Incidence, predictors, and long term clinical outcome of angiographic definite stent thrombosis in real world scenario - A prospective cohort study

Zinc Ion-crosslinked polycarbonate/heparin composite coatings for biodegradable Zn-alloy stent applications

Zinc and its alloys are the best candidates for biodegradable cardiovascular stents due to their good corrosion rate and biocompatibility in vasculature. However, the cytotoxicity caused by the rapid release of zinc ions during the initial degradation stage and the lack of an anticoagulant function are huge challenges for their practical clinical applications. In this work, we developed a zinc ion-crosslinked polycarbonate/heparin composite coating via electrophoretic deposition (EPD) to improve the biocompatibility and provide anticoagulant functions for Zn-alloy stents. Both electrochemical tests and in vitro immersion tests demonstrated an enhanced corrosion resistance and lower Zn ion release rate of the coated Zn alloys. Enhanced adhesion and proliferation of endothelial cells on coated Zn alloys were also observed, indicating faster reendothelialization than that on bare Zn alloys. Moreover, the surface erosion of the composite coating led to the uniform and long-term release of heparin, which remarkably inhibited the adhesion and activation of platelets, and may have endowed the coated Zn-alloy stents with long-term anticoagulant functions.

Balancing thrombosis and bleeding after out-of-hospital cardiac arrest related to acute coronary syndrome: A literature review

Balance between thrombosis and bleeding is now well recognized in patients treated for acute coronary syndrome, with impact on short- and long-term prognosis, including survival. Recent data suggest that patients who are resuscitated after out-of-hospital cardiac arrest related to myocardial infarction are at an even higher risk of bleeding and thrombosis than those with uncomplicated acute coronary syndrome. Delayed enteral absorption of medication due to induced hypothermia and systemic inflammation increases thrombosis risk, whereas transfemoral access site, cardiopulmonary resuscitation manoeuvres and mechanical circulatory support devices increase bleeding risk. In addition, post-resuscitation syndrome and renal or hepatic impairment are potential risk factors for both bleeding and thrombotic complications. There are currently no randomized controlled trials comparing various P₂Y₁₂ inhibitor and/or anticoagulation strategies in the setting of out-of-hospital cardiac arrest, and current practice is largely derived from management of patients with uncomplicated acute coronary syndrome. The aim of this review is therefore to describe the bleeding and thrombosis risk factors in this specific population, and to review recent data on antithrombotic drugs in this patient subset.

Exosomes secreted from mesenchymal stem cells mediate the regeneration of endothelial cells treated with rapamycin by delivering pro-angiogenic microRNAs

Delayed endothelial healing after drug eluting stent (DES) implantation is a critical clinical problem in treatment of coronary artery diseases. Exosomes exhibit proangiogenic potential in a variety of ischemic diseases. However, the association of exosomes with endothelial regeneration after DES implantation has been rarely reported. In this study, we aimed to investigate the therapeutic effects of mesenchymal stem cell (MSC)-derived exosomes on endothelial cells treated with rapamycin and explore the potential mechanisms of MSC-derived exosomes in promoting endothelial regeneration. Exosomes were isolated from MSCs by ultracentrifugation and identified by transmission electron microscopy, nanoparticle tracking analysis, and Western blot assay. The in vitro effects of MSC-derived exosomes on the proliferation and migration of endothelial cells treated with rapamycin were evaluated by integrated experiment, cell counting kit-8, scratch, tube formation, and transwell assays. And the apoptosis of rapamycin-induced endothelial cells loaded with MSC-derived exosomes was detected using TUNEL and Annexin-V FITC and PI double-staining assays. The microRNA (miRNA) cargo of MSC-derived exosomes was identified by high-throughput RNA sequencing. Pro-angiogenic miRNAs and key pathways were further characterized. Our results indicated that MSC-derived exosomes could be ingested into umbilical vein endothelial cells (HUVECs) and significantly enhanced cell proliferation rate, migratory and tube-forming capabilities in vitro. MSC-derived exosomes also inhibited the apoptosis of HUVECs induced by rapamycin. A distinct class of exosomal miRNAs was further identified, including six miRNAs tightly related to neovasculogenesis. Silencing the expression of exosomal miRNA-21-5p and let-7c-5p attenuated the pro-proliferative and pro-migratory capacity of MSC-derived exosomes. Moreover, functional enrichment analysis indicated that metabolic pathways might contribute to reendothelialization. This study highlights a proregenerative effect of MSC-derived exosomes in vitro, which may be partly explained by the delivery of pro-angiogenic miRNAs to endothelial cells.

Clinical outcomes after percutaneous coronary intervention for early versus late and very late stent thrombosis: a systematic review and meta-analysis

Whether the clinical outcomes of stent thrombosis (ST) are different when stratified by time of occurrence remains unclear. The objective of this study was to compare the short- and long-term clinical outcomes after percutaneous coronary intervention (PCI) for early stent thrombosis (EST) versus late stent thrombosis (LST) and very late stent thrombosis (VLST). We enrolled eligible studies searched from the main electronic databases (EMBASE, PubMed, Cochrane). The primary endpoints were in-hospital, 30-day, 1-year and long-term mortality. The secondary endpoints included recurrent stent thrombosis (RST) and target vessel/lesion revascularization (TVR/TLR) during hospitalization, at 30 days, at 1 year and at long-term follow-up. A total of 23 studies with 17,592 patients were included. Compared with mortality rates of the late and very late thrombosis (LST/VLST) group, in-hospital (P = 0.004), 30-day (P < 0.00001), 1-year (P < 0.00001) and long-term mortality rates (P = 0.04) were significantly higher in the EST group. The in-hospital TVR/TLR rates were similar between the EST group and the LST/VLST group. However, a higher trend in TVR/TLR rate at 30 days and a significantly higher TVR/TLR rate at 1 year (P = 0.002) as well as at long-term follow up (P = 0.009) were found in the EST group. EST patients also trended toward higher risk of RST in both short- and long-term follow-up than LST/VLST patients, although differences were not statistically significant. After PCI treatment, patients with EST have worse clinical outcomes in both short- and long-term follow-up than patients with LST/VLST. Further studies are warranted to determine the optimal treatment strategies for EST.