982 resultados para arterial thrombosis
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AIM: To investigate the putative modifying effect of dual antiplatelet therapy (DAPT) use on the incidence of stent thrombosis at 3 years in patients randomized to Endeavor zotarolimus-eluting stent (E-ZES) or Cypher sirolimus-eluting stent (C-SES). METHODS AND RESULTS: Of 8709 patients in PROTECT, 4357 were randomized to E-ZES and 4352 to C-SES. Aspirin was to be given indefinitely, and clopidogrel/ticlopidine for ≥3 months or up to 12 months after implantation. Main outcome measures were definite or probable stent thrombosis at 3 years. Multivariable Cox regression analysis was applied, with stent type, DAPT, and their interaction as the main outcome determinants. Dual antiplatelet therapy adherence remained the same in the E-ZES and C-SES groups (79.6% at 1 year, 32.8% at 2 years, and 21.6% at 3 years). We observed a statistically significant (P = 0.0052) heterogeneity in treatment effect of stent type in relation to DAPT. In the absence of DAPT, stent thrombosis was lower with E-ZES vs. C-SES (adjusted hazard ratio 0.38, 95% confidence interval 0.19, 0.75; P = 0.0056). In the presence of DAPT, no difference was found (1.18; 0.79, 1.77; P = 0.43). CONCLUSION: A strong interaction was observed between drug-eluting stent type and DAPT use, most likely prompted by the vascular healing response induced by the implanted DES system. These results suggest that the incidence of stent thrombosis in DES trials should not be evaluated independently of DAPT use, and the optimal duration of DAPT will likely depend upon stent type (Clinicaltrials.gov number NCT00476957).
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Members of the Sox gene family of transcription factors are defined by the presence of an 80 amino acid homology domain, the High Mobility Group (HMG) box. Here we report the cloning and initial analysis of murine Sox-13 . The 984 amino acids Sox-13 protein contains a single HMG box, a leucine zipper motif and a glutamine-rich stretch. These characteristics are shared with another member of the Sox gene family, Sox-6. High level embryonic expression of Sox-13 occurs uniquely in the arterial walls of 13.5 days post coitum (dpc) mice and later. Low level expression was observed in the inner ear of 13.5 dpc mice and in a limited number of cells in the thymus of 16.5 dpc mice, from which Sox-13 was originally cloned. At 18.5 dpc, Sox-13 is expressed in the tracheal epithelium below the vocal cord and in the hair follicles. The Sox-13 protein binds to the consensus HMG box motif, AACAAAG, but does not transactivate transcription through a concatamer of this motif. Sox-13, like other members of the Sox family likely plays an important role in development.
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Numerous genetic loci have been associated with systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Europeans. We now report genome-wide association studies of pulse pressure (PP) and mean arterial pressure (MAP). In discovery (N = 74,064) and follow-up studies (N = 48,607), we identified at genome-wide significance (P = 2.7 × 10(-8) to P = 2.3 × 10(-13)) four new PP loci (at 4q12 near CHIC2, 7q22.3 near PIK3CG, 8q24.12 in NOV and 11q24.3 near ADAMTS8), two new MAP loci (3p21.31 in MAP4 and 10q25.3 near ADRB1) and one locus associated with both of these traits (2q24.3 near FIGN) that has also recently been associated with SBP in east Asians. For three of the new PP loci, the estimated effect for SBP was opposite of that for DBP, in contrast to the majority of common SBP- and DBP-associated variants, which show concordant effects on both traits. These findings suggest new genetic pathways underlying blood pressure variation, some of which may differentially influence SBP and DBP.
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The Center for Transportation Research and Education (CTRE) used the traffic simulation model CORSIM to access proposed capacity and safety improvement strategies for the U.S. 61 corridor through Burlington, Iowa. The comparison between the base and alternative models allow for evaluation of the traffic flow performance under the existing conditions as well as other design scenarios. The models also provide visualization of performance for interpretation by technical staff, public policy makers, and the public. The objectives of this project are to evaluate the use of traffic simulation models for future use by the Iowa Department of Transportation (DOT) and to develop procedures for employing simulation modeling to conduct the analysis of alternative designs. This report presents both the findings of the U.S. 61 evaluation and an overview of model development procedures. The first part of the report includes the simulation modeling development procedures. The simulation analysis is illustrated through the Burlington U.S. 61 corridor case study application. Part I is not intended to be a user manual but simply introductory guidelines for traffic simulation modeling. Part II of the report evaluates the proposed improvement concepts in a side by side comparison of the base and alternative models.
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BACKGROUND: For patients with acute iliofemoral deep vein thrombosis, it remains unclear whether the addition of intravascular high-frequency, low-power ultrasound energy facilitates the resolution of thrombosis during catheter-directed thrombolysis. METHODS AND RESULTS: In a controlled clinical trial, 48 patients (mean age 50 ± 21 years, 52% women) with acute iliofemoral deep vein thrombosis were randomized to receive ultrasound-assisted catheter-directed thrombolysis (N = 24) or conventional catheter-directed thrombolysis (N = 24). Thrombolysis regimen (20 mg r-tPA over 15 hours) was identical in all patients. The primary efficacy end point was the percentage of thrombus load reduction from baseline to 15 hours according to the length-adjusted thrombus score, obtained from standardized venograms and evaluated by a core laboratory blinded to group assignment. The percentage of thrombus load reduction was 55% ± 27% in the ultrasound-assisted catheter-directed thrombolysis group and 54% ± 27% in the conventional catheter-directed thrombolysis group (P = 0.91). Adjunctive angioplasty and stenting was performed in 19 (80%) patients and in 20 (83%) patients, respectively (P > 0.99). Treatment-related complications occurred in 3 (12%) and 2 (8%) patients, respectively (P > 0.99). At 3-month follow-up, primary venous patency was 100% in the ultrasound-assisted catheter-directed thrombolysis group and 96% in the conventional catheter-directed thrombolysis group (P = 0.33), and there was no difference in the severity of the post-thrombotic syndrome (mean Villalta score: 3.0 ± 3.9 [range 0-15] versus 1.9 ± 1.9 [range 0-7]; P=0.21), respectively. CONCLUSIONS: In this randomized controlled clinical trial of patients with acute iliofemoral deep vein thrombosis treated with a fixed-dose catheter thrombolysis regimen, the addition of intravascular ultrasound did not facilitate thrombus resolution. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT01482273.
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Acute pancreatitis can complicate non-selective transcatheter arterial embolization of hepatocellular carcinoma with an incidence ranging from 1,7% (acute clinical pancreatitis) to 40% (biological pancreatitis). This complication is thought to be related to embolization of extrahepatic arterial collaterals.We report herein a case of acute clinical pancreatitis developing within 24 hours after a second course of selective transcatheter arterial chemo-embolization into the proper hepatic artery. Neither anatomical arterial variation nor particular risk factor for acute pancreatitis could be identified. This complication is unusual after selective arterial embolization. Because it may clinically mimick a postembolization syndrome, dosage of serum pancreatic enzymes should be performed systematically in case of abdominal pain following chemoembolization.
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OBJECTIVES: Determine if arm veins are good conduits for infrainguinal revascularisation and should be used when good quality saphenous vein is not available. DESIGN: Retrospective study. MATERIALS AND METHODS: We evaluated a consecutive series of infrainguinal bypass (IB) using arm vein conduits from March 2001 to December 2006.We selected arm vein by preoperative ultrasound mapping to identify suitable veins. We measured vein diameter and assessed vein wall quality. We followed patients with systematic duplex imaging at 1 week, 1, 3, 6 and 12 months, and annually thereafter. We treated significative stenoses found during the follow-up. RESULTS: We performed 56 infrainguinal revascularisation using arm vein conduits in 56 patients. Primary patency rates at 1, 2 and 3 years were 65%, 51% and 47%. Primary assisted patencies at 1, 2 and 3 years were 96%, 96% and 82%. Secondary patency rates at 1, 2 and 3 years were 92%, 88% and 88%. The three-year limb salvage rate was 88%. CONCLUSIONS: We conclude that infrainguinal bypass using arm vein for conduits gives good patency rates, if selected by a preoperative US mapping to use the best autogenous conduit available.
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Anticoagulants are a mainstay of cardiovascular therapy, and parenteral anticoagulants have widespread use in cardiology, especially in acute situations. Parenteral anticoagulants include unfractionated heparin, low-molecular-weight heparins, the synthetic pentasaccharides fondaparinux, idraparinux and idrabiotaparinux, and parenteral direct thrombin inhibitors. The several shortcomings of unfractionated heparin and of low-molecular-weight heparins have prompted the development of the other newer agents. Here we review the mechanisms of action, pharmacological properties and side effects of parenteral anticoagulants used in the management of coronary heart disease treated with or without percutaneous coronary interventions, cardioversion for atrial fibrillation, and prosthetic heart valves and valve repair. Using an evidence-based approach, we describe the results of completed clinical trials, highlight ongoing research with currently available agents, and recommend therapeutic options for specific heart diseases.
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Lower limbs superficial venous thrombosis (SVT) is a relatively frequent disease. Its prevalence among patients consulting their treating physician is estimated to be 10.8% among women and 4.9% among men. Up to 25% of at risk patients with isolated SVT present with a concomitant DVT. Ultrasound imaging may play a role in the management of these patients allowing precise diagnosis, determination of thrombus extension and presence of associated DVT. From data recently appeared in the literature treatment of SVT with prophylactic doses of fondaparinux may be proposed to at risk patients with isolated SVT.
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If regions of the anterior pituitary gland received systemic blood via a direct arterial blood supply these regions would escape hypothalamic regulation and thus be a sequela in endocrine disorders. Since, in the untreated rat, all of the blood supply to the anterior pituitary gland is via the hypophyseal portal vessels, we hypothesized that partial interruption of the portal vessels could provoke the establishment of a direct arterial blood supply (arteriogenesis). We utilized the injection of polystyrene microspheres (15 or 9 micron diameter) into the left ventricle of the heart to test this hypothesis. Microspheres are trapped in the first capillary plexus they reach since they are too large to traverse the capillaries. No microspheres reached the anterior pituitary gland of control rats, a finding consistent with the fact that the anterior pituitary gland receives all of its blood supply via the hypophyseal portal blood vessels. Microspheres were observed in the primary portal capillary plexus in the infundibulum (median eminence), infundibular stalk (pituitary stalk), and infundibular process (pars nervosa), the first capillary plexus which they reached. A lesion of the medial basal hypothalamus (MBH) which destroyed the long portal vessels did not result in arteriogenesis since few, if any, microspheres were observed in the anterior pituitary gland. We confirmed, using vascular casts, that these lesions resulted in the long-term destruction of the primary portal capillaries in the infundibulum and of the long portal vessels. In MBH-lesioned animals it appears that all of the blood supply of the anterior pituitary gland is via short portal vessels arising from the infundibular stem and process.(ABSTRACT TRUNCATED AT 250 WORDS)
Local re-inversion coronary MR angiography: arterial spin-labeling without the need for subtraction.
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PURPOSE: To implement a double-inversion bright-blood coronary MR angiography sequence using a cylindrical re-inversion prepulse for selective visualization of the coronary arteries. MATERIALS AND METHODS: Local re-inversion bright-blood magnetization preparation was implemented using a nonselective inversion followed by a cylindrical aortic re-inversion prepulse. After an inversion delay that allows for in-flow of the labeled blood-pool into the coronary arteries, three-dimensional radial steady-state free-precession (SSFP) imaging (repetition/echo time, 7.2/3.6 ms; flip angle, 120 degrees, 16 profiles per RR interval; field of view, 360 mm; matrix, 512, twelve 3-mm slices) is performed. Coronary MR angiography was performed in three healthy volunteers and in one patient on a commercial 1.5 Tesla whole-body MR System. RESULTS: In all subjects, coronary arteries were selectively visualized with positive contrast. In addition, a middle-grade stenosis of the proximal right coronary artery was seen in one patient. CONCLUSION: A novel T1 contrast-enhancement strategy is presented for selective visualization of the coronary arteries without extrinsic contrast medium application. In comparison to former arterial spin-labeling schemes, the proposed magnetization preparation obviates the need for a second data set and subtraction.
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A single coronary artery can complicate the surgical technique of arterial switch operations, impairing early and late outcomes. We propose a new surgical approach, successfully applied in a 2.1 kg neonate, aimed at reducing the risk of early and late compression and/or distortion of the newly constructed coronary artery system.
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OBJECTIVE: This study aims to assess the predictive value of residual venous obstruction (RVO) for recurrent venous thrombo-embolism (VTE) in a study using D-dimer to predict outcome. DESIGN: This is a multicentre randomised open-label study. METHODS: Patients with a first episode of idiopathic VTE were enrolled on the day of anticoagulation discontinuation when RVO was determined by compression ultrasonography in those with proximal deep vein thrombosis (DVT) of the lower limbs. D-dimer was measured after 1 month. Patients with normal D-dimer did not resume anticoagulation while patients with abnormal D-dimer were randomised to resume anticoagulation or not. The primary outcome measure was recurrent VTE over an 18-month follow-up. RESULTS: A total of 490 DVT patients were analysed (after excluding 19 for different reasons and 118 for isolated pulmonary embolism (PE)). Recurrent DVT occurred in 19% (19/99) of patients with abnormal D-dimer who did not resume anticoagulation and 10% (31/310) in subjects with normal D-dimer (adjusted hazard ratio: 2.1; p = 0.02). Recurrences were similar in subjects either with (11%, 17/151) or without RVO (13%, 32/246). Recurrent DVT rates were also similar for normal D-dimer, with or without RVO, and for abnormal D-dimer, with or without RVO. CONCLUSIONS: Elevated D-dimer at 1 month after anticoagulation withdrawal is a risk factor for recurrence, while RVO at the time of anticoagulation withdrawal is not.
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PURPOSE: To assess the technical feasibility of multi-detector row computed tomographic (CT) angiography in the assessment of peripheral arterial bypass grafts and to evaluate its accuracy and reliability in the detection of graft-related complications, including graft stenosis, aneurysmal changes, and arteriovenous fistulas. MATERIALS AND METHODS: Four-channel multi-detector row CT angiography was performed in 65 consecutive patients with 85 peripheral arterial bypass grafts. Each bypass graft was divided into three segments (proximal anastomosis, course of the graft body, and distal anastomosis), resulting in 255 segments. Two readers evaluated all CT angiograms with regard to image quality and the presence of bypass graft-related abnormalities, including graft stenosis, aneurysmal changes, and arteriovenous fistulas. The results were compared with McNemar test with Bonferroni correction. CT attenuation values were recorded at five different locations from the inflow artery to the outflow artery of the bypass graft. These findings were compared with the findings at duplex ultrasonography (US) in 65 patients and the findings at conventional digital subtraction angiography (DSA) in 27. RESULTS: Image quality was rated as good or excellent in 250 (98%) and in 252 (99%) of 255 bypass segments, respectively. There was excellent agreement both between readers and between CT angiography and duplex US in the detection of graft stenosis, aneurysmal changes, and arteriovenous fistulas (kappa = 0.86-0.99). CT angiography and duplex US were compared with conventional DSA, and there was no statistically significant difference (P >.25) in sensitivity or specificity between CT angiography and duplex US for both readers for detection of hemodynamically significant bypass stenosis or occlusion, aneurysmal changes, or arteriovenous fistulas. Mean CT attenuation values ranged from 232 HU in the inflow artery to 281 HU in the outflow artery of the bypass graft. CONCLUSION: Multi-detector row CT angiography may be an accurate and reliable technique after duplex US in the assessment of peripheral arterial bypass grafts and detection of graft-related complications, including stenosis, aneurysmal changes, and arteriovenous fistulas.