Quantification of coronary artery calcium by electron beam computed tomography for determination of severity of angiographic coronary artery disease in younger patients

Objectives.This study attempted to 1) evaluate five quantitative measures of coronary artery calcium and determine which best agreed with coronary artery disease severity at angiography; and 2) determine optimal quantity cutpoints to distinguish among no, mild and significant disease.Background.Coronary artery calcium identified noninvasively by electron beam computed tomography is a sensitive marker for atherosclerosis. Quantitative assessments of calcium could distinguish among patients with no, mild and significant disease in clinical, screening and research settings.Methods.One hundred sixty patients, 23 to 59 years old, underwent coronary angiography and electron beam computed tomography. Coronary artery calciumwas defined as dense (> 130 Hounsfield units) foci ≥2 mm2on the tomogram. Regression and receiver operating characteristic analyses were used to evaluate five quantitative measures of calcium as predictors of the largest stenosis in the coronary arteries and to identify optimal cutpoints for distinguishing among disease categories. No diseasewas defined as no stenosis, mild diseaseas 10% to 49% diameter stenosis in one or more major branches and significant diseaseas ≥ 50% diameter stenosis in one or more major branches.Results.All measures evaluated performed well. With calcific area as the quantitative measure, the best cutpoint for discriminating between patients with and without disease was the presence of calcium: sensitivity 81%, specificity 86% and overall accuracy 83%. The best cutpoint for discriminating between patients with and without significant disease was 18 mm2: sensitivity 86%, specificity 81% and accuracy 83%.Conclusions.Because the ranges of calcium quantity overlapped across disease categories, no cutpoints would distinguish among categories with absolute certainty. However, selected cutpoints could rule out disease in most healthy subjects and identify most patients with significant disease

Hypertension during Pregnancy is Associated with Coronary Artery Calcium Independent of Renal Function

Abstract Background: Hypertension during pregnancy (HDP) increases the risk of future coronary heart disease (CHD), but it is unknown whether this association is mediated by renal injury. Reduced renal function is both a complication of HDP and a risk factor for CHD. Methods: Logistic regression models were fit to examine the association between a history of HDP and the presence and extent of coronary artery calcification (CAC), a measure of subclinical coronary artery atherosclerosis, in 498 women from the Epidemiology of Coronary Artery Calcification Study (mean age 63.3+/-9.3 years). Results: Fifty-two (10.4%) women reported a history of HDP. After adjusting for age at time of study participation, HDP was associated with increased serum creatinine later in life (p=0.014). HDP was positively associated with the presence of CAC after adjusting for age at time of study participation (OR=2.7, 95% CI 1.4-5.4). This association was slightly attenuated with adjustment for body size and blood pressure (OR=2.4, 95% CI 1.2-4.9) but was not further attenuated with adjustment for serum creatinine and urinary albumin/creatinine ratio (OR=2.6, 95% CI 1.3-5.3). Results were similar for CAC extent. Conclusions: HDP may increase a woman's risk of future CHD beyond traditional risk factors and renal function. Women with a history of HDP should be monitored for potential increased risk of CHD as they age.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78144/1/jwh.2008.1285.pd

Circulating CD34+ Cell Count is Associated with Extent of Subclinical Atherosclerosis in Asymptomatic Amish Men, Independent of 10-Year Framingham Risk

Background Bone-marrow derived progenitor cells (PCs) may play a role in maintaining vascular health by actively repairing damaged endothelium. The purpose of this study in asymptomatic Old Order Amish men (n = 90) without hypertension or diabetes was to determine if PC count, as determined by CD34+ cell count in peripheral blood, was associated with 10-year risk of cardiovascular disease (CVD) and measures of subclinical atherosclerosis. Methods and Results CD34+ cell count by fluorescence-activated cell sorting, coronary artery calcification (CAC) by electron beam computed tomography, and CVD risk factors were obtained. Carotid intimal-medial thickness (CIMT) also was obtained in a subset of 57 men. After adjusting for 10-year CVD risk, CD34+ cell count was significantly associated with CAC quantity ( p =0.03) and CIMT ( p < 0.0001). A 1-unit increase in natural-log transformed CD34+ cell count was associated with an estimated 55.2% decrease (95% CI: −77.8% to −9.3%) in CAC quantity and an estimated 14.3% decrease (95% CI: −20.1% to −8.1%) in CIMT. Conclusions Increased CD34+ cell count was associated with a decrease in extent of subclinical atherosclerosis in multiple arterial beds, independent of 10-year CVD risk. Further investigations of associations of CD34+ cell count with subclinical atherosclerosis in asymptomatic individuals could provide mechanistic insights into the atherosclerotic process

Risk governance in organizations

Dieses Buch dokumentiert 10 Jahre Risk-Governance-Forschung an der Universität Siegen. In 50 Beiträgen reflektieren Forscher und Praktiker Risk Governance vor dem Hintergrund ihrer eigenen Forschungen und/oder Erfahrungen und geben jeweils einen Entwicklungsimpuls für die Zukunft der Risk Governance. Das Buch zeigt die große Bandbreite und Tiefe des Forschungsgebietes auf und diskutiert Grundannahmen, Implementierungsfragen, die Rolle der Risk Governance als Transformationsmotor, ihre Wirkung in den verschiedenen betrieblichen Funktionen, Entwicklungsperspektiven und den Beitrag der Risk Governance zu einer nachhaltigen Ausrichtung von Unternehmen.This book documents 10 years of risk governance research at the University of Siegen. In 50 contributions, researchers and practitioners reflect on risk governance against the background of their own research and/or experience and provide a development impetus for the future of risk governance. The book shows the wide range and depth of the research field and discusses basic assumptions, implementation issues, the role of risk governance as transformation engine, its impact in the various operational functions, development perspectives, and the contribution of risk governance to a sustainable orientation of companies

The relationship between diastolic blood pressure and coronary artery calcification is dependent on single nucleotide polymorphisms on chromosome 9p21.3

Abstract Background Single nucleotide polymorphisms (SNPs) within the 9p21.3 genomic region have been consistently associated with coronary heart disease (CHD), myocardial infarction, and quantity of coronary artery calcification (CAC), a marker of subclinical atherosclerosis. Prior studies have established an association between blood pressure measures and CAC. To examine mechanisms by which the 9p21.3 genomic region may influence CHD risk, we investigated whether SNPs in 9p21.3 modified associations between blood pressure and CAC quantity. Methods As part of the Genetic Epidemiology Network of Arteriopathy (GENOA) Study, 974 participants underwent non-invasive computed tomography (CT) to measure CAC quantity. Linear mixed effects models were used to investigate whether seven SNPs in the 9p21.3 region modified the association between blood pressure levels and CAC quantity. Four SNPs of at least marginal significance in GENOA for a SNP-by-diastolic blood pressure (DBP) interaction were then tested for replication in the Framingham Heart Study’s Offspring Cohort (N = 1,140). Results We found replicated evidence that one SNP, rs2069416, in CDKN2B-AS1, significantly modified the association between DBP and CAC quantity (combined P = 0.0065; Bonferroni-corrected combined P = 0.0455). Conclusions Our results represent a novel finding that the relationship between DBP and CAC is dependent on genetic variation in the 9p21.3 region. Thus, variation in 9p21.3 may not only be an independent genetic risk factor for CHD, but also may modify the association between DBP levels and the extent of subclinical coronary atherosclerosis.http://deepblue.lib.umich.edu/bitstream/2027.42/109464/1/12881_2014_Article_89.pd