Accelerated atherosclerosis in prolonged maintenance hemodialysis

The effects of serum apolipoprotein E genetic variants and concentration on serum lipid parameters in haemodialysis patients

Objectives

Many epidemiological studies demonstrate that the apolipoprotein E gene (ApoE) is an important candidate gene for playing key roles in the development of haemodialysis (HD). The purpose of this study is to evaluate the effects of ApoE genetic variants and concentration on serum lipid parameters in HD.

Methods

A total of 288 HD patients and 292 healthy controls were enrolled in this case–control study. The genotypes of ApoE genetic variants were investigated through the created restriction site-polymerase chain reaction and DNA-sequencing methods.

Key findings

Our data indicated that the levels of triglyceride, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, apolipoprotein A-I (ApoA-I), ApoB, ApoE, lipoprotein (a) (Lp(a)) of mutant genotypes in ApoE c.61G > A and c.761T > A genetic variants were different from those subjects with wild genotype in HD patients and healthy controls.

Conclusions

These preliminary results from this study suggest that the ApoE genetic variants and concentration could affect the serum lipid parameters in HD and could be risk factors for evaluating HD.

Influence of hemodialysis duration on mid-term clinical outcomes in hemodialysis patients with coronary artery disease after drug-eluting stent implantation

Accelerated atherosclerosis in prolonged maintenance hemodialysis (HD) has been recognized; however, whether HD duration is associated with poor clinical outcome in HD patients with coronary artery disease (CAD) after drug-eluting stent (DES) implantation is unknown. We evaluated the impact of HD duration on clinical outcomes in HD patients with CAD after DES implantation. Between April 2007 and December 2012, 168 angina pectoris patients (320 de novo lesions) on HD were treated with DES. Major adverse cardiovascular events (MACE) and target lesion revascularization (TLR) were investigated at 3 years according to the HD duration (≤ 3 years, 83 patients; >3 years, 85 patients). The incidence of MACE was significantly higher in the long HD duration group (25.3 vs. 50.6 %; P = 0.001). Especially, sudden cardiac death (SCD) was significantly higher in the long HD duration group (3.6 vs. 16.5 %; P = 0.006). On the other hand, the rates of TLR were similar between the two groups (12.0 vs. 14.1 %; P = 0.69). Cox's proportional hazard analysis revealed that HD duration (HR 1.08 per year, 95 % CI 1.03-1.13, P = 0.002), β-blocker use (0.28, 0.17-0.46, P < 0.001), and diabetes mellitus (2.10, 1.23-3.56, P = 0.007) were independent predictors of MACE. Longer HD duration did not affect TLR; however, SCD was significantly higher in the long HD duration group.

Correlation of lower concentrations of hydrogen sulfide with atherosclerosis in chronic hemodialysis patients with diabetic nephropathy

BACKGROUND/AIMS

To explore the relationship between hydrogen sulfide (H2S) and uremic accelerated atherosclerosis (UAAS) in chronic hemodialysis patients with diabetic nephropathy (CHD/DN).

METHODS

A total of 36 CHD/DN and 32 chronic hemodialyzed non-diabetic patients with chronic glomerulonephritis (CHD/non-DN) were studied. Plasma H2S was measured with a sulfide sensitive electrode.

RESULTS

Plasma H2S in CHD/DN was significantly lower than that in CHD/non-DN patients. Plasma H2S was positively correlated with plasma TGF-β1, and negatively correlated with MMP-12 in CHD/DN patients. CHD/DN patients exhibited higher CCA-IMT, hsCRP, and lower H2S levels than in CHD/non-DN patients. Moreover, in CHD/DN patients, CCA-IMT was negatively correlated with plasma H2S, and positively correlated with hsCRP and LDL. On multiple regression analysis, H2S levels exhibited independent association with IMT in CHD/DN patients.

CONCLUSIONS

These findings suggest possible linkage between H2S metabolism and TGF-β/Smad signaling pathway modulation abnormalities that may contribute to the development of UAAS in CHD/DN patients.

Effect of time on dialysis and renal transplantation on endothelial function: a longitudinal analysis

Background

Soluble vascular cell adhesion molecule-1 (sVCAM-1) is a marker of endothelial injury and a potent predictor of cardiovascular mortality in patients with kidney failure on dialysis. The longitudinal effects of dialysis on endothelial dysfunction and in particular the effects of renal transplantation on markers of endothelial function including sVCAM-1 have not been well characterized.

Methods

We used the Transplant Manitoba registry and biobank to assemble a retrospective cohort of all patients receiving a first kidney transplant between January 1, 2000, and December 31, 2005 (n=186). One hundred seventy-four patients had at least two serum samples pretransplant and at least two samples posttransplant. In total, 1,004 serial samples (median 5/patient) were analyzed. Factors associated with sVCAM-1 were examined using mixed linear models.

Results

The sVCAM-1 levels increased progressively on dialysis (0.15 [0.10 to 0.20] ng/mL/day; P<0.0001), fell significantly within 1 month after transplantation (−625 ng/mL/day; P<0.0001) and continued to fall thereafter (−0.23 [−0.34 to −0.12] ng/mL/day). Smoking and heart failure were associated with higher sVCAM-1 levels, whereas transplantation was associated with lower sVCAM-1 levels. The relationship between sVCAM-1 and transplantation was not changed by multivariate adjustment.

Conclusion

Endothelial injury worsens over time on dialysis but improves significantly after renal transplantation.

Supplemental digital content is available in the article.

Renal function, uraemia and early arteriovenous fistula failure

BACKGROUND

Guidance varies regarding the optimal timing of arteriovenous fistula (AVF) creation. The aim of this study was to evaluate the association between uraemia, haemodialysis and early AVF failure.

METHODS

Immunoblotting and cell proliferation assays were performed on vascular smooth muscle cells (VSM) cells isolated from long saphenous vein samples to evaluate the cells' ability to proliferate when stimulated with uraemic (post-dialysis) and hyperuraemic (pre-dialysis) serum. Clinical data was collected prospectively for 569 consecutive radiocephalic (RCF) and brachiocephalic (BCF) fistulae. The primary outcome was AVF failure at 6 weeks. Dialysis status (haemodialysis (HD); pre-dialysis (Pre-D)), eGFR and serum urea were evaluated to determine if they affected early AVF failure.

RESULTS

Human VSM cells demonstrated increased capacity to proliferate when stimulated with hyperuraemic serum. There was no significant difference in early failure rate of either RCF or BCF depending on dialysis status (pre-D RCF 31.4% (n=188); pre-D BCF 22.4% (n=165); HD RCF 29.3% (n=99); HD BCF 25.9% (n=116); p=0.34). There was no difference in mean eGFR between those patients with early AVF failure and those without (11.2+/-0.2 ml/min/1.73 m2 vs. 11.6+/-0.4 ml/min/1.73 m2; p=0.47). Uraemia was associated with early AVF failure (serum urea: 35.0+/-0.7 mg/dl vs. 26.6+/-0.3 mg/dl (p<0.001)).

CONCLUSIONS

We present the first in vivo evidence of an association between adverse early AVF outcomes and uraemia. This is supported mechanistically by in vitro work demonstrating a pro-mitogenic effect of hyperuraemic serum. We hypothesise that uraemia-driven upregulation of VSM cell proliferation at the site of surgical insult in contributes to higher early AVF failure rates.

Inflammatory markers as mortality predictors in continuous ambulatory peritoneal dialysis patients

BACKGROUND/AIM

Besides peritonitis, the most common complication, indicators of chronic inflammation are also present in patients treated by peritoneal dialysis. The aim of this study was to analyze the predictive value of inflammatory parameters on mortality of continuous ambulatory peritoneal dialysis (CAPD) patients.

METHODS

Eighty-seven patients (57 males), aged from 30 to 85 [62.92 (10.61)] years who had been treated by a chronic program of CAPD for 3-113 months were analyzed. The basal period lasted 3 months with a follow-up of 30 months. Clinical parameters, dialysis adequacy and laboratory parameters including some inflammatory markers: serum amyloid-A (SAA), high sensitive C-reactive protein (hs-CRP), fibrinogen, erythrocyte sedimentation rate (ESR) and leukocytes were determined for each patient. Cox regression analysis selected the parameters of univariate and multivariate survival analysis.

RESULTS

During the follow-up period, 37 patients (42.5%) died. Univariate analysis selected the following potential mortality predictors (p<0.10): age, months on CAPD, residual urine output, presence of cerebrovascular insult (CVI), KT/V, serum urea and albumin concentrations, SAA, hs-CRP, fibrinogen and ESR. In the multivariate survival analysis four models were created, each with a single inflammatory parameter. In all of these models, besides the age and CVI, inflammatory parameters were the most significant mortality predictors. When the inflammatory markers were analyzed altogether, multivariate analysis established that independent mortality predictors in this group of patients were: SAA, age and CVI.

CONCLUSION

It may be concluded that in this studied group treated by CAPD, SAA was the most significant independent mortality predictor among the analyzed inflammatory markers.

The urea decomposition product cyanate promotes endothelial dysfunction

The dramatic cardiovascular mortality of patients with chronic kidney disease is attributable in a significant proportion to endothelial dysfunction. Cyanate, a reactive species in equilibrium with urea, is formed in excess in chronic kidney disease. Cyanate is thought to have a causal role in promoting cardiovascular disease, but the underlying mechanisms remain unclear. Immunohistochemical analysis performed in the present study revealed that carbamylated epitopes associate mainly with endothelial cells in human atherosclerotic lesions. Cyanate treatment of human coronary artery endothelial cells reduced expression of endothelial nitric oxide synthase, and increased tissue factor and plasminogen activator inhibitor-1 expression. In mice, administration of cyanate, promoting protein carbamylation at levels observed in uremic patients, attenuated arterial vasorelaxation of aortic rings in response to acetylcholine without affecting the sodium nitroprusside-induced relaxation. Total endothelial nitric oxide synthase and nitric oxide production were significantly reduced in aortic tissue of cyanate-treated mice. This coincided with a marked increase of tissue factor and plasminogen activator inhibitor-1 protein levels in aortas of cyanate-treated mice. Thus, cyanate compromises endothelial functionality in vitro and in vivo. This may contribute to the dramatic cardiovascular risk of patients suffering from chronic kidney disease.

A case report on concomitant coronary artery bypass operation and renal transplantation

Renal transplantation is successfully implemented in patients undergoing coronary bypass surgery. We performed concomitant coronary bypass surgery and renal transplantation in a patient found to have a left main coronary artery lesion after coronary angiography, which was performed in our clinic during preoperative evaluation of renal transplantation. We suggest the application of coronary-artery bypass grafting (CABG) or stent implantation 2 months after renal transplantation in asymptomatic patients with coronary artery disease. But, if severe coronary artery disease is detected in symptomatic patients, we suggest the concurrent application CABG and renal transplantation.

Cardiorenal syndrome: acute kidney injury secondary to cardiovascular disease and role of protein-bound uraemic toxins

Cardiovascular disease (CVD) and kidney disease are closely interrelated. Disease of one organ can induce dysfunction of the other, ultimately leading to failure of both. Clinical awareness of synergistic adverse clinical outcomes in patients with coexisting CVD and kidney disease or 'cardiorenal syndrome (CRS)' has existed. Renal dysfunction, even mild, is a strong independent predictor for poor prognosis in CVD patients. Developing therapeutic interventions targeting acute kidney injury (AKI) has been limited due mainly to lack of effective tools to accurately detect AKI in a timely manner. Neutrophil gelatinase-associated lipocalin and kidney injury molecule-1 have been recently demonstrated to be potential candidate biomarkers in patients undergoing cardiac surgery. However, further validation of AKI biomarkers is needed in other CVD settings, especially acute decompensated heart failure and acute myocardial infarction where AKI commonly occurs. The other concern with regard to understanding the pathogenesis of renal complications in CVD is that mechanistically oriented studies have been relatively rare. Pre-clininal studies have shown that activation of renal inflammation-fibrosis processes, probably triggered by haemodynamic derangement, underlies CVD-associated renal dysfunction. On the other hand, it is postulated that there still are missing links in the heart-kidney connection in CRS patients who have significant renal dysfunction. At present, non-dialysable protein-bound uraemic toxins (PBUTs) appear to be the main focus in this regard. Evidence of the causal role of PBUTs in CRS has been increasingly demonstrated, mainly focusing on indoxyl sulfate (IS) and p-cresyl sulfate (pCS). Both IS and pCS are derived from colonic microbiotic metabolism of dietary amino acids, and hence the colon has become a target of treatment in addition to efforts to improve dialysis techniques for better removal of PBUTs. Novel therapy targeting the site of toxin production has led to new prospects in early intervention for predialysis patients with chronic kidney disease.

Epidemiology, contributors to, and clinical trials of mortality risk in chronic kidney failure

Patients with chronic kidney failure--defined as a glomerular filtration rate persistently below 15 mL/min per 1·73 m(2)--have an unacceptably high mortality rate. In developing countries, mortality results primarily from an absence of access to renal replacement therapy. Additionally, cardiovascular and non-cardiovascular mortality are several times higher in patients on dialysis or post-renal transplantation than in the general population. Mortality of patients on renal replacement therapy is affected by a combination of socioeconomic factors, pre-existing medical disorders, renal replacement treatment modalities, and kidney failure itself. Characterisation of the key pathophysiological contributors to increased mortality and cardiorenal risk staging systems are needed for the rational design of clinical trials aimed at decreasing mortality. Policy changes to improve access to renal replacement therapy should be combined with research into low-cost renal replacement therapy and optimum clinical care, which should include multifaceted approaches simultaneously targeting several of the putative contributors to increased mortality.

Human monoclonal Fab and human plasma antibodies to carbamyl-epitopes cross-react with malondialdehyde-adducts

Oxidized low-density lipoprotein (OxLDL) plays a crucial role in the development of atherosclerosis. Carbamylated LDL has been suggested to promote atherogenesis in patients with chronic kidney disease. Here we observed that plasma IgG and IgM antibodies to carbamylated epitopes were associated with IgG and IgM antibodies to oxidation-specific epitopes (ρ = 0·65-0·86, P < 0·001) in healthy adults, suggesting a cross-reaction between antibodies recognizing carbamyl-epitopes and malondialdehyde (MDA)/malondialdehyde acetaldehyde (MAA) -adducts. We used a phage display technique to clone a human Fab antibody that bound to carbamylated LDL and other carbamylated proteins. Anti-carbamyl-Fab (Fab106) cross-reacted with oxidation-specific epitopes, especially with MDA-LDL and MAA-LDL. We showed that Fab106 bound to apoptotic Jurkat cells known to contain these oxidation-specific epitopes, and the binding was competed with soluble carbamylated and MDA-/MAA-modified LDL and BSA. In addition, Fab106 was able to block the uptake of carbamyl-LDL and MDA-LDL by macrophages and stained mouse atherosclerotic lesions. The observed cross-reaction between carbamylated and MDA-/MAA-modified LDL and its contribution to enhanced atherogenesis in uraemic patients require further investigation.

Association between circulating endothelial cells and carotid atherosclerosis in patients receiving maintenance hemodialysis

Accelerated atherosclerosis is the major cause of mortality in maintenance hemodialysis (MHD) patients, and endothelial injury associated with MHD might contribute strongly to pathogenesis. The current study was designed to explore possible associations between circulating endothelial cells (CECs) and intima-media thickness of common carotid artery (CCA-IMT) as an indicator of carotid atherosclerosis. Sixty-two MHD patients and 26 age- and sex-matched healthy volunteers were recruited. The number of CECs was determined in peripheral blood using multiparametric flow cytometry. CCA-IMT and presence of plaques in the common carotid arteries were assessed with ultrasound. Laboratory tests results and the demographics were recorded. The finding indicated that numbers of CECs were higher in patients before hemodialysis (predialysis) compared with numbers in controls (P = 0.045). CCA-IMT was also significantly higher in patients than in controls (P < 0.01). A positive relationship was observed between predialysis CECs numbers and CCA-IMT (P < 0.01) in MHD patients. In multiple linear regression analysis, the relationship between the predialysis CECs level and CCA-IMT remained the same even if adjusting for confounding effects. Accordingly, the investigation indicates that the CECs level is positively associated with CCA-IMT in our hemodialysis patients. CECs might be an important marker to the severity of carotid atherosclerosis in MHD patients.

Comparison of zotarolimus- and everolimus-eluting stents in patients with ST-elevation myocardial infarction and chronic kidney disease undergoing primary percutaneous coronary intervention

BACKGROUND

Chronic kidney disease (CKD) is associated with poor outcomes after percutaneous coronary intervention (PCI). The aim of the study was to compare zotarolimus- and everolimus-eluting stents used during primary PCI in patients with acute myocardial infarction (AMI) and CKD.

METHODS

We selected 854 consecutive ST-elevation MI patients with CKD (estimated glomerular filtration rate <60 mL/min/1.73 m(2)) undergoing primary PCI who were followed up for 12 months. They were divided into two groups based on type of stents implanted: (1) zotarolimus-eluting stent (ZES) and (2) everolimus-eluting stent (EES). The study end point was the 12-month major adverse cardiac events (MACE) which included all-cause death, non-fatal MI, target lesion revascularization (TLR), and target vessel revascularization (TVR).

RESULTS

The average number of stents used per vessel was 1.4 ± 0.7. A total of 433 patients received ZES and 421 patients received EES. There was no significant difference in the incidence of 12-month MI, TLR, or TVR. All-cause death was found to be borderline significant between two groups (2.8% in ZES vs 0.9% in EES, p=0.05). The incidence of 12-month MACE in ZES and EES was 5.7% and 2.6% respectively, p=0.022. Stent thrombosis did not differ between groups (p=0.677). Kaplan-Meier analysis did not show significant difference for 12-month MACE-free survival between groups (log-rank p=0.158). It remained the same even after propensity adjustment for multiple confounders in Cox model (p=0.326).

CONCLUSIONS

Implantation of ZES or EES provided comparable clinical outcomes with similar risk of 12-month MACE and death in STEMI patients with CKD undergoing primary PCI.

Visceral fat level is an independent risk factor for cardiovascular mortality in hemodialysis patients

BACKGROUND

Obesity is an independent risk factor for morbidity and mortality in cardiovascular diseases not only in the general population, but also in hemodialysis (HD) patients. We previously reported that an increased visceral fat area (VFA) determined using computed tomography (CT) scans was associated with atherosclerosis in HD patients. However, whether a high VFA is associated with increased cardiovascular mortality in HD patients remains unknown. Therefore, we investigated the relationship between VFA and prognosis in HD patients.

METHODS

VFA was estimated in 126 patients on maintenance HD using CT scans. These patients were followed for 60 months.

RESULTS

Kaplan-Meier analysis revealed that the cardiovascular survival rate was significantly lower in the high-VFA group, with a VFA of 71.5 cm(2) or greater, than in the low-VFA group, with a VFA of less than 71.5cm(2). In univariate Cox proportional hazards analyses, age, albumin, low-density lipoprotein cholesterol, cardio-thoracic ratio and VFA above 71.5 cm(2) were significantly correlated with cardiovascular deaths. In multivariate analyses testing these factors as dependent variables, VFA above 71.5 cm(2) was estimated to be an independent predictor of cardiovascular deaths.

CONCLUSION

These results suggest that an increased VFA is a stronger risk factor for cardiovascular deaths in HD patients. Measuring VFA may be recommended for predicting the risk of cardiovascular diseases in HD patients.

Myocardial revascularization in dyalitic patients: in-hospital period evaluation

BACKGROUND

Coronary artery bypass grafting currently is the best treatment for dialytic patients with multivessel coronary disease, but hospital morbidity and mortality related to procedure is still high.

OBJECTIVE

Evaluate results and in-hospital outcomes of coronary artery bypass grafting in dialytic patients.

METHODS

Retrospective unicentric study including 50 consecutive and not selected dialytic patients, who underwent coronary artery bypass grafting in a tertiary university hospital from 2007 to 2012.

RESULTS

High prevalence of cardiovascular risk factors was observed (100% hypertensive, 68% diabetic and 40% dyslipidemic). There was no intra-operative death and 60% of the procedures were performed off-pump. There were seven (14%) in-hospital deaths. Postoperative infection, previous heart failure, cardiopulmonary bypass, abnormal ventricular function and surgical re-exploration were associated with increased mortality.

CONCLUSION

Coronary artery bypass grafting is feasible to dialytic patients although high in-hospital morbidity and mortality. It is necessary better understanding about metabolic aspects to plan adequate interventions.

Reduction of albumin urinary excretion is associated with reduced cardiovascular events in hypertensive and/or diabetic patients. A meta-regression analysis of 32 randomized trials

BACKGROUND

The association between renal dysfunction and risk of cardiovascular (CV) events and mortality has been reported in several studies. However, it is unclear whether reduction in urinary albumin excretion (UAE) is associated with reduced risk of clinical events. Therefore, we sought to investigate, in a meta-regression analysis of randomized studies enrolling hypertensive and/or diabetic patients, whether changes in UAE are associated with changes in CV outcomes and all-cause mortality.

METHODS

MEDLINE, ISI Web of Science, Cochrane Database and Scopus were searched for randomized trials enrolling more than 200 diabetic and/or hypertensive patients, reporting UAE at baseline and at end of follow-up and CV events [CV death, myocardial infarction (MI), and stroke], as well all-cause mortality.

RESULTS

Thirty-two trials enrolling 80,812 participants were included in analyses. Meta-regression analysis showed that each 10% reduction of UAE was significantly associated with 13% reduction of MI (Regression Coefficient [RC]:0.0055; 95% Confidence Interval [CI]:0.0014 to 0.0095; p=0.010), with 29% reduction of stroke (RC:0.0124; CI:0.0030 to 0.0218; p=0.013) and with 14% reduction of the composite outcome (CV death, MI, stroke)(RC:0.0059; CI:0.0027 to 0.0090; p=0.001), whereas not significantly associated with all-cause (RC:0.0028; CI:-0.0047 to 0.0103; p=0.486) and CV mortality (RC:0.0028; CI:-0.0047 to 0.0103; p=0.447). Results were mostly confirmed by sensitivity analysis. No heterogeneity or publication bias was detected.

CONCLUSIONS

Reduction in UAE is associated with reduced risk of MI and stroke in diabetic and/or hypertensive patients. These findings suggest that UAE changes may represent a valuable intermediate end-point for CV risk evaluation in clinical practice.

Metabolic syndrome in children with chronic kidney disease and after renal transplantation

Visceral obesity and metabolic abnormalities typical for metabolic syndrome (MS) are the new epidemic in adolescence. MS is not only the risk factor for cardiovascular disease but also for chronic kidney disease (CKD). Thus, there are some reasons to recognize MS as a new challenge for pediatric nephrologists. First, hypertensive and diabetic nephropathy, the main causes of CKD in adults, both share the same pathophysiological abnormalities associated with visceral obesity and insulin resistance and have their origins in childhood. Secondly, as the obesity epidemic also affects children with CKD, MS emerges as the risk factor for progression of CKD. Thirdly, metabolic abnormalities typical for MS may pose additional risk for cardiovascular morbidity and mortality in children with CKD. Finally, although the renal transplantation reverses uremic abnormalities it is associated with an exposure to new metabolic risk factors typical for MS and MS has been found to be the risk factor for graft loss and cardiovascular morbidity after renal transplantation. MS is the result of imbalance between dietary energy intake and expenditure inducing disproportionate fat accumulation. Thus, the best prevention and treatment of MS is physical activity and maintenance of proper relationship between lean and fat mass.

Statin improves flow-mediated vasodilation in chronic kidney diseases

Background. Numbers of drugs are required to manage patients with chronic kidney disease (CKD). Drug adherence is relatively poor in this population. Methods. In 36 CKD patients with hypertension and dyslipidemia, who were prescribing amlodipine 5 mg and atorvastatin 10 mg daily, the influences of exchanging to a combination drug containing equivalent doses of amlodipine and atorvastatin were observed for 6 months. Results. At the baseline, flow-mediated dilation (FMD) was reduced (2.4 ± 0.3%), and proteinuria was significantly contributed to decrements of FMD (R (2) = 0.38, F = 3.7, df (6,29), and  P < 0.01). Six months later from exchanging to combination drug, total cholesterol (TC, 197 ± 5 to 183 ± 3 mg/dL,  P < 0.01) and triglycerides (142 ± 14 to 129 ± 10 mg/dL, P < 0.05) were decreased, but high density lipoprotein cholesterol (53 ± 3 to 56 ± 3 mg/dL, P < 0.05) was increased. FMD was slightly albeit significantly improved to 2.7 ± 0.3% (P < 0.05). No serious adverse effects were seen by the combination drug. Subanalysis for the patients with considerable reductions of TC demonstrated that the combination drug decreased proteinuria and high sensitive CRP (P < 0.05 for both). Conclusion. Our data indicate that proteinuria constitutes a determinant of a reduced FMD. The present results implicate that combination drug is useful to improve adherence and suggest that atorvastatin refines endothelium function as well as lipid profiles in CKD patients.

Pathogenesis of chronic cardiorenal syndrome: is there a role for oxidative stress?

Cardiorenal syndrome is a frequently encountered clinical condition when the dysfunction of either the heart or kidneys amplifies the failure progression of the other organ. Complex biochemical, hormonal and hemodynamic mechanisms underlie the development of cardiorenal syndrome. Both in vitro and experimental studies have identified several dysregulated pathways in heart failure and in chronic kidney disease that lead to increased oxidative stress. A decrease in mitochondrial oxidative metabolism has been reported in cardiomyocytes during heart failure. This is balanced by a compensatory increase in glucose uptake and glycolysis with consequent decrease in myocardial ATP content. In the kidneys, both NADPH oxidase and mitochondrial metabolism are important sources of TGF-β1-induced cellular ROS. NOX-dependent oxidative activation of transcription factors such as NF-kB and c-jun leads to increased expression of renal target genes (phospholipaseA2, MCP-1 and CSF-1, COX-2), thus contributing to renal interstitial fibrosis and inflammation. In the present article, we postulate that, besides contributing to both cardiac and renal dysfunction, increased oxidative stress may also play a crucial role in cardiorenal syndrome development and progression. In particular, an imbalance between the renin-angiotensin-aldosterone system, the sympathetic nervous system, and inflammation may favour cardiorenal syndrome through an excessive oxidative stress production. This article also discusses novel therapeutic strategies for their potential use in the treatment of patients affected by cardiorenal syndrome.

In vivo kinetic studies to further understand pathogenesis of abnormal lipoprotein metabolism in chronic kidney disease

Patients undergoing hemodialysis (HD) have been shown to be at increased risk for cardiovascular disease (CVD) morbidity and mortality which are, at least in part, due to uremic dyslipidemia including increased triglyceride-rich lipoproteins, in particular remnants, decreased high-density lipoprotein (HDL), and increased lipoprotein(a) [Lp(a)]. In vivo kinetic studies using stable isotope revealed that apolipoprotein (apo)A-I, a primary apoprotein constitute of HDL, was catabolized at a faster rate in HD patients, leading to decreased apoA-I, and therefore reduced HDL cholesterol concentrations. Likewise, apoB catabolic rates were significantly lower in intermediate-density lipoprotein (IDL) and low-density lipoprotein (LDL) apoB; the latter is also accompanied by a decreased production rate. In HD patients, IDL apoB levels were elevated, but LDL apoB levels remained within the normal range. Nonetheless, a prolonged residence time for LDL apoB of 2-5 days, made LDL more atherogenic. Atorvastatin completely ameliorated impaired LDL apoB catabolism. With regard to Lp(a) metabolism, both apoB and apo(a) were found to be slowly catabolized, indicating roles of normal kidney function on Lp(a) catabolism. Finally, a compartmental model suggests intracellular, rather than extracellular, assembly of Lp(a). This in vivo kinetic evidence will uncover the underlying mechanism for uremic dyslipidemia and provide strategies to reduce CVD in HD patients.

Carbamyl adducts on low-density lipoprotein induce IgG response in LDLR-/- mice and bind plasma autoantibodies in humans under enhanced carbamylation

AIMS

Post-translational modification of proteins via carbamylation predicts increased risk for coronary artery disease. Uremia and smoke exposure are known to increase carbamylation. The aim was to investigate the role of carbamylated low-density lipoprotein (LDL) immunization on antibody formation and atherogenesis in LDL receptor-deficient (LDLR-/-) mice, and to study autoantibodies to carbamylated proteins in humans with carbamylative load.

RESULTS

LDLR-/- mice immunized with carbamylated mouse LDL (msLDL; n=10) without adjuvant showed specific immunoglobulin G (IgG) antibody levels to carbamyl-LDL and malondialdehyde-modified LDL (MDA-LDL) but not to oxidized LDL or native LDL. Immunization did not influence the atherosclerotic plaque area compared with control LDLR-/- mice immunized with native msLDL (n=10) or phosphate-buffered saline (n=11). Humans with high plasma urea levels, as well as smokers, had increased IgG autoantibody levels to carbamyl-modified proteins compared to the subjects with normal plasma urea levels, or to nonsmokers.

INNOVATION

Carbamyl-LDL induced specific IgG antibody response cross-reactive with MDA-LDL in mice. IgG antibodies to carbamyl-LDL were also found in human plasma and related to conditions known to have increased carbamylation, such as uremia and smoking. Plasma antibodies to carbamylated proteins may serve as new indicator of in vivo carbamylation.

CONCLUSION

These data give insight into mechanisms of in vivo humoral recognition of post-translationally modified structures. Humoral IgG immune response to carbamylated proteins is suggested to play a role in conditions leading to enhanced carbamylation, such as uremia and smoking.

Serum catalytic Iron: A novel biomarker for coronary artery disease in patients on maintenance hemodialysis

Cardiovascular disease is the leading cause of morbidity and mortality in maintenance hemodialysis (MHD) patients. We evaluated the role of serum catalytic iron (SCI) as a biomarker for coronary artery disease (CAD) in patients on MHD. SCI was measured in 59 stable MHD patients. All patients underwent coronary angiography. Significant CAD was defined as a > 70% narrowing in at least one epicardial coronary artery. Levels of SCI were compared with a group of healthy controls. Significant CAD was detected in 22 (37.3%) patients, with one vessel disease in 14 (63.63%) and multi-vessel disease in eight (36.36%) patients. The MHD patients had elevated levels of SCI (4.70 ± 1.79 μmol/L) compared with normal health survey participants (0.11 ± 0.01 μmol/L) (P < 0.0001). MHD patients who had no CAD had SCI levels of 1.36 ± 0.34 μmol/L compared with those having significant CAD (8.92 ± 4.12 μmol/L) (P < 0.0001). Patients on MHD and diabetes had stronger correlation between SCI and prevalence of CAD compared with non-diabetics. Patients having one vessel disease had SCI of 8.85 ± 4.67 μmol/L versus multi-vessel disease with SCI of 9.05 ± 8.34 μmol/L, P = 0.48. In multivariate analysis, SCI and diabetes mellitus were independently associated with significant CAD. We confirm the high prevalence of significant CAD in MHD patients. Elevated SCI levels are associated with presence of significant coronary disease in such patients. The association of SCI is higher in diabetic versus the non-diabetic subgroup. This is an important potentially modifiable biomarker of CAD in MHD patients.

Clinical detection, risk factors, and cardiovascular consequences of medial arterial calcification: a pattern of vascular injury associated with aberrant mineral metabolism

Patients with end-stage renal disease are characterized by extensive vascular calcification and high cardiovascular disease (CVD) risk. Calcification in end-stage renal disease patients represents at least two distinct pathologic processes. Calcification within the tunica intima frequently is associated with lipid-laden, flow-limiting atherosclerotic plaques. These appear as spotty areas of calcification interspersed with noncalcified arterial segments on plain radiography and generally are found near arterial branch points in medium-sized conduit arteries. In contrast, medial arterial calcification (MAC) involves deeper layers of the arterial wall; tends to affect the artery diffusely, appearing as a linear contiguous tram-track pattern of calcification on plain radiography; and often involves smaller muscular arteries such as the radial artery, intermammary arteries, and arteries in the ankle and foot. Both are related to CVD events, but potentially through different mechanisms. Atherosclerotic calcification may be marking the total burden of atherosclerosis, whereas MAC may lead to arterial stiffness and left ventricular hypertrophy. Existing data suggest that altered mineral metabolism may promote MAC, whereas heightened inflammation and oxidative stress contribute to atherosclerosis. Dysregulation of normal anticalcification factors and elastin degradation are common to both processes. Risk of vascular calcification also may be increased by the use of certain medications in the setting of chronic kidney disease. This review compares and contrasts known risk factors for MAC and atherosclerosis, describes existing and emerging technologies to distinguish between them, and reviews the existing literature linking each with CVD events in dialysis patients and in other settings.

Glutamine supplementation alleviates vasculopathy and corrects metabolic profile in an in vivo model of endothelial cell dysfunction

Endothelial Cell Dysfunction (ECD) is a recognized harbinger of a host of chronic cardiovascular diseases. Using a mouse model of ECD triggered by treatment with L-Nω-methylarginine (L-NMMA), we previously demonstrated that renal microvasculature displays a perturbed protein profile, including diminished expression of two key enzymes of the Krebs cycle associated with a Warburg-type suppression of mitochondrial metabolism. We hypothesized that supplementation with L-glutamine (GLN), that can enter the Krebs cycle downstream this enzymatic bottleneck, would normalize vascular function and alleviate mitochondrial dysfunction. To test this hypothesis, mice with chronic L-NMMA-induced ECD were co-treated with GLN at different concentrations for 2 months. Results confirmed that L-NMMA led to a defect in acetylcholine-induced relaxation of aortic rings that was dose-dependently prevented by GLN. In caveolin-1 transgenic mice characterized by eNOS inactivation, L-NMMA further impaired vasorelaxation which was partially rescued by GLN co-treatment. Pro-inflammatory profile induced by L-NMMA was blunted in mice co-treated with GLN. Using an LC/MS platform for metabolite profiling, we sought to identify metabolic perturbations associated with ECD and offset by GLN supplementation. 3453 plasma molecules could be detected with 100% frequency in mice from at least one treatment group. Among these, 37 were found to be differentially expressed in a 4-way comparison of control vs. LNMMA both with and without GLN. One of such molecules, hippuric acid, an “uremic toxin” was found to be elevated in our non-uremic mice receiving L-NMMA, but normalized by treatment with GLN. Ex vivo analysis of hippuric acid effects on vasomotion demonstrated that it significantly reduced acetylcholine-induced vasorelaxation of vascular rings. In conclusion, functional and metabolic profiling of animals with early ECD revealed macrovasculopathy and that supplementation GLN is capable of improving vascular function. Metabolomic analyses reveal elevation of hippuric acid, which may further exacerbate vasculopathy even before the development of uremia.

ADMA and C-reactive protein as mortality predictors in dialysis patients

There is a higher mortality between patients with end-stage renal disease than patients in the general population. These circumstances have led to a search for risk factors as predictors of mortality in dialysis patients. Amongst those, inhibitors of the nitric-oxide (NO) synthesis deserve special attention, since patients with end-stage renal disease are also characterized by accelerated atherosclerosis. Asymmetric-dimethylarginine (ADMA) and symmetric-dimethylarginine (SDMA), as well as C-reactive protein (CRP), have also been recognized as predictors of mortality in patients on dialysis. The aim of our study was to compare the prediction power of ADMA, SDMA and CRP for all-cause mortality in patients with end stage renal disease during the fourteen month follow-up. In total 162 patients on hemodialysis were included. ADMA and SDMA were measured by the high-performance liquid chromatography (HPLC); CRP was measured using immunonephelometric assays. During the 14-month period 28 patients (34.1%) died from all-cause mortality. Using univariate analysis, hazard ratios (HR) of the potential independent predictors of mortality in hemodialysis patients were ADMA (HR 1.39 (1.01–1.91) p=0.043) and CRP (HR 1.024 (1.009–1.1.040) p=0.001). Further, multivariate analysis (MVA), however, showed that ADMA is the only predictor of all-cause mortality (HR 1.76 (1.002–3.11) P=0.049), while SDMA failed to predict death in this population. Therefore, our data shows that ADMA is an independent and better marker of all-cause mortality compared with CRP.

Subendocardial viability ratio predicts cardiovascular mortality in chronic kidney disease patients

BACKGROUND

The subendocardial viability ratio (SEVR), calculated by pulse wave analysis, is an index of myocardial oxygen supply and demand. Here we analyze the relation between SEVR and cardiovascular mortality in the chronic kidney disease (CKD) population of a post hoc analysis of a multicenter, prospective, randomized, nonblinded study.

METHODS

We studied 212 consecutive asymptomatic outpatients receiving care at 12 nephrology clinics in south Italy. Inclusion criteria were age >18 years, 6 months of follow-up before the enrollment and stage 3-4 CKD.

RESULTS

During follow-up, 34 subjects died, 29 of them for cardiovascular causes. SEVR correlated inversely with vascular calcifications (r = -0.37) and myocardial mass (r = -0.45); SEVR changed from 1.33 ± 0.24 to 1.36 ± 0.16 (p = NS; baseline and final values, respectively) in living patients, and from 1.16 ± 0.31 to 0.68 ± 0.26 in deceased patients (p < 0.001). Kaplan-Meier curves show that that a greater reduction of SEVR values during the study (third tertile) significantly predicts cardiovascular mortality (p < 0.0001).

CONCLUSIONS

This post hoc analysis shows that a reduction of SEVR values impacts cardiovascular mortality in CKD patients.

Chronic kidney disease is associated with neovascularization and intraplaque hemorrhage in coronary atherosclerosis in elders: results from the Hisayama Study

There is little information regarding whether patients with chronic kidney disease (CKD) have a high incidence of vulnerable plaques in their coronary arteries. To gain additional evidence on this, we conducted a population-based study by randomly selecting 126 subjects from 844 consecutive autopsies of elderly residents of Hisayama, Japan. We then determined the relationships of CKD with neovascularization and intraplaque hemorrhage in coronary atherosclerosis with the subjects classified into four categories based on their estimated glomerular filtration rate (eGFR). Areas of oxidized low-density lipoprotein (oxLDL) and vascular endothelial growth factor (VEGF) expression, assessed by immunohistochemistry in a total of 375 coronary arteries, increased significantly with decreasing eGFR. A lower eGFR was also associated with increased numbers of newly formed blood vessels. These relationships remained substantially unchanged after adjustment for confounding factors. The multivariate-adjusted odds ratio of the presence of intraplaque hemorrhages was 6.2 (95% confidence interval, 1.1-35.0) in patients with an eGFR <30 ml/min/1.73 m(2) compared with those with an eGFR of ≥ 60 ml/min/1.73 m(2). Thus, elderly patients with CKD have intimal neoangiogenesis and an increased risk of intraplaque hemorrhage in coronary arteries, possibly favored by local accumulation of oxLDL and VEGF.

Effect of statin therapy on cardiovascular and renal outcomes in patients with chronic kidney disease: a systematic review and meta-analysis

AIMS

The effects of statin therapy in patients with chronic kidney disease (CKD) remain uncertain. We undertook a systematic review and meta-analysis to investigate the effects of statin on major clinical outcomes.

METHODS AND RESULTS

We systematically searched MEDLINE, Embase, and the Cochrane Library for trials published between 1970 and November 2011. We included prospective, randomized, controlled trials assessing the effects of statins on cardiovascular outcomes in people with kidney disease. Summary estimates of relative risk (RR) reductions were calculated with a random effects model. Thirty-one trials that include at least one event were identified, providing data for 48 429 patients with CKD, including 6690 major cardiovascular events and 6653 deaths. Statin therapy produced a 23% RR reduction (16-30) for major cardiovascular events (P<0.001), an 18% RR reduction (8-27) for coronary events, and 9% (1-16) reduction in cardiovascular or all-cause deaths, but had no significantly effect on stroke (21%, -12 to 44) or no clear effect on kidney failure events (5%, -1 to 10). Adverse events were not significantly increased by statins, including hepatic (RR 1.13, 95% CI 0.92-1.39) or muscular disorders (RR 1.02, 95% CI 0.95-1.09). Subgroup analysis demonstrated the relative effects of statin therapy in CKD were significantly reduced in people with advanced CKD (P < 0.001) but that the absolute risk reductions were comparable.

CONCLUSION

Statin therapy reduces the risk of major cardiovascular events in patients with chronic kidney disease including those receiving dialysis.

Effect of isovolemic, isothermic hemodialysis on cerebral perfusion and vascular stiffness using contrast computed tomography and pulse wave velocity

Background

Patients undergoing hemodialysis treatment have a six-fold increased risk for stroke relative to the general population. However, the effect of hemodialysis on cerebral blood flow is poorly studied and confounding factors like blood pressure and ultrafiltration as well as temperature changes have rarely been accounted for. The aim of our study was to use state-of-the-art technology to evaluate the effect of a single dialysis session on cerebral perfusion as well as on vascular stiffness.

Methods

Chronic hemodialysis patients (7 male/3 female, mean age 58 years) were recruited. Cerebral blood flow and arterial pulse wave velocity were measured before and immediately after a hemodialysis session. To exclude effects of volume changes we kept ultrafiltration to a minimum, allowing no change in body weight. Isothermic conditions were maintained by using the GENIUS single-pass batch-dialysis system with a high-flux polysulfone dialyser. Cerebral blood flow was measured by contrast-enhanced computed tomography. Pulse wave velocity was measured using the SphygmoCor (AtCor Medical, USA) device by a single operator.

Results

This study shows for the first time that isovolemic, isothermic hemodialysis neither affected blood pressure or heart rate, nor total or regional cerebral perfusion. There was also no change in pulse wave velocity.

Conclusions

Mechanisms other than the dialysis procedure itself might be causative for the high incidence of ischemic strokes in this patient population. Moreover, the sole removal of uremic toxins does not lead to short-term effects on vascular stiffness, underlying the importance of volume control in this patient population.

Activation of platelets upon contact with a vitamin E-coated/non-coated surface

The purpose of this study was to determine the effects of a vitamin E-coated surface on platelet activation, focusing on the interactions among the vitamin E-coated surface, platelets and leukocytes. Platelet-rich plasma (PRP) or PRP containing leukocytes (LPRP) was used. No difference was observed in platelet activation between PRP and LPRP for a vitamin E-coated membrane, meaning that platelet activation triggered by leukocytes was suppressed in plasma coming in contact with a vitamin E-coated membrane, while the membrane itself directly induced platelet activation. The antioxidant capacity of the vitamin E-coated membrane in contact with PRP or LPRP was partially reduced, but sufficient residual capacity remained. The in vitro experiments using an oxidized vitamin E-coated surface revealed that P-selectin expression and superoxide anion production in the platelets and platelet adhesion were induced by contact with the oxidized vitamin E-coated surface. We conclude that contact with a vitamin E-coated surface reduces platelet activation mediated by superoxide anions, probably by reducing superoxide anions, but during the process of the reduction, the vitamin E-coated surface itself becomes oxidized, which again causes platelet activation. The beneficial effects of a vitamin E-coated dialyzer in respect of platelet activation were counteracted by the formation of oxidized vitamin E.

Cardiorenal syndrome: the emerging role of protein-bound uremic toxins

Cardiorenal syndrome is a condition in which a complex interrelationship between cardiac dysfunction and renal dysfunction exists. Despite advances in treatment of both cardiovascular and kidney disease, cardiorenal syndrome remains a major global health problem. Characteristic of the pathophysiology of cardiorenal syndrome is bidirectional cross-talk; mediators/substances activated by the disease state of 1 organ can play a role in worsening dysfunction of the other by exerting their biologically harmful effects, leading to the progression of the syndrome. Accumulation of uremic toxins is a hallmark of renal excretory dysfunction. Removal of some toxins by conventional dialysis is particularly problematic because of their high protein binding. In this review, we demonstrate that protein-bound uremic toxins may play an important role in progression of cardiovascular disease in the setting of chronic kidney disease. The highly protein-bound uremic toxin indoxyl sulfate has emerged as a potent toxin adversely affecting both the kidney and heart. Direct cardiac effects of this toxin have been recently demonstrated both in vitro and in vivo. Specifically, potent fibrogenic and prohypertrophic effects, as well as oxidative stress-inducing effects, appear to play a central role in both renal and cardiac pathology. Many of these adverse effects can be suppressed by use of a gut adsorbent, AST-120. Potential mechanisms underlying indoxyl sulfate-induced cardiorenal fibrosis are discussed. Future research and clinical implications conclude this review.

Calcification of coronary arteries and abdominal aorta in relation to traditional and novel risk factors of atherosclerosis in hemodialysis patients

Background

Process of accelerated atherosclerosis specific for uremia increases cardiovascular risk in patients with chronic kidney disease (CKD) and may be influenced by the different structure of arteries. The study assesses the influence of traditional and novel risk factors on calcification of coronary arteries (CAC) and abdominal aorta (AAC) in hemodialysis patients (HD).

Methods

CAC and AAC were assessed by CT in 104 prevalent adult HD and 14 apparently healthy subjects with normal kidney function (control group). Mineral metabolism parameters, plasma levels of FGF-23, MGP, osteoprotegerin, osteopontin, fetuin-A, CRP, IL-6 and TNF-α were measured.

Results

CAC and AAC (calcification score ≥ 1) were found in 76 (73.1%) and 83 (79.8%) HD respectively, more frequent than in the control group. In 7 HD with AAC no CAC were detected. The frequency and severity of calcifications increased with age. Both CAC and AAC were more frequently detected in diabetics (OR = 17.37 and 13.00, respectively). CAC score was significantly greater in males. CAC and AAC scores were correlated significantly with pack-years of smoking and plasma osteoprotegrin levels. However the independent contribution of plasma osteoprotegerin levels was not confirmed in multiple regression analysis. Age (OR = 1.13) and hemodialysis vintage (OR = 1.14) were the independent risk factor favoring the occurrence of CAC; while age (OR = 1.20) was the only predictor of AAC occurrence in HD.

Conclusions

1. AAC precedes the occurrence of CAC in HD patients. 2. The exposition to uremic milieu and systemic chronic microinflammation has more deteriorative effect on the CAC than the AAC.

Association between uremic toxins and depression in patients with chronic kidney disease undergoing maintenance hemodialysis

OBJECTIVE

Patients with chronic kidney disease (CKD) who are undergoing maintenance hemodialysis have a higher prevalence of depression than the general population. The underlying cause of this association is unknown, but may be related to accumulation of uremic toxins. Little is known about the association of accumulation of uremic toxins and depression in hemodialysis patients.

METHOD

We conducted a cross-sectional study of 209 CKD patients from a single institution to evaluate the associations of a soluble small uremic toxin (urea), a soluble large uremic toxin (β2 microglobulin) and two protein-bound uremic toxins [total p-cresol sulfate (PCS) and indoxyl sulfate (IS)] with the presence of depression.

RESULTS

A total of 47 patients (22.4%) had depression. Depressive patients had lower body mass index, lower serum creatinine, lower serum albumin and lower total IS. Univariate and multivariate logistic regression analyses that adjusted for age, gender and other statistically significant variables indicated that depression was significantly and independently associated with lower serum albumin and lower total IS. The levels of urea, β2 microglobulin and PCS were not significantly associated with depression.

CONCLUSION

Our results indicate that depression in patients with CKD was significantly and independently associated with lower serum albumin and lower total IS. However, the pathological mechanisms underlying these associations are unknown.

Coronary Stents in Patients with ST-Elevation Myocardial Infarction and Chronic Kidney Disease Undergoing Primary Percutaneous Coronary Intervention

Background and Objectives

Chronic kidney disease (CKD) is associated with poor outcomes after percutaneous coronary intervention (PCI). We sought to compare different coronary stents used during primary PCI in patients with ST-elevation myocardial infarction (STEMI) and CKD.

Subjects and Methods

We selected 2408 consecutive STEMI patients with CKD (estimated glomerular filtration rate <60 mL/min/1.73 m²) undergoing primary PCI and divided them into 5 groups based on the type of stent implanted: 1) bare metal stent (BMS), 2) paclitaxel-eluting stent (PES), 3) sirolimus-eluting stent (SES), 4) zotarolimus-eluting stent (ZES), or 5) everolimus-eluting stent (EES). The study endpoint was the number of major adverse cardiac events (MACE) at 12 months.

Results

There was no significant difference in the incidence of 12-month myocardial infarction, target lesion revascularization, or target vessel revascularization between stent groups; however, the overall rate of repeat revascularization differed significantly between groups. All-cause death differed significantly among the groups. The incidence of 12-month MACE in BMS, PES, SES, ZES, and EES was 8.3%, 9.8%, 8.6%, 5.5%, and 2.6%, respectively (p<0.001). Kaplan-Meier analysis did not show a significant differences in 12-month MACE-free survival among the groups (log-rank p=0.076). This finding remained the same after adjusting for multiple confounders (p=0.147).

Conclusion

Any of the 5 stents can be used to treat STEMI patients with CKD undergoing primary PCI; all have similar risk of 12-month MACE. This result is hypothesis-generating and warrants further evaluation with a long-term randomized study.

Managing cardiovascular risk in people with chronic kidney disease: a review of the evidence from randomized controlled trials

Cardiovascular disease is the leading cause of death and morbidity in people with chronic kidney disease (CKD) making measures to modify cardiovascular risk a clinical priority. The relationship between risk factors and cardiovascular outcomes is often substantially different in people with CKD compared with the general population, leading to uncertainty around pathophysiological mechanisms and the validity of generalizations from the general population. Furthermore, published reports of subgroup analyses from clinical trials have suggested that a range of interventions may have different effects in people with kidney disease compared with those with normal kidney function. There is a relative scarcity of randomized controlled trials (RCTs) conducted in CKD populations, and most such trials are small and underpowered. As a result, evidence to support cardiovascular risk modification measures for people with CKD is largely derived from small trials and post hoc analyses of RCTs conducted in the general population. In this review, we examine the available RCT evidence on interventions aimed at preventing cardiovascular events in people with kidney disease to identify beneficial treatments as well as current gaps in knowledge that should be a priority for future research.

Erectile dysfunction in hemodialysis: A systematic review

Men with chronic renal failure (CRF) on hemodialysis have been frequently associated with erectile dysfunction (ED), with an of between 20% to 87.7%. As a result of the multi-system disease processes present in many uremic men, it is apparent that the pathogenesis of ED is most probably multifactorial. Factors to be considered include peripheral vascular disease, neurogenic abnormalities, hormonal disturbances and medications used for treatment of conditions associated with CRF. These physiological abnormalities may be supplemented by significant psychological stresses and abnormalities resulting from chronic illness. Treatment must start with the determination and treatment of the underlying causes. In addition to psychological treatment, further lines of treatment of ED in CRF can be classified as 1st line (medical treatment which includes oral phosphodiesterase-5 inhibitors and hormone regulation), 2nd line (intracavernosal injection, vacuum constriction devices and alprostadil urethral suppositories) or 3rd line (surgical treatment). Renal transplantation improves the quality of life for some patients with CRF and subsequently it may improve erectile function in a significant number of them, however still there is high incidence of ED after transplantation.

Is There any Time Dependant Echocardiographical Finding in Chronic Hemodialysis Patients?

BACKGROUND

Cardiac disease is the main cause of death in hemodialysis patients. In hemodialysis patients cardiovascular complications are great clinical challenge, and function, shape and left ventricle abnormalities are present in 70 - 80 percent of dialysis patients. Changes in heart function occur in hemodialysis period and are effective in patient's prognosis. In this study we aim to evaluate time dependant clinical and echocardiographical findings in chronic hemodialysis patients.

METHODS

In a cross-sectional study, 100 adult hemodialysis patients (51% male and 49% female with mean age 52.13 ± 12.69 years) visiting dialysis unit in Imam Reza and Madani hospitals between years 2010 and 2011 were studied in group 1 (hemodialysis ≤ 6 months), group 2 (hemodialysis for 6 months to 3 years) and group 3 (hemodialysis ≥ 3 years). Demographic, laboratory and echocardiographic findings were compared between groups.

RESULTS

Among demographic findings, group 3 had significantly higher diastolic blood pressure and weight gain and was older than other two groups (P < 0.05). By increase in hemodialysis period, patients had higher blood urea nitrogen and lower serum albumin levels (P < 0.05). Potassium level in group 2 was significantly higher than group 3 and that was higher than group 1. There was no difference between groups in left ventricular hypertrophy (LVH), left atrium dilatation, ejection fraction and mitral insufficiency. Diastolic dysfunction increased in line with increase in hemodialysis period (P = 0.007). Hemodialysis period was higher in patients with LVH than those without (34.80 ± 9.2 months versus 18.51 ± 2.22 months, P = 0.01).

CONCLUSION

In hemodialysis patients, diastolic dysfunction increases by the hemodialysis time (years). LVH and LA dilation also increase during time, but not significantly.