoint of a short-term 3months DAPT strategy as compared to standard 12-month DAPT strategy in ACS patients treated with the COMBO stent.

DESIGN

A prospective, multicenter, randomized study designed to enroll 1500 patients with ACS treated with the COMBO stent. Patients will be randomized before discharge in a 1:1 fashion to either 3 or 12months of DAPT. A clinical follow-up is scheduled at 3, 6, 12, and 24months. The primary endpoint is the time to event as defined by the occurrence of one of the following: all cause mortality, myocardial infarction, stent thrombosis, stroke, target vessel revascularization or bleeding (Bleeding Academic Research Council type II, III and V) within 12months. The study has recruited patients since July 2014, and the results are expected in 2017.

SUMMARY

A reduction of the DAPT duration in ACS patients after PCI without affecting the thrombotic risk is an attractive option with regard to the associated bleeding risk. The REDUCE trial will be the first to investigate the efficacy and safety of a 3-month DAPT strategy compared to a 12-month DAPT strategy in an ACS only population treated with the COMBO stent.

Drug deposition in coronary arteries with overlapping drug-eluting stents

Drug-eluting stents are accepted as mainstream endovascular therapy, yet concerns for their safety may be under-appreciated. While failure from restenosis has dropped to below 5%, the risk of stent thrombosis and associated mortality remain relatively high. Further optimization of drug release is required to minimize thrombosis risk while maintaining therapeutic dose. The complex three-dimensional geometry of deployed stents together with the combination of diffusive and advective drug transport render an intuitive understanding of the situation exceedingly difficult. In situations such as this, computational modeling has proven essential, helping define the limits of efficacy, determine the mode and mechanism of drug release, and identify alternatives to avoid toxicity. A particularly challenging conformation is encountered in coronary arteries with overlapping stents. To study hemodynamics and drug deposition in such vessels we combined high-resolution, multi-scale ex vivo computed tomography with a flow and mass transfer computational model. This approach ensures high geometric fidelity and precise, simultaneous calculation of blood flow velocity, shear stress and drug distribution. Our calculations show that drug uptake by the arterial tissue is dependent both on the patterns of flow disruption near the wall, as well as on the relative positioning of drug-eluting struts. Overlapping stent struts lead to localized peaks of drug concentration that may increase the risk of thrombosis. Such peaks could be avoided by anisotropic stent structure or asymmetric drug release designed to yield homogeneous drug distribution along the coronary artery and, at the least, suggest that these issues need to remain in the forefront of consideration in clinical practice.

The Systems Biocompatibility of Coronary Stenting

The coronary stent has propelled our understanding of the term "biocompatibility." Stents are expanded at sites of arterial blockage and mechanically reestablish blood flow. This simplicity belies the complex reactions that occur when a stent contacts living substrates. Biocompatible seek to elicit the intended response; stents should perform rather than merely exist. Because performance is assessed in the patient, stent biocompatibility is the multiscale examination of material and cell, and of material, structure, and device in the context of cell, tissue, and organism. This review tracks major biomaterial advances in coronary stent design and discusses biocompatibility clinical performance.

Drug-Induced Thrombophilic or Prothrombotic States: An Underestimated Clinical Problem That Involves Both Legal and Illegal Compounds

Vascular thrombosis, both arterial and venous, is a condition associated with significant morbidity and mortality. There are multiple risk factors for thrombosis, both congenital and acquired, and in the majority of cases, these risk factors are not modifiable. Over the past 2 decades, multiple drugs (both illegal and legal) have been associated with increased risk of thrombosis. However, due to limited scientific literature regarding the prothrombotic tendencies of these drugs, there is a concomitant limited understanding of the pathophysiology of drug-induced thrombosis. As drugs are one of the few modifiable risk factors for thrombosis, further study and dissemination of knowledge regarding drug-associated and drug-induced thrombosis are essential and have the potential to lead to decreased future incidence of thrombosis. The mechanisms at the basis of the thrombophilic activity of these drugs are variable and sometimes still ill recognized. Increased levels of clotting factors, reduction in coagulation natural inhibitors, decreased fibrinolysis, activated clotting factors, increased blood viscosity, endothelial damage, and increased platelet number and activation are the most frequent causes. Arterial steal or coronary arteries no flow has also been implicated. In some cases due to the intake of several drugs, more than one mechanism is present in a given patient. The purpose of the present review is to analyze all the drugs demonstrated to be potentially thrombotic. It is hoped that a prudent use or nonuse of these drugs might result in a reduction of thrombosis-associated diseases.

Prolonged Clopidogrel Use is Associated with Improved Clinical Outcomes Following Drug-Eluting But Not Bare Metal Stent Implantation

BACKGROUND

Guidelines recommend clopidogrel use for 6-12 months following drug-eluting stent (DES) implantation and 1-12 months following bare metal stent (BMS) implantation. The role of clopidogrel beyond 12 months is unclear.

METHODS

We linked hospital administrative, community pharmacy and cardiac revascularization data to determine clopidogrel use and outcomes for all patients (those with acute presentations and those with stable angina) receiving a coronary stent in British Columbia 2004-2006, with follow-up until the end of 2008. Cox proportional hazard regression was performed to evaluate the effect of clopidogrel duration (≤12 vs. >12 months) on outcomes following BMS or DES implantation. Patients who died ≤12 months from index stent placement were excluded.

RESULTS

A total of 15,629 patients were included in the study. Of 3599 patients who received at least one DES and 12,030 patients who received only BMS, 1326 (37 %) and 2121 (18 %), respectively, filled a prescription for clopidogrel >12 months from the index procedure. The mean duration of clopidogrel was 406 ± 35 days and 407 ± 37 days in the prolonged use (>12 months) DES and BMS cohorts, respectively, compared with 224 ± 112 days (p < 0.001) and 122 ± 117 days (p < 0.001), respectively, for patients receiving clopidogrel ≤12 months. Clopidogrel use beyond 12 months was associated with a reduction in mortality [hazard ratio (HR) 0.66, 95 % confidence interval (CI) 0.45-0.97] and the composite of mortality and readmission for myocardial infarction (HR 0.72, 95 % CI 0.55-0.94) in patients treated with DES, but not BMS alone. Prolonged clopidogrel use was not associated with bleeding-related mortality.

CONCLUSIONS

Clopidogrel use beyond 12 months was associated with a reduction in death and hospitalization for myocardial infarction following DES, but not BMS, implantation. Our findings support a longer duration of clopidogrel therapy for patients treated with DES.

Ultrathin Strut Biodegradable Polymer Sirolimus-Eluting Stent Versus Durable-Polymer Everolimus-Eluting Stent for Percutaneous Coronary Revascularization: 2-Year Results of the BIOSCIENCE Trial

Background

No data are available on the long‐term performance of ultrathin strut biodegradable polymer sirolimus‐eluting stents (BP‐SES). We reported 2‐year clinical outcomes of the BIOSCIENCE (Ultrathin Strut Biodegradable Polymer Sirolimus‐Eluting Stent Versus Durable Polymer Everolimus‐Eluting Stent for Percutaneous Coronary Revascularisation) trial, which compared BP‐SES with durable‐polymer everolimus‐eluting stents (DP‐EES) in patients undergoing percutaneous coronary intervention.

Methods and Results

A total of 2119 patients with minimal exclusion criteria were assigned to treatment with BP‐SES (n=1063) or DP‐EES (n=1056). Follow‐up at 2 years was available for 2048 patients (97%). The primary end point was target‐lesion failure, a composite of cardiac death, target‐vessel myocardial infarction, or clinically indicated target‐lesion revascularization. At 2 years, target‐lesion failure occurred in 107 patients (10.5%) in the BP‐SES arm and 107 patients (10.4%) in the DP‐EES arm (risk ratio [RR] 1.00, 95% CI 0.77–1.31, P=0.979). There were no significant differences between BP‐SES and DP‐EES with respect to cardiac death (RR 1.01, 95% CI 0.62–1.63, P=0.984), target‐vessel myocardial infarction (RR 0.91, 95% CI 0.60–1.39, P=0.669), target‐lesion revascularization (RR 1.17, 95% CI 0.81–1.71, P=0.403), and definite stent thrombosis (RR 1.38, 95% CI 0.56–3.44, P=0.485). There were 2 cases (0.2%) of definite very late stent thrombosis in the BP‐SES arm and 4 cases (0.4%) in the DP‐EES arm (P=0.423). In the prespecified subgroup of patients with ST‐segment elevation myocardial infarction, BP‐SES was associated with a lower risk of target‐lesion failure compared with DP‐EES (RR 0.48, 95% CI 0.23–0.99, P=0.043, P_interaction=0.026).

Conclusions

Comparable safety and efficacy profiles of BP‐SES and DP‐EES were maintained throughout 2 years of follow‐up.

Clinical Trial Registration

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01443104.

Laminin Receptor-Avid Nanotherapeutic EGCg-AuNPs as a Potential Alternative Therapeutic Approach to Prevent Restenosis

In our efforts to develop new approaches to treat and prevent human vascular diseases, we report herein our results on the proliferation and migration of human smooth muscles cells (SMCs) and endothelial cells (ECs) using epigallocatechin-3-gallate conjugated gold nanoparticles (EGCg-AuNPs) as possible alternatives to drug coated stents. Detailed in vitro stability studies of EGCg-AuNPs in various biological fluids, affinity and selectivity towards SMCs and ECs have been investigated. The EGCg-AuNPs showed selective inhibitory efficacy toward the migration of SMCs. However, the endothelial cells remained unaffected under similar experimental conditions. The cellular internalization studies have indicated that EGCg-AuNPs internalize into the SMCs and ECs within short periods of time through laminin receptor mediated endocytosis mode. Favorable toxicity profiles and selective affinity toward SMCs and ECs suggest that EGCg-AuNPs may provide attractive alternatives to drug coated stents and therefore offer new therapeutic approaches in treating cardiovascular diseases.

Safety and efficacy of resolute zotarolimus-eluting stents compared with everolimus-eluting stents: a meta-analysis

BACKGROUND

Although new-generation drug-eluting stents represent the standard of care among patients undergoing percutaneous coronary intervention, there remains debate about differences in efficacy and the risk of stent thrombosis between the Resolute zotarolimus-eluting stent (R-ZES) and the everolimus-eluting stent (EES). The aim of this study was to evaluate the safety and efficacy of the R-ZES compared with EES in patients undergoing percutaneous coronary intervention.

METHODS AND RESULTS

A systematic literature search of electronic resources was performed using specific search terms until September 2014. Random-effects meta-analysis was performed comparing clinical outcomes between patients treated with R-ZES and EES up to maximum available follow-up. The primary efficacy end point was target-vessel revascularization. The primary safety end point was definite or probable stent thrombosis. Secondary safety end points were cardiac death and target-vessel myocardial infarction. Five trials were identified, including a total of 9899 patients. Compared with EES, R-ZES had similar risks of target-vessel revascularization (risk ratio [RR], 1.06; 95% confidence interval [CI], 0.90-1.24; P=0.50), definite or probable stent thrombosis (RR, 1.26; 95% CI, 0.86-1.85; P=0.24), cardiac death (RR, 1.01; 95% CI, 0.79-1.30; P=0.91), and target-vessel myocardial infarction (RR, 1.10; 95% CI, 0.89-1.36; P=0.39). Moreover, R-ZES and EES had similar risks of late definite or probable very late stent thrombosis (RR, 1.06; 95% CI, 0.53-2.11; P=0.87). No evidence of significant heterogeneity was observed across trials.

CONCLUSIONS

R-ZES and EES provide similar safety and efficacy among patients undergoing percutaneous coronary intervention.

Vascular Response to Experimental Stent Malapposition and Under-Expansion

Up to 80% of all endovascular stents have malapposed struts, and while some impose catastrophic events others are inconsequential. Thirteen stents were implanted in coronary arteries of seven healthy Yorkshire pigs, using specially-designed cuffed balloons inducing controlled stent malapposition and under-expansion. Optical coherence tomography (OCT) imaging confirmed that 25% of struts were malapposed (strut-wall distance <strut thickness) to variable extent (max. strut-wall distance malapposed group 0.51 ± 0.05 mm vs. apposed group 0.09 ± 0.05 mm, p = 2e-3). Imaging at follow-up revealed malapposition acutely resolved (<1% of struts remained malapposed at day 5), with strong correlation between lumen and the stent cross-sectional areas (slope = 0.86, p < 0.0001, R (2) = 0.94). OCT in three of the most significantly malapposed vessels at baseline showed high correlation of elastic lamina area and lumen area (R (2) = 0.96) suggesting all lumen loss was related to contraction of elastic lamina with negligible plaque/intimal hyperplasia growth. Simulation showed this vascular recoil could be partially explained by the non-uniform strain environment created from sub-optimal expansion of device and balloon, and the inability of stent support in the malapposed region to resist recoil. Malapposition as a result of stent under-expansion is resolved acutely in healthy normal arteries, suggesting existing animal models are limited in replicating clinically observed persistent stent malapposition.

Hemodynamic Performance of a New Punched Stent Strut: A Numerical Study

Local flow disturbance by arterial stent struts has been shown to play an important role in stent thrombosis. To reduce the local flow disturbance near a stent strut, we proposed a new concept of stent design with small holes in the stent struts. The present study evaluated the new design numerically by comparing it with the traditional stent in terms of local hemodynamic parameters such as flow velocity, flow recirculation area, time-averaged wall shear stress (TAWSS), oscillating shear index (OSI), and relative residence time (RRT). The results demonstrated that when compared with the traditional strut, the new design could significantly enhance flow velocity and reduce the flow recirculation zone in the vicinity of the strut. Moreover, the new design would significantly elevate TAWSS and remarkably reduce OSI and RRT along the host arterial wall. In conclusion, the new design of stent struts with punched holes is advantageous over the traditional one in the aspect of improving local hemodynamics, which may reduce thrombosis formation and promote re-endothelialization after stenting.

Successful Prasugrel Therapy for Recurrent Left Main Stent Thrombosis in a Clopidogrel Hyporesponder

Stent thrombosis is a life-threatening sequela of drug-eluting stent implantation. Dual antiplatelet therapy with aspirin and thienopyridine is typically used to prevent this catastrophic event. In terms of stent thrombosis, the major concern is the variable response of patients to clopidogrel, and this has raised interest in new antiplatelet agents. We present the case of a 64-year-old woman whom we successfully treated with prasugrel after she had repeated episodes of stent thrombosis caused by a poor response to clopidogrel. This case highlights the potential role of new antiplatelet agents for patients who are undergoing drug-eluting stent implantation.