Development of a universal, oriented antibody immobilization method to functionalize vascular prostheses for enhanced endothelialization for potential clinical application.

BACKGROUND: Thrombosis is a common cause of vascular prosthesis failure. Antibody coating of prostheses to capture circulating endothelial progenitor cells to aid endothelialization on the device surface appears a promising solution to prevent thrombus formation. Compared with random antibody immobilization, oriented antibody coating (OAC) increases antibody-antigen binding capacity and reduces antibody immunogenicity in vivo. Currently, few OAC methods have been documented, with none possessing clinical application potential. RESULTS: Dopamine and the linker amino-PEG8-hydrazide-t-boc were successfully deposited on the surface of cobalt chromium (CC) discs, CC stents and expanded polytetrafluoroethylene (ePTFE) grafts under a slightly basic condition. CD34 antibodies were immobilized through the reaction between aldehydes in the Fc region created by oxidation and hydrazides in the linker after t-boc removal. CD34 antibody-coated surfaces were integral and smooth as shown by scanning electron microscopy (SEM), had significantly reduced or no substrate-specific signals as revealed by X-ray photoelectron spectroscopy, were hospitable for HUVEC growth as demonstrated by cell proliferation assay, and specifically bound CD34 + cells as shown by cell binding testing. CD34 antibody coating turned hydrophobic property of ePTFE grafts to hydrophilic. In a porcine carotid artery interposition model, a confluent monolayer of cobblestone-shaped CD31 + endothelial cells on the luminal surface of the CD34 antibody coated ePTFE graft were observed. In contrast, thrombi and fibrin fibers on the bare graft, and sporadic cells on the graft coated by chemicals without antibodies were seen. CONCLUSION: A universal, OAC method was developed. Our in vitro and in vivo data suggest that the method can be potentially translated into clinical application, e.g., modifying ePTFE grafts to mitigate their thrombotic propensity and possibly provide for improved long-term patency for small-diameter grafts.

The Potential Role of MiRs-139-5p and -454-3p in Endoglin-Knockdown-Induced Angiogenic Dysfunction in HUVECs.

Hereditary hemorrhagic telangiectasia (HHT) is a rare genetic disease characterized by aberrant angiogenesis and vascular malformations. Mutations in the transforming growth factor beta co-receptor, endoglin (ENG), account for approximately half of known HHT cases and cause abnormal angiogenic activity in endothelial cells (ECs). To date, how ENG deficiency contributes to EC dysfunction remains to be fully understood. MicroRNAs (miRNAs) regulate virtually every cellular process. We hypothesized that ENG depletion results in miRNA dysregulation that plays an important role in mediating EC dysfunction. Our goal was to test the hypothesis by identifying dysregulated miRNAs in ENG-knockdown human umbilical vein endothelial cells (HUVECs) and characterizing their potential role in EC function. We identified 32 potentially downregulated miRNAs in ENG-knockdown HUVECs with a TaqMan miRNA microarray. MiRs-139-5p and -454-3p were found to be significantly downregulated after RT-qPCR validation. While the inhibition of miR-139-5p or miR-454-3p had no effect on HUVEC viability, proliferation or apoptosis, angiogenic capacity was significantly compromised as determined by a tube formation assay. Most notably, the overexpression of miRs-139-5p and -454-3p rescued impaired tube formation in HUVECs with ENG knockdown. To our knowledge, we are the first to demonstrate miRNA alterations after the knockdown of ENG in HUVECs. Our results indicate a potential role of miRs-139-5p and -454-3p in ENG-deficiency-induced angiogenic dysfunction in ECs. Further study to examine the involvement of miRs-139-5p and -454-3p in HHT pathogenesis is warranted.

Antibody functionalized intravascular devices combined with genetically engineered endothelial colony-forming cells for targeted drug delivery: A proof-of-concept study.

This study was designed to test the ability of ex vivo antibody-coated intravascular devices to capture genetically engineered pig endothelial colony-forming cells (ECFCs) as proof of concept for their potential for in vivo targeted drug delivery. Human α-calcitonin gene-related peptide (α-CGRP) was chosen as the therapeutic molecule as it is unsuitable for systemic administration due to its potent peripheral arterial vasodilatory effect and short half-life in blood, requiring local delivery to yield therapeutic benefit in a particular vascular bed. H-2Kk, a murine leukocyte surface antigen, served as the selection marker for genetically modified ECFCs. H-2Kk antibody was immobilized on electropolished cobalt-chromium (CC) discs, CC stents and ePTFE grafts through dopamine self-polymerization. The functionalized surface was integral and smooth, lacked or had significantly reduced chemical signals specific for substrates. Pig bone marrow-derived ECFCs transfected with a plasmid constructed for H-2Kk and α-CGRP expression produced H-2Kk on cell surface and biologically active α-CGRP in culture medium. H-2Kk antibody-coated substrates bound H-2Kk ECFCs but not control ECFCs in vitro. Bare or only dopamine-coated substrates did not bind H-2Kk ECFCs. These data suggest that implantation of antibody functionalized devices combined with injection of genetically modified ECFCs could be potentially applied for targeted drug delivery.

Exploring Endothelial Colony-Forming Cells to Better Understand the Pathophysiology of Disease: An Updated Review.

Endothelial cell (EC) dysfunction has been implicated in a variety of pathological conditions. The collection of ECs from patients is typically conducted postmortem or through invasive procedures, such as surgery and interventional procedures, hampering efforts to clarify the role of ECs in disease onset and progression. In contrast, endothelial colony-forming cells (ECFCs), also termed late endothelial progenitor cells, late outgrowth endothelial cells, blood outgrowth endothelial cells, or endothelial outgrowth cells, are obtained in a minimally invasive manner, namely, by the culture of human peripheral blood mononuclear cells in endothelial growth medium. ECFCs resemble mature ECs phenotypically, genetically, and functionally, making them excellent surrogates for ECs. Numerous studies have been performed that examined ECFC function in conditions such as coronary artery disease, diabetes mellitus, hereditary hemorrhagic telangiectasia, congenital bicuspid aortic valve disease, pulmonary arterial hypertension, venous thromboembolic disease, and von Willebrand disease. Here, we provide an updated review of studies using ECFCs that were performed to better understand the pathophysiology of disease. We also discuss the potential of ECFCs as disease biomarkers and the standardized methods to culture, quantify, and evaluate ECFCs and suggest the future direction of research in this field.

MicroRNA-132-3p, Downregulated in Myeloid Angiogenic Cells from Hereditary Hemorrhagic Telangiectasia Patients, Is Enriched in the TGFß and PI3K/AKT Signalling Pathways.

BACKGROUND: Hereditary hemorrhagic telangiectasia (HHT) is a rare, autosomal dominant genetic disorder characterized by life-threatening vascular dysplasia. Myeloid angiogenic cells (MACs), alternatively called early endothelial progenitor cells or circulating angiogenic cells, do not directly incorporate into developing blood vessels, but augment angiogenesis in a paracrine manner. MAC dysfunction has been reported in HHT. MicroRNAs (miRNAs) regulate cellular function by modulating gene expression post-transcriptionally. To date, the role of miRNAs in HHT MAC dysfunction has not been documented. OBJECTIVE: The goal of this study was to comparatively profile miRNAs in HHT patient and control MACs to identify dysregulated miRNAs that may be responsible for the observed MAC dysfunction in HHT. METHODOLOGY/RESULTS: Twenty-three dysregulated miRNAs (twenty-one upregulated and two downregulated) in HHT MACs were identified with a TaqMan miRNA microarray. Pathway enrichment analysis showed that the dysregulated miRNAs were significantly enriched in pathways involved in HHT pathogenesis, such as the transforming growth factor ß (TGFß), phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT), and Hippo signalling pathways. Furthermore, miR-132-3p was determined to be significantly reduced in HHT MACs compared with controls by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Bioinformatic analysis revealed that miR-132-3p is significantly enriched in the TGFß and PI3K/AKT signalling pathways, targeting SMAD4, an effector of the TGFß signalling pathway and RASA1, a negative regulator of the PI3K/AKT signalling pathway, respectively. CONCLUSION: MiRNA dysregulation, specifically reduced expression of miR-132-3p, in HHT MACs was identified. The dysregulated miRNAs are significantly enriched in the TGFß, PI3K/AKT, and Hippo signalling pathways. These data suggest that alteration in miRNA expression may impair these pathways and contribute to MAC dysfunction in HHT.

An optimal non-viral gene transfer method for genetically modifying porcine bone marrow-derived endothelial progenitor cells for experimental therapeutics.

No currently available treatment is able to generate new contractile tissue or significantly improve cardiac function after myocardial infarction (MI), a leading cause of morbidity and mortality worldwide. Although gene transfer-enhanced endothelial progenitor cells (GTE-EPCs) show effectiveness in MI treatment in small animal models, no clinical trials using GTE-EPCs have been documented. Before the introduction of GTE-EPCs into human trials, gene-transfer-mediated augmentation of EPC function in animal models that reflect the human MI scenario should be tested. In this regard, a porcine model is the best choice since pigs have cardiac size, hemodynamics and coronary anatomy similar to that of humans. To examine GTE-EPC therapeutic efficacy in pig MI models, an efficient method for gene transfer into pig EPCs is required, which however, has been poorly documented. Pig bone marrow mononuclear cells were isolated and cultured in EGM-2 medium to obtain bone marrow-derived EPCs (BM-EPCs) that were characterized by immunostaining and the tube formation assay. Gene transfer was optimized in 6-well plates using a GFP and a VEGF plasmid, and scaled up in T75 flasks. Gene transfer efficiency was determined by fluorescence microscopy and flow cytometry. VEGF levels were measured by ELISA. Cell proliferation was assayed by the CCK-8 kit. (1) BM-EPCs expressed VEGFR2 and eNOS but not CD45 protein, and formed tube structures on Matrigel; (2) several chemical compounds were explored with the highest transfection efficiency of 41.4% ± 5.8% achieved using Lipofectamine 3000; (3) the VEGF level in culture medium after VEGF transfection was 378 ± 48 ng/106 cells; and (4) BM-EPCs overexpressing VEGF had significantly enhanced proliferation than GFP-transfected EPCs. A simple, easy and cheap method that can be applied to produce a large number of genetically-modified BM-EPCs was established, which will facilitate the study of GTE-EPC therapeutic efficacy in pig MI model.

Endoglin deficiency impairs VEGFR2 but not FGFR1 or TIE2 activation and alters VEGF-mediated cellular responses in human primary endothelial cells.

Hereditary hemorrhagic telangiectasia (HHT) is a genetic disease characterized by vascular dysplasia. Mutations of the endoglin (ENG) gene that encodes a co-receptor of the transforming growth factor ß1 signaling pathway cause type I HHT. ENG is primarily expressed in endothelial cells (ECs), but its interaction with other key angiogenic pathways to control angiogenesis has not been well addressed. The aim of this study is to investigate ENG interplay with VEGFR2, FGFR1 and TIE2 in primary human ECs. ENG was knocked-down with siRNA in human umbilical vein ECs (HUVECs) and human lung microvascular ECs (HMVEC-L). Gene expression was measured by RT-qPCR and Western blotting. Cell signaling pathway activation was analyzed by detecting phosphor-ERK and phosphor-AKT levels. Cell migration and apoptosis were assessed using the Boyden chamber assay and the CCK-8 Kit, respectively. Loss of ENG in HUVECs led to significantly reduced expression of VEGFR2 but not TIE2 or FGFR1, which was also confirmed in HMVEC-L. HUVECs lacking ENG had significantly lower levels of active Rac1 and a substantial reduction of the transcription factor Sp1, an activator of VEGFR2 transcription, in nuclei. Furthermore, VEGF- but not bFGF- or angiopoietin-1-induced phosphor-ERK and phosphor-AKT were suppressed in ENG deficient HUVECs. Functional analysis revealed that ENG knockdown inhibited cell migratory but enhanced anti-apoptotic activity induced by VEGF. In contrast, bFGF, angiopoietin-1 and -2 induced HUVEC migration and anti-apoptotic activities were not affected by ENG knockdown. In conclusion, ENG deficiency alters the VEGF/VEGFR2 pathway, which may play a role in HHT pathogenesis.

Non-Coding RNAs and Hereditary Hemorrhagic Telangiectasia.

Non-coding RNAs (ncRNAs) are functional ribonucleic acid (RNA) species that include microRNAs (miRs), a class of short non-coding RNAs (∼21-25 nucleotides), and long non-coding RNAs (lncRNAs) consisting of more than 200 nucleotides. They regulate gene expression post-transcriptionally and are involved in a wide range of pathophysiological processes. Hereditary hemorrhagic telangiectasia (HHT) is a rare disorder inherited in an autosomal dominant fashion characterized by vascular dysplasia. Patients can develop life-threatening vascular malformations and experience severe hemorrhaging. Effective pharmacological therapies are limited. The study of ncRNAs in HHT is an emerging field with great promise. This review will explore the current literature on the involvement of ncRNAs in HHT as diagnostic and pathogenic factors.

Safety and Performance of the Orsiro Sirolimus-Eluting Stent in the Treatment of All-Comers Patient Population in Daily Clinical Practice.

BACKGROUND: The BIOFLOW-III Canada registry aimed to evaluate the safety and efficacy of Orsiro sirolimus-eluting stents (SES) with biodegradable polymer, in an all-comers patient population. METHODS: We conducted a prospective, non-randomized, multi-center, observational all-comers registry of patients undergoing percutaneous coronary intervention (PCI) with Orsiro SES at two high-volume Canadian centers. The primary endpoint was one-year target lesion failure (TLF) defined as a composite of cardiac death, target-vessel myocardial infarction (MI), coronary artery bypass grafting and clinically driven target lesion revascularization. Four subgroups were pre-defined: i) diabetic patients; ii) small vessels (≤2.75 mm); iii) chronic total occlusions (CTO) and iv) acute MI. RESULTS: From May 2014 to July 2016, 250 patients (mean age 66.2 ± 10.8 years, 75.6% males, 30% diabetes) underwent PCI with Orsiro SES for 385 coronary lesions. The mean stent diameter was 2.98 ± 0.50 mm and the mean stent length was 22 ± 8 mm. Clinical device and procedural success rates were with 99.5% and 97.6%, respectively. The overall one-year TLF rate was 2.8% [95% confidence interval (CI) 1.4-5.8%], whereas TLF rates were 4.1% [95%CI 1.3-12.2%], 3.2% [95%CI 1.2-8.4%], 8.3% [95%CI 2.2-29.4%], and 2.6% [95%CI 0.7-9.9%] in patients with diabetes, small vessels, CTO, and acute MI, respectively. One case of possible stent thrombosis (ST) was reported (0.4% [95%CI 0.1-2.8%]), while no cases of definite/probable ST was observed at one year. CONCLUSION: Our data provide further evidence of the safety and clinical performance of Orsiro SES in an unselected, real-world, complex patient population. CONDENSED ABSTRACT: The BIOFLOW-III Canada registry is a prospective, non-randomized, multi-center, observational all-comers registry designed to evaluate the safety and performance of the Orsiro SES in non-selected, real-world patients. A total of 250 patients (mean age 66.2 ± 10.8 years, 75.6% males, 30% diabetes) who underwent PCI with Orsiro SES, were enrolled at two high-volume Canadian centers. The overall rate of TLF at one year was 2.8% [95%CI 1.4-5.8%], whereas TLF rates were 4.1%, 3.2%, 8.3%, and 2.6% in patients with diabetes, small vessels ≤2.75 mm, CTO, and acute MI, respectively. No case of definite/probable ST was observed.

MicroRNA profiling of human myeloid angiogenic cells derived from peripheral blood mononuclear cells.

Human myeloid angiogenic cells (MACs), also termed early endothelial progenitor cells, play an important role in neovascularization and vascular repair. MicroRNAs (miRNAs) are a class of naturally occurring, noncoding, short (∼22 nucleotides), single-stranded RNAs that regulate gene expression post-transcriptionally. MiRNAs have been shown to regulate MAC function. A miRNA signature of MACs was described approximately a decade ago, and many new miRNAs have been discovered in recent years. In this study, we aimed to provide an up-to-date miRNA signature for human MACs. MACs were obtained by culture of human peripheral blood mononuclear cells in endothelial medium for 7 days. Using qPCR array analysis we identified 72 highly expressed miRNAs (CT value < 30) in human MACs. RT-qPCR quantification of select miRNAs revealed a strong correlation between the CT values detected by the array analysis and RT-qPCR, suggesting the miRNA signature generated by the qPCR array assay is accurate and reliable. Experimentally validated target genes of the 10 most highly expressed miRNAs were retrieved. Only a few of the targets and their respective miRNAs have been studied for their role in MAC biology. Our study therefore provides a valuable repository of miRNAs for future exploration of miRNA function in MACs.

Cascade screening for familial hypercholesterolemia-identification of the C308Y mutation in multiple family members and relatives for the first time in mainland China.

BACKGROUND: Familial hypercholesterolemia (FH), an autosomal dominant genetic disorder, is underdiagnosed and undertreated. The majority of FH cases are caused by low density lipoprotein receptor (LDL-R) gene mutations. The C308Y mutation in LDL-R results in approximately 70% loss of LDL-R activity, leading to the elevation of low density lipoprotein-cholesterol (LDL-C) and an increased risk of premature coronary heart disease (CHD). The aim of this study was to identify FH cases by cascade screening in family members and relatives of a 37-year old male with premature CHD and hypercholesterolemia. METHODS: Clinical exam, blood lipid profiling and genomic DNA sequencing of all exons of LDL-R were performed for the proband and his 14 family members and relatives. FH diagnosis was carried out using the Dutch Lipid Clinic Network (DLCN) criteria. RESULTS: Lipid profiling showed that 9 individuals, including the proband, had hypercholesterolemia. All these 9 subjects had a G > A substitution at nucleotide 986 in exon 7 resulting in the C308Y mutation as determined by DNA sequencing, and all those carrying the mutation were diagnosed as having definite FH under the DLCN criteria. However, most (7/9) did not have suggestive clinical manifestations of CHD. CONCLUSIONS: The C308Y mutation was discovered in multiple family members and relatives for the first time in mainland China. Cascade screening is key for the confirmatory diagnosis of FH. Our hypothesis that the C308Y is a common variant in the population of Southern China origin warrants further validation by screening for the C308Y mutation in a large population.

MicroRNA signature of human blood mononuclear cells.

MicroRNAs (miRNAs) regulate a wide range of cellular processes and functions. Blood mononuclear cells (BMNCs) participate in the immune response, inflammatory reaction and angiogenesis. In 2010, a total of 157 miRNAs were quantified by RT-qPCR and a miRNA signature was determined for human peripheral BMNCs. With the advent of technologies such as RNA sequencing, many new miRNAs have been identified. This study was designed to provide an up-to-date miRNA signature for human BMNCs. Peripheral BMNCs were isolated by Ficoll density gradient centrifugation. Using the qPCR array assay, we identified 108 highly expressed miRNAs (Ct value < 30) in human BMNCs. Further validation of the array results by quantifying select miRNAs with RT-qPCR revealed a strong correlation between Ct values derived from array analysis and RT-qPCR, suggesting the array results presented in this study are accurate and reliable. Of note, the function of the majority of the highly expressed miRNAs we have identified has not yet been studied. Our findings may help direct further studies of the regulatory roles of miRNAs in BMNC function.

Decreased levels of miR-28-5p and miR-361-3p and increased levels of insulin-like growth factor 1 mRNA in mononuclear cells from patients with hereditary hemorrhagic telangiectasia 1.

Hereditary hemorrhagic telangiectasia (HHT) is a rare vascular disorder inherited in an autosomal dominant manner. Patients with HHT can develop vascular dysplasias called telangiectasias and arteriovenous malformations (AVMs). Our objective was to profile and characterize micro-RNAs (miRNAs), short noncoding RNAs that regulate gene expression posttranscriptionally, in HHT patient-derived peripheral blood mononuclear cells (PBMCs). PBMCs, comprised mostly of lymphocytes and monocytes, have been reported to be dysfunctional in HHT. A total of 40 clinically confirmed HHT patients and 22 controls were enrolled in this study. PBMCs were isolated from 16 mL of peripheral blood and purified for total RNA. MiRNA expression profiling was conducted with a human miRNA array analysis. Select dysregulated miRNAs and miRNA targets were validated with reverse transcription-quantitative polymerase chain reaction. Of the 377 miRNAs screened, 41 dysregulated miRNAs were identified. Both miR-28-5p and miR-361-3p, known to target insulin-like growth factor 1 (IGF1), a potent angiogenic growth factor, were found to be significantly downregulated in HHT patients. Consequently, IGF1 mRNA levels were found to be significantly elevated. Our research successfully identified miRNA dysregulation and elevated IGF1 mRNA levels in PBMCs from HHT patients. This novel discovery represents a potential pathogenic mechanism that could be targeted to alleviate clinical manifestations of HHT.

Myeloid angiogenic cells exhibit impaired migration, reduced expression of endothelial markers, and increased apoptosis in idiopathic pulmonary arterial hypertension 1.

Idiopathic pulmonary arterial hypertension (IPAH) is a rare and devastating condition. There is no known cure for IPAH, and current treatment options are not always effective. Autologous myeloid angiogenic cells (MACs) have been explored as a novel therapy for IPAH, but preliminary data from clinical trials show limited beneficial effects. A complete understanding of IPAH MAC function remains elusive. This study was designed to comprehensively compare cell function between IPAH MACs and healthy control MACs. MACs were procured through the culture of peripheral blood mononuclear cells in endothelial selective medium for 7 days. Compared with healthy MACs, IPAH MACs exhibited (1) significantly lower levels of endothelial markers as shown by fluorescence microscopy; (2) a markedly higher rate of apoptosis under both normal culture condition and serum starvation as shown by the TUNEL assay; (3) significantly decreased migration towards vascular endothelial growth factor as shown by a modified Boyden chamber migration assay; and (4) similar vascular endothelial growth factor and endothelial nitric oxide synthase mRNA levels as shown by reverse transcription quantitative PCR. In conclusion, various aspects of IPAH MAC function are impaired. To achieve greater therapeutic benefits, pharmacologic and (or) genetic manipulations to improve IPAH MAC function, particularly to promote cell survival and migration, are warranted.

Association of Achilles tendon thickness and LDL-cholesterol levels in patients with hypercholesterolemia.

BACKGROUND: Achilles tendons are the most common sites of tendon xanthomas that are commonly caused by disturbance of lipid metabolism. Achilles tendon thickening is the early characteristic of Achilles tendon xanthomas. The relationship between Achilles tendon thickness (ATT) and LDL-C levels, and risk factors of ATT in patients with hypercholesterolemia, have thus far been poorly documented. METHODS: A total of 205 individuals, aged 18-75 years, were enrolled from March 2014 to March 2015. According to the LDL-C levels and the "Chinese Guidelines on Prevention and Treatment of Dyslipidemia in Adults", all subjects were divided into 3 groups: normal group (LDL-C < 3.37 mmol/L, n = 51); borderline LDL-C group (3.37 mmol/L ≤ LDL-C ≤ 4.12 mmol/L, n = 50); and hypercholesterolemia group (LDL ≥ 4.14 mmol/L, n = 104). ATT was measured using a standardized digital radiography method and the results were compared among the 3 groups. The correlation between ATT and serum LDL-C levels was analyzed by Pearson's correlation, and the risk factors of ATT were determined by the logistic regression model. RESULTS: ATT in borderline LDL-C group was 8.24 ± 1.73 mm, markedly higher than 6.05 ± 0.28 mm of normal group (P < 0.05). ATT in hypercholesterolemia group was 9.42 ± 3.63 mm which was significantly higher than that of normal group (P < 0.005) and that of borderline LDL-C group (P < 0.05). There was a positive correlation between the serum LDL-C levels and ATT (r = 0.346, P < 0.001). The serum LDL-C level was a risk factor (OR = 1.871, 95% CI: 1.067-3.280) while the levels of HDL-C (OR = 0.099, 95% CI: 0.017-0.573) and Apo AI (OR = 0.035, 95% CI: 0.003-0.412) were protective factors of ATT. CONCLUSIONS: ATT might serve as a valuable auxiliary diagnostic index for hypercholesterolemia and used for the assessment and management of cardiovascular disease.

The evolution of coronary stents.

INTRODUCTION: Percutaneous coronary intervention (PCI) is 40 years old this year. From its humble beginnings of experimental work, PCI has transitioned over years with coronary artery stenting now a standard medical procedure performed throughout the world. Areas covered: The conversion from plain old balloon angioplasty (POBA) to the present era of drug eluting stents (DES) has been driven by many technological advances and large bodies of clinical trial evidence. The journey to present day practice has seen many setbacks, such as acute vessel closure with POBA; rates of instant restenosis with bare metal stents (BMS) and more recently, high rates of stent thrombosis with bioabsorbable platforms. This work discusses POBA, why there was a need for BMS, the use of inhibiting drugs to create 1st generation DES, the change of components to 2nd generation DES, the use of absorbable drug reservoirs and platforms, and possible future directions with Prohealing Endothelial Progenitor Cell Capture Stents. Expert commentary: This paper reviews the evolution from the original pioneering work to modern day practice, highlighting landmark trials that changed practice. Modern day contemporary practice is now very safe based on the latest drug eluting stents and supported by large datasets.

Transcatheter Closure Versus Repeat Surgery for the Treatment of Postoperative Left-to-Right Shunts: A Single Center 15-Year Experience.

BACKGROUND: Repeat surgery and the percutaneous approach (transcatheter closure (TCC)) have been used for the management of postoperative left-to-right shunts. In this study, we described our 15 years of experience in treating postoperative left-to-right shunts with these two approaches. METHODS: From February 2002 to February 2017, 50 patients with residual left-to-right shunts, following cardiac surgery, were treated using TCC or repeat surgery. Clinical examination, standard 12-lead electrocardiography, chest X-ray, and a transthoracic echocardiogram were performed before hospital discharge and at all follow-ups. RESULTS: The closure rate was 100% in both groups and there was no procedure-related mortality. Patients with TCC had few complications. The procedure time and duration of hospital stay for TCC patients were 58.9 ± 27.7 min and 6.1 ± 0.8 days, respectively. Eleven out of 19 patients receiving reoperation suffered serious complications after surgery, e.g., bleeding and nosocomial infections. The operation time and duration of hospital stay for reoperation patients were 256.7 ± 60.5 min and 17.0 ± 4.0 days, respectively. No other serious complications were seen at all follow-up visits for both groups. CONCLUSIONS: In conclusions, TCC is safe and effective for the management of postoperative left-to-right shunts, and is associated with few complications, which can be the favored closure strategy over repeat surgery for the management of postoperative left-to-right shunts.

Transcatheter closure of calcified patent ductus arteriosus in older adult patients: Immediate and 12-month follow-up results.

OBJECTIVE: To present our experience in transcatheter closure of calcified patent ductus arteriosus (PDA) in older adult patients, which has rarely been reported. PATIENTS: From 2009 to 2014, a total of 16 patients (median age 58 years) with calcified PDA underwent transcatheter closure in our center. All patients were symptomatic with major symptoms being exertional dyspnea (in 12), palpitations (in 8), and fatigue (in 5). A continuous murmur was heard in all patients. The median ductus diameter was 4 mm (range 3-7 mm). The median Qp/Qs was 1.6 (range 1.4-2.9). INTERVENTIONS: Transcatheter closure was performed for all patients. The size of the occluder selected was 2-3 mm greater than the narrowest portion of PDA. We experienced difficulties in advancing the multipurpose catheter through the calcified duct in about one third of patients (5/16). Considering that calcified tissue has a greater tendency to rupture, hence, to close PDA in these patients, they adopted the retrograde wire-assisted technique and modified the procedure to reduce the shear stress of sheath and avoid any sheath kinking. For the remaining 11 patients, the advancement of the multipurpose catheter through the calcified duct was smooth and the conventional antegrade approach was applied. OUTCOME MEASURES: Clinical examination, standard 12-lead electrocardiography, chest x-ray, and transthoracic echocardiography were performed before hospital discharge, at 1-, 3-, 6-, and 12-months follow-ups. RESULTS: All PDAs were successfully closed. There were no deaths. Three patients had a trivial residual shunt, with one also having intravascular hemolysis. Following pharmacological treatment, hemolysis signs vanished at 7 days postprocedure. The trivial residual shunt disappeared in all three patients at 3-month follow-up. No new-onset residual shunt, device embolization, device dislocation, infective endocarditis, or embolism was observed at all follow-up time points. CONCLUSION: Successful closure of calcified PDA with few complications in older adult patients was achieved using the duct occluder.

Repatriation to referral hospital after reperfusion of STEMI patients transferred for primary percutaneous coronary intervention: Insights of a Canadian regional STEMI care system.

BACKGROUND: In regional systems of ST-segment elevation myocardial infarction (STEMI) care, patients presenting to hospitals without percutaneous coronary intervention (PCI) are transferred to PCI-capable hospitals for primary PCI. Repatriation, a practice whereby such patients are transferred back to non-PCI referral hospitals after reperfusion is prevalent in many jurisdictions, yet little is known of this practice and its safety. METHODS: We studied 979 consecutive STEMI patients transported from the emergency department and catchment area of two non-PCI hospitals in Ontario, Canada to a regional PCI-hospital for primary PCI between January 2008 and June 2014. Logistic regression modeling was performed to determine factors associated with delayed repatriation beyond 24 hours and to evaluate the association between repatriation and index-admission mortality. RESULTS: Eight hundred and fifteen (83.2%) patients were repatriated with 524 (65.2%) patients repatriated within 24 hours. Factors independently associated with delayed repatriation included systolic blood pressure (OR 1.03 per 5 mmHg decrease, 95% CI 1.01-1.06, P= .04), requirement for mechanical ventilation (OR 24.9, 95% CI 5.4-115.3, P< .0001), ventricular arrhythmia (OR 3.0, 95% CI 1.3-6.6, P= .01), infarct-related artery (P= .03), final TIMI flow grade (P= .01) and access-site complications (OR 2.36, 95% CI 1.04-5.4, P= .04). After repatriation, 9 (1.3%) patients returned to the PCI-hospital for urgent care, and 16 (2.0%) died during index-admission. After adjustment, repatriation was not associated with increase in index-admission mortality (adjusted OR 0.46, 95% CI 0.16-1.32, P= .15). CONCLUSIONS: In a regional STEMI care system in Ontario, Canada, patients are routinely repatriated to non-PCI hospitals after primary PCI. This practice was associated with very low and acceptable rate of return to the PCI-hospital during index-admission without an adverse impact on short-term outcomes.