Cardiovascular calcification in end-stage renal disease.

Cardiovascular diseases are common in patients with end-stage renal disease (ESRD) and cardiovascular morbidity and mortality among dialysis patients are substantially higher than in the general population. The reasons for this high incidence are multiple. They include traditional factors such as hypertension, diabetes, dyslipidaemia, sodium overload, and elevated homocysteine levels as well as disturbances of mineral metabolism, specifically abnormalities in phosphorus and calcium homeostasis. This review will describe the specific cardiovascular complications related to calcifications in ESRD, the implications of the abnormalities of mineral metabolism in its pathogenesis and the current imaging techniques available for the detection of cardiovascular calcifications. Excess of calcium load contributes to the development of cardiac calcifications; therefore, alternative strategies to diminish exogenous calcium load should be considered in patients with ESRD.     

Cardiovascular complications in pediatric end-stage renal disease

Mortality from end-stage renal disease (ESRD) is often due to cardiac causes. Although cardiovascular complications of ESRD have long been recognized, only recently has the presence of traditional cardiovascular risk factors been associated with late cardiovascular complications. This review presents a history of cardiac involvement in ESRD, the pathophysiology of accelerated atherosclerosis and left ventricular hypertrophy, and a summary of the literature on cardiovascular risk assessment in children. Techniques for non-invasive assessment of cardiac end-organ injury are also discussed. Recommendations for monitoring of risk factors and treatment in the pediatric ESRD population are presented.     

终末期肾脏病腹膜透析患者的心血管疾病

目的 了解终末期肾脏病（ESRD）腹膜透析患者的心血管疾病（CVD）发病率和有关高发危险因素,以及并发CVD的腹膜透析患者治疗时需关注的问题。 方法 研究对象为上海交通大学医学院附属仁济医院慢性肾脏病（CKD）5期接受腹膜透析的患者,共254例入选,采用横断面回顾性调查分析方法。平均随访时间中位数为49个月。采集病史、血生化检测结果、腹膜透析充分性评估、颈动脉及心脏彩色多普勒超声检测结果。评估CVD事件的发生、发展和预后,以及进行相关因素分析。 结果 CVD事件发生率为37%（93/254）。发生CVD的患者多伴有糖尿病、透析龄较长、血三酰甘油水平较高、血清白蛋白较低、前白蛋白较低。彩色多普勒超声显示,发生CVD组的左房内径（LAD）（mm）、室间隔厚度（LVST）（mm）、左室心肌质量指数（LVMI）（g/m2）显著高于未发生CVD组（43.16±4.93比 38.02±4.77、11.19±2.05比10.01±1.45、中位数192.03比150.28,均P < 0.05）;颈动脉内膜中层厚度（IMT）较厚（中位数0.80比0.65）,颈动脉内径增宽;收缩期峰值流速（SPV）和舒张期峰值流速（DV）流速降低。既往无CVD的患者在随访过程中发生CVD时,其Ccr、Kt/V、D/Pr、理想体质量校正的蛋白分解率（nPCR）及血清白蛋白水平与无发生CVD组差异有统计学意义（P = 0.045、0.015、0.051、0.029及0.005）。在随访过程中出现新发CVD或CVD病情恶化的原有CVD的患者,都是透析龄较长以及三酰甘油水平较高者。LAD、LVST、LVMI及IMT在新发CVD和未发CVD两组间差异有统计学意义（P=0.033、0.022、0.045及0.029）。Kaplan-Meier生存分析显示,既往CVD史和CVD症状是生存的独立危险因素。血清白蛋白<330 g/L、LAD>39.6 mm及曾患腹膜炎的患者生存率较低。 结论 ESRD腹膜透析患者是CVD的高发群体,需了解这些患者的病史和伴随症状;保持透析的充分性;同时要防止腹膜炎的发生。     

Cardiovascular disease as a late complication of end-stage renal disease in children

As in older adults, cardiovascular disease is the most important cause of death in adolescents and young adult patients with end-stage renal disease (ESRD) since childhood. This concerns patients on dialysis as well as transplant patients, despite the fact that a long duration of dialysis during childhood is an extra mortality risk factor. Left ventricular hypertrophy (LVH), aortic valve calcification, and increased arterial stiffness, but not increased arterial intima media thickening, are the most frequently observed alterations in young adult survivors with childhood ESRD. In transplanted patients a concentric LVH as a result of chronic hypertension is mostly observed; in dialysis patients a more asymmetric septal LVH is found as a result of chronic volume overload. These results suggest that in children and young adults with ESRD chronic pressure and volume overload, a high calcium-phosphate product, and chronic inflammation, but not dyslipidemia, play a role in the development of cardiovascular disease.This work was presented in part at the IPNA Seventh Symposium on Growth and Development in Children with Chronic Kidney Disease: The Molecular Basis of Skeletal Growth, 1–3 April 2004, Heidelberg, Germany     

Disparities in end-stage renal disease care in South America

South America is one of the most heterogeneous regions in the world regarding ethnical composition and socioeconomic development level. Our aim was to analyze the status of end-stage renal disease (ESRD) management in the Portuguese-speaking and Spanish-speaking countries of South America. Data were collected using a survey sent to the Society of Nephrology of each country, and complemented with data available in the Latin American Dialysis and Transplant Registry or personal communication with collaborators within the nephrology societies. Most of South America countries have a hybrid of public and private healthcare system. Universal access to renal replacement therapy (RRT) is provided in Argentina, Brazil, Chile, Uruguay and Venezuela which comprise nearly 73% of South America population. The expenditure on health per capita varies from nearly US$ 200 per year in Bolivia to more than US$ 1,600 per year in Argentina. The prevalence of patients on RRT varies from 95 pmp. in Paraguay and 924 pmp in Chile. There is an important association between the prevalence of diabetes and the number of patients on RRT. Older people also are at a higher risk of developing ESRD. The rapid aging of the population and a higher prevalence of diabetes will probably translate into a burden of ESRD in the future. It is to be hoped that political and economical stability in the region can ease the adoption of universal access to ESRD treatment in all South American countries.     

Preventive health care in chronic kidney disease and end-stage renal disease

The complex care that must be provided for patients with renal disease might interfere with provision of basic preventive measures in this population. Preventive health care, including infection screening and prophylaxis, vaccinations, management of blood glucose and lipid levels, and cancer screening, is important, as it might decrease acute morbidity and mortality. This Review highlights useful preventive and health maintenance strategies for patients with chronic kidney disease and those with end-stage renal disease.     

Cardiovascular disease in patients with end-stage renal disease on hemodialysis in a developing country

Cardiovascular disease is the main cause of death among patients with end-stage renal disease (ESRD). The present study was undertaken to identify the main cardiovascular diseases and their risk factors in 160 patients with ESRD on hemodialysis (HD) in Brazil. Their mean age was 47 ± 39 years. The main risk factors for cardiovascular diseases were arterial hypertension (89.4%), dyslipidemia (78.3%), low high-density lipoprotein levels (84.2%) and low physical activity (64.1%). Family history of coronary insufficiency and high low-density lipoprotein levels were significantly associated with coronary artery disease (P = 0.005 and P = 0.029, respectively). Sedentary life style, diabetes mellitus, secondary hyperparathyroidism and hyperglycemia also showed a significant association with the underlying vascular disease (P = 0.017, P = 0.039, P = 0.037 and P = 0.030, respectively). Hypercalcemia, hypertension and black race were factors significantly associated with left ventricular systolic dysfunction (P = 0.01, P = 0.0013 and P = 0.024, respectively). Our study shows that the most prevalent cardiovascular diseases in patients with ESRD were left ventricular hypertrophy, atherosclerotic disease, valvular disease and coronary artery disease. Hypertension and dyslipidemia were the common risk factors associated with cardiovascular diseases. The present study was undertaken to identify the main cardiovascular diseases and their risk factors in 160 patients with ESRD on HD in a single center in Brazil.     

Cardiovascular calcification in patients with end-stage renal disease: a century-old phenomenon

The mortality risk from cardiovascular disease is increased in patients with end-stage renal disease (ESRD). This is due to both traditional and dialysis-specific factors. Recently, a number of the dialysis-specific risk factors have been implicated in the pathogenesis of cardiovascular calcification. These include: hyperphosphatemia, high calcium-phosphate (Ca x P) product, elevated parathyroid hormone levels, duration of dialysis, and treatment with calcium-containing phosphate binders and vitamin D analogs. The recent availability of electron beam computed tomography (EBCT) has triggered increased awareness of the occurrence of cardiovascular calcification in ESRD patients. Given the development of transient hypercalcemia with calcium-containing binders, a link between calcium load from use of calcium-containing phosphate binders and development coronary calcification has been proposed. However, a causal relationship between use of these agents and cardiovascular calcification has not been established. Moreover, this phenomenon had been recognized over a century ago, long before these phosphate binders became available. Although its pathogenesis is likely to be multifactorial, available data strongly implicate elevated serum phosphorus as the primary culprit. Furthermore, the risk of calcification may be aggravated by vitamin D therapy, particularly in patients with severe secondary hyperparathyroidism. Therefore, achieving vigorous control of serum phosphorus, Ca x P product and parathyroid hormone level might decrease cardiovascular calcification and improve survival of patients on maintenance hemodialysis. Since calcium acetate is the most cost-effective phosphate binder available, we recommend that it should remain the first line treatment of hyperphosphatemia in patients with ESRD.     

Exercise in end-stage renal disease

Available studies indicate that exercise tolerance in renal patients is low. Although significant improvements in maximal oxygen consumption have been reported following exercise training in these patients, there may be physiologic limitations to the attainable levels of aerobic capacity due to the multisystemic nature of the disease. Long-term exercise training may result in other medical benefits. Compliance to regular exercise in hemodialysis patients remains a problem, however, exercise training during the dialysis treatment may prove beneficial in terms of compliance and supervision.     

Hyperphosphatemia in end-stage renal disease

Hyperphosphatemia occurs universally in end-stage renal disease (ESRD) unless efforts are made to prevent positive phosphate balance. Positive phosphate balance results from the loss of renal elimination of phosphate and continued obligatory intestinal absorption of dietary phosphate. Increased efflux of phosphate from bone because of excess parathyroid hormone-mediated bone resorption can also contribute to increased serum phosphate concentrations in the setting of severe hyperparathyroidism. It is important to treat hyperphosphatemia because it contributes to the pathogenesis of hyperparathyroidism, vascular calcifications, and increased cardiovascular mortality in ESRD patients. Attaining a neutral phosphate balance, which is the key to the management of hyperphosphatemia in ESRD, is a challenge. Control of phosphorus depends on its removal during dialysis and the limitation of gastrointestinal absorption by dietary phosphate restriction and chelation of phosphate. Knowledge of the quantitative aspects of phosphate balance is useful in optimizing our use of phosphate binders, dialysis frequency, and vitamin D sterols. The development of new phosphate binders and efforts to find new ways to inhibit gastrointestinal absorption of phosphate will lead to improvements in the control of serum phosphate levels in ESRD.     

Hyperthyroidism in end-stage renal disease

We report the 2nd patient to have hyperthyroidism while on maintenance hemodialysis. This case is instructive because the diagnosis of hyperthyroidism in uremic patients is difficult due to similar signs and symptoms. This case report describes, for the first time, the unique interaction between hemodialysis and thyrotoxic heart disease. Paroxysmal atrial fibrillation and severe hypotension interfered with all hemodialyses. Only the correction of the hyperthyroid state and withdrawal of all beta-blocking agents allowed resumption of normal hemodialysis. The delayed gastric emptying and hypercalcemia ultimately resolved with return to the euthyroid state and did not recur during 10 months of follow-up.     

Thrombosis in end-stage renal disease

Although renal failure has classically been associated with a bleeding tendency, thrombotic events are common among patients with end-stage renal disease (ESRD). A variety of thrombosis-favoring hematologic alterations have been demonstrated in these patients. In addition, "nontraditional" risk factors for thrombosis, such as hyperhomocysteinemia, endothelial dysfunction, inflammation, and malnutrition, are present in a significant proportion of chronic dialysis patients. Hemodialysis (HD) vascular access thrombosis, ischemic heart disease, and renal allograft thrombosis are well-recognized complications in these patients. Deep venous thrombosis and pulmonary embolism are viewed as rare in chronic dialysis patients, but recent studies suggest that this perception should be reconsidered. Several ESRD treatment factors such as recombinant erythropoietin (EPO) administration, dialyzer bioincompatibility, and calcineurin inhibitor administration may have prothrombotic effects. In this article we review the pathogenesis and clinical manifestations of thrombosis in ESRD and evaluate the evidence that chronic renal failure or its management predisposes to thrombotic events.     

Rationing of health care and the end-stage renal disease program

The potential impact of rationing health care on the end-stage renal disease (ESRD) program is considered. The possible implications of the recommendations emanating from the study being conducted by the Institute of Medicine of the National Academy of Sciences are also mentioned. Particular emphasis is given to the potential consequences of rationing health care on the elderly and on certain socioeconomic groups with ESRD.     

Cardiovascular disease in end-stage renal disease: the challenge of assessing and managing cardiac disease in dialysis patients

Cardiovascular disease (CVD) is the leading cause of mortality in end-stage renal disease (ESRD), approximating a 10- to 20-fold higher risk of death in dialysis patients than in the general population. Despite this, dialysis patients often undergo fewer investigations, receive less invasive procedures, and are prescribed fewer medications compared with age-matched non-ESRD patients. A lack of randomized control trials for evidence-based treatment strategies in this population may explain some of these discrepancies, but there is concern that an attitude of “therapeutic nihilism” may be impacting on the medical care of these patients. In this review, we will explore CVD in the ESRD population. Specifically, we will try to address the following issues in patients with ESRD: (1) mechanisms of CVD, (2) cardiac evaluation and the role of coronary revascularization with percutaneous or coronary artery bypass procedures, and (3) cardiac pharmacotherapy use.     

Hypertension in end-stage renal disease patients

The prevalence of hypertension is extremely high in end-stage renal disease, and is a probable contributor to the epidemic of cardiovascular disease in end-stage renal disease. However, the paucity of prospective, randomized clinical trials makes it difficult to precisely define treatment strategies. Therefore, at present time the guidelines developed by the National Kidney Foundation's Cardiovascular Disease Task Force should be followed.