Search

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., (© 2023. The Author(s).)

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/10 6 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.

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.

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.

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., Competing Interests: None.

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., (© 2016 Wiley Periodicals, Inc.)

The secreted neurorepellent Slit2, acting through its transmembrane receptor, Roundabout (Robo)-1, inhibits chemotaxis of varied cell types, including leukocytes, endothelial cells, and vascular smooth muscle cells, toward diverse attractants. The role of Slit2 in regulating the steps involved in recruitment of monocytes in vascular inflammation is not well understood. In this study, we showed that Slit2 inhibited adhesion of monocytic cells to activated human endothelial cells, as well as to immobilized ICAM-1 and VCAM-1. Microfluidic live cell imaging showed that Slit2 inhibited the ability of monocytes tethered to endothelial cells to stabilize their actin-associated anchors and to resist detachment in response to increasing shear forces. Transfection of constitutively active plasmids revealed that Slit2 inhibited postadhesion stabilization of monocytes on endothelial cells by preventing activation of Rac1. We further found that Slit2 inhibited chemotaxis of monocytes toward CXCL12 and CCL2. To determine whether Slit2 and Robo-1 modulate pathologic monocyte recruitment associated with vascular inflammation and cardiovascular disease, we tested PBMC from patients with coronary artery disease. PBMC from these patients had reduced surface levels of Robo-1 compared with healthy age- and sex-matched subjects, and Slit2 failed to inhibit chemotaxis of PBMC of affected patients, but not healthy control subjects, toward CCL2. Furthermore, administration of Slit2 to atherosclerosis-prone LDL receptor-deficient mice inhibited monocyte recruitment to nascent atherosclerotic lesions. These results demonstrate that Slit2 inhibits chemotaxis of monocytes, as well as their ability to stabilize adhesions and resist detachment forces. Slit2 may represent a powerful new tool to inhibit pathologic monocyte recruitment in vascular inflammation and atherosclerosis., (Copyright © 2015 by The American Association of Immunologists, Inc.)

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant vascular disorder. Circulating angiogenic cells (CACs) play an important role in vascular repair and regeneration. This study was designed to examine the function of CACs derived from patients with HHT. Peripheral blood mononuclear cells (PBMNCs) isolated from patients with HHT and age- and gender-matched healthy volunteers were assessed for expression of CD34, CD133 and VEGF receptor 2 by flow cytometry. PBMNCs were cultured to procure early outgrowth CACs. Development of endothelial cell (EC) phenotype in CACs was analyzed by fluorescence microscopy. CAC apoptosis was assayed with Annexin V staining, and CAC migration assessed by a modified Boyden chamber assay. mRNA expression of endoglin (ENG), activin receptor-like kinase-1 (ACVLR1 or ALK1) and endothelial nitric oxide synthase (eNOS) in CACs was measured by real time RT-PCR. The percentage of CD34+ cells in PBMNCs from HHT patients was significantly higher than in PBMNCs of healthy controls. CACs derived from patients with HHT not only showed a significant reduction in EC-selective surface markers following 7-day culture, but also a significant increase in the rate of basal apoptosis and blunted migration in response to vascular endothelial growth factor and stromal cell-derived factor-1. CACs from HHT patients expressed significantly lower levels of ENG, ALK1 and eNOS mRNAs. In conclusion, CACs from patients with HHT exhibited various functional impairments, suggesting a reduced regenerative capacity of CACs to repair the vascular lesions seen in HHT patients.

Background: Long-term outcome after bifurcation stenting with drug-eluting stents (DES) for obstructive coronary artery disease is poorly understood. In this study, we report 6-9-month angiographic follow-up and long-term clinical outcomes after implantation of drug-eluting stents by crush and kissing stent technique for coronary bifurcation lesions., Methods: Consecutive patients undergoing bifurcation stenting with DES by crush or kissing stent technique were enrolled in a prospective registry. Angiographic follow-up was obtained at 6-9 months and clinical follow-up completed for a median of 38 months., Results: A total of 86 patients participated in the study. Bifurcation stenting by crush technique was performed in 73 (85%) and by kissing stent in 13 (15%) patients. Stenting of left main bifurcation was applied in 24 (28%) patients. Angiographic follow-up was completed in 75 (87%) patients and showed restenosis in the main for 8 (11%) and side branch for 20 (27%) patients. Clinical follow-up was available for a median duration of 38 months. During follow-up, 2 (2%) patients died, 4 (5%) experienced myocardial infarction (MI), and 11 (13%) underwent target vessel revascularization (TVR) with an overall major adverse cardiac event (MACE) rate of 16%. In left main cohort, angiographic restenosis occurred in 9 (37%) patients, and 3 (12%) patients required TVR. There were no deaths or stent thrombosis. A comparison of crush and kissing stent technique showed significantly higher angiographic restenosis with crush (26% vs 13% in kissing stent patients, P = 0.046) and 95% of restenosis in crush group involved ostium of the side branch. There was no difference in clinical outcomes between the crush and kissing stent groups. Final kissing balloon dilatation (FKB) was successful in 65 (89%) patients in the crush group and associated with a significant reduction in MACE (8% in FKB successful vs 37% in FKB unsuccessful, P = 0.04) during follow-up., Conclusion: Bifurcation stenting with crush or kissing stent technique is safe and associated with a low rate of TLR and MACE on long-term follow-up. Crush stenting is associated with a significantly higher rate of side branch restenosis compared to kissing stent technique. FKB is associated with significant reduction in MACE during follow-up., (© 2013, Wiley Periodicals, Inc.)

Pulmonary arteriovenous malformations (PAVMs), which can lead to life-threatening bleeding and other complications, have been reported to occur in 30-50% of patients with hereditary hemorrhagic telangiectasia (HHT). Circulating microRNAs (miRNAs) have emerged as new biomarkers for human diseases. This study was conducted to explore circulating miRNAs as biomarkers for the screening of HHT patients with PAVMs. MicroRNA array analysis revealed eight altered circulating miRNAs in patients with PAVMs. Real time RT-PCR showed that the levels of circulating miR-210 were significantly elevated in HHT patients with PAVMs but not changed in patients without PAVMs as compared with healthy controls. Circulating miR-210 therefore may be used as a new and sensitive biomarker for the screening of patients with HHT for clinically significant PAVMs.

Objectives: Diabetes mellitus (DM) is associated with impairment of endothelial progenitor cells (EPCs), but the effects of metabolic syndrome (MS) on EPCs have been less well characterized. We hypothesized that in the presence of MS, the number and functionality of EPCs would be markedly reduced, and would be similar to DM., Methods: Mononuclear cells were isolated from the bone-marrow (BM) and peripheral blood of lean Zucker, obese Zucker, a model of MS, and Zucker diabetic fatty rats. Cultured BM-EPCs underwent in vitro functional testing and the ability of BM-EPCs to promote neovascularization in vivo was assessed in a model of hindlimb ischemia in athymic mice., Results: While circulating EPC numbers were similarly reduced in both MS and DM rats, BM-derived EPC numbers were less affected. In vitro testing of cultured BM-EPCs from obese Zucker demonstrated a marked reduction in EPC differentiation, a greater propensity to apoptosis, a reduced migratory response and matrigel tubule formation, similar to findings in Zucker diabetic fatty rats. When delivered to the ischemic hindlimb of athymic mice, the recovery of perfusion using both BM-EPCs from obese Zucker and Zucker diabetic fatty rats were diminished, as compared to lean Zuckers., Conclusion: In the presence of the MS, BM-derived EPCs develop marked functional impairment, resulting in severely reduced angiogenic capacity in vivo. Similar to DM, EPC dysfunction may play a prominent role in the pathogenesis of vascular complications in the MS, and may potentially limit the use of BM-derived EPCs for therapeutic angiogenesis., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

Endothelial progenitor cells (EPCs) have been used in clinical trials to treat ischemic heart disease. Monocyte infiltration plays an important role in inflammation, angiogenesis, and tissue repair during tissue ischemia. It is important to understand the interactions between EPCs and monocytes. In this study, a human EPC/THP-1 monocytic cell coculture system was used to examine EPC effect on IL-1 α , IL-1 β , and TNF- α expression in THP-1 cells. Late, but not early, EPCs upregulated IL-1 β expression at both mRNA and protein levels. In contrast, neither early nor late EPCs affected IL-1 α or TNF- α expression. Coculture with human umbilical vein endothelial cells did not alter IL-1 β expression. It has been shown that activation of integrin β 2 in human neutrophils augments IL-1 β synthesis; however integrin β 2 was not involved in IL-1 β expression in THP-1 cells. Addition of late EPC conditioned medium to THP-1 cell culture led to a modest increase of IL-1 β mRNA levels, indicating that late EPCs upregulate IL-1 β expression partly through a paracrine pathway. IL-1 β , an important inflammation mediator, has been shown to promote EPC function. Our data therefore suggest that late EPCs can exert self-enhancement effects by interacting with monocytes and that EPCs might modulate inflammatory reactions by regulating IL-1 β expression in monocytes.

Objectives: The purpose of this study was to characterize clopidogrel hypersensitivity and describe its successful management with oral steroids without clopidogrel discontinuation., Background: Hypersensitivity reactions to clopidogrel are poorly understood and present difficulty in management., Methods: Patients diagnosed with clopidogrel hypersensitivity after percutaneous coronary intervention underwent evaluation and received oral prednisone without clopidogrel discontinuation. Cutaneous testing was performed after completion of clopidogrel therapy for diagnosis and assessment of cross-reactivity., Results: Sixty-two patients representing 1.6% of the percutaneous coronary intervention population developed clopidogrel hypersensitivity during the study period. The mean age was 62 ± 11 years, 71% of patients were male, and 35% reported prior adverse drug reaction. Clopidogrel hypersensitivity manifested as generalized exanthema in 79%, localized skin reaction in 16%, and angioedema or urticaria in 5% of patients. Biopsy of affected areas demonstrated a lymphocyte-mediated delayed hypersensitivity reaction. Complete resolution of hypersensitivity reaction was observed in 61 patients (98%) with a short course of oral prednisone. Cutaneous testing confirmed delayed hypersensitivity reaction to clopidogrel in 34 (81%) and immediate hypersensitivity in 3 of 42 patients (7%) tested. Allergenic cross-reactivity was observed for ticlopidine in 10 (24%), prasugrel in 7 (17%), and both ticlopidine and prasugrel in 3 patients (7%). Histological examination showed lymphocyte-mediated hypersensitivity in abnormal patch test areas., Conclusions: Clopidogrel hypersensitivity is manifested as generalized exanthema and is caused by a lymphocyte-mediated delayed hypersensitivity in most patients. This can be managed with oral steroids without clopidogrel discontinuation. Allergenic cross-reactivity with ticlopidine, prasugrel, or both is present in a significant number of patients with clopidogrel hypersensitivity., (Copyright © 2011 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Transradial percutaneous coronary intervention (TR-PCI) improves clinical outcomes compared to the transfemoral (TF) approach. However, inadequate training and experience has limited widespread adoption by interventional cardiologists., Methods and Results: Clinical and procedural characteristics for TR-PCI were prospectively collected from 1999 to 2008. To identify minimum case volume for optimum clinical benefit, single-vessel TR-PCI cases were chronologically ranked and stratified into 1 to 50, 51 to 100, 101 to 150 and 151 to 300 case volume groups for operators starting the TR approach at the study institution. Cases by operators with a >300 TR-PCI case volume comprised the control group. TR-PCI failure rates, contrast use, guide usage, and fluoroscopy time were compared among groups. A total of 1672 patients underwent TR-PCI by 28 operators. TR-PCI failure occurred in 4% and was higher in the 1 to 50 case volume group compared to the 51 to 100 (P=0.007) and control (P=0.01) groups. Contrast use was greater in the 1 to 50 group (180±79 mL) compared to the 151 to 300 (157±75 mL, P=0.02) and control (168±79 mL, P=0.05) groups. Fluoroscopy time was higher in the 1 to 50 group (15±10 minutes) compared to the 101 to 150 (13±10 minutes, P=0.04) and control (12±9 minutes, P=0.02) groups. Reasons for TR-PCI failure included spasm (38%), subclavian tortuousity (16%), poor guide support (16%), failed access (10%), and radial loop (7%). Case volume was significantly correlated with TR-PCI failure (β=-0.0076, P=0.0028), and odds of failure was reduced by 32% for each 50 increments in case volume., Conclusions: TR-PCI success depends on operator experience, and a case volume of ≥50 cases is required to achieve outcomes comparable to experienced operators. These findings have implications both for PCI operators looking to expand their skills and for defining standards for training.

Circulating angiogenic cells (CACs), represent a potential new therapeutic tool for the treatment of cardiovascular diseases, but their regenerative function is impaired in patients with coronary artery disease (CAD) and cardiac risk factors. The objective of this study is to assess the effect of lentiviral overexpression of endothelial nitric oxide synthase (eNOS) on the activity of CACs from patients with CAD and cardiac risk factors. In vitro and in vivo assays were employed to evaluate the regenerative capacity of the cells compared to CACs derived from healthy volunteers. Lentiviral eNOS transduction of cells from CAD patients significantly improved chemotactic migration compared with sham transduction, and increased the ability of CACs to induce angiogenic tube formation when cocultured with human umbilical vein endothelial cells (HUVECs) on Matrigel. In addition, eNOS transduction restored the ability of patient-derived CACs to enhance neovascularization and improve ischemic hind limb perfusion, approaching the efficacy of cells from healthy donors. These data indicate that CAC dysfunction seen in high-risk patients can be partially reversed by eNOS overexpression, suggesting that ex vivo gene delivery may improve the efficacy of autologous cell therapy for cardiovascular disease.

Endothelial progenitor cells (EPCs) play an important role in vascular repair and maintenance of vascular homeostasis through re-endothelialization and neovascularization. Cardiovascular risk factors that contribute to coronary artery disease (CAD) have been shown to negatively impact EPCs, although the mechanisms are poorly understood. MicroRNAs (miRNAs) which negatively regulate gene expression at the post-transcriptional level have been shown to impact endothelial cell (EC) angiogenic actions, but little is known about their role in modulating EPC function. In this study we first investigated if EPCs expressed EC specific, angiogenesis-related miRNAs; then determined whether the expression of these miRNAs was altered in EPCs from CAD patients as compared with healthy controls. Furthermore, we examined if atorvastatin, known to increase circulating EPC numbers, had any effect on EPC miRNA expression. We found EPCs produced miR-126, miR-130a, miR-221, miR-222 and miR-92a which have thus far been identified as the most important angiogenic miRNAs. Dysregulation of these miRNAs was detected in EPCs from CAD patients and atorvastatin treatment selectively impacted miRNA expression in EPCs. Our data provide evidence that angiogenic miRNAs might play an important role in the control of EPC function, and that their dysregulation might contribute to EPC dysfunction in patients suffering from coronary artery disease. These findings might lead to the development of novel therapeutic modalities for the prevention and treatment of CAD., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Background: Adjunctive administration of the glycoprotein IIb/IIIa platelet receptor antagonist (GPA), abciximab, improves outcomes in patients undergoing rescue percutaneous coronary intervention (PCI). However, it is unknown if other GPAs provide a similar benefit in this setting., Objective: We sought to compare angiographic and clinical outcomes of patients receiving abciximab or eptifibatide as an adjunct to rescue PCI., Methods: In this prospective, nonrandomized study, consecutive patients who underwent rescue PCI and received adjunctive preprocedural GPA comprised the study population. Thrombolysis in myocardial infarction (TIMI) flow, corrected TIMI frame count (CTFC) and myocardial blush grade (MBG) were determined before and immediately after rescue PCI. Residual ST-segment elevation at 90-120 minutes and peak creatine kinase (CK) values for 48 hours after PCI were recorded. Major adverse cardiac events (MACE) including death, reinfarction and target vessel revascularization (TVR) were determined at discharge, 1 and 6 months., Results: A total of 241 patients were included in the study. 162 patients received abciximab and 79 received eptifibatide. There were no differences in baseline clinical and angiographic characteristics between groups. Post-PCI TIMI flow was similar but post-PCI CTFC was significantly lower (17 +/- 10 vs. 22 +/- 18; p = 0.01) and post-PCI MBG significantly higher (2.8 +/- 0.5 vs. 2.6 +/- 0.6; p = 0.01) in the abciximab group. Patients in the abciximab group had less ST-segment elevation (1.0 +/- 0.9 vs. 1.5 +/- 1.0 mm; p = 0.003) and lower peak CK (2,484 +/- 2,176 vs. 2,650 +/- 2,798 U/L; p = 0.001) after PCI. On multivariate analyses, abciximab administration (OR = 0.50, CI = 0.26, 0.96; p = 0.03), pre-PCI TIMI 3 flow (OR = 0.22, CI = 0.05, 0.99; p = 0.04) and female gender (OR = 0.24, CI = 0.08, 0.66; p = 0.006) were positive and cardiogenic shock (OR = 2.76, CI = 1.16, 6.58; p = 0.02) was a negative predictor of normal epicardial perfusion post PCI. Abciximab administration (OR = 0.46, CI = 0.24, 0.87; p = 0.02) and pre-PCI CTFC < 25 (OR = 0.09, CI = 0.02, 0.31, 0.0001) were positive predictors and cardiogenic shock (OR = 3.96, CI = 1.55, 10.12; p = 0.004) was a negative predictor of normal myocardial perfusion post-PCI as determined by CTFC. Abciximab administration (OR = 0.31, CI = 0.15, 0.63; p = 0.001) and pre-PCI MBG 3 (OR = 0.07, CI = 0.02, 0.23; p < 0.0001) were positive predictors of normal myocardial perfusion post-PCI as determined by MBG. In-hospital, 1- and 6-month clinical events and MACE rates did not differ between groups., Conclusions: In the setting of rescue PCI, adjunctive administration of abciximab resulted in greater improvement in angiographic and electrical estimates of myocardial perfusion and smaller infarct size compared to eptifibatide. These findings suggest that all GPA may not provide equal benefit in rescue PCI.

Background: Despite the widespread use of pharmacological and/or interventional reperfusion therapies, recovery of cardiac function in myocardial infarction (MI) patients is often modest or even absent. Unlike classical pharmacological treatments, the use of progenitor cells could potentially restore functional tissue in regions that otherwise would form only scar. However, a major limitation of autologous cell therapy is the deleterious influence of age and cardiac risk factors on progenitor cell activity., Trial Design: The ENACT-AMI trial is a phase IIb, double-blind, randomized placebo-controlled trial, using transplantation of autologous early endothelial progenitor cells (EPCs) for patients who have suffered large MI. Circulating mononuclear cells (MNCs) are obtained by apheresis and subjected to differential culture for 3 days to select a population of highly regenerative, endothelial-like, culture modified MNCs (E-CMMs), often referred to as "early EPCs." A total of 99 patients will be randomized to placebo (Plasma-Lyte A), autologous E-CMMs, or E-CMMs transfected with human endothelial nitric oxide synthase delivered by coronary injection into the infarct-related artery. The primary efficacy end point is change from baseline to 6 months in global left ventricular ejection fraction by cardiac MRI; secondary endpoints include regional wall motion, wall thickening, infarct volume, time to clinical worsening, and quality of life., Conclusions: This will be the first clinical trial to include a strategy designed to enhance the function of autologous progenitor cells by overexpressing endothelial nitric oxide synthase, and the first to use combination gene and cell therapy for the treatment of cardiac disease.

Objectives: The study aimed to determine the mechanism and predictors of procedural failure in patients undergoing percutaneous coronary intervention (PCI) from the transradial approach (TR)., Background: Transradial approach PCI reduces vascular complications compared with a transfemoral approach (TF). However, the mechanism and predictors of TR-PCI failure have not been well-characterized., Methods: The study population consisted of patients undergoing TR-PCI by low-to-intermediate volume operators with traditional TF guide catheters. Baseline characteristics, procedure details, and clinical outcomes were prospectively collected. Univariate and multivariate analyses were performed to determine independent predictors of TR-PCI failure., Results: A total of 2,100 patients underwent TR-PCI and represented 38% of PCI volume. Mean age was 64 +/- 12 years, and 17% were female. Vascular complications occurred in 22 (1%), and TR-PCI failure was observed in 98 (4.7%) patients. The mechanism of TR-PCI failure included inability to advance guide catheter to ascending aorta in 50 (51%), inadequate guide catheter support in 35 (36%), and unsuccessful radial artery puncture in 13 (13%) patients. The PCI was successful in 94 (96%) patients with TR-PCI failure by switching to TF. On multivariate analysis, age >75 years (odds ratio [OR]: 3.86; 95% confidence interval [CI]: 2.33 to 6.40, p = 0.0006), prior coronary artery bypass graft surgery (OR: 7.47; 95% CI: 3.45 to 16.19, p = 0.0002), and height (OR: 0.97; 95% CI: 0.95 to 0.99, p = 0.02) were independent predictors of TR-PCI failure., Conclusions: Transradial approach PCI can be performed by low-to-intermediate volume operators with standard equipment with a low failure rate. Age >75 years, prior coronary artery bypass graft surgery, and short stature are independent predictors of TR-PCI failure. Appropriate patient selection and careful risk assessment are needed to maximize benefits offered by TR-PCI.

Despite the promise of proangiogenic gene therapy most clinical trials have failed to show benefit for the primary end point analysis. The NOGA angiogenesis Revascularization Therapy: assessment by RadioNuclide imaging (NORTHERN) trial was a double-blind, placebo-controlled study of intramyocardial vascular endothelial growth factor (VEGF165) gene therapy versus placebo, involving seven sites across Canada, designed to overcome major limitations of previous proangiogenic gene therapy trials. A total of 93 patients with refractory Canadian Cardiovascular Society (CCS) class 3 or 4 anginal symptoms were randomized to receive 2,000 microg of VEGF plasmid DNA or placebo (buffered saline) delivered via the endocardial route using an electroanatomical NOGA guidance catheter. There was no difference between the VEGF-treated and the placebo groups in the primary end point of change in myocardial perfusion from baseline to 3 or 6 months, assessed by single photon emission tomography (SPECT) imaging, although a significant reduction in the ischemic area was seen in both groups. Also, similar improvements in exercise treadmill time and anginal symptoms were seen in the VEGF and the placebo groups at 3 and 6 months, although again there were no differences between these groups. Despite the intramyocardial administration of a high "dose" of plasmid DNA using a percutaneous guidance catheter system, there was no benefit of VEGF gene therapy at 3 or 6 months for any of the end points studied.

Objectives: We sought to examine angiographic and clinical outcomes with sirolimus-eluting stents (SES) in total coronary occlusion (TCO) revascularization., Background: Despite evaluation of drug-eluting stents beyond approved indications, few studies have evaluated their clinical benefit in TCO revascularization., Methods: Among 15 centers in North America, 200 consecutive TCO patients (78.8% >6 weeks TCO age) were enrolled for treatment with SES. The primary end point was 6-month angiographic binary restenosis within the treated segment., Results: Patient characteristics included: diabetes, 24.5%; prior infarction, 33.5%; and stent length, 45.9 mm median (quartile 1, 30.2 mm; quartile 2, 62.1 mm). A total of 199 patients (99.5%) were treated with SES, and procedural success was 98.0%. The 6-month binary restenosis rates were 9.5% in-stent, 12.4% in-segment, and 22.6% in-"working length" representing the entire treatment segment. Rates of 1-year target lesion revascularization, myocardial infarction, and target vessel failure were 9.8%, 1.0%, and 10.9%, respectively. Stent thrombosis occurred in 2 patients (1.0%). Using logistic regression modeling with propensity score adjustment, the absolute reduction in binary restenosis with SES compared with a historical bare-metal stent control was 37.7% (95% confidence interval [CI]: 27.2% to 48.3%, p < 0.001; odds ratio: 0.17, 95% CI: 0.09 to 0.30, p < 0.0001). Among 32 patients (16%) identified with stent fracture, target lesion revascularization was more common than patients without fracture (25.0% vs. 6.7%, p = 0.005)., Conclusions: Despite greater lesion complexity than prior TCO trials, percutaneous revascularization with SES appears safe and results in substantial reductions in angiographic restenosis and failed patency and a low rate of repeat revascularization. These findings support the use of SES in TCO revascularization. (The ACROSS/TOSCA Trial; NCT00378612).

Since their identification in 1997, bone marrow derived endothelial progenitor cells (EPCs) have been studied for their role in the endogenous maintenance and repair of endothelium and their potential regenerative capacity beyond the endothelium. In particular, EPCs have been tested in cell therapy approaches with the aim of developing novel therapies for conditions currently lacking effective treatment options. In this review, we discuss the scientific background and clinical experience using EPC delivery or mobilization for the treatment of post-angioplasty restenosis, acute myocardial infarction and pulmonary arterial hypertension. Although these approaches are safe, efficacy has yet to be proven in large randomized clinical trials. Unfortunately, the biology of EPCs is still poorly understood. The success of future clinical trials depends on a better understanding of EPC biology and intelligent design., (Copyright 2007 Wiley-Liss, Inc.)

Background: The safety and efficacy of a radial approach for percutaneous coronary intervention (PCI) in octogenarians is not well established., Methods: To evaluate the benefits of a radial approach for preventing vascular complications after PCI, clinical, procedural, and outcome data were prospectively collected and compared for 228 octogenarians undergoing elective PCI either through a radial or a femoral approach., Results: Radial approach was associated with longer cannulation (3.1 +/- 2.9 vs. 2.0 +/- 2.0 min, P < 0.001) and fluoroscopy times (19.3 +/- 16.1 vs. 16.1 +/- 11.8 min, P = 0.04), greater utilization of contrast media (224 +/- 46 vs. 182 +/- 20 ml, P < 0.001) and higher crossover rate (11 vs 4%, P = 0.03) to alternate access site compared with the femoral approach. However, ambulation time (5.2 +/- 3.1 vs. 11.6 +/- 6.3 hr, P < 0.001), access site bleeding (4 vs. 14%, P = 0.007), hematoma (1 vs. 11%, P = 0.001) or any vascular complication (5 vs 26%, P = 0.001) were significantly reduced with a radial approach. Procedural success rates were equivalent with both approaches. Multivariate regression analysis identified radial approach (OR = 0.23; CI = 0.08, 0.65) as an independent negative predictor of postprocedural vascular complications., Conclusion: Radial approach for PCI in octogenarians is technically challenging for the operator and exposes patients to greater volume of nephrotoxic contrast media. However, it results in early ambulation and significantly reduces vascular complications in this high risk population. These findings support a strategy of preprocedural risk assessment and use of radial approach for PCI in a select group of octogenarians to maximize benefits offered by this technique., ((c) 2006 Wiley-Liss, Inc.)

Purpose: The objective of this study was to determine the effects of different doses of gamma-emitting radioactive stents on intimal hyperplasia in a porcine coronary stent model at 28 days., Methods: Sixty-four bare stents and those coated with palladium-103 [activities of 0 (control), 0.5, 1.0, 2.0, and 4.0 mCi] were implanted in the coronary arteries of 32 pigs. Stented segments were evaluated by histomorphometry at 28 days., Results: There was significantly more intima in the 0.5- and 1-mCi stents than in controls (4.27+/-0.52 and 4.71+/-1.13 vs. 1.71+/-0.61 mm(2); P<.0001). Neointimal formation in 2-mCi stents was similar to that in controls, while that in 4-mCi stents was reduced compared to that in controls (2.34+/-1.61 and 0.82+/-0.25 vs. 1.71+/-0.61 mm(2); P=NS and P<.05, respectively). Stent margin neointimal response was representative of that within the stent body, with nonsignficant modest increases in intimal area at adjacent nonstented segments in radioactive stent groups. There was a dose-dependent increase in inflammation scores. Radioactive stents had lower intimal smooth muscle and higher fibrin scores. There was an increase in adventitial fibrosis in 1- and 2-mCi stents versus controls (1.26+/-0.99, and 2.25+/-1.27 vs. 0.21+/-0.31; P<.001)., Conclusion: Dose-response inhibition of in-stent hyperplasia with minimal "edge effects" occurs with low-energy gamma-emitting stents. An increased inflammatory response at higher doses in palladium-103 stents indicates that later follow-up studies are necessary.

Endothelial progenitor cells (EPCs) participate in angiogenesis and the response to chronic ischemia. Risk factors and cardiovascular disease attenuate EPC number, function, and survival. Continuous therapy with nitroglycerin (glyceryl trinitrate; GTN) is associated with increased vascular oxidative stress, leading to nitrate tolerance and endothelial dysfunction. Thus, GTN therapy may also affect EPCs. The purpose of this study was to determine whether continuous exposure to GTN in vivo or during ex vivo expansion affects the circulating number and functional characteristics of human EPCs. To determine the effects of continuous in vivo GTN exposure, EPCs isolated from 28 healthy males before and after receiving 0.6 mg/h GTN (n=17) or no treatment (n=11) for 1 week were expanded for 6 days and compared. To determine the effects of continuous ex vivo GTN exposure, EPCs isolated before randomization were expanded for 6 days in medium supplemented with 100 nM, 300 nM, or 1 microM GTN. EPCs expanded without GTN served as controls (n=10). In vivo, GTN exposure significantly increased the percentage of circulating cells expressing the EPC marker CD34 and increased the susceptibility of expanded EPCs to apoptosis but had no impact on the phenotypic differentiation or migration of EPCs. Ex vivo, GTN exposure increased apoptosis while decreasing phenotypic differentiation, migration, and mitochondrial dehydrogenase activity of EPCs, compared with EPCs expanded in the absence of GTN. Taken together, these results suggest that continuous GTN therapy might impair EPC-mediated processes, an effect that could be detrimental in the setting of ischemic cardiovascular disease.

Mutations in the bone morphogenetic protein (BMP) receptor-2 (BMPR2) have been found in patients with idiopathic pulmonary arterial hypertension (IPAH); however, the mechanistic link between loss of BMPR2 signaling and the development of pulmonary arterial hypertension is unclear. We hypothesized that, contrary to smooth muscle cells, this pathway promotes survival in pulmonary artery endothelial cells (ECs) and loss of BMPR2 signaling will predispose to EC apoptosis. ECs were treated with BMP-2 or BMP-7 (200 ng/mL) for 24 hours in regular or serum-free (SF) medium, with and without addition of tumor necrosis factor alpha, and apoptosis was assessed by flow cytometry (Annexin V), TUNEL, or caspase-3 activity. Treatment for 24 hours in SF medium increased apoptosis, and both BMP-2 and BMP-7 significantly reduced apoptosis in response to serum deprivation to levels not different from serum controls. Transfection with 5 microg of small interfering RNAs for BMPR2 produced specific gene silencing assessed by RT-PCR and Western blot analysis. BMPR2 gene silencing increased apoptosis almost 3-fold (P=0.0027), even in the presence of serum. Circulating endothelial progenitor cells (EPCs) isolated from normal subjects or patients with IPAH were differentiated in culture for 7 days and apoptosis was determined in the presence and absence of BMPs. BMP-2 reduced apoptosis induced by serum withdrawal in EPCs from normal subjects but not in EPCs isolated from patients with IPAH. These results support the hypothesis that loss-of-function mutations in BMPR2 could lead to increased pulmonary EC apoptosis, representing a possible initiating mechanism in the pathogenesis of pulmonary arterial hypertension.

Objectives: This study was designed to evaluate whether rapid endothelialization of stainless steel stents with a functional endothelium prevents stent thrombosis and reduces the restenotic process., Background: A "pro-healing" approach for prevention of post-stenting restenosis is theoretically favored over the use of cytotoxic or cytostatic local pharmacologic therapies. It is believed that the central role of the vascular endothelium is to maintain quiescence of the underlying media and adventitia., Methods: Sixteen patients with de novo coronary artery disease were successfully treated with implantation of endothelial progenitor cell (EPC) capture stents., Results: Complete procedural and angiographic success was achieved in all 16 patients. The nine-month composite major adverse cardiac and cerebrovascular events (MACCE) rate was 6.3% as a result of a symptom-driven target vessel revascularization in a single patient. There were no other MACCE despite only one month of clopidogrel treatment. At six-month follow-up, mean angiographic late luminal loss was 0.63 +/- 0.52 mm, and percent stent volume obstruction by intravascular ultrasound analysis was 27.2 +/- 20.9%., Conclusions: This first human clinical investigation of this technology demonstrates that the EPC capture coronary stent is safe and feasible for the treatment of de novo coronary artery disease. Further developments in this technology are warranted to evaluate the efficacy of this device for the treatment of coronary artery disease.

Coronary artery stenting is currently the most frequently performed percutaneous coronary intervention for the treatment of coronary artery disease. The endothelium is a single layer of endothelial cells lining the vascular wall and plays an integral part in maintaining vascular homeostasis. Stenting however causes significant injury to the vascular wall and endothelium, resulting in inflammation, repair and the development of neointimal hyperplasia. The ability of the endothelium to repair itself depends on both the migration of surrounding mature endothelial cells, and the attraction and adhesion of circulating endothelial progenitor cells (EPCs) to the injured region, which then differentiate into endothelial-like cells. Current therapies with drug-eluting stents interrupt the natural response to damage. Accelerating the reendothelialization of the damaged arterial segment following stent implantation is an attractive form of therapy as it is seen as hastening the natural process of repair. It potentially has the benefit of reducing the amount of neointimal hyperplasia and stent thrombosis. Studies have been performed to identify agents that augment the mobilisation and recruitment of EPCs to the injured area (statins, exercise, estrogen and cytokines). Other studies have looked at seeding stents with endothelial cells or EPCs. The most current approach is to coat anti-CD34 antibodies on a stent surface to attract circulating EPCs to the stent which then differentiate into endothelial-like cells. This approach is currently being tested in safety and feasibility clinical studies.

Objective: This study sought to characterize changes in the angiopoietin system in a rat model of myocardial infarction (MI)., Background: Angiopoietin-1 (Ang-1) and angiopoietin-2 (Ang-2) bind to the endothelial-specific receptor tyrosine kinase, TIE-2. Ang-2 has been suggested to be an antagonist of TIE-2, possibly acting to release endothelial cells from the tonic stabilizing influence of Ang-1. However, on prolonged exposure, Ang-2 has been shown to acquire agonistic activity at TIE-2, raising the possibility that this isoform may play a direct role in neovascularization., Methods: Sprague-Dawley rats were subjected to left coronary ligation and myocardial tissues were harvested from the infarct and peri-infarct regions, or from non-infarcted myocardium. Changes in gene expression were determined by RT-PCR and confirmed by Northern analysis. Changes in protein expression were confirmed by Western analysis and immunocytochemistry, and TIE-2 activity was determined by immunoprecipitation with anti-TIE-2 and antiphosphotyrosine immunoblotting., Results: At 24 h, Ang-1 mRNA and protein expression within the infarct and peri-infarct regions were decreased compared to non-infarcted myocardium, whereas Ang-2 mRNA levels were markedly increased and TIE-2 expression was unchanged. Immunohistochemical staining revealed Ang-1 and TIE-2 immunoreactivity localized to vascular endothelium. In the infarct territory, Ang-2 immunostaining was localized primarily to invading leukocytes at 24 h. At 1 week, Ang-1 expression was partially restored, whereas Ang-2 expression remained elevated. At the time of peak elevation in Ang-2, Tie2 phosphorylation was found to be markedly increased, consistent with receptor activation., Conclusions: Thus, myocardial ischemia induced by left coronary artery ligation resulted in a sustained increase in Ang-2 expression and a reciprocal decrease in Ang-1, consistent with a predominant role for Ang-2 in the angiogenic response to MI.

The demonstration that angiogenic growth factors stimulate new blood vessel growth and restore perfusion in animal models of myocardial and peripheral vascular ischemia has prompted the translation of therapeutic angiogenesis from bench to bedside. The enthusiasm generated from early, open-label, safety trials using primarily vascular endothelial growth factors or fibroblast growth factor protein or gene therapy has been tempered by double-blind randomized placebo controlled studies that have yielded variable though potentially promising results. This article reviews the basis of angiogenic therapy, lessons learned from the latest major trials and potential refinements for future therapy.

Background: Myocardial ischemia provides a potent stimulus to angiogenesis, and the mobilization and differentiation of endothelial progenitor cells (EPCs) has been shown to be important in this process. An elevated level of C-reactive protein (CRP) has emerged as one of the most powerful predictors of cardiovascular disease. However, the impact of CRP on EPC biology is unknown., Methods and Results: EPCs were isolated from the peripheral venous blood of healthy male volunteers. Cells were cultured in endothelial cell basal medium-2 in the absence and presence of CRP (5 to 20 microg/mL), rosiglitazone (1 micromol/L), and/or vascular endothelial growth factor. EPC differentiation, survival, and function were assayed. CRP at concentrations > or =15 microg/mL significantly reduced EPC cell number, inhibited the expression of the endothelial cell-specific markers Tie-2, EC-lectin, and VE-cadherin, significantly increased EPC apoptosis, and impaired EPC-induced angiogenesis. EPC-induced angiogenesis was dependent on the presence of nitric oxide, and CRP treatment caused a decrease in endothelial nitric oxide synthase mRNA expression by EPCs. However, all of these detrimental CRP-mediated effects on EPCs were attenuated by pretreatment with rosiglitazone, a peroxisome proliferator-activated receptor-gamma (PPARgamma) agonist., Conclusions: Human recombinant CRP, at concentrations known to predict adverse vascular outcomes, directly inhibits EPC differentiation, survival, and function, key components of angiogenesis and the response to chronic ischemia. This occurs in part via an effect of CRP to reduce EPC eNOS expression. The PPARgamma agonist rosiglitazone inhibits the negative effects of CRP on EPC biology. The ability of CRP to inhibit EPC differentiation and survival may represent an important mechanism that further links inflammation to cardiovascular disease.

It has long been recognized that certain indigenous populations, such as the traditional living Inuit, have been relatively spared from ischemic heart disease despite their high fat diet. There is evidence to suggest that elevated serum levels of oxidated cholesterol may be a strong risk factor for atherogenesis. This study was performed to examine the plasma levels of lipid, triglyceride, lipoprotein cholesterol and oxidated cholesterol derivatives in the Inuit of the Keewatin district of Canada. Lipoprotein isolation from plasma was performed by serial centrifugation and apolipoprotein concentrations and native and esterified cholesterol content of the lipoprotein isolated were determined. Analysis of cholesterol and its oxidation products was performed using high pressure liquid chromatography. The Inuit showed a decreased concentration of both VLDL apolipoprotein and LDL apolipoprotein. The incidence of oxidatived cholesterol in Inuit VLDL and LDL was higher than control except for the 25 alpha-hydroxy derivative in VLDL. These data provide insight into the relative contributions of genetic and environmental influences on the development of ischemic heart disease.

Despite continued advances in the prevention and treatment of coronary artery disease, there are still a large number of patients who are not candidates for the conventional revascularization techniques of balloon angioplasty and stenting, or coronary artery bypass grafting (CABG). Therapeutic angiogenesis, in the form of the administration of growth factor protein or gene therapy, has emerged as a promising new method of treatment for patients with coronary artery disease. The goal of this strategy is to promote the development of supplemental blood conduits that will act as endogenous bypass vessels. New vessel formation occurs through the processes of angiogenesis, vasculogenesis, and arteriogenesis, under the control of growth factors such as those that belong to the vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF) and angiopoeitin (Ang) families of molecules. Preclinical studies have suggested that such an approach is both feasible and effective; however many questions remain to be answered. This review will address the elements of pharmacologic revascularization, focusing on gene and protein-based therapy. The important growth factors, the vector (for gene therapy), routes of delivery, the desired therapeutic effect, and quantifiable clinical end points for trials of angiogenesis will all be addressed., (Copyright 2003 Wiley-Liss, Inc.)

Purpose: To determine the long-term dose response of novel low-dose gamma-emitting stents in a rabbit iliac artery model., Methods and Materials: Control stents (n=24) and 103Pd stents 1.0 to 4.0 mCi (n=36) were implanted in the iliac arteries of 30 New Zealand rabbits. Stents were evaluated by intravascular ultrasound (immediately post procedure and before killing) and by histomorphometry., Results: At 26 weeks, 28 rabbits were killed, with no evidence of stent thrombosis. In the body of the stent there was a dose-response relationship with 50% inhibition of intimal hyperplasia at the highest activity compared to control stents (p=0.07) and a significant increase in intimal hyperplasia at the lowest activity (p < 0.01). At the stent edges, there was a significant reduction of lumen area at all activity levels compared to control stents, which was most prominent at the proximal stent edge. Higher-activity stents demonstrated incomplete endothelialization and immature neointimal formation., Conclusions: Continuous low-dose-rate irradiation by gamma-emitting 103Pd stents is feasible with reduction of in-stent hyperplasia in a dose-related manner. However, significant narrowing at the stent edges, increased in-stent hyperplasia at lower activities, and incomplete vascular healing with persistence of immature neointima at higher activities are significant limitations.

Objective: This study was designed to determine whether antisense oligodeoxynucleotides (ODN) directed against the nuclear proto-oncogene c-myc could inhibit restenosis when given by local delivery immediately after coronary stent implantation., Background: Failure of conventional pharmacologic therapies to reduce the incidence of coronary restenosis after percutaneous revascularization techniques has prompted interest in the use of agents that target intracellular central regulatory mechanisms., Methods: Eighty-five patients were randomly assigned to receive either 10 mg of phosphorothioate-modified 15-mer antisense ODN or saline vehicle by intracoronary local delivery after coronary stent implantation. The primary end point was percent neointimal volume obstruction measured by computerized analysis of electrocardiogram-gated intravascular ultrasound (IVUS) at six-month follow-up. Secondary end points included clinical outcome and quantitative coronary angiography analysis., Results: Analysis of follow-up IVUS data was performed on 77 patients. In-stent volume obstruction was similar between groups (44 +/- 16% and 46 +/- 14%, placebo vs. ODN; p = 0.57; 95% confidence interval: -1.13 to 0.85). Minimum luminal diameter increased from 0.84 +/- 0.36 and 0.90 +/- 0.45 (p = 0.55) to 2.70 +/- 0.37 and 2.80 +/- 0.37 (p = 0.28) after stent implantation, which decreased to 1.50 +/- 0.61 and 1.50 +/- 0.53 (p = 0.98) by six months, yielding similar loss indexes (placebo vs. ODN, respectively). There were no differences in angiographic restenosis rates (38.5 and 34.2%; p = 0.81; placebo vs. ODN) or clinical outcome., Conclusions: Treatment with 10 mg of phosphorothioate-modified ODN directed against c-myc does not reduce neointimal volume obstruction or the angiographic restenosis rate in this patient population.

The aim of the study was to determine the safety and efficacy of the second-generation ACS Multi-Link Duet coronary stent system for the treatment of single, symptomatic, de novo, native coronary artery lesions. Between February and June 1998, 427 patients (69.3% male, 51.5% class 3 or 4 angina, 20.1% diabetic, 43.6% hyperlipidemia) were included at 38 centers in this prospective observational study. All patients received ticlopidine 500 mg/day for 1 month and aspirin > or =100 mg/day. The Duet stent was available in 8, 18, and 28 mm length and 3.0, 3.5, and 4.0 mm diameter. After adequate predilatation, stents were successfully implanted, at up to 16 atm, in 99.3% of patients. Mean vessel diameter by core laboratory quantitative coronary angiography was 3.0 +/- 0.53 mm and postprocedural minimum luminal diameter was 2.79 +/- 0.43 mm (12% +/- 9.3% diameter stenosis). At 30 days, 96.7% of patients were event-free and at 6 months 88.1% remained free of major adverse cardiac events. The restenosis rate was 18.1%. The ACS Duet stent was safely implanted in >99% of target lesions by a diverse group of international investigators. With late outcomes at least comparable to the best published results, this stent platform provides safe and effective percutaneous treatment of obstructive coronary artery disease. Cathet Cardiovasc Intervent 2001;54:25-33., (Copyright 2001 Wiley-Liss, Inc.)

Purpose: Endovascular radiation therapy is a promising strategy for the prevention of restenosis. Radiation prevents proliferation of vascular smooth muscle cells, thereby reducing the incidence of restenosis, but may also affect the remaining endothelial cells. For this reason, a comparison was made between irradiated and nonirradiated endothelial cells and their effects on the proliferation of vascular smooth muscle cells in a coculture system was evaluated., Materials and Methods: A coculture system was used, in which both endothelial cells and vascular smooth muscle cells were grown on opposite sides of a semipermeable membrane. After a period of growth arrest, the proliferation of vascular smooth muscle cells was measured during four subsequent days., Results: The presence of endothelial cells stimulated the proliferation of vascular smooth muscle cells during the first days of analysis but had an inhibitory effect during the subsequent days (P <.5). gamma-irradiation of endothelial cells resulted in a complete blockage of the proliferation of these cells. However, irradiated endothelial cells affected the proliferation of vascular smooth muscle cells in coculture in a fashion comparable to nonirradiated endothelial cells (P >.5)., Conclusion: The results suggest that, in endovascular radiation therapy, irradiation of endothelial cells does not change their effects on the proliferative behavior of vascular smooth muscle cells.

BACKGROUND: The NOGA (Biosense Webster, Markham, ON, Canada) injection catheter is an innovative navigational device that provides an ideal platform for intra-myocardial injection material. However, injection through a long (1.91 m), narrow (27G) nitinol needle could result in deterioration in the integrity and functionality of DNA. METHODS: To test this possibility, DNA in plasmid form (pcDNA3.1) containing the Lac Z transgene (250 micro l) was passed through the NOGA needle using a hand-held 1 cc syringe at a gentle hand injection pressure (43 +/- 3 PSI, 3.0 +/- 0.2 kg/cm(2)) or at maximal manual pressure (90 +/- 6 PSI, 6.3 +/- 0.4 kg/cm(2)), either once or 20 times. This DNA, compared to DNA not passed through the NOGA needle (control), was then used to transfect primary cultures of rat skin fibroblasts (FB) from Fisher 344 rats and the cells were subsequently stained for beta galactosidase (betagal). RESULTS: Transfection efficiency was significantly reduced by passing the DNA through the needle at both 43 +/- 3 PSI (78 +/- 4% of control, n = 10, P < 0.05 versus control) and 90 +/- 6 PSI (66 +/- 4 % of control, n = 10, P < 0.01 versus control, P < 0.02 versus 43 +/- 3 PSI). Passage of the DNA through the NOGA needle 20 times resulted in a transfection efficiency of only 5 +/- 1% of control (n = 20, P < 0.1 x 10(-11) versus control). Capillary Electrophoresis revealed that the reduction in transfection efficiency was due to a conformational change in the DNA from predominantly supercoiled to nicked and linearized DNA. Transfection efficiency as compared with control decreased as the concentration of the DNA solution which was passed through the needle was increased from 0.3 micro g/ micro l to 2.4 micro g/ micro l. Recovery experiments confirmed that the reduction in transfection efficiency was not due to loss of DNA by binding to the NOGA needle. CONCLUSION: These results suggest that DNA is susceptible to shear forces when injected through the NOGA needle even at nominal clinical injection pressures, suggesting that careful and controlled injections will be required to achieve optimal gene integrity and expression.

Objectives: To evaluate the effectiveness of electively placed heparin-coated stents in the treatment of coronary saphenous vein bypass grafts with de novo lesions less than 15 mm in diameter in a prospective study with all eligible consecutive patients presenting to Middelheim Hospital, Antwerp, Belgium between September 1997 and August 1998., Patients and Methods: Fifty patients with 53 lesions were studied. Anginal class, risk factors, quantitative coronary angiographic measurements pre- and postprocedure, procedural outcome, in-hospital events, clinical status on discharge, and six-month clinical and angiographic follow-up (in 48 patients) were recorded. All patients received acetylsalicylic acid and ticlopidine, unless known intolerance was present., Results: On average, 1.1 stents/patient were placed in very old saphenous vein grafts (11. 7+/-3.9 years). Procedural success was 98%. Only two non-Q wave myocardial infarctions (MIs) occurred, with no Q-wave MIs and no deaths during hospital stay. Length of hospital stay was short (2. 4+/-1.7 days), and 96% of patients were free of angina on discharge. At six-months' follow-up, two patients had died, one of whom died of a noncardiac cause. One patient suffered a non-Q wave MI. At six months, 86% of patients were free from angina. Minimal luminal diameter decreased from 1.14 mm before to 3.33 mm after stenting and to 2.52 mm at six months. Restenosis was present in 22% of patients (21.6% of lesions)., Conclusions: In a selected population with coronary saphenous vein bypass graft disease, Wiktor heparin-coated stents can be delivered with an excellent periprocedural outcome. Six-month outcome appears favourable with a low recurrence of angina (18%) and a low rate of angiographic restenosis (21.6%).

While quantitative coronary angiography (QCA) remains the standard used to assess new interventional therapies, intracoronary ultrasound (ICUS) is gaining interest. The aim of the study was to determine the relationship between QCA and quantitative coronary ultrasound (QCU) measurements after stenting. Sixty-two consecutive patients with both QCA and QCU analysis after stent implantation were included in the study. The mean luminal diameter (QCU vs. QCA) were 2.74 +/- 0.46 mm and 2.41 +/- 0.49 mm (P < 0.0001), the minimal luminal diameter (MLD) 2.08 +/- 0.44 mm and 1.62 +/- 0.42 mm (P < 0. 0001), and the projected QCU MLD 1.90 +/- 0.42 mm (P < 0.0001 with respect to QCA). Percentage obstruction diameter (QCU vs. QCA) were 41.53% +/- 10.78% and 43.15% +/- 12.72% (P = NS). The stent diameter (QCU vs. QCA) were 3.54 +/- 0.65 mm and 3.80 +/- 0.37 mm (P = 0. 0004). Stent length measured by QCU were longer at 31.11 +/- 13.54 mm against 28.63 +/- 12.75 mm, P < 0.0001 with respect to QCA. In conclusion, while QCA and QCU appear to be comparable tools for measuring corrected stent diameters and stent lengths, smaller luminal diameters were found using QCA. This is of particular relevance to quantitative studies addressing absolute changes in vascular or luminal diameters. Cathet. Cardiovasc. Intervent. 48:133-142, 1999., (Copyright 1999 Wiley-Liss, Inc.)

Percutaneous therapy of coronary bifurcated lesions is associated with greater risk of acute complications and late restenosis. Numerous innovative techniques using various stent types have been proposed. We report the first clinical use of a truly bifurcated stent (Bard XT Carina). The implantation procedure, favorable medium-term angiographic and 1-year clinical follow-up of the first human use in a 43-year-old female are illustrated with angiography and intravascular ultrasound. As a single prosthesis that effectively covers the bifurcation, this stent presents appealing alternative for the treatment of coronary bifurcation lesions when compared to methods that involve multiple-stent implantation. Cathet. Cardiovasc. Intervent. 47:361-369, 1999., (Copyright 1999 Wiley-Liss, Inc.)

BACKGROUND: Coronary stents have been used with increasing frequency and in increasingly complex coronary disease. A new 316 LVM stainless steel coronary stent, the R Stent, has been designed to provide maximum flexibility for tracking and high radial strength post-deployment. PURPOSE: To assess the clinical feasibility of the R Stent in a tertiary referral population of patients with coronary heart disease. Specific objectives are to assess the R Stent's deployment success, angiographic and procedural success (<20% residual stenosis and >TIMI 2 flow), safety (absence of complications), and 30-day clinical success (angiographic/procedural success plus no major adverse coronary events). METHODS: Between April and November 1998, stent deployment was attempted in 27 patients with stable (46%) or unstable (54%) angina pectoris who qualified for percutaneous transluminal coronary angioplasty. Eighty per cent of patients had a pre-existing history of myocardial infarction, coronary bypass surgery or percutaneous transluminal coronary angioplasty, and several of the lesions were anatomically complex (totally occluded, n 32; thrombus present, n 32; heavily calcified, n 33; ostial, n 31; >20 mm long, n 39; angulation >45 degrees, n 37). Lesions in aortocoronary saphenous vein grafts were excluded. Adjunctive medical management included intraprocedural aspirin and heparin and post-procedural aspirin and ticlopidine. After deployment, patients were followed up in the hospital and at 30 days post procedure. RESULTS: Stent deployment was achieved in 32 of 33 attempts (26 of 27 patients). There was one deployment failure in a long, calcified ostial and proximal left coronary lesion. In the 26 successful deployments, TIMI 3 flow was achieved. One other patient experienced a painless increase in creatine kinase to 375 (CK-MB of 59) at 12 h without ECG changes. At 30 days, there were no deaths, no myocardial infarctions, no subacute thromboses, no repeat interventions, no bypass surgeries and no bleeding complications. Only the patient with post-procedural CK-MB elevation experience recurrence of CCS class 2 angina within the 30 days. CONCLUSION: The R Stent is a promising new device for the treatment of complex coronary heart disease. A larger, more broadly-based study is warranted.

Background: The non-uniform extent and distribution of atherosclerotic plaque at bifurcations have been described by necropsy studies and they are related to local blood-flow disturbances. Systematic evaluation of plaque extent and distribution upstream and downstream of major coronary side-branches has not yet been evaluated in vivo., Methods: We used intravascular ultrasound imaging in 41 patients with atherosclerotic disease to study the region of 73 major coronary side-branches at 2 mm increments proximal and distal to the side-branch (657 images: 73 at origin of side-branch; 292 proximal; 292 distal). The maximum (MXT) and minimum (MINT) plaque thickness and the plaque burden percentage (% PB) were measured in all the segments. The angle of distribution of maximum plaque thickness with respect to the origin of the side-branch was determined in each cross-section and assigned to S1 when located on the semicircle in the direction of the origin of the side-branch and to S2 when located on the opposite wall., Results: The mean value of maximum plaque thickness and the plaque burden percentage were similar at the origin and in the two adjacent segments proximal and distal to the side-branch (1.0 +/- 0.48 mm, 1.06 +/- 0.48 mm and 0.98 +/- 0.48 mm; 45 +/- 19%, 46 +/- 19% and 44 +/- 18%). In distal sites of analysis, the plaque was more frequently eccentric in comparison to proximal sites (presence of an arc of plaque-free wall: 79% versus 62% in very distal and in very proximal sites respectively; p < 0.05). The prevalence of maximum plaque in S2 was higher at the origin (84%) and in adjacent distal segments (86%) as compared with the adjacent proximal segments (60%; p < 0.0001)., Conclusions: The distribution of plaque is influenced by the origin of a major coronary side-branch in patients with coronary atherosclerosis: in distal sites the location of maximum plaque is almost always eccentrically distributed on the wall opposite the take-off.

A novel approach of cell seeding of stents using xenotransplanted endothelium is proposed. The advantages of this approach are that these doubly transgenic animals will provide a limitless supply of endothelial cells producing controllable levels of active compound. These foreign cells will act as Trojan horses, graciously accepted at face value by the host organism, but capable of modifying the pathophysiological response to vessel damage, typified by the process of restenosis. Once implanted, the production of the bioactive compound is under exogenous control by means of 'designer' genes coding for modified cell surface receptors, which are introduced with the transgene to provide controllable levels of compound. Interaction of an orally administered compound with the modified cell receptor will switch on the transgene, while in its absence the transgene remains dormant. We have been able to show the feasibility this type of approach has for other animal species, and it shows great potential for application to humans.

Intravascular ultrasound (IVUS) permits the detailed examination of coronary stent apposition and expansion in vivo. IVUS assessment of the extent and distribution of in-stent neointima at follow-up is an ideal model for the evaluation of new antiproliferative drugs that aim at a reduced in-stent neointimal hyperplasia. Recently, automated systems for three-dimensional reconstruction and analysis of IVUS images have been developed. This manuscript illustrates the methodology and clinical use of automated three-dimensional IVUS analysis systems during coronary stenting, and highlights the first randomized trials to apply such a technique for the assessment of in-stent neointima.