Influence of hypertension on cardiovascular outcomes in hemodialysis patients

Cardiovascular disease is a leading cause of morbidity and mortality in chronic hemodialysis patients. Most patients with chronic kidney disease have hypertension and its prevalence remains high following renal replacement therapy. Early studies suggested that hypertension was a risk factor for total and cardiovascular mortality in chronic hemodialysis patients, but the results of more recent studies have caused experts to question these assertions. Systolic hypertension, widened pulse pressure, and nondipping may be better predictors of mortality compared to diastolic hypertension or increased mean arterial pressure. Hypertension in hemodialysis patients is a risk factor for left ventricular hypertrophy (LVH), diastolic dysfunction, and congestive heart failure; good blood pressure control may promote its regression. Atherosclerosis and ventricular arrhythmias may also be linked to hypertension. Thus blood pressure control with a focus on systolic pressure appears to be a prudent strategy to improve cardiovascular outcomes in hemodialysis patients.     

心脏B超和心电图在高血压性心脏病诊断中的应用分析

目的：探讨心脏B超和心电图在高血压性心脏病诊断中的临床价值。方法对我院2012年1月～2013年12月收治的30例高血压性心脏病患者分别性心脏B超和心电图诊断，对两种诊断方法的检出率进行比较和分析。结果心脏B超检测出9例左室肥厚，10例左室增大，8例左房增大，3例主动脉扩张。心电图检测出2例左室肥厚，3例左室增大，2例左房增大，0例主动脉扩张。两种诊断结果差异显著（P＜0.05）。结论心脏B超诊断高血压性心脏病的特异性和灵敏性与心电图相比，效果较好。在临床诊断中，因结合B超和心电图的优势，取长补短，以提高疾病的检出率。     

青年维持性血液透析患者心血管疾病调查及危险因素分析

目的调查青年维持性血液透析（MHD）患者心血管疾病的发病情况和病变特点，并探讨其危险因素。方法采用横断面研究。MHD患者98例，以45岁为界分为青年组（47例）和中老年组（51例）。收集患者临床资料和生化指标。心脏超声检查测量心脏腔径及心功能参数。分析青年组患者心脏结构和功能异常的患病率、病变特点及其影响因素。结果（1）47例青年患者中有30例（63．8％）存在心脏结构异常，主要表现为左心室肥厚、左心房增大和瓣膜反流，患病率分别为61．7％、38．3％和34．0％。（2）青年组患者向心性肥厚的患病率为86．2％，离心性肥厚的患病率为13．8％，与中老年组相比，差异有统计学意义（P〈0．05）。（3）与无心脏病变青年MHD患者相比，伴心脏病变者的超滤量、收缩压、血磷和甲状旁腺激素明显增高，而Kt／V、血红蛋白和血清白蛋白明显降低，差异有统计学意义（P〈0．05）。Logistic回归分析结果显示，超滤量、收缩压、血红蛋白和血甲状旁腺激素是青年MHD患者并发心脏病变的独立危险因素。结论青年MHD患者心血管疾病的患病率较高，主要表现为左心室肥厚、左房增大和瓣膜反流。超滤量、收缩压、血红蛋白和血甲状旁腺激素水平可能是影响青年MHD患者并发心脏病变的独立危险因素。     

Left ventricular mass monitoring in the follow-up of dialysis patients: prognostic value of left ventricular hypertrophy progression

BACKGROUND: Regression of left ventricular hypertrophy (LVH) in the setting of a well-planned intervention study has been associated with longer survival in hemodialysis patients. Whether changes in left ventricular mass (LVM) in clinical practice predict survival and cardiovascular events in these patients is still unknown. METHODS: In a prospective study in 161 hemodialysis patients we tested the prognostic value of changes in LVM on survival and incident cardiovascular events. Echocardiography was performed twice, 18 +/- 2 SD months apart. Changes in LVM occurring between the first and the second echocardiographic study were then used to predict mortality and cardiovascular events during the ensuing 29 +/- 13 months. The prognostic value of LVM changes was tested in a multivariate Cox's model with LVM index (LVMI) [expressed as LVM/height(2.71)], included as a covariate to control for regression to the mean. RESULTS: The rate of increase of LVMI was significantly (P= 0.029) higher in patients with incident cardiovascular events than in those without such events. Accordingly, cardiovascular event-free survival in patients with changes in LVMI below the 25th percentile was significantly (P= 0.004) higher than in those with changes above the 75th percentile. In a multiple Cox regression analysis, including age, diabetes, smoking, homocysteine, 1 g/m(2.7)/month increase in LVMI was associated with a 62% increase in the incident risk of fatal and nonfatal cardiovascular events [hazard ratio 1.62 (95% CI 1.13-2.33), P= 0.009]. CONCLUSION: Changes in LVMI have an independent prognostic value for cardiovascular events and provide scientific support to the use of repeated echocardiographic studies for monitoring cardiovascular risk in dialysis patients.     

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.     

Regression of left ventricular hypertrophy in hemodialysis patients is possible

Regression of left ventricular hypertrophy in hemodialysis patients is possible. Left ventricular hypertrophy represents the major risk factor for cardiac morbidity and mortality. Therefore, their regression is mandatory. Since the causes of uremia-associated left ventricular hypertrophy are multifactorial, various therapeutic options can be considered: optimal control of arterial hypertension and volume status, optimal correction of metabolic acidosis, best possible correction of hypoalbuminemia and severe secondary hyperparathyroidism, modern pharmacotherapeutic strategy for the treatment of heart failure (use of angiotensin-converting enzyme inhibitors in combination with angiotensin II receptor blockers and beta-blockers) and total correction of renal anemia. Following the proposed therapeutic strategies we could, by using echocardiography, distinguish in 100 hemodialysis patients the following 3 groups (on the average after 1.5 years): 36 patients with initially normal left ventricular mass index (LVMI (g/m2), F < 110; M < 130) maintained normal (group 1); in 31 patients with moderately increased LVMI full regression resulted (group 2); 33 patients with severely increased LVMI (group 3) had to be further divided into 2 sub-groups: 22 patients with significant improvement of LVMI, 11 patients with no, regression. For the first time we were able to show that it is possible to maintain initially normal LVMI during long-term treatment and to achieve complete regression and significant improvement of LVMI in our patients. However, since LVMI requires a long time to develop, a similarly long time must be estimated for its regression. However, 11 patients remained therapeutically resistant. In this group, severe heart diseases were often combined and highly prevalent, including ischemic heart and valve diseases and end-stage dilatative cardiomyopathy. These patients had to be transferred to cardiac surgery. Anemia is considered to be one of the most important factors for the development of left ventricular hypertrophy. Therefore, total correction of renal anemia has to be strongly recommended in addition to other measures of our therapeutic strategy to maintain full or significant regression of left ventricular hypertrophy.     

终末期肾病患者左心室结构与功能改变及影响因素

目的探讨维持性血液透析患者左心室结构与功能的改变及其影响因素。方法本组收集50例维持性血液透析患者的超声心动图结果以及血压、血红蛋白、白蛋白、血脂、钙、磷、甲状旁腺激素（PTH）和尿酸水平，并分析它们之间的关系。结果其中41例（82％）患者有左心室肥厚，左心室肥厚组与无左心室肥厚组相比，收缩压、舒张压、血红蛋白和PTH水平有显著差异（P〈0．05）；12例（24％）患者有左心室收缩功能障碍，左心室功能障碍组与无左心室功能障碍组相比，血清白蛋白、甘油三酯、钙、尿酸、肌酐和尿素氮等指标有显著性差异（P〈0．05）；31例（62％）患者有左心室舒张功能障碍。左心室舒张功能障碍组与无左心室舒张功能障碍组相比，收缩压、舒张压、血红蛋白和白蛋白水平有显著性差异（P〈0．05）。结论维持性血液透析患者左心室结构与功能异常发生率较高，血压、贫血和营养状况与之相关。     

Rio de La Plata study: a multicenter, cross-sectional study on cardiovascular risk factors and heart failure prevalence in peritoneal dialysis patients in Argentina and Uruguay

A multicenter cross-sectional study was performed to evaluate the prevalence of heart failure (HF) and the associated cardiovascular (CV) risk factors in 298 peritoneal dialysis (PD) patients from Argentina and Uruguay, representing almost 30% of the total number of PD patients in the two countries. Bidimensional echocardiography, electrocardiography, and biochemical analysis were performed. Systolic HF was defined as an ejection fraction <50%. According to echocardiography, 84.6% showed left ventricular hypertrophy (LVH), 38.3% valvular heart disease, and 35.4% valvular calcification, whereas 20% showed intraventricular conduction disturbances on the electrocardiogram. The prevalence of CV risk factors was of 73% hypertension, 51% sedentarism, 18% diabetes, 16.8% obesity, 12% smokers, 42.3% phosphorus >5.5 mg per 100 ml, 42.3% parathyroid hormone>300 pg ml(-1), and 29.6% calcium phosphate product >55. The prevalence of systolic HF was 9.9%, being significantly associated with diabetes: odds ratio (OR)=4.11 (P<0.006) and hypoalbuminemia: OR=3.45 (P<0.011). Forty percent of patients with a diagnosis of left ventricular dysfunction at the time of the study were asymptomatic. Variables associated with LVH in the multivariate analysis were anemia (OR=4.06; P<0.001) and previous hemodialysis (OR=1.99; P<0.031). The identification of reversible risk factors associated to HF and the diagnosis of asymptomatic ventricular dysfunction in this PD population will lead our efforts to establish guidelines for prevention and early treatment of congestive HF in patients on PD.     

Hypertension in chronic renal failure and ESRD: prevalence, pathophysiology, and outcomes

Hypertension and cardiovascular disease were detected to be major problems in end-stage renal disease patients soon after the application of chronic dialysis to treat uremia. Nearly 40 years later, and despite awesome technological and pharmacological advances, cardiovascular diseases remain the number one cause of death in all categories of renal patients, ie, chronic renal insufficiency, end-stage renal disease on dialysis and the renal transplant recipient. This is quite likely related to the massive clinical burden of cardiovascular risk factors: hypertension, cardiac fibrosis and hypertrophy, abnormal lipid profiles, smoking, dietary factors, and enhanced sympathetic activity. For example, left ventricular hypertrophy and abnormal echocardiograms are present in up to 75% to 80% of incident dialysis patients related to the interactions of these cardiovascular risks. It is important to understand how hypertension and the other cardiovascular disease risk factors interact in these patients. Based on the latest national data from the USRDS, the prevalence of underlying cardiac disease is increasing during the period of chronic renal failure. A proper understanding of the pathophysiology and prevalence of hypertension and its consequences in renal patients may lead to more rational therapies and clinical trials. At this time, the nephrologists are dealing with an epidemic of cardiovascular diseases in their patients.     

Risk of sudden death in patients with chronic renal failure and hemodialysis

Cardiovascular mortality in uremic patients treated by hemodialysis overrates ten times cardiovascular mortality in general population. Approximatively 40% of patients on iterative hemodialysis die from cardiac diseases, half of cases by sudden death. Several risk factors for sudden death are well known: QTc interval prolongation, decrease of RR interval <750 msec, decrease of heart rate variability, presence of late ventricular potentials (LVP), presence of high risk ventricular extrasystoles, decrease of ejection fraction (EF) <40 %, presence of left ventricular hypertrophy. Our study evaluated the above-mentioned risk factors for sudden death in patients with chronic renal failure on hemodialysis. We studied 37 patients, 22 males and 15 females, with mean age of 42 years old, without diabetes, heart failure and arrhythmias, without myocardial ischemia on ECG, being on hemodialysis (HD) programme for minimum 1 year (HD parameters are: 4 h x 3/week, qB = 300 ml/min, buffer = bicarbonate, Ca dialysate = 1.75 mmol/l, K dialysate = 2.1 mmol/l, conductivity = 135 mS). The patients were evaluated by echocardiography, standard and Holter ECG. Statistics evaluation was performed in SPSS v.9.0. Program. The results proved that 80% of patients on HD have risk factors for sudden death, which are closely related with age and hyperhydration. Statistics proved that presence of high-risk arrhythmias is connected with heart rate variability and prolongation of QTc interval (favored by HD). 50% of our patients have 2 to 4 risk factors for sudden death, which increase incidence of sudden death in patients on HD.     

Cardiovascular disease in the dialysis population: prognostic significance of arterial disorders

PURPOSE OF REVIEW: Cardiovascular disease is a major factor in the high mortality of patients with end-stage renal disease, and this population is particularly appropriate to analyse the impact of cardiovascular risk markers on outcome. RECENT FINDINGS: Cardiovascular risk markers in end-stage renal disease include age, left ventricular mass, carotid intima-media thickness, blood pressure and aortic stiffness (pulse wave velocity). Aortic pulse wave velocity has been shown to be an independent predictor of cardiovascular mortality in patients with end-stage renal disease and the general population. Aortic pulse wave velocity has the highest sensitivity and specificity as a predictor of cardiovascular death in end-stage renal disease patients. Pulse wave velocity is an integrated index of vascular function and structure, and is a major determinant of systolic hypertension, thereby increasing left ventricular afterload, left ventricular hypertrophy and left ventricular oxygen consumption. Decreased diastolic blood pressure, another consequence of arterial stiffening, is associated with decreased coronary perfusion contributing to ischaemic heart disease and evolution of adaptive into maladaptive left ventricular hypertrophy. SUMMARY: Aortic stiffness measurements could serve as an important tool in identifying end-stage renal disease patients at higher risk of cardiovascular disease. The ability to identify these patients would lead to better risk stratification and earlier and more cost-effective preventive therapy.     

Therapy insight: management of cardiovascular disease in the renal transplant recipient

Cardiovascular disease causes the deaths of up to 50% of renal transplant recipients who have a functioning graft. As in other states of chronic kidney disease, both overload cardiomyopathy (chronic heart failure and left ventricular hypertrophy) and ischemic heart disease are evident; age and gender are important risk factors for both of these disorders. Potentially treatable risk factors include smoking, hyperlipidemia, diabetes and hypertension for ischemic heart disease, and anemia, hypertension and diabetes for cardiomyopathy. Although definitive evidence on the effectiveness of interventions is lacking, it seems reasonable to treat renal transplant recipients as patients at the highest risk of cardiovascular disease. Aggressive targeting of lifestyle factors, blood pressure, cholesterol and sugar regulation is likely to have a major impact on patient and graft survival and should be initiated well before transplantation. Maintenance of hemoglobin with erythropoietic agents is controversial but might improve quality of life. Although immunosuppressive agents have distinct effects on cardiovascular risk factors, the impact on outcomes is impossible to predict on the basis of current data, and no firm recommendations can be made.     

Cardiovascular risk factors in predialysis patients: baseline data from the Chronic Renal Impairment in Birmingham (CRIB) study

BACKGROUND: Patients with end-stage kidney failure have a greatly increased risk of developing premature cardiac and vascular disease. However, little is known about the evolution of cardiovascular diseases in individuals with less severely impaired kidney function. METHODS: The prevalence of cardiovascular diseases and of suspected cardiovascular risk factors was studied in a group of 369 individuals (median age, 63 years, 67% male) with various degrees of impaired kidney function (calculated creatinine clearances 6 to 105 mL/min), in 103 patients with angiographically proven coronary artery disease, and in 103 apparently healthy individuals. These patients are being followed prospectively. RESULTS: Of those patients with kidney disease, 34% had a history of vascular disease and 21% had left ventricular hypertrophy on electrocardiogram at baseline. Traditional risk factors were prevalent, with a history of hypertension in 76% of kidney disease patients, diabetes in 15%, and dyslipidemia with reduced low-density lipoprotein (LDL) cholesterol, elevated serum triglycerides, and decreased high-density lipoprotein (HDL) levels. Other possible cardiovascular risk factors include elevated concentrations of plasma homocysteine, as well as low serum albumin and hemoglobin levels. Patients with more severely impaired renal function had lower diastolic blood pressures, lower LDL and HDL cholesterol levels, were more anemic, and had higher plasma homocysteine concentrations. CONCLUSIONS: Vascular disease and left ventricular hypertrophy are prevalent among patients with chronic kidney disease not requiring dialysis. In addition to traditional risk factors, other features of the uremic syndrome such as anemia, hyperhomocysteinemia, and inflammation (suggested by hypoalbuminemia) may contribute.     

The role of non-haemodynamic factors of the genesis of LVH.

"Things are never so simple as they look"

Left ventricular hypertrophy (LVH) is a common finding in arterialhypertension. In mild hypertension, the prevalence of LVH is20% and in severe hypertension 50% [1]. Evidence of LVH eitherby electrocardiography or echocardiography clearly increasesthe risk for myocardial infarction, cardiac sudden death, congestiveheart failure and stroke. Most intriguingly, the cumulativeincidence of cardiovascular events increases progressively withincreasing left ventricular mass, without evidence of any threshold[2]. In other words, hypertensive patients with left ventricularmass in the upper normal range already have increased risk forcardiovascular events [2]. Although the pathogenesis of cardiac hypertrophy in hypertensionis not yet completely understood, several haemodynamic and non-haemodynamicfactors are of pathogenetic relevance [3].     

Effect of hemodialysis on left ventricular performance. Analysis of echocardiographic subsets

To assess the effect of hemodialysis on left ventricular performance, we performed M-mode echocardiography on 31 patients with end-stage renal disease prior to and immediately following 4-hour chronic maintenance hemodialysis. Overall, hemodialysis produced a significant increase in mean heart rate and the mean velocity of circumferential fiber shortening (mean Vcf), a significant decrease in mean stroke index and no significant change in mean cardiac index. Hemodialysis resulted in a significant increase in mean Vcf in the subset of patients with reduced mean Vcf prior to dialysis, but produced no significant change in mean Vcf in the group with normal predialysis mean Vcf. Hemodialysis resulted in a significant increase in mean Vcf in the subset of patients with normal left ventricular end-diastolic volume prior to dialysis, but produced no significant change in mean Vcf in the group with increased predialysis left ventricular end-diastolic volume. The presence of left ventricular hypertrophy appeared to blunt the expected increase in mean Vcf in the group with reduced mean Vcf prior to hemodialysis. These results suggest that predialysis left ventricular volume, wall thickness and contractility are important determinants of the effect of hemodialysis on left ventricular performance.     

Therapy with recombinant human erythropoietin reduces cardiac size and improves heart function in chronic hemodialysis patients.

The substitution of recombinant human erythropoietin (rhEPO) in chronic hemodialysis patients is often associated with the development of severe hypertension. In the present study, a systematical echocardiographic analysis was performed in 25 patients on maintenance hemodialysis during rhEPO therapy for at least 4 months. Referred to the total group, indices of left ventricular size decreased significantly. Left ventricular total volume and left ventricular mass were reduced considerably. Fractional fiber shortening and ejection fraction showed an impressing improvement. At a constant heart rate, stroke volume and cardiac output were reduced. Myocardial thickness did not alter under chronic rhEPO therapy. When subgroups were formed with respect to changes in blood pressure, all parameters investigated behaved very similar to the total group, irrespective of changes in blood pressure. Five patients with coronary heart disease and clinical signs of myocardial insufficiency were evaluated separately. These patients showed a decrease in left ventricular size and no evidence of a deterioration of myocardial function. We conclude from our results that rhEPO therapy in patients on maintenance renal replacement therapy has beneficial effects on left ventricular size and function; these effects are not significantly counteracted by the development of hypertension.     

维持性血液透析患者心脏结构功能的危险因素分析

目的探讨影响维持性血液透析（MHD）患者心脏结构功能的危险因素。方法选择MHD患者153例,超声心动图测定心脏各项指标,并计算左心室心肌重量指数（LVMI）。生存函数乘积限（Kaplan-Meier）分析观察LVMI对患者预后的影响,分析影响LVMI的危险因素关系。结果153例MHD患者中,84例（占55．2％）患者存在左心室肥厚。多元回归结果显示超滤量（UF）和血红蛋白是影响左心室肥厚的独立危险因素。每周3次透析与每周2次透析的患者左心室肥厚的发生率分别为59．3％和52．1％。Kaplan-Meier生存分析显示左心室肥厚患者的5、10和15年生存率分为78．3％、54．3％和36．2％。结论MHD患者存在较高的左心室肥厚发生率,UF、血红蛋白与左心室肥厚相关,预防患者左心室肥厚可能有助于提高患者生存率。     

Asymmetric septal hypertrophy and left atrial dilatation in patients with end-stage renal disease on long-term hemodialysis

Some literature reports associate a reduced weekly duration of treatment (3 x 4 h/week) for patients on maintenance hemodialysis with an increased cardiovascular mortality. To determine whether the improved survival of patients on long weekly hemodialysis (LHD: 3 x 8 h/week) can be associated with different cardiac changes, the cardiac characteristics of a group of 50 patients on LHD were analyzed in a non-invasive assessment. The main findings were an increased left ventricular (LV) muscle mass (176 + 54 g/m2), mass/volume ratio (1.69 + 0.37 g/ml) and left atrial diameter (39.7 + 5.7 mm). The increase in LV muscle mass was due mainly to a high prevalence of asymmetric septal thickening. The ratio septum/LV posterior wall was directly correlated with the left atrial diameter (r = 0.52), LV end-diastolic diameters were inversely correlated with hemoglobin concentration (r = 0.62). LV dilatation and/or LV systolic dysfunction were not characteristic findings: Only 6% of patients had a moderately enlarged (less than 65 mm) LV diameter, LV ejection fraction was decreased in 12%. There was no significant correlation between the degree of LV hypertrophy or left atrial dilatation and patient age, total dialysis duration, interdialytic weight gain, hemoglobin concentration, parameters of blood purification, blood pressure before and after dialysis, history of hypertension. We conclude that cardiac characteristics in patients on LHD are comparable to those described for large patient groups on short hemodialysis. Our findings do not explain improved survival on LHD.     

Renal sympathetic nerve ablation for the treatment of difficult-to-control or refractory hypertension in a haemodialysis patient

Haemodialysis patients show sympathetic hyperactivity. Hyperactivation of the sympathetic nervous system aggravates hypertension and it is related to left ventricular hypertrophy, heart failure, arrhythmias and atherogenesis. We report the first use of renal sympathetic nerve ablation for correction of uncontrolled hypertension in an end-stage renal disease patient on maintenance dialysis. We observed a progressive and sustained reduction of systemic blood pressure. Our case demonstrates the safety, the feasibility and the efficacy of this procedure. These findings suggest, however, that further clinical trials are needed into renal nerve radiofrequency ablation therapy for the treatment of hypertension and for the improvement of cardiovascular prognosis in this high-risk patient group.     

The relationship between chronic volume overload and elevated blood pressure in hemodialysis patients: use of bioimpedance provides a different perspective from echocardiography and biomarker methodologies

Background  

Chronic volume overload is very frequent in hemodialysis (HD) patients and is directly associated with hypertension, increased arterial stiffness, left ventricular hypertrophy (LVH), heart failure and ultimately with higher mortality and morbidity. One major issue is that presently there are very few comparative studies of the various methods (clinical, bioimpedance, inferior cava vein diameter (ICV) and Brain Natriuretic Peptide (NT-proBNP)) for volume status evaluation and their correlation with cardiovascular disease.