Epicardial Adipose Tissue and Coronary Artery Calcification in Diabetic and Nondiabetic End-Stage Renal Disease Patients

Background/aims: Atherosclerosis, coronary artery calcification, diabetes mellitus, inflammation, endothelial dysfunction, and left ventricular hypertrophy are the most commonly encountered risk factors in the pathogenesis of cardiovascular disease in end-stage renal disease (ESRD) patients. Epicardial adipose tissue (EAT) is the true visceral fat depot of the heart. The relationship between coronary artery disease (CAD) and EAT was shown in healthy subjects and patients with high risk of CAD. To date, there is not enough data about EAT in diabetic and nondiabetic ESRD patients. Therefore, we aimed to investigate the EAT and coronary artery calcification score (CACS) in diabetic and nondiabetic ESRD patients and healthy subjects. Methods: Sixty ESRD patients (17 diabetic, 43 nondiabetic ESRD patients) and 20 healthy subjects were enrolled in the study. EAT and CACS were performed by a 64-slice multidetector computed tomography scanner. Results: There were no differences in age, gender, body mass index, predialysis systolic and diastolic blood pressure levels, biochemical parameters including serum low-density lipoprotein and high-density lipoprotein cholesterol, triglycerides, and C-reactive protein between healthy subjects, diabetic, and nondiabetic ESRD patients. Total CACSs and EAT measurements were significantly higher in diabetic ESRD patients when compared with nondiabetic ESRD patients and healthy subjects. There was statistically significant relationship between EAT and CACS in ESRD patients (p < 0.0001, r = 0.48). Conclusion: In conclusion, we found a significant increase in terms of EAT and CACS in diabetic ESRD patients when compared with nondiabetic ESRD patients and healthy subjects.     

Cardiac Findings in Asymptomatic Chronic Hemodialysis Patients with Persistently Elevated Cardiac Troponin I Levels

Background. The prevalence and significance of higher than normal cardiac troponin I (cTnI) levels in asymptomatic chronic hemodialysis (HD) patients remains a source of discussion. The aim of the present study was to evaluate the prevalence of higher than normal cTnI levels in asymptomatic HD patients, as determined by the last generation of immunoassay, and to perform further cardiological investigations in those patients with persistently elevated cTnI levels. Methods. All chronic HD patients in our center who had exhibited no symptoms of coronary artery disease (CAD) during the previous four weeks were screened. cTnI levels were determined before dialysis in all patients using the last generation AccuTnI? assay (UniCel DxI 800, Beckman Coulter). The cTnI levels of those patients with elevated cTnI at the screening evaluation were then measured monthly for six months. We were thus able to identify a group of patients with persistently elevated cTnI levels (> 3 consecutive months) who subsequently underwent cardiac echography and dipyridamole-exercise (D-E) thallium testing. If stress myocardial ischemia was detected, a coronary angiography was then performed. Results. Fifty patients (32 males) were included: mean age 62.8 ± 13.6 years, 20 (40%) with a history of CAD, and 21 (42%) diabetic. At the initial screening, the mean cTnI concentration was 0.05 ± 0.06 μg/L and the cTnI levels were higher than normal (> 0.09 μg/L) in six patients (12%). In the follow-up, the cTnI normalized immediately in two patients but remained persistently elevated (range, 0.10–0.48 μg/L) in four (8%). These four patients (all males, one diabetic) had a mean age of 70.2 ± 6.6 years, and all had heart failure with a history of severe CAD with previous myocardial infarction (n = 4), coronary stenting (n = 3), and/or bypass (n = 2). D-E thallium imaging showed reversible myocardial ischemia in all. The stress ischemia involved one to four cardiac segments and was slight to moderate in three patients and severe in the diabetic patient. A coronary angiogram was performed in all patients, and showed lesions of variable severity: severe three-vessel CAD with severe systolic dysfunction in two patients (including the diabetic), and non-critical/peripheral coronary stenosis in the other two. Conclusions. Among the asymptomatic HD patients in our center, we identified four (8%) with persistently elevated cTnI levels, as determined using the last generation AccuTnI? assay. All of them had a history of severe CAD with heart failure and exhibited reversible myocardial ischemia upon D-E thallium imaging; coronary angiography revealed coronary lesions of variable severity. Overall, our data indicate that persistent low-grade cTnI elevation occurs in HD patients having longstanding severe cardiac disease, but, from our data, it is difficult to reach a conclusion as to the best clinical approach for this group of patients.     

Determinants of Coronary Artery Disease in Nondiabetic Hemodialysis Patients: A Matched Case-Control Study

Background/Aims. The aim of this matched case-control study was to evaluate the determinants of coronary artery disease (CAD) other than conventional risk factors in nondiabetic hemodialysis (HD) patients. Methods. Among 312 consecutive patients on regular HD, 26 nondiabetic patients with angiographically defined coronary artery disease (20 men, 6 women; mean age 57.0 ± 13 years) constituted the case group (group 1). A subject group of the same gender, smoking status, and hypertension with similar ages and body mass indexes who had normal electrocardiography and myocardial perfusion scintigraphy served as controls (20 men, 6 women; mean age 54.1±12 years, group 2). Demographics, high sensitivity C-reactive protein (hs-CRP), erythrocytes dimentation rate (ESR), hematocrit-corrected ESR, beta-2 microglobulin, cardiac troponin I, parathyroid hormone, albumin, calcium (Ca), phosphorus (P), Ca × P, and lipid profiles were compared between the groups. Results. Patients in group 1 had higher hs-CRP and troponin I (18.0±12 vs. 7.2±5 mg/L, p < 0.001; 0.36±0.16 vs. 0.22±0.05 ng/mL, p < 0.001, respectively) and lower HDL cholesterol levels than group 2 (37.0±10mg/dL vs. 46.3±17mg/dL, p = 0.02). Backwards stepwise logistic regression analysis revealed that high hs-CRP and troponin I levels (p = 0.03 and p = 0.01) and low HDL cholesterol levels (p = 0.02) were independently related with CAD. Conclusion. According to these results, in nondiabetic patients on regular hemodialysis, high hs-CRP, troponin I levels and low HDL-cholesterol were the determinants of CAD.     

Aortic Stiffness in Patients Undergoing Hemodialysis is Positively Related to Antigen Presenting Cell-Dependent T-Lymphocyte Reactivity

Background. Aortic stiffness is increased in patients undergoing hemodialysis (HD), and it is associated with an increased cardiovascular mortality. Among others, aortic stiffness has been correlated with serum markers of inflammation, indicating a role of the immune system in its pathogenesis. The aim of this study was to evaluate the impact of antigen-presenting cell-dependent T-lymphocyte reactivity on aortic stiffness in HD patients.

Patients and methods. Twenty patients were enrolled in the study. Exclusion criteria were medications or conditions, other than HD, that are known to influence the immune response or aortic stiffness. Antigen-presenting cell-dependent T-lymphocyte reactivity was assessed by cell proliferation of peripheral blood mononuclear cells cultured with or without stimulation with Staphylococcal enterotoxin B (SEB). Cell proliferation was estimated by immunoenzymatic measurement of bromodeoxyuridine uptake. Aortic stiffness was assessed by carotid-femoral pulse wave velocity (PWV) measurement.

Results. Linear regression analysis revealed a strong positive relation between carotid-femoral PWV and antigen-presenting cell-dependent T-lymphocyte reactivity, when SEB at concentrations of 1 ng/mL or 10 ng/mL was used as stimulant.

Conclusion. The present study confirms that aortic stiffness in HD patients is positively related to antigen-presenting cell-dependent T-lymphocyte reactivity. The greater the ability of the immune system to react to a monocyte-dependent stimulant and, consequently, to provoke an inflammatory response, the greater the stiffness of the aorta. This is in agreement with the observation that aortic stiffness in HD patients is positively related to various serum inflammation markers.     

Optimal Phosphate Control Related to Coronary Artery Calcification in Dialysis Patients

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Association Among Serum Fetuin-A Level, Coronary Artery Calcification, and Bone Mineral Densitometry in Maintenance Hemodialysis Patients

Patients with end‐stage renal disease have a very high prevalance and extent of arterial calcification. A number of studies suggest that similar pathophysiologic mechanisms are responsible for development and progression of calcification of atherosclerotic plaque and bone formation. Fetuin‐A is a potent calcification inhibitor and is expressed in bone, with not‐yet well‐defined functions. The aim of this study was to investigate the relation between bone mineral densitometry parameters, coronary artery calcification, and serum fetuin‐A levels. In a cross‐sectional design, we included 72 maintenance hemodialysis (HD) patients and 30 age‐ and gender‐ matched healthy controls. Serum fetuin‐A levels were studied both in maintenance HD patients and healthy controls. Maintenance HD patients had radius, hip, and lumbar spine bone mineral density (BMD) assessed by dual‐energy X‐ray absorptiometry and coronary artery calcification score (CACS) measured by electron‐beam computed tomography. The associations between site‐specific BMD parameters, CACS, and serum fetuin‐A levels were studied in maintenance HD patients. CACS, mass, and volume of plaques in coronary arteries were significantly higher in patients with a T‐score below ?2.5 than above in the proximal region of the radius, neck and trochanter of the femur, and the lumbar spine. Mean serum fetuin‐A concentration was 0.636 ± 0.118 g/L in maintenance HD patients and it was less than healthy controls (0.829 ± 0.100 g/L, P < 0.0001). CACS, mass, and volume of plaques in coronary arteries correlated significantly with the serum fetuin‐A levels. Moreover, significant positive correlations were shown between the serum fetuin‐A levels, BMD values, and T‐scores of proximal radius, neck, and trochanter of the femur, but not with the lumbar spine. The present study demonstrates an association between serum fetuin‐A levels, coronary artery calcification, and bone mineral densities—except for the lumbar spine, in maintenance HD patients. However, the results should be interpreted with caution because of the cross‐sectional design of the study.     

CKD患者冠状动脉钙化的危险因素分析

目的:分析CKD患者冠状动脉钙化与临床指标的相关性,探讨其发生的危险因素。方法:选取473例曾在我院行冠脉CT检查的CKD及非CKD患者,通过收集其生化指标及冠脉CT检查结果,分析CKD患者冠状动脉钙化与临床检查指标的关系。结果:患者冠状动脉钙化积分(CACs)与年龄、尿素氮、肌酐水平、血磷水平和钙磷乘积呈正相关(P<0.05),与肾小球滤过率和血红蛋白呈负相关(P<0.05)。结论:年龄、尿素氮和血磷是患者冠脉发生钙化的独立危险因素,年龄、肌酐水平、肾小球滤过率和血磷水平与冠状动脉钙化严重程度有线性关系。     

CKD与非CKD患者冠状动脉钙化发生情况的比较研究

目的:比较CKD患者与非CKD患者的冠状动脉钙化情况。方法:选取473例曾在我院行冠脉CT检查的CKD及非CKD患者,通过收集其生化指标及冠脉CT检查结果,分析并比较两组患者冠状动脉钙化的发生情况。结果:CKD患者冠状动脉钙化的发生率为76.5%,且钙化累及分支更多,LAD、RCA多发。钙化组的尿素氮、血磷水平及钙磷乘积显著高于非钙化组,而GFR则显著低于非钙化组(P<0.01)。结论:CKD患者冠状动脉钙化发生率高,累及范围广,程度更重,且LAD、RCA钙化多发。钙化组的尿素氮、血磷水平及钙磷乘积显著高于非钙化组,而GFR则显著低于非钙化组。     

低钙透析联合高通量透析对透析患者颈动脉钙化的影响

目的：探讨低钙透析联合高通量透析（ HFHD）对透析患者颈动脉钙化的影响。方法：将36例维持性血液透析（ MHD）患者随机分为A组（使用高通量透析器）和B组（使用低通量透析器）,两组均为低钙透析,共观察12个月。观察治疗前后两组颈动脉内-中膜厚度（IMT）、生化指标、血压、碳酸钙和活性维生素D3用量变化,记录不良反应。结果：（1） A组颈动脉IMT轻微增加,B组IMT明显增加,两组比较差异有统计学意义;（2）两组血钙、磷均有降低,A组较明显,B组甲状旁腺素（iPTH）明显升高,A组营养及炎症指标、血压改善优于B组;（3）两组碳酸钙及活性维生素D用量均增加;（4）无严重不良反应发生。结论：低钙透析联合高通量透析可改善血管钙化危险因素,延缓血管钙化的发生发展,可成为一种有效、安全且经济的治疗方法。     

Fibroblast Growth Factor 23 is a Predictor of Aortic Artery Calcification in Maintenance Hemodialysis Patients

Background: Our study aimed to investigate the factors associated with elevated plasma FGF23 (cFGF23) levels in maintenance hemodialysis (MHD) patients and to determine whether plasma FGF23 level is related to aortic artery calcification (AAC). Methods: This study included 120 MHD patients and 20 controls. The FGF23 level was measured using a C-terminal assay and AAC was detected by a lateral lumbar X-ray plain. Results: Plasma FGF23 levels were significantly higher among dialysis patients compared to controls: FGF23 level of 27691.42 ± 55646.41 RU/mL in MHD patients versus 49.89 ± 23.94 RU/mL in health people. Significant correlations were observed between FGF23 levels and vintage, intact parathyroid hormone (iPTH), serum phosphate, total calcium, 25(OH)D, urea nitrogen (BUN), and serum creatinine (SCR). Stepwise multiple regression analysis showed that the independent parameters associated with FGF23 level were serum phosphate, total calcium, parathyroid hormone (PTH), SCR, and prealbumin. There were 73 patients (60.83%) with visible calcification in the abdominal aorta. Bivariate analysis showed that AAC score correlated with FGF23, phosphate, total calcium, vintage, age, and diastolic blood pressure. Forward logistic analysis showed that the independent parameters associated with AAC were age, total protein, and Lg FGF23. Conclusion: Plasma FGF23 level is significant increased in hemodialysis patients and is independently associated with AAC.     

High Parathyroid Hormone Level and Osteoporosis Predict Progression of Coronary Artery Calcification in Patients on Dialysis

Coronary artery calcifications (CACs) are observed in most patients with CKD on dialysis (CKD-5D). CACs frequently progress and are associated with increased risk for cardiovascular events, the major cause of death in these patients. A link between bone and vascular calcification has been shown. This prospective study was designed to identify noninvasive tests for predicting CAC progression, including measurements of bone mineral density (BMD) and novel bone markers in adult patients with CKD-5D. At baseline and after 1 year, patients underwent routine blood tests and measurement of CAC, BMD, and novel serum bone markers. A total of 213 patients received baseline measurements, of whom about 80% had measurable CAC and almost 50% had CAC Agatston scores>400, conferring high risk for cardiovascular events. Independent positive predictors of baseline CAC included coronary artery disease, diabetes, dialysis vintage, fibroblast growth factor-23 concentration, and age, whereas BMD of the spine measured by quantitative computed tomography was an inverse predictor. Hypertension, HDL level, and smoking were not baseline predictors in these patients. Three quarters of 122 patients completing the study had CAC increases at 1 year. Independent risk factors for CAC progression were age, baseline total or whole parathyroid hormone level greater than nine times the normal value, and osteoporosis by t scores. Our results confirm a role for bone in CKD–associated CAC prevalence and progression.     

Early Subclinical Coronary Artery Calcification in Young Adults Who Were Pediatric Kidney Transplant Recipients

Coronary artery disease (CAD) is the leading cause of death in adults after successful kidney transplantation. Children who have undergone successful kidney transplantation are entering young adulthood; however, the prevalence and extent of CAD in this population is unknown. We conducted a pilot study in young adults with stable allograft function, who received kidney transplants as children to measure coronary artery calcification (CAC), a marker of coronary artery atherosclerosis and CAD. We evaluated 19 young adults after successful pediatric kidney transplantation for known CAD risk factors; these patients underwent noninvasive imaging with electron-beam computed tomography (EBCT) for measurement of CAC. Prevalence and quantity of CAC were then compared to asymptomatic individuals from the community. All patients had multiple risk factors for CAD. Mean age at evaluation was 32 years (range: 21-48 years). CAC is uncommon in individuals in the community in this age range; however, nearly half of our patients had CAC detected with the quantity of CAC comparable to asymptomatic individuals from the community 10-40 years older. These data suggest young adults who received pediatric kidney transplants are at increased risk for developing early CAC and need close monitoring to detect early CAD so as to prevent premature cardiac morbidity and mortality.     

Serum Calcification Propensity and Coronary Artery Calcification Among Patients With CKD: The CRIC (Chronic Renal Insufficiency Cohort) Study

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Mortality Risk Factors in Chronic Renal Failure Patients after Coronary Artery Bypass Grafting

Perioperative risk during coronary artery bypass grafting (CABG) is high in patients with chronic renal disease. We aimed to determine postoperative two-year mortality and identify the preoperative risk factors of mortality during CABG surgery in hemodialysis (HD)-dependent and HD-non-dependent CRF patients. We included 102 CRF patients who underwent CABG in Baskent University Hospital between 2000 and 2005. There were 47 patients with CRF undergoing HD (Group I) and 55 CRF patients without dialysis requirement (Group II). We retrospectively retrieved demographic variables; clinical, operative, and echocardiographic data; and biochemical parameters at the time of the operation and six months postoperation. Postoperative HD requirement in Group II patients and infectious complications were recorded. In the second postoperative year, mortality rate was 27.7% in group I and 16.4% in group II (p > .05). When preoperative risk factors evaluated by univariate Cox analysis, only age (RR = 1.06, p = .04) was a significant determinant of survival in Group I patients. Among the operative and postoperative risk factors of mortality such as duration of operation, numbers of coronary vessel bypass, HD requirement, and infection were investigated in Group I and II patients. Rate of infectious complication (including mediastinitis) was found to be a major determinant of mortality by multivariate Cox analyses in both group I (RR = 4.42, p ≤ .05) and group II (RR = 9.39, p ≤ .05). HD dependency did not increase mortality if the patients are younger and were electively prepared for CABG surgery. High infection rates have increased the postoperative mortality and hospitalization in CRF patients. Early diagnosis of infections in CRF patients is important for early recovery, shorter hospitalization, and lower mortality after CABG operation     

The Effects of Near-Infrared Spectroscopy on the Neurocognitive Functions in the Patients Undergoing Coronary Artery Bypass Grafting with Asymptomatic Carotid Artery Disease: A Randomized Prospective Study

Purpose: The purpose of this study was to research the use of near-infrared spectroscopy (NIRS) on the neurocognitive functions in the patients undergoing coronary artery bypass grafting (CABG) with asymptomatic carotid artery disease.Methods: The study design was carried out with the participation of 79 patients in a prospective, randomized and double blind control method. The patients were separated into two groups as NIRS (n = 43) and no NIRS (n = 36). A neurocognitive test was applied preoperatively and postoperatively to all patients before discharge. Cognitive functions were evaluated by applying the Montreal Cognitive Assessment test (MoCA).Results: The decrease in the postoperative score of mean MoCA in no NIRS group was statistically significant when compared to preoperatively (p <0.001). Postoperative mean MoCA score was found to be significantly higher in NIRS group (NIRS: 26.8 ± 1.9 vs. no NIRS: 23.6 ± 2.5, p <0.001). It has been determined that there was a moderately positive significant correlation between the increase in the NIRS used patients (%) and increase in the MoCA score of the patients (r = 0.59, p <0.001).Conclusion: Intraoperative NIRS usage in the patients undergoing CABG with carotid artery disease might be useful due to its postoperative positive effects on the cognitive functions.     

Clinical Burden of Screening Asymptomatic Patients for Coronary Artery Disease Prior to Liver Transplantation

The aim of this study is to assess the clinical burden of silent coronary artery disease (CAD) in cirrhotic candidates for liver transplantation (LT), and to evaluate the usefulness of a CAD screening approach. Between July 1999 and January 2006, we evaluated 627 LT candidates. All of them underwent a detailed clinical history. Sixteen had a previous diagnosis of CAD or symptoms suggestive (2.5%). The remaining 611 underwent further tests according to a predefined protocol, including EKG, echocardiogram and, on the basis of CAD risk factors, heart stress tests. Selective coronary angiography (SCA) was performed in the 30 patients with positive heart stress test: in only 2 did SCA show any CAD, and in both it was subcritical disease requiring neither intervention nor contraindicating LT. The 611 screened patients continued their follow-up until study closure or death. No coronary events occurred in the study population in a mean follow-up of 32.50 months (+/− 23.67 DS). No perioperative mortality related to CAD occurred in the 233 transplanted patients. In conclusion, no prognostic advantage was achieved by following a strict CAD screening protocol, leading us to believe that the cost-effectiveness of a similar screening can be unacceptably high in our setting.     

多层螺旋CT冠状动脉成像在冠心病诊断中的临床应用

近年来,冠心病(coronary artery disease,CAD)在我国的发病率明显增高,早期诊断、早期治疗尤为重要。随着计算机断层成像(CT)技术的迅速发展,多层螺旋CT(multidetector-row computed tomography,MDCT)逐步成为冠心病筛查和诊断的首选检查方法。现就MDCT的发展概况、钙化积分、检测冠状动脉狭窄程度、斑块评价、解剖变异显示、旁路血管评价、冠状动脉支架术后评价、心肌灌注、心功能分析等方面的临床应用进行综述