1,720,962 research outputs found
The role of glycoprotein IIb/IIIa inhibitors in acute coronary syndromes and the interference with anemia
No full textThe role played by glycoprotein (GP) IIb/IIIa inhibitors (GPI) has continuously evolved until the most recent Guidelines whereby they were stepped down from class I to class II recommendation for treating acute coronary syndromes (ACS). GPI compete with a wider use of ADP inhibitors and novel anticoagulant drugs although GPI use has greatly narrowed. However, GPI may still have a role. Several criteria were proposed to define post-PCI anemia which is strictly related to bleeding and transfusion. In ACS, it should be important to define anemia in comparative terms versus baseline levels: ≥ 15% of red blood cell decrease should be a practical cut-off value. If one wishes to concentrate on hemoglobin (Hb), a≥2g/dl Hb decrease from baseline should be considered. It is important to recognize post-PCI anemia in the setting of ACS. There are sub-populations exposed to short-term hemorrhagic and/or long-term ischemic risks. Ischemic and hemorrhagic risks need to be carefully evaluated along with thrombocytopenia and its prognostic significance in order to put all these blood and rheological parameters into a clinically oriented perspective on which therapeutical decisions should be based. Definition of high risk procedures (complexity, angiographic characteristics and patient's risk profile, regardless whether STEMI or NSTEMI) may help selecting GPI. There are positive elements in GPI use: efficacy, rapid onset and reversibility of action, absence of pharmacogenomic variability, pharmacoeconomic considerations and the possibility of intracoronary administration. All these elements should be evaluated when selecting these agents for therapeutics
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Speckle-Tracking Echocardiographic Assessment in Post-Myocardial Infarction Patients With Ventricular Arrhythmias.
No full textEchocardiographic findings in simple and complex patent foramen ovale before and after transcatheter closure
No full textAims. Percutaneous closure of patent foramen ovale (PFO) in cryptogenic cerebrovascular events is an alternative to medical therapy. The interpretation of residual shunts after implantation of different devices for PFO with different morphologies is controversial.
Methods and results. Transcatheter PFO closure was performed in 123 patients with a history of ≥1 paradoxical embolism using three different devices: Amplatzer (n=46), Figulla Occlutech (n=41) and Atriasept Cardia (n=36). Fifty-six patients presented with simple PFO and 67 patients had complex morphologies. All patients were studied with contrast-enhanced transesophageal echocardiography (TEE) before interventional procedure and thereafter at 1 and 6 months and every 6 to 12 months in case of incomplete closure. Definite closure was confirmed in at least two consecutive TEE studies. Various PFO morphologies were identified by TEE before device implantation. The device size to PFO diameter ratio was significantly increased in patients with complex PFO compared to those patients with a simple PFO morphology (p<0.05). The difference between the closure rate of S-PFO and C-PFO concerning each device type was significant (Amplatzer p=0.0027, Figulla p=0.0043, Atriasept p<0.01). The mean follow up period was 3.4 years (median 2.7 years) with a cerebrovascular re-event-rate of 2.4% per year. In three patients thrombi were detected in the six month TEE controls and resolved after medical therapy. In three other patients the implantation of an adjunctive device was necessary for residual shunt.
Conclusion. In our series of patients the closure rate was dependent on PFO morphology more than occluder size and type. An adjunctive device was implanted in selected cases
Aspirin reload before elective percutaneous coronary intervention: Impact on serum thromboxane B<inf>2</inf> and myocardial reperfusion indexes
No full textMicrovascular obstruction seems to predict poor outcome in patients undergoing elective percutaneous coronary intervention (PCI), but the underlying mechanism is still unclear. We analyzed whether serum thromboxane B2, a stable metabolite of thromboxane A2, may be implicated in post-PCI microvascular obstruction. We enrolled 91 patients (74 males, 66±10 years) on chronic low-dose aspirin therapy (aspirin, 100 mg daily) scheduled for elective PCI and randomly assigned to receive aspirin reload (325 mg orally, n=46) or no reload (control group, n=45) ≥1 hour before elective PCI. Serum levels of thromboxane B2, reperfusion indexes (corrected Thrombolysis In Myocardial Infarction frame count and myocardial blush grade), and serum cardiac troponin I were assessed before and after PCI. Serum thromboxane B2 significantly increased after 120 minutes (P=0.0447) from PCI in control but not in aspirin reload group. After PCI, both groups showed a statistically significant reduction in corrected Thrombolysis In Myocardial Infarction frame count more evident in aspirin reload group (P=0.0023). Moreover, after PCI, 61% of patients allocated to aspirin reload and only 32% of patients allocated to control group reached normal microcirculatory reperfusion (myocardial blush grade=3); patients with myocardial blush grade=3 exhibited lower values of serum thromboxane B2 compared with those with myocardial blush grade <3 (P=0.05). Periprocedural cardiac troponin I significantly increased (F=3.64; P=0.01334) and correlated with serum thromboxane B2 (ρ=0.31; P=0.0413) in control but not in aspirin reload group. In addition, left ventricular ejection fraction significantly increased after PCI only in the aspirin reload group (P=0.0005). Aspirin loading dose before elective PCI improves myocardial reperfusion and injury indexes, suggesting a possible role of platelet thromboxane A2 in microvascular occlusion. http://www.clinicaltrials.gov. Unique identifier: NCT01374698. © 2014 American Heart Association, Inc
Assessment of biventricular function by three-dimensional speckle tracking echocardiography in secondary mitral regurgitation after repair with the mitraclip system
No full textBackground. The goal of this study was to determine the changes of left (LV) and right (RV) ventricular function with three-dimensional speckle-tracking echocardiography (3DSTE) after percutaneous mitral valve repair with the MitraClip system in high-risk surgical patients with moderate-to-severe or severe secondary mitral regurgitation (MR).
Methods. Thirty-two patients with MR undergoing MitraClip were prospectively included. Patients underwent two-dimensional and three-dimensional transthoracic echocardiography before clip implantation and after 6-month follow-up. LV and RV longitudinal strains were obtained by two-dimensional speckle-tracking echocardiography (2DSTE) and 3DSTE. LV circumferential, radial, and area strains were calculated by 3DSTE. Data analysis was performed offline.
Results. At 6-month follow-up a significant improvement was shown in LV 2D global longitudinal strain (p<0.005), 3D global longitudinal strain (p=0.0002), and 3D area strain (p=0.0003). Overall, a significant improvement was also shown in 3D RV ejection fraction (p<0.05) and 3D RV free-wall longitudinal strain (p<0.05). A poor increase in LV strains after clip implantation (p=ns) occurred in patients with pronounced pre-existing RV dysfunction. The areas under the ROC curve (AUC) for LV-RV 3DSTE parameters showed high discriminative values (0.87-0.91) in predicting unfavorable outcome with persistent symptoms (NYHA>II) after the procedure.
Conclusions. 3DSTE analysis showed overall LV-RV strain improvement after clip implantation as well as lower post-procedural LV strain values in patients with worse pre-existing RV function. These findings could help in guiding MR treatment strategies suggesting different therapies in the presence of marked RV impairment or viceversa anticipating the procedure in case of evolving RV dysfunction
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