1,720,991 research outputs found
Preoperative Angiotensin-converting enzyme inhibitors and acute kidney injury after coronary artery bypass grafting
No full textBACKGROUND: Angiotensin-converting enzyme (ACE) inhibitors confer renal protection in different clinical settings. No final conclusions are available on the renal benefits of ACE inhibitors after coronary artery bypass grafting (CABG). Because ACE inhibitors decrease glomerular perfusion pressure, they may exacerbate kidney injury during cardiopulmonary bypass (CPB)-related hypoperfusion. We evaluated the effect of preoperative ACE inhibitors on acute kidney injury (AKI) after CABG. METHODS: A propensity score-based analysis of 536 patients undergoing CABG on CPB was performed, among which 281 received ACE inhibitors preoperatively. Patients with preoperative end-stage renal failure requiring dialysis were excluded. Postoperative AKI was defined as 50% or more decrease in the glomerular filtration rate from preoperative or postoperative mechanical renal support. RESULTS: After CABG, AKI developed in 49 patients (9.1%), and 23 (4.2%) required dialysis. The incidence of AKI was 6.4% in patients who received preoperative ACE inhibitors and 12.2% in patients who did not (p = 0.02). The incidence of AKI requiring dialysis was 2.4% in the treatment group and 6.3% in controls (p = 0.03). After adjusting for propensity score and covariates, preoperative ACE inhibitors were found to reduce the incidence of postoperative AKI (odds ratio, 0.48; 95% confidence interval, 0.23 to 0.77; p = 0.04). Other independent predictors were age, preoperative glomerular filtration rate, left ventricular ejection fraction of less than 0.35, preoperative use of intraaortic balloon pump, emergency operation, and CPB time. CONCLUSIONS: Preoperative ACE inhibitors are associated with a reduced rate of AKI after on-pump CABG surgery
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
Prophylactic tricuspid annuloplasty in patients with dilated tricuspid annulus undergoing mitral valve surgery
No full textObjective: Progression of functional tricuspid regurgitation is not uncommon after mitral valve surgery and is associated with poor outcomes. We tested the hypothesis that concomitant tricuspid valve annuloplasty in patients with tricuspid annulus dilatation (>= 40 mm) prevents tricuspid regurgitation progression after mitral valve surgery.Methods: We enrolled 44 patients undergoing mitral valve surgery (both repair or replacement) showing less than moderate (= 40 mm) at preoperative echocardiography. They were randomized to receive (n = 22) or not receive (n = 22) concomitant tricuspid annuloplasty (Cosgrove-Edwards annuloplasty ring; Edwards Lifesciences, Irvine, Calif) at the time of mitral valve surgery. Clinical and echocardiographic follow-up was 100% completed at 12 months after surgery.Results: Preoperative clinical and echocardiographic characteristics were comparable in the 2 groups. Operative mortality was 4.4%(1 death in each group). At 12 months follow-up, tricuspid regurgitation was absent in 71% (n 15) versus 19%(n 4) of patients in the treatment and control groups, respectively (P = .001). Moderate to severe tricuspid regurgitation (>=+3) was present in 0% versus 28%(n = 6) of patients in the treatment and control groups, respectively (P = .02). Pulmonary artery systolic pressure significantly decreased from baseline in all cases (P < .001) and was comparable in the 2 groups (41 +/- 8 mmHg vs 40 +/- 5 mm Hg; P = .4). Right ventricular reverse remodeling was marked in the treatment group (right ventricular long axis: 71 +/- 7mmvs 65 +/- 8 mm; P = .01; short axis: 33 +/- 4 mm vs 27 +/- 5 mm; P = .001) but only minimal in the control group (right ventricular long axis: 72 +/- 6 mm vs 70 +/- 7 mm; P = .08; short axis: 34 +/- 5 mm vs 33 +/- 5 mm; P = .1). The 6-minute walk test improved from baseline in both groups (P < .001), but this improvement was greater in the treatment group (+115 +/- 23 m from baseline vs +75 +/- 35 m; P = .008).Conclusions: Prophylactic tricuspid valve annuloplasty in patients with dilated tricuspid annulus undergoing mitral valve surgery was associated with a reduced rate of tricuspid regurgitation progression, improved right ventricular remodeling, and better functional outcomes. (J Thorac Cardiovasc Surg 2012;143:632-8
Indexed effective orifice area after mechanical aortic valve replacement does not affect left ventricular mass regression in elderly
Full text linkObjective: After aortic valve replacement, the effects of a small functional prosthesis on the extent and pattern of regression of Left ventricular hypertrophy and on clinical outcomes may be less significant in older patients with tow cardiac output requirements. The objective of this study was therefore to determine whether patient-prosthesis mismatch affects left ventricular mass regression in the elderly.Methods: The population studied was made up of 88 patients over 65 years of age with pure aortic stenosis who underwent mechanical aortic valve replacement. The effective orifice area index was calculated for each patient on the basis of the projected prosthesis in vivo effective orifice area. It was considered a continuous variable and influence of its entire range of values on the extent of left ventricular mass regression was analyzed in a multivariate prediction model.Results: Even though, in the group with prosthesis-patient mismatch there was a trend for tower postoperative left ventricular mass index (115 +/- 24 g/m(2) VS 102 +/- 27 g/m(2), p = 0.24) and postoperative peak trans-prosthetic gradients (32 +/- 9.8 mmHg vs 28.9 +/- 7.79 mmHg, p = 0.35) these differences were not statistically significant. The prevalence of residual left ventricular hypertrophy at follow-up was 50% in the group with patient-prosthesis mismatch and 50% in the group without patient-prosthesis mismatch (p = 0.83). In multivariate analysis the only factors associated with indexed left ventricular mass were the follow-up time (p = 0.015, r(2) = 0.22) and preoperative indexed Left ventricular mass (p = 0.0012, r(2) = 0.11).Conclusions: The major finding of our study is that patient-prosthesis mismatch does not affect Left ventricular mass regression in patients older than 65 with pure aortic stenosis who underwent mechanical aortic valve replacement. In older patients with tow cardiac output requirements, even a small change in the valve effective orifice area after aortic valve replacement with modern efficient mechanical prosthesis, will result in a marked reduction of pressure gradient and this will be associated with a significant regression of left ventricular mass. (c) 2005 Elsevier B.V. All rights reserved
Intraoperative continuous venovenous hemofiltration during coronary surgery
Full text linkPostoperative continuous venovenous hemofiltration decreases acute renal failure in patients with moderate renal dysfunction undergoing coronary artery bypass grafting, but it prolongs intensive care unit stay. We developed a simple method to connect a hemofiltration machine to the cardiopulmonary bypass system. To evaluate the benefit of intraoperative hemofiltration, 124 consecutive patients (mean age, 67 +/- 6 years) with moderate renal dysfunction were studied. Surgery was preformed between January 2005 and May 2007. On-pump coronary artery bypass with hemofiltration was carried out in 40 patients (group A), 44 had on-pump coronary artery bypass without hemofiltration (group B), and 40 had off-pump coronary artery bypass (group C). Postoperative acute renal failure was defined as either renal failure requiring dialysis or >or=50% decline from the baseline glomerular filtration rate but not requiring dialysis. The 3 groups had similar demographic data and preoperative renal function. After adjusting for covariates and propensity scores, multivariate analysis showed that intraoperative hemofiltration and off-pump surgery protected postoperative renal function. Independent risk factors for postoperative renal dysfunction were age >70 years, left ventricular ejection fraction <35%, and the preoperative glomerular filtration rate
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
- …
