1,721,031 research outputs found
Diagnostic and prognostic value of coronary artery calcium screening
No full textPurpose of review Algorithms and equations to calculate risk of cardiovascular events, though very useful as an in-office tool to conduct a preliminary assessment demonstrate a limited ability to predict risk in the individual patient. This has favored the development of several imaging modalities for subclinical atherosclerosis such as imaging of coronary calcium,by computed tomography.
Recent findings Arterial wall calcification is intimately associated With atherosclerosis development and is therefore, an optimal marker of the presence of disease. The paradigm underlying the use of imaging technologies to identify subclinical disease is that the quantification of plaque burden may provide a better risk stratification approach for the individual patient than the currently available tools. Summary The most recent evidence supports this approach as will be discussed in the current review
Metodiche di immagine per valutare la progressione della placca aterosclerotica
No full textCardiovascular disease is the first cause of morbidity and mortality for both men and women in
developed countries. Tracking the progression of the atherosclerotic plaque appears to be an effective way to predict modification of risk in individual patients. Quantitative coronary angiography was initially proposed as a method of choice to assess coronary disease progression. With this methodology it was possible to demonstrate a strong association of plaque regression with reduction in adverse cardiovascular outcomes. More recently, the focus of research has turned to the development of noninvasive modalities to image the atherosclerotic plaque in its preclinical stages and to evaluate the effectiveness of preventive therapies with sequential imaging. The ease of performance of these tests enabled their use as intermediate endpoints in clinical trials to test new strategies to treat atherosclerosis.
If proven successful, these imaging tools may allow a reduction in size and duration of clinical trials
with a substantial cost benefit for society
Lipid-lowering therapy with statins in postmenopausal women : a few answered and many unanswered questions
No full textTechniques and technologies to assess vascular calcification
No full textCardiovascular calcification (CV) is highly prevalent in chronic kidney disease stage V and has been associated with an increased risk for all-cause as well as cardiovascular mortality. A number of noninvasive imaging techniques are available to screen for the presence of CV-plain x-rays of the abdomen and extremities to identify macroscopic calcifications of aorta and peripheral arteries; echocardiography for assessment of valvular calcification; two-dimensional ultrasound for calcification of carotid arteries, femoral arteries and aorta, and computed tomography technologies that constitute the gold standard for quantification of coronary artery and aorta calcification. Some of these modalities are also useful to monitor calcification progression and to assess the effect of different therapeutic strategies directed at modifying calcification progression. In this article we review the strengths and limitations of the most common noninvasive techniques employed for the imaging of vascular calcification
Ischemia Imaging and Plaque Imaging in Diabetes : Complementary Tools to Improve Cardiovascular Risk Management: Response to Rutter and Nesto
No full textCardiovascular disease is the most frequent cause of death and disability in diabetes, and the morbidity and mortality for coronary artery disease (CAD) in this population is two to four times higher than in nondiabetic subjects. Traditional risk factors do not fully explain the level of cardiovascular risk, and coronary disease events are often silent in diabetic patients. Thus, research has recently focused on improving the risk assessment of an individual patient with new tools in an effort to better identify subjects at highest risk and in need of aggressive management. Cardiovascular imaging has proven very helpful in this regard. Traditional methods to assess CAD are based on detection of obstructive luminal disease responsible for myocardial ischemia. However, acute coronary syndromes often occur in the absence of luminal stenoses. Hence, the utilization of imaging methodologies to visualize atherosclerosis in its presymptomatic stages has received mounting attention in recent years. In this article, we review the current literature on the utility of traditional imaging modalities for obstructive CAD (nuclear and echocardiographic stress testing) as well as atherosclerosis plaque imaging with carotid intima-media thickness and coronary artery calcium for risk stratification of diabetic patients
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
Hybrid myocardial imaging for risk stratification prior to kidney transplantation : added value of coronary calcium and epicardial adipose tissue
No full textBACKGROUND:
Patient selection and optimal approach to risk stratification prior to kidney transplantation remain uncertain. We sought new predictors of an abnormal myocardial perfusion (MYP) stress test result.
METHODS:
Retrospective study of 411 consecutive chronic kidney disease stages 4-5D patients awaiting kidney transplantation referred for risk stratification. PET-CT or SPECT-CT was used to assess MYP and quantify coronary artery calcium (CAC) and epicardial adipose tissue (EAT). Abnormal MYP was defined as a perfusion defect involving ≥5% of the left ventricular myocardium.
RESULTS:
Fixed or reversible MYP defects were present in 41 patients (10%). Male sex, smoking, and history of cardiovascular disease were more prevalent; age was higher and CAC and EAT were greater in patients with MYP defects than in those with normal MYP. On multivariate logistic regression, EAT and CAC were independent predictors of abnormal MYP while diabetes mellitus showed a borderline association (P = .08). EAT added incremental diagnostic value to a model including age, CAC and diabetes mellitus [AUC 0.73 (95% CI 0.64-0.81) to 0.76 (95% CI 0.68-0.84; P = .02)]. Furthermore, the model containing EAT showed improved diagnostic discrimination.
CONCLUSIONS:
Abnormal MYP on screening stress testing appears to be rare in patients awaiting kidney transplantation suggesting an excess of testing. EAT and CAC may help predict what patients are at higher risk of developing abnormalities of MYP under stress.
Comment in
Does hybrid imaging have a role in cardiac risk evaluation of the pre-renal transplant patient? [J Nucl Cardiol. 2013
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