Tight relations between coronary calcification and atherosclerotic lesions in the carotid artery in chronic dialysis patients.
ABSTRACT Both vascular calcification and atherosclerosis are highly prevalent in patients with end-stage renal disease (ESRD) and have been associated with increased cardiovascular morbidity. Because those two phenomena might be only coincidentally related in chronic haemodialysis (HD) patients, in this study, coronary artery calcification (CAC), common carotid artery intima media thickness (CCA-IMT) and thickness of atherosclerotic plaques in the carotid artery were simultaneously measured.
In a cross-sectional study of 47 HD patients (31 male, mean age 56.8 +/- 11.4 years, and 16 female, mean age 56.0 +/- 7.5 years) without history of major cardiovascular complications. CCA-IMT and presence and thickness of atherosclerotic plaques were measured with ultrasound and CAC with multidetector computed tomography.
The CAC were present in 70.2% of patients. The mean CAC was 1055 +/- 232, the mean CCA-IMT was 0.96 +/- 0.21. The atherosclerotic plaques in the common carotid arteries were visualized in 38 patients (80.1%), the mean thickness of the atherosclerotic plaque was 1.61 +/- 0.8 mm. We found a significant positive correlation between CAC and CCA-IMT (r = 0.70, P < 0.001). The thickness of atherosclerosis plaque positively correlated with CAC as well as with CCA-IMT (r = 0.60, P < 0.001 and r = 0.7, P < 0.003, respectively).
The study revealed close relationships between CAC, intima media thickness and the thickness of atherosclerotic plaques in dialysis patients. It may indicate that both vascular calcification and atherosclerotic lesions frequently coexist in patients with ESRD and that the intima media thickness could serve as a surrogate marker of vascular calcification.
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ABSTRACT: B-mode ultrasound is a noninvasive method of examining the walls of peripheral arteries and provides measures of the intima-media thickness (IMT) at various sites (common carotid artery, bifurcation, internal carotid artery) and of plaques that may indicate early presymptomatic disease. The reported associations between cardiovascular risk factors, clinical disease, IMT, and plaques are inconsistent. We sought to clarify these relationships in a large, representative sample of men and women living in 2 British towns. The study was performed during 1996 in 2 towns (Dewsbury and Maidstone) of the British Regional Heart Study that have an approximately 2-fold difference in coronary heart disease risk. The male participants were drawn from the British Regional Heart Study and were recruited in 1978-1980 and form part of a national cohort study of 7735 men. A random sample of women of similar age to the men (55 to 77 years) was also selected from the age-sex register of the general practices used in the original survey. A wide range of data on social, lifestyle, and physiological factors, cardiovascular disease symptoms, and diagnoses was collected. Measures of right and left common carotid IMT (IMTcca) and bifurcation IMT (IMTbif) were made, and the arteries were examined for plaques 1.5 cm above and below the flow divider. Totals of 425 men and 375 women were surveyed (mean age, 66 years; range, 56 to 77 years). The mean (SD) IMTcca observed were 0. 84 (0.21) and 0.75 (0.16) mm for men and women, respectively. The mean (SD) IMTbif were 1.69 (0.61) and 1.50 (0.77) mm for men and women, respectively. The correlation between IMTcca and IMTbif was similar in men (r=0.36) and women (r=0.38). There were no differences in mean IMTcca or IMTbif between the 2 towns. Carotid plaques were very common, affecting 57% (n=239) of men and 58% (n=211) of women. Severe carotid plaques with flow disturbance were rare, affecting 9 men (2%) and 6 women (1.6%). Plaques increased in prevalence with age, affecting 49% men and 39% of women aged <60 years and 65% and 75% of men and women, respectively, aged >70 years. Plaques were most common among men in Dewsbury (79% affected) and least common among men in Maidstone (34% affected). IMTcca showed a different pattern of association with cardiovascular risk factors from IMTbif and was associated with age, SBP, and FEV1 but not with social, lifestyle, or other physiological risk factors. IMTbif and carotid plaques were associated with smoking, manual social class, and plasma fibrinogen. IMTbif and carotid plaques were associated with symptoms and diagnoses of cardiovascular diseases. IMTbif associations with cardiovascular risk factors and prevalent cardiovascular disease appeared to be explained by the presence of plaques in regression models and in analyses stratified by plaque status. IMTcca, IMTbif, and plaque are correlated with each other but show differing patterns of association with risk factors and prevalent disease. IMTcca is strongly associated with risk factors for stroke and with prevalent stroke, whereas IMTbif and plaque are more directly associated with ischemic heart disease risk factors and prevalent ischemic heart disease. Our analyses suggest that presence of plaque, rather than the thickness of IMTbif, appears to be the major criterion of high risk of disease, but confirmation of these findings in other populations and in prospective studies is required. The association of fibrinogen with plaque appears to be similar to its association with incident cardiovascular disease. Further work elucidating the composition of plaques using ultrasound imaging would be helpful, and more data, analyzed to distinguish plaque from IMTbif and IMTcca, are required to understand the significance of thicker IMT in the absence of plaque.Stroke 04/1999; 30(4):841-50. · 6.16 Impact Factor
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ABSTRACT: Calcification of the vascular tree is common in physiologic and pathologic conditions, i.e., aging, diabetes, dyslipidemia, genetic diseases, and diseases with disturbances of calcium metabolism. In chronic kidney disease, vascular calcification is even more common, develops early, and contributes to the markedly increased cardiovascular risk in this particular population. Pathomorphologically, atherosclerosis (i.e., plaque-forming degenerative changes of the aorta and of large elastic arteries) and arteriosclerosis (i.e., concentric media thickening of muscular arteries) can be distinguished. Increasing knowledge about calcification together with improved imaging techniques provided evidence that also vascular calcification has to be divided into two distinct entities according to the specific sites of calcification within the vascular wall: Patchy calcification of the intima in the vicinity of lipid or cholesterol deposits as present in plaque calcification and calcification of the media in the absence of such lipid or cholesterol deposits, known as Mönckeberg-type atherosclerosis. The two types of calcification may vary according to the type of vessel (large elastic versus smaller muscular type artery) and proximal versus distal sites of the arterial tree. Furthermore, clinical studies showed that it is not purely academic to distinguish between intimal and medial calcification but rather relevant for the clinical presentation, treatment, and prognosis because each type leads to different clinical consequences. In vivo studies in animal models provided evidence in favor of common pathomechanisms between vascular calcification and atherosclerosis; however, there is other, strong experimental and clinical evidence that pleads for the continued distinction between intimal and medial calcification.Clinical Journal of the American Society of Nephrology 10/2008; 3(6):1599-605. · 5.07 Impact Factor
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ABSTRACT: Cardiac calcifications are a frequent occurrence in uraemic subjects and are probably connected to the increased cardiovascular mortality of haemodialysis patients. There is substantial support to the hypothesis that low levels of serum PTH in haemodialysis patients are associated with increased vascular and cardiac calcium deposits, due to decreased buffering capacity of bone in low turnover osteodystrophy. The present study has been carried out on a cohort of patients on haemodialysis, with exclusion of previously parathyroidectomized patients, with the aim to evaluate the association between PTH serum levels and coronary calcifications. The study has been carried out in a cohort of 197 haemodialysis patients. There were 133 males and 64 females. Twenty-two patients had diabetes mellitus. Average age was 58.6 +/- 12.9 years. Patients were divided into groups of intact PTH levels, 0-150 (A), 150-300 (B), 300-600 (C) and >600 (D) pg/ml. The values of coronary scores in the PTH groups were as follows: (A) 624.7 +/- 939, (B) 866.4 +/- 1080, (C) 1202.8 +/- 1742.3 and (D) 1872.7 +/- 2961.9. The difference between coronary calcium scores was significant (P < 0.01). A general linear model identified serum calcium and dialysis age as independent factors of calcium deposits in the high PTH group. No prominent association between low PTH serum levels and the severity of coronary calcium deposits in haemodialysis patients was found while increased levels of PTH, with special regard to very elevated levels, associated with more frequent hypercalcaemia and hyperphosphataemia, should be considered a major risk factor of coronary calcifications and cardiac events.Nephrology Dialysis Transplantation 11/2007; 22(11):3262-7. · 3.37 Impact Factor