Coronary artery disease in uremia: Etiology, diagnosis, and therapy

Association between reduced left ventricular ejection fraction and peritoneal dialysis related peritonitis: a single center retrospective cohort study in Japan

We present a single-center retrospective analysis of 228 Japanese patients with peritoneal dialysis, in which we examined whether reduced left ventricular ejection fraction (LVEF) is a risk factor for peritonitis development. Time-dependent multivariable-adjusted Cox proportional hazards models revealed that reduced LVEF (LVEF < 50% vs. preserved LVEF ≥ 50%, hazard ratio (HR) 2.10; 95% confidence interval (CI) 1.16-3.82) was associated with peritonitis. Qualitatively, similar associations with reduced LVEF (< 50%) were observed for enteric peritonitis (adjusted HR 7.68; 95% CI 2.51-23.5) but not for non-enteric peritonitis (adjusted HR 1.15; 95% CI 0.54-2.44). Reduced LVEF is associated with a significantly higher risk of subsequent peritonitis, particularly enteric peritonitis. These results indicate that patients with reduced LVEF may be at risk of enteric peritonitis from bowel sources caused by intestinal involvement due to cardiac dysfunction.

Bleeding in acute coronary syndrome: from definitions, incidence, and prognosis to prevention and management

INTRODUCTION

In patients with acute coronary syndrome (ACS), the ischemic benefit of antithrombotic treatment is counterbalanced by the risk of bleeding. The recognition that bleeding events have prognostic implications (i.e. mortality) similar to recurrent ischemic events led to the development of treatment regimens aimed at balancing both ischemic and bleeding risks.

AREAS COVERED

This review aims at describing definitions, incidence, and prognosis related to bleeding events in ACS patients as well as bleeding-avoidance strategies for their prevention and management of bleeding complications.

EXPERT OPINION

Management of ACS patients has witnessed remarkable progress after the shift in focusing on the trade-off between ischemia and bleeding. Efforts in standardizing bleeding definitions will allow for better defining the prognostic impact of different types of bleeding events and enable to identify the high-bleeding risk patient. Such efforts will allow to balance the trade-off between the thrombotic and bleeding risk of the individual patient translating into better downward diagnostic and therapeutic decision-making. Novel strategies aiming at maximizing the safety and efficacy of antithrombotic regimens as well as the development of novel antithrombotic drugs and reversal agents and technological advances will allow for optimization of bleeding-avoidance strategies and management of bleeding complications.

Oxidative Stress in ESRD Patients on Dialysis and the Risk of Cardiovascular Diseases

Chronic kidney disease is highly prevalent worldwide. The decline of renal function is associated with inadequate removal of a variety of uremic toxins that exert detrimental effects on cells functioning, thus affecting the cardiovascular system. The occurrence of cardiovascular aberrations in CKD is related to the impact of traditional risk factors and non-traditional CKD-associated risk factors, including anemia; inflammation; oxidative stress; the presence of some uremic toxins; and factors related to the type, frequency of dialysis and the composition of dialysis fluid. Cardiovascular diseases are the most frequent cause for the deaths of patients with all stages of renal failure. The kidney is one of the vital sources of antioxidant enzymes, therefore, the impairment of this organ is associated with decreased levels of these enzymes as well as increased levels of pro-oxidants. Uremic toxins have been shown to play a vital role in the onset of oxidative stress. Hemodialysis itself also enhances oxidative stress. Elevated oxidative stress has been demonstrated to be strictly related to kidney and cardiac damage as it aggravates kidney dysfunction and induces cardiac hypertrophy. Antioxidant therapies may prove to be beneficial since they can decrease oxidative stress, reduce uremic cardiovascular toxicity and improve survival.

Coronary artery disease in dialysis patients: evidence synthesis, controversies and proposed management strategies

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality among patients with end-stage renal disease (ESRD). Clustering of traditional atherosclerotic and non-traditional risk factors drive the excess rates of coronary and non-coronary CVD in this population. The incidence, severity and mortality of coronary artery disease (CAD) as well as the number of complications of its therapy is higher in dialysis patients than in non-chronic kidney disease patients. Given the lack of randomized clinical trial evidence in this population, current practice is informed by observational data with a significant potential for bias. Furthermore, guidelines lack any recommendation for these patients or extrapolate them from trials performed in non-dialysis patients. Patients with ESRD are more likely to be asymptomatic, posing a challenge to the correct identification of CAD, which is essential for appropriate risk stratification and management. This may lead to "therapeutic nihilism", which has been associated with worse outcomes. Here, the ERA-EDTA EUDIAL Working Group reviews the diagnostic work-up and therapy of chronic coronary syndromes, unstable angina/non-ST elevation and ST-elevation myocardial infarction in dialysis patients, outlining unclear issues and controversies, discussing recent evidence, and proposing management strategies. Indications of antiplatelet and anticoagulant therapies, percutaneous coronary intervention and coronary artery bypass grafting are discussed. The issue of the interaction between dialysis session and myocardial damage is also addressed.

Outcomes of Routine Coronary Angiography in Asymptomatic Patients With End-Stage Renal Disease Prior to Kidney Transplantation

We report the prevalence of coronary artery disease (CAD) in asymptomatic patients with end-stage kidney disease (ESKD) on hemodialysis and explore the best revascularization strategies prior to kidney transplantation. This is a retrospective single-center study, which included all patients who were candidates for kidney transplantation and underwent coronary angiography between 2003 and 2018. All included patients underwent coronary angiography without noninvasive testing and were asymptomatic cardiac-wise. Out of the 368 patients with ESRD, 45% had coronary vessel disease, 17% had 3-vessel disease, 11% had 2-vessel disease, 5.2% had significant left main artery narrowing, and 17% had single-vessel disease. Patients with 3-vessel disease had the worst survival rate at 5 and 10 years. The patients with significant 3-vessel disease or left main artery involvement underwent revascularization; 19% underwent coronary artery bypass grafting, 5% had stenting of the coronary arteries, and 4.7% were on maximal medical therapy. The patients who underwent stenting had a better survival than those on medical therapy, but the difference was not significant ( P = .445). Our findings reflect a high prevalence of CAD in patients with ESKD. There is a need for further studies to evaluate benefits of cardiovascular screening in this patient population.

Abdominal aortic calcification score predicts the occurrence of coronary artery disease in middle-aged peritoneal dialysis patients

AIM

Abdominal aortic calcification (AAC) score in dialysis patients was associated with coronary artery disease (CAD) in cross-sectional study, but the use of AAC score in the CAD prediction was not clear. We aimed to use AAC score in the estimation of CAD occurrence in middle-aged peritoneal dialysis (PD) patients.

METHODS

Middle-aged (45-65 years old) PD patients were recruited and followed up until CAD occurrence, patient mortality, or PD failure. We quantified AAC score by lateral lumbar radiography, and used receiver operation curve (ROC) analysis to find the cut-off value for CAD prediction.

RESULTS

There were 187 patients recruited for study with a mean follow-up of 1027 ± 427 days. AAC score in patients with CAD during follow-up period (9.7 ± 7.6, n = 41) was higher than in patients without CAD occurrence (5.5 ± 6.1, n = 146) (P < 0.001). Multivariate hazard ratio of AAC score for CAD was 1.07 (P = 0.044). ROC showed that AAC score of 5.5 had a sensitivity of 0.667 and a specificity of 0.581 in the prediction of CAD occurrence. Patients with AAC score above 5.5 had significantly higher cumulative incidence of CAD than patients with AAC score below 5.5 (Log-rank test, P = 0.003). Age (P = 0.002), diabetes (P = 0.002), hypertension (P = 0.032), longer dialysis vintage (P < 0.001) and lower serum potassium (P = 0.012) were parameters significantly associated with higher AAC score.

CONCLUSION

AAC score can predict CAD occurrence in PD patients. Age, diabetes, hypertension, dialysis vintage and serum potassium level are factors associated with higher AAC score.

Coronary Angiography Profile at the Time of Hemodialysis Initiation in End-Stage Renal Disease Population: A Retrospective Analysis

Cardiovascular disease is associated with increased mortality in dialysis population. However, there are very few studies that assessed the prevalence of coronary artery disease (CAD) at the time of initiation of hemodialysis (HD). The present study was aimed to assess the prevalence of CAD in end-stage renal disease (ESRD) patients at the time of initiation of HD and the risk factors for CAD in this population. This was a single-center retrospective study and included ESRD patients who underwent coronary angiography (CAG) at the time of initiation of HD. Inclusion criteria were age >18 years and those who were subjected to CAG within 2 weeks of initiation of HD. According to the findings on CAG, patients were divided into no CAD and CAD groups. CAD was diagnosed if there was >50% stenosis of vessel. Clinical and laboratory parameters between these two groups were analyzed. Ninety-seven patients were included in the study based on the inclusion criteria. Forty-four (45%) patients were diagnosed with CAD. Patients who had CAD were younger compared to no CAD group (50.7 + 10 vs. 55.8 + 9.3 years; P = 0.01). Majority of them were males. Diabetic nephropathy (DN) was associated with increased risk of CAD (60% vs. 40%, P = 0.007). History of smoking, high high-sensitivity C-reactive protein (hs-CRP), low total cholesterol, and low high-density lipoprotein (HDL) were associated with significantly increased risk of CAD. Gender, symptoms of CAD, serum low-density lipoprotein (LDL), very LDL, and triglycerides were not associated with increased risk of CAD. Neither calcium (Ca), phosphorus (PO₄), nor Ca × PO₄products were associated with an increased risk of CAD. Resting electrocardiogram abnormalities had no significance in predicting CAD (32% in CAD and 19% in no CAD group). Echocardiography showed regional wall motion abnormalities/global hypokinesia in 18% patients of CAD group and 3.8% patients of no CAD group (P = 0.03). Single-, double-, and triple-vessel disease was documented in 17 (38%), 13 (29.5%), and 14 (32.5%) patients, respectively, and the most common vessel involved was the left anterior descending artery. At the initiation of HD in ESRD patients, CAD was seen in almost half of the patients. DN was a significant risk factor for CAD. Other risk factors for CAD include smoking, low cholesterol, low HDL, and high hs-CRP levels.

Pharmacological and non pharmacological strategies in the management of coronary artery disease and chronic kidney disease

Patients with advanced chronic kidney disease (CKD), including those treated with dialysis, are at high risk for the development of cardiovascular disease (CVD). CVD accounts for 45-50% of deaths among dialysis patients. Therapy of acute and chronic coronary heart disease (CHD) that is effective in the general population is frequently less effective in patients with advanced CKD. Drug therapy in such patients may require dose modification in some cases. Oral anti-platelet drugs are less effective in those with advanced CKD than in persons with normal or near normal renal function. The intravenous antiplatelet drugs eptifibatide and tirofiban both require dose reductions in patients with advanced CKD. Enoxaparin requires dose reduction in early stage CKD and is contraindicated in hemodialysis patients. Unfractionated heparin and warfarin maybe used without dose adjustment in CKD patients. Atenolol, acetbutolol and nadolol may require dose adjustments in CKD. Metoprolol and carvedilol do not. Calcium channel blockers and nitrates do not require dose adjustment, whereas ranolazine does. Angiotensin converting enzyme inhibitors and angiotensin receptor blockers may safely be used in CKD patients with close observation for hyperkalemia. The safety of spironolactone in such patients is questionable. Statins are less effective in reducing cardiovascular complication in CKD patients and their initiation is not recommended in dialysis patients. Coronary artery bypass grafting is associated with higher short-term mortality, but better long-term morbidity and mortality than percutaneous coronary interventions in patients with advanced CKD with non-ST segment ACS and chronic CHD.

Mortality in hemodialysis patients over 65 years of age

INTRODUCTION

Based on the statistics the population in Bosnia and Herzegovina is getting older. In 2013 the average life span for women was 73.6 years and 68.1 for men. The chronic hemodialysis program is mainly reserved for elderly patients with high mortality risk. The most common cause of hemodialysis mortality relates to cardiovascular diseases (60.2%), regardless of frequent innovations and improvement of hemodialysis procedures.

THE AIM OF THE STUDY

was to determine the mortality rate by age groups with comments on the presence of non-traditional predictors (anemia, hypoalbuminemia, CRP, vascular access and PTH) in dialysis patients in the follow-up period of 36 months.

METHODS

The study included all patients undergoing chronic hemodialysis treatment at the Clinic of Hemodialysis of the Clinical Center University of Sarajevo (CCUS).

RESULTS

Out of a total number of hemodialysis patients (n=232), the specific mortality rate in patients under 65 years of age was 16.8%, and 50.5% in patients over 65 years of age. According to the age groups the mortality rate in elderly patients is as follows: from 65 to 74 years (45.1%), from 75 to 84 years (55.0%), over ≥85 years (75.0%). The most frequent vascular access in patients under and above 65 is arteriovenous fistula (79.6% and 62.1 %), temporary hemodialysis catheter (11.7% and 43.8 %) and long-term hemodialysis catheter (8.8% and 4.2 %). In the age group under 65 years of age the temporary hemodialysis catheter is significantly and more frequently used in diseased patients in respect to survivors (34.8% vs. 7.0%) [χ(2)(2)=15.769, p=0.001]. Diseased patients from the age group over 65 had a significantly lower mean value of haemoglobin in blood (M=100.9±17.5 g/L) in respect to survivors (M=109.2±17.1)[t(93)=2.339; p=0.021], lower mean value of albumin in blood (Me=32.0; IQR=29.0 do 35.0) in respect to survivors (Me=34.0; IQR=32.0 to 38.0) [U=762.5; p=0.006], and higher mean value of CRP in blood (Me=19.3 mg/L; IQR=6.6 to 52.0) in respect to survivors (Me=7.8; IQR=4.0 to 16.7) [U=773.5; p=0.008]. Diseased patients belonging to the age group over 65 had lower mean value of PTH, but without statistical significance (p>0.05).

CONCLUSION

older age, temporary vascular access, anaemia and hypoalbuminemia are strong predictors of mortality in hemodialysis patients. Old age does not present contraindication for hemodialysis treatment, and treatment of terminal renal illness should not be abandoned.

Cardiovascular co-morbidity in chronic kidney disease: Current knowledge and future research needs

Chronic kidney disease (CKD) is recognised as a health concern globally and leads to high rates of morbidity, mortality and healthcare expenditure. CKD is itself an independent risk factor for unfavorable health outcomes that include cardiovascular disease (CVD). Coronary artery disease is the primary type of CVD in CKD patients and a significant cause of death among renal transplant patients. Traditional and non-traditional risk factors for CVD exist in patients with CKD. Traditional factors include smoking, hypertension, dyslipidemia and diabetes which are highly prevalent in CKD patients. Non-traditional risk factors of CKD are mainly uraemia-specific and increase in prevalence as kidney function declines. Some examples of uraemia-specific risk factors that have been well documented include low levels of haemoglobin, albuminuria, and abnormal bone and mineral metabolism. Therapeutic interventions targeted at more traditional risk factors which contribute to CVD, have not had the desired effect on lowering CVD events and mortality in those suffering with CKD. Future research is warranted to delineate clear evidence to the benefit of modifying non-traditional risk factors.

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.

Patients with end-stage renal disease: optimal diagnostic and prognostic performance of myocardial gated-SPECT, initial results

PURPOSE

We investigated the role of Tc-99m sestamibi myocardial perfusion gated single photon emission computed tomography (GSPECT) in identifying those patients with end-stage renal disease (ESRD) in whom optimal diagnosis of coronary artery disease and prediction of cardiac events (CEs) could be achieved.

METHODS

This was a prospective study that included 41 asymptomatic ESRD patients who had been undergoing hemodialysis for 12 months or less (22 men and 19 women) with restricted selection criteria (asymptomatic traditional risk). Tc-99m sestamibi GSPECT was carried out for all patients, whereas coronary angiography (Cath) was carried out only for abnormal GSPECT patients, with a 2-year follow-up for CEs. Twenty individuals matched for age, sex, and BMI formed the control group.

RESULTS

Of the 41 ESRD patients, 13 showed abnormal GSPECT [11/13 with myocardial perfusion defects and left ventricular dysfunction in concordance with Cath and 2/13 with only left ventricular dysfunction (i.e. stunning)] compared with 1/20 in the control group. None of the patients with negative results experienced CEs (negative predictive value 100%); these patients had a 2-year CE-free survival rate of 100% compared with 46% for patients with positive results on GSPECT (P<0.0001; seven GSPECT-positive patients developed CEs during their follow-up). Patients with positive results were more frequently male (P<0.001), were significantly older (P=0.01), and had highly sensitive C-reactive protein levels (P=0.002). Abnormal GSPECT was the only independent predictor of CEs (95% confidence interval, 7.1-46.7; hazard ratio, 46.1; P<0.001).

CONCLUSION

GSPECT exhibited optimum performance for coronary artery disease detection and risk stratification in asymptomatic ESRD patients during their first year of regular hemodialysis who were selected according to our modification of the traditional risk category. This may help in selecting suitable candidates for Cath, revascularization, and future renal transplantation.

Chronic kidney disease--is it a true risk factor of reduced clopidogrel efficacy in elderly patients with stable coronary artery disease?

BACKGROUND

Chronic kidney disease (CKD) is an established predictor of recurrent ischemic events in patients with coronary artery disease (CAD). This association has been partially ascribed to high post-treatment platelet reactivity (HPPR) according to platelet function testing. However, the influencing factors of HPPR are assay-dependent, and the relevant data of elderly patients with stable CAD are absent.

PATIENTS AND METHODS

310 elderly patients (>80years of age) with stable CAD taking prolonged maintenance clopidogrel (75mg/day) were studied. Maximal platelet aggregation rate (MPA%) with light transmittance aggregometry and Platelet Reactive Units (PRU) with VerifyNow (VN) P2Y12 system were obtained. Markers of platelet activation, including PAC-1 and CD62P, were also determined.

RESULTS

Patients on different stages of CKD presented similar MPA% and expression of PAC-1 and CD62P. Although severe CKD patients were more likely to present HPPR identified by VNP2Y12 (odds ratio: 1.85, p=0.038), multiple logistic regression diminished this effect (adjusted odds ratio: 1.19, p=0.642), and revealed anemia as a possible predictor of HPPR (adjusted odds ratio: 5.92, p=0.001). However, in a parallel way, hemoglobin correlated with baseline PRU values as well as with post-treatment values (r=-0.624 and r=-0.463, respectively, p<0.001). Association between hemoglobin and PRU inhibition rate was not found. Moreover, hemoglobin exerted no influence on MPA% at all.

CONCLUSION

CKD is not necessarily associated with reduced antiplatelet effects of clopidogrel in elderly patients with stable CAD taking prolonged maintenance clopidogrel, and the seemingly influence of CKD on HPPR assessed by VNP2Y12 assay may be due to the artifactual effect of hemoglobin on VNP2Y12.

Cardiovascular disease in chronic kidney disease: untying the Gordian knot

Chronic kidney disease (CKD) affects around 10-13% of the general population, with only a small proportion in end stage renal disease (ESRD), either on dialysis or awaiting renal transplantation. It is well documented that CKD patients have an extremely high risk of developing cardiovascular disease (CVD) compared with the general population, so much so that in the early stages of CKD patients are more likely to develop CVD than they are to progress to ESRD. Various pathophysiological pathways and explanations have been advanced and suggested to account for this, including endothelial dysfunction, dyslipidaemia, inflammation, left ventricular hypertrophy and cardiac autonomic dysfunction. In this review, we try to understand and further explore the link between CKD and CVD, as well as offering interventional advice where available, while exposing the current lack of RCT-based research and trial evidence in this area. We also suggest pragmatic Interim measures we could take while we wait for definitive RCTs.

Diagnosis and treatment of coronary artery disease in hemodialysis patients evaluated for transplant

We present a review of current strategies for the diagnosis and treatment of coronary artery disease (CAD) in patients with advanced chronic kidney disease who are on the waiting list for transplants, based on data from the literature and originated from a single-center cohort of 1,250 patients with maximum follow-up of 12 years. We discuss the best way to select patients to be tested for CAD, how to choose the more adequate screening test for CAD and cardiovascular disease, how to select patients for invasive treatment studies and how to treat patients with significant CAD. We also suggest new research avenues to be explored to resolve some problems in this area.

Relation between estimated glomerular filtration rate and composition of coronary arterial atherosclerotic plaques

It is well known that chronic kidney disease is a risk factor for atherosclerosis. The present study was conducted to identify any relation between the estimated glomerular filtration rate (eGFR) and coronary plaque characteristics using integrated backscatter intravascular ultrasound (IB-IVUS), which can detect coronary plaque composition. We performed IB-IVUS for 201 consecutive patients undergoing percutaneous coronary intervention, and they were divided into 3 groups according to the eGFR values (group 1 [n = 20], ≥90 ml/min/1.73 m(2); group 2 [n = 123], 60 to 90 ml/min/1.73 m(2); and group 3 [n = 58], <60 ml/min/1.73 m(2)). Coronary plaques in nonculprit lesions on 3-dimensional analysis were evaluated using IB-IVUS. The baseline characteristics were similar, except for older age and a greater prevalence of men in group 3. IB-IVUS showed a percentage of lipid volume of 44.7 ± 5.0% in group 1, 53.6 ± 6.2% in group 2, and 63.5 ± 6.2% in group 3 (p <0.01), with a corresponding percentage of fibrous volume of 53.9 ± 4.9%, 45.1 ± 6.0%, and 35.3 ± 6.1%, respectively (p <0.01). The eGFR correlated significantly with both parameters (r = -0.68, p <0.001 and r = 0.68, p <0.001, respectively). In conclusion, lower eGFR levels were associated with greater lipid and lower fibrous contents, contributing to coronary plaque vulnerability.

Relationship of haemodialysis therapy duration and cardiac adrenergic system function assessed by iodine-123 metaiodobenzylguanidine imaging in haemodialysed nondiabetic patients

OBJECTIVE

The aim of the study was to evaluate the relationship of haemodialysis therapy duration with the function of the cardiac adrenergic system in nondiabetic patients.

METHODS

Thirty haemodialysed male patients were enrolled in this study; all patients were evaluated by myocardial perfusion imaging at rest and after dynamic stress, with the assessment of left ventricular ejection fraction (LVEF) at rest and after stress and summed stress score (SSS). Single photon emission computed tomography and planar iodine-123 metaiodobenzylguanidine myocardial scintigraphy were also performed in all the patients. Semiquantitative analysis of iodine-123 metaiodobenzylguanidine myocardial uptake was expressed as the routine heart-to-mediastinum ratio (HMR): 15 min [early HMR (eHMR)] and 4 h [delayed HMR (dHMR)] post administration as well as the washout rate. Twenty-four hours of Holter studies were carried out and heart rate variability was evaluated.

RESULTS

Significant correlations (Spearman's tests) were found between the duration of haemodialysis treatment and the following ratios: eHMR (P=0.03; r=-0.378), dHMR (P=0.04; r=-0.367) and washout rate (P=0.05; r=0.352). Further significant correlations were found between eHMR and LVEFs (P=0.03; r=0.379), SSS (P=0.01; r=-0.429) and between dHMR and LVEFs (P=0.005; r=0.496), LVEFr (P=0.03; r=0.379) and SSS (P=0.02; r=-0.404).

CONCLUSION

The duration of haemodialysed patients appears to be an important factor influencing the cardiac sympathetic nervous system.

Relationship Between Erythropoietin Responsiveness, Insulin Resistance, and Malnutrition-Inflammation-Atherosclerosis (Mia) Syndrome in Hemodialysis Patients with Diabetes

Background

This study aimed to explore the relationship between recombinant human erythropoietin (EPO) responsiveness, insulin resistance, and malnutrition-inflammation-atherosclerosis (MIA) syndrome in hemodialysis patients.

Methods

This was an observational cohort study in hemodialysis patients. Adipokines, inflammatory cytokines, and required EPO dosage were measured in diabetes (DM; n=58) and non-diabetes (non-DM; n=58) groups over 48 weeks. Furthermore, the EPO responsiveness index (required EPO dosage divided by hemoglobin) was evaluated with or without MIA syndrome in both groups.

Results

The DM group had significantly higher plasma leptin, interleukin-6 (IL-6), and high sensitivity C-reactive protein (hs-CRP) levels but lower plasma high molecular weight (HMW) adiponectin levels compared to the non-DM group. Although hemoglobin levels were not significantly different, required EPO dosage was significantly higher in the DM group than in the non-DM group, particularly in the presence of MIA syndrome. The DM group with MIA syndrome had significantly higher plasma leptin, IL-6, and hs-CRP levels but lower plasma HMW adiponectin levels compared to the non-DM group with MIA syndrome. There was also a significant association between EPO dosage and homeostasis model assessment for insulin resistance (HOMA-IR), hs-CRP, IL-6, tumor necrosis factor α, leptin, and HMW adiponectin levels in DM patients with MIA syndrome.

Conclusion

Diabetic hemodialysis patients with MIA syndrome have a lower response to EPO and a higher resistance to insulin. This fact may explain the poor outcome of these patients and demonstrate the importance of diagnosis and therapeutic management.

Prognostic value of reduced left ventricular ejection fraction at start of hemodialysis therapy on cardiovascular and all-cause mortality in end-stage renal disease patients

BACKGROUND AND OBJECTIVES

Cardiac failure is directly affected by left ventricular (LV) dysfunction, and particularly LV systolic dysfunction is strongly associated with survival in ESRD patients. The aim of this study was to determine the prognostic value of reduced LV ejection fraction (LVEF) measured at the time of initiation of hemodialysis (HD) in incident HD patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

1254 consecutive ESRD patients who electively started HD therapy were screened by echocardiography within 1 month after its inception. They were divided into five groups according to LVEF levels with a decrease of 0.1 each and were followed up for up to 7 years. Survival was examined with the Kaplan-Meier method and compared using the log-rank test.

RESULTS

Among the 1254 patients, LVEF levels ≥0.6, 0.5 to 0.6, 0.4 to 0.5, 0.3 to 0.4, and <0.3 were seen in 842 (67.1%), 247 (19.7%), 107 (8.5%), 41 (3.3%), and 17 (1.4%) patients, respectively. On Kaplan-Meier analysis, 7-year event-free rates from cardiovascular death were 84.2, 83.7, 73.6, 59.4, and 30.9% in order of groups with decreasing LVEF of 0.1 each, respectively. Seven-year event-free rates from all-cause death were 69.2, 61.7, 57.1, 45.9, and 23.1% in the respective groups. Even after adjustment for other risk factors, decreasing LVEF was a strong independent predictor for cardiovascular death.

CONCLUSIONS

Reduced LVEF on starting HD therapy could stratify risk of cardiovascular and all-cause mortality in ESRD patients. Screening by echocardiography at start of HD therapy might be recommended to predict prognosis in patients with ESRD.

Comparison of patients starting hemodialysis with those underwent hemodialysis 15 years ago at the same dialysis center in Korea

BACKGROUND/AIMS

Maintenance dialysis is made decreased the death rate of patients with end-stage renal disease; however, mortality is still high. The aim of this study was to identify the association between clinical parameters at the start of hemodialysis with survival and compare these findings with data from patients who underwent hemodialysis about 15 years ago at the same dialysis center.

METHODS

We reviewed 117 patients who started hemodialysis between 2000 and 2004. We analyzed medical histories, laboratory findings, and clinical outcomes, and compared them with patients who started hemodialysis 15 years ago at the same center.

RESULTS

The proportion of elderly patients and those with diabetes increased from 17% and 18% in the previous study to 33% and 49% in this study, respectively. Elderly and patients with diabetes had much higher mortalities than their counterparts. Nevertheless, the overall survival rate (66% vs. 71% at 5 years) and survival of patients with diabetes improved (55% vs. 75% at 1.5 years). Common causes of death were infection and cardiovascular disease in the present study; however, inadequate dialysis accounted for 25% of deaths in the previous study.

CONCLUSIONS

The overall survival rate of patients undergoing hemodialysis has improved over the 15-year interval, even with an increased proportion of elderly patients and patients with diabetes. Adequate dialysis and further medical improvements could ameliorate mortality in patients undergoing dialysis.

Impact of chronic kidney disease on early (30-day) and late (1-year) outcomes of patients with acute coronary syndromes treated with alternative antithrombotic treatment strategies: an ACUITY (Acute Catheterization and Urgent Intervention Triage strategY) substudy

OBJECTIVES

In this substudy of the ACUITY (Acute Catheterization and Urgent Intervention Triage strategY) trial, we investigated the relationship between chronic kidney disease (CKD) and clinical outcomes, and compared the safety and efficacy of bivalirudin monotherapy versus heparin plus a glycoprotein IIb/IIIa inhibitor (GPI).

BACKGROUND

CKD is an important predictor of prognosis in the general population. The outcomes of patients with CKD and acute coronary syndromes (ACS) have not been well studied.

METHODS

In the ACUITY study, 13,819 patients with moderate- and high-risk ACS undergoing an early, invasive strategy were randomly assigned to 1 of 3 antithrombin regimens: a heparin plus a GPI, bivalirudin plus a GPI, or bivalirudin monotherapy. CKD (creatinine clearance <60 ml/min) was present in 2,469 (19.1%) of 12,939 randomized patients with baseline creatinine clearance data.

RESULTS

Patients with CKD had worse 30-day and 1-year clinical outcomes than those with normal renal function. There were no significant differences between bivalirudin monotherapy and heparin plus a GPI in rates of 30-day composite ischemia (11.1% vs. 9.4%, p = 0.27) and net clinical adverse outcomes (16.1% vs. 16.9%, p = 0.65). There was remarkably less major bleeding (6.2% vs. 9.8%, p = 0.008) at 30 days, but no significant difference in 1-year composite ischemia (22.0% vs. 18.9%, p = 0.10) or mortality (7.1% vs. 7.3%, p = 0.96).

CONCLUSIONS

In patients with ACS, CKD is associated with higher 30-day and 1-year adverse event rates. Compared with heparin plus a GPI, the use of bivalirudin monotherapy in patients with CKD results in nonstatistically different ischemic outcomes, but significantly less 30-day major bleeding.

Impact of renal function on coronary plaque composition

BACKGROUND

Recent studies have demonstrated that patients with chronic kidney disease are at high risk of atherosclerosis. Recently it has been found that coronary plaque components can be evaluated by integrated backscatter intravascular ultrasound (IB-IVUS), and lipid-rich plaque is associated with vulnerable plaque. The aim of the study was to investigate the relationship between renal function and tissue characterization of coronary plaque composition at the target stenotic site for percutaneous coronary intervention (PCI).

METHODS

We prospectively performed IB-IVUS before elective PCI in 89 consecutive patients with stable angina. According to estimated glomerular filtration rate (eGFR), they were divided into two groups (eGFR <60 ml/min/ 1.73 m(2) or eGFR > or =60 ml/min/1.73 m(2)). The tissue characteristics of the coronary plaque at each target stenotic site were evaluated by three-dimensional (3D) IB-IVUS just before PCI procedure.

RESULTS

The patients with eGFR <60 ml/min/1.73 m(2) had higher percentage of lipid volume and lower percentage of fibrous volume compared to the patients with eGFR > or = 60 ml/min/1.73 m(2) on the 3D IB-IVUS images (36.7 +/- 10.6% versus 28.7 +/- 9.3%, P < 0.001 and 59.1 +/- 8.7% versus 66.3 +/- 8.3%, P < 0.001, respectively). eGFR showed a significant negative correlation with lipid volume and had a significant positive correlation with fibrous volume in coronary plaques (r = -0.44, P < 0.0001, and r = 0.46, P < 0.0001, respectively).

CONCLUSIONS

Impaired renal function was related to higher percentage of lipid volume and lower percentage of fibrous volume in coronary plaque. Our findings may explain the increasing risk of cardiovascular events in patients with renal dysfunction.

Carotid intima media thickness and aortic calcification index closely relate to cerebro- and cardiovascular disorders in hemodialysis patients

AIM

Atherosclerosis can be evaluated by carotid intima media thickness (IMT), the aortic calcification index (ACI), and pulse wave velocity (PWV). We investigated which test was most closely related to cerebro- and cardiovascular disorders (CCVD) in hemodialysis patients.

METHODS

Maximum IMT (max-IMT), ACI, and PWV were examined in 110 hemodialysis patients, using carotid ultrasonography, abdominal CT and a blood pressure pulse wave instrument, respectively. Blood hemoglobin A1c (HbA1c), serum total cholesterol, high density lipoprotein cholesterol, triglyceride, total protein, albumin, high sensitivity C reactive protein (hs-CRP), and tumor necrosis factor alpha were measured. The patients were divided into two groups; with and without CCVD and the degree of atherosclerosis was evaluated in each group.

RESULTS

Compared to the CCVD (-) group, the CCVD (+) group showed significantly higher percentages of males and diabetic patients, higher levels of HbA1c (5.14 vs 4.83%) and hs-CRP (0.320 vs 0.167 mg/dL), an older age group (64.5 vs 57.5 years), a greater max-IMT (2.05 vs 1.19 mm), and a higher ACI (71.8 vs 41.0%); and significantly lower diastolic blood pressure (82.8 vs 89.2 mmHg). Multiple logistic regression analysis showed that the factors influencing the development of CCVD were age (odds ratio: 1.092), ACI (odds ratio: 1.025), and max-IMT (odds ratio: 2.006). However, PWV did not significantly relate to CCVD.

CONCLUSIONS

In hemodialysis patients, the ACI and max-IMT were significantly associated with CCVD, but the association of PWV was weak. A prospective cohort study is warranted to determine the risk factors for CCVD in hemodialysis patients.

Influence of chronic renal failure on the heart rate response to dipyridamole in patients undergoing myocardial perfusion SPECT

BACKGROUND

Dipyridamole promotes a reduction in blood pressure and an increase in heart rate (HR), considered the normal hemodynamic response to the drug. Data suggest that patients with chronic renal failure (CRF) have an attenuation of this hemodynamic response. This study sought to evaluate the HR response to dipyridamole and its determinants in patients with or without CRF undergoing gated myocardial perfusion single photon emission computed tomography.

METHODS AND RESULTS

Consecutive patients (n = 355, 9.6% with CRF) undergoing rest/dipyridamole myocardial perfusion single photon emission computed tomography were evaluated. The HR response to dipyridamole was considered to be reduced if the HR ratio (maximal HR/rest HR) was 1.20 or less. A logistic regression analysis determined independent predictors of a blunted HR response. A reduced HR response was found in 84.4% of patients with CRF and 40.6% of those without CRF (P < .0001). In patients without CRF the independent predictors of abnormal HR response were hypertension, rest and differential perfusion scores, and left ventricular ejection fraction. In contrast, in CRF patients there was no significant association of any of the studied variables with abnormal HR response.

CONCLUSIONS

An abnormal HR response to dipyridamole is frequently found in patients with CRF. Different mechanisms may account for abnormal HR response in patients with or without CRF.

Cilostazol improves long-term patency after percutaneous transluminal angioplasty in hemodialysis patients with peripheral artery disease

BACKGROUND AND OBJECTIVES

Peripheral artery disease (PAD) is common in patients on hemodialysis (HD). Recently, cilostazol has been reported to reduce target lesion revascularization (TLR) after percutaneous transluminal angioplasty (PTA) for PAD in the general population. This study aimed to clarify the effects of cilostazol administration on long-term patency after PTA in HD patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Three-hundred seventy-two consecutive lesions in 193 HD patients successfully undergoing PTA were enrolled in the study and divided into two groups: patients receiving 100 mg cilostazol twice daily in conjunction with standard therapy (130 lesions in 71 patients) and those not administered cilostazol (242 lesions in 122 patients). Effects of cilostazol on preventing restenosis after PTA in these patients were investigated.

RESULTS

Kaplan-Meier analysis demonstrated the 5-yr patency rate was significantly higher in the cilostazol group than in the control group [52.4 versus 32.9%, hazard ratio (HR) 0.55; 95% confidence interval (CI) 0.39 to 0.77, P = 0.0005]. Cox multivariate analysis revealed that administration of cilostazol was an independent predictor of preventing restenosis (HR 0.56, 95% CI 0.36 to 0.87, P = 0.010). In 102 lesions matched after propensity score analysis, cilostazol had a beneficial effect on preventing restenosis (58.4 versus 34.7%, HR 0.47, 95% CI 0.30 to 0.75, P = 0.0017) and was an independent predictor of preventing restenosis (HR 0.50; 95% CI 0.26 to 0.87, P = 0.014) after multivariate Cox analysis.

CONCLUSIONS

Cilostazol administration improves long-term patency after PTA in HD patients with PAD.

Management of ischemic heart disease in patients with chronic kidney disease

Patients with chronic kidney disease (CKD) and ischemic heart disease (IHD) have strikingly high mortality rates. In the general population, there has been a reduction in the mortality and morbidity rates for IHD through the implementation of effective risk-factor-reduction programs and better interventions for patients with established IHD. No such trend has been observed in patients with end-stage kidney disease. This review article addresses the following topics: (i) epidemiology, pathogenesis, clinical CKD patients with IHD; (ii) diagnostic modalities for IHD and their limitation in CKD patients; (iii) medical treatment options and revascularization strategies for these high-risk patients; and (iv) optimal cardiovascular risk management. Generally, in CKD patients with IHD an aggressive approach to IHD is warranted, a low threshold for diagnostic testing should be employed, and awaiting a clinical trial targeting these patients they should be considered for all proven strategies to improve outcomes.

Evaluation of aortic stiffness in children with chronic renal failure

The measurement of aortic stiffness (As) [aortic strain (S), pressure strain elastic modulus (Ep) and pressure strain normalized by diastolic pressure (Ep*)] is suggested as an excellent marker of subclinical arterial sclerosis. We aimed to investigate the presence of As and to determine the relationship between As and some risk factors in children with chronic renal failure (CRF). Twenty-six pre-dialysis (PreD) [female/male (F/M) 7/19] patients and 23 chronic peritoneal dialysis (CPD) (F/M 13/10) patients were assessed. Twenty-nine healthy children were selected as a control group (F/M 14/15). We determined anemia, abnormal calcium/phosphate metabolism, hypertension, diastolic dysfunction, increased left ventricular mass (LVM), hypertriglyceridemia, increased stiffness (Ep, Ep*), and decreased strain (S) in the CRF (PreD and CPD) group compared with the controls (P < 0.05). Presence of renal disease, LVM and usage of angiotensin-converting enzyme inhibitor (ACE-I) in all groups; female gender, duration of disease and the usage of anti-hypertensive drug therapy in CRF patients; and LVM and LVM index in healthy children were found to be independent predictors for aortic stiffness and/or strain. In conclusion, CRF is associated with significant arterial functional abnormalities in uremic children and not controlled by dialysis treatment. These results suggest that, even in young children, uremia has a profound impact on arterial function.

Glomerular filtration rate and coronary artery disease burden in patients with acute coronary syndrome

BACKGROUND

Mild renal dysfunction may be associated with increased cardiovascular morbidity and mortality.

METHODS

The relation between estimated glomerular filtration rate (eGFR), as calculated from plasma creatinine at admission, and coronary artery disease burden (CADB), was studied in a cohort of 110 patients with acute coronary syndrome and coronary atherosclerosis.

RESULTS

A relatively weak but significant negative correlation was found between eGFR and CADB as measured by angiography (coefficient correlation of - 0.26, probability value of 0.006); a similar association was seen in multiple regression analysis, taking CADB as dependent variable, and eGFR, age, plasma calcium and plasma phosphorus as independent variables. After dividing the 110 patients into eGFR tertiles (with mean values of 102.9 +/- 22.8, n = 37, 75.7 + or - 5.6, n = 36, and 53.1 +/- 13.4, n = 37, all in mL/min per 1.73 m(2)), mean CADB values of the lower and higher eGFR tertiles were found to be significantly different (270.6 +/- 176.4 and 192.9 +/- 78.5, respectively). Similar mean values for CADB and for eGFR were noted when patients with elevated ST segment/new left bundle branch block and patients with nonelevated ST segment acute coronary syndrome were compared.

CONCLUSIONS

We conclude that renal function of patients with acute coronary syndromes and coronary atherosclerosis, as estimated at admission, is negatively correlated with coronary artery disease burden. It is unknown whether renal dysfunction acts as a cause for accelerated coronary artery disease or if it merely acts as a surrogate marker for the overall systemic vascular system status.

Efficacy of oral nicorandil in patients with end-stage renal disease: A retrospective chart review after coronary angioplasty in japanese patients receiving hemodialysis

BACKGROUND

Patients receiving hemodialysis for end-stage renal disease (ESRD) are at high risk for death from ischemic heart disease (IHD). Nicorandil, a hybrid compound of adenosine triphosphate-sensitive potassium channel opener and nitric oxide donor, has been reported to improve the clinical prognosis of patients with IHD.

OBJECTIVE

This study sought to investigate the efficacy of oral nicorandil in reducing the risks for cardiovascular events (CVEs) and CVE-related death in patients receiving hemodialysis for ESRD after undergoing percutaneous coronary intervention (PCI) for angina pectoris.

METHODS

For this retrospective chart review, we used data from telephone interviews and medical charts from 3 hospitals in Japan. Data from patients aged <80 years who were receiving hemodialysis for ESRD and who had undergone successful PCI for angina between January 1999 and December 2004 were included in the analysis. Patients were stratified based on status of nicorandil treatment before PCI, as follows: patients receiving nicorandil 5 mg PO TID (the recommended dosage in Japan) for >1 month before PCI (nicorandil group) or those who did not receive nicorandil (control group). We investigated 6-year follow-up data on the primary end point, defined as CVEs (ie, unplanned hospital admission for worsening anginal status, or CVE-related death). The secondary end point was CVE-related death. After the data were initially analyzed, we performed a propensity-matched analysis to minimize selection bias.

RESULTS

Data from 356 patients were included in the study (235 men, 121 women; mean [SD] age, 69 [9] years; mean [SD] weight, 52.3 [9.1] kg; nicorandil group, 198 patients; control group, 158 patients). According to the estimated propensity scores, 107 patients from each group were matched. There were no differences between the 2 groups in the baseline characteristics. On propensity-matched patient analysis, the estimated rates of patients who were CVE-free at 6 years were 33.5% in the nicorandil group and 21.8% in the control group on Kaplan-Meier analysis (hazard ratio [HR] = 0.53; 95% CI, 0.36-0.78; P < 0.002), and the rates of 6-year survival (ie, patients who did not experience CVE-related death) were 92.7% in the nicorandil group and 85.8% in the control group (HR = 0.27; 95% CI, 0.07-0.89; P = 0.047). Cox multivariate analysis found that nico-randil treatment status was an independent predictor of CVEs (HR = 0.40; 95% CI, 0.18-0.91; P = 0.028) and CVE-related death (HR = 0.38; 95% CI, 0.14-0.78; P = 0.030).

CONCLUSION

Results obtained in this retrospective study suggest the potential efficacy of nicorandil treatment in improving clinical outcomes in patients with IHD receiving hemodialysis following PCI.

Carotid artery thickness in children and young adults with end stage renal disease

Atherosclerosis is a major cause of morbidity and mortality for ESRD patients and we have little knowledge about the presence and risk factors of atherosclerosis in children with CRF. The measurement of carotid artery intima-media thickness (cIMT) using high-resolution ultrasonography is suggested as an excellent marker of subclinical atherosclerosis. In this study, we aimed to investigate the presence of atherosclerosis and to determine the relationship between atherosclerosis and some risk factors in children and young adults with ESRD. Thirty-four patients with ESRD and 20 controls were included in this study. The measurement of cIMT was performed by using a linear B-mode 7.5-MHz ultrasound transducer. We determined anemia, abnormal calcium/phosphate metabolism, hyperhomocysteinemia, hypertriglyceridemia and increased lipoprotein (a) levels in the ESRD group. The cIMT in the ESRD group was higher than in the control group (P<0.05). SBP, DBP, MAP, LVMI and LVH prevalence were statistically higher in the ESRD group (P<0.05). There were significant positive correlations between cIMT and LVMI, MBP, whereas a significant negative correlation was determined between cIMT and PTH in the ESRD group (P<0.05). When a multiple linear regression analysis was performed with cIMT as a dependent variable and LVMI, MBP, PTH, as independent variables, a significant positive correlation was determined between cIMT and LVMI (P<0.05). In conclusion, we think that arteriopathy occurs in children with ESRD. Left ventricular hypertrophy and hypertension may associate with vascular changes in children and young adults with ESRD. Further investigations are necessary to explain association of LVMI index with cIMT.

Care of the end-stage renal disease patient on dialysis in the ED

End-stage renal disease is a major public health problem. In the United States, more than 350,000 patients are being treated with either hemodialysis or continuous ambulatory peritoneal dialysis. Given the high burden of comorbidities in these patients, it is imperative that emergency physicians be aware of the complexities of caring for acute illnesses in this population. This article reviews the common medical problems that bring patients with end-stage renal disease to the emergency department, and their evaluation and management.

Clopidogrel diminishes hemodialysis access graft thrombosis

BACKGROUND

The most common complication of hemodialysis access graft is thrombosis. Clopidogrel, an inhibitor of platelet aggregation, was assessed to prevent this serious complication.

METHODS

Nineteen patients on chronic hemodialysis whose vascular accesses were grafts were divided into two groups: Group A (n=11, 58%) consisted of patients who did not receive anti-thrombotic therapy after graft placement; Group B (n=8, 42%) received clopidogrel 75 mg/day from two days after surgery onwards. Both groups were well matched with respect to age, gender, cause of renal failure, hematocrit, platelet count and Kt/V. All patients' thrombotic episodes were followed up from the day of graft surgery until thrombosis was diagnosed. Finally, the survival difference between both groups was determined.

RESULTS

Ten thrombotic episodes were diagnosed in Group A while no events were reported in Group B (p<0.001). Graft access days of patency were significantly more in Group B than in Group A (350.8+/-166 vs 86.8+/-69, p<0.001). The time elapsed from dialysis initiation to graft placement was not different (Group A: 18+/-12 days; Group B: 20+/-10 days). Days in hemodialysis were different between both groups (Group A: 195.9+/-96; Group B: 545.5+/-291, p<0.001) and all patients of Group A (n=11, 57.9%) and two patients of Group B (25%) died (p=0.001). No major bleeding events were reported.

CONCLUSIONS

Clopidogrel significantly decreased thrombotic graft episodes. Patients on clopidogrel had a prolonged vascular access patency, longer time on hemodialysis and longer survival.

Coronary artery and other vascular calcifications in patients with cystinosis after kidney transplantation

Cystinosis, an autosomal recessive disorder of lysosomal cystine accumulation, results from mutations in the CTNS gene that encodes the lysosomal cystine transporter, cystinosin. Renal tubular Fanconi syndrome occurs in infancy, followed by rickets, growth retardation, photophobia, and renal failure, which requires renal transplantation at approximately 10 yr of age. Treatment with cysteamine decreases cellular cystine levels, retards renal deterioration, and allows for normal growth. Patients with a history of inadequate cystine depletion therapy may survive, after renal transplantation, into the third to fifth decades but will experience other, extrarenal complications of the disease. Routine chest and head computed tomography scans of 41 posttransplantation patients with cystinosis were reviewed for vascular calcification. The radiologic procedures had been performed to examine lung and brain parenchyma, so there was little ascertainment bias. Thirteen of the 41 patients had vascular calcification, including 11 with coronary artery calcification. One 25-yr-old man required three-vessel coronary artery bypass graft surgery. There were no significant differences between the 13 patients with calcification and the 28 without calcification in the following parameters: Time on dialysis, frequency of transplantation, hypertension, hypercholesterolemia, homozygosity for the 57-kb deletion in CTNS, serum creatinine, and calcium-phosphate product. However, the finding of vascular calcification correlated directly with duration of life without cysteamine therapy and inversely with duration of life under good cystine-depleting therapy. The accumulation of intracellular cystine itself maybe a risk factor for vascular calcifications, and older patients with cystinosis should be screened for this complication.

Practical ways to deal with the high burden of cardiovascular disease in hemodialysis patients

Cardiovascular disease is the main cause of death among hemodialysis patients. Although uremia by itself may be considered to be a cardiovascular risk factor, a significant proportion of dialysis patients die because of cardiovascular disease not directly attributable to uremia. Indeed, many of the cardiovascular diseases and cardiovascular risk factors in these patients are common to those occurring in the general population and are amenable to intervention. Lack of proper medical care during the early stages of renal insufficiency and present-day dialysis routines, by failing to correct hypertension, hypervolemia and left ventricular hypertrophy in many patients, may also add to the cardiovascular burden. The author suggests that, in addition to early treatment and referral to a specialist, chronic renal failure patients should undergo intensive cardiovascular screening and treatment, and correction of cardiovascular risk factors based on guidelines established for the general population.

Clopidogrel Diminishes Hemodialysis Access Graft Thrombosis

BACKGROUND

The most common complication of hemodialysis (HD) access graft is thrombosis. Clopidogrel, an inhibitor of platelet aggregation, was assessed to prevent this serious complication.

METHODS

A prospective study in which 24 patients on chronic HD whose vascular accesses were grafts were divided into two groups: group A (n = 12, 50%) consisted of patients who did not receive antithrombotic therapy after graft creation, and group B (n = 12, 50%) received clopidogrel 75 mg/day from 2 days after surgery onwards. Both groups were not different according to age, gender, cause of renal failure, hematocrit levels, platelet counts and Kt/V. All patients' thrombotic episodes were followed up from the day of graft surgery until thrombosis was diagnosed. Finally, the patient survival difference between both groups was determined.

RESULTS

Eleven thrombotic episodes were diagnosed in group A while one event was reported in group B (p < 0.001). Graft access days of patency were significantly longer in group B compared to group A (380.8 +/- 170 vs. 90.1 +/- 57.2, p < 0.001). Time that elapsed from dialysis initiation to graft creation was not different (group A 18 +/- 12 days, group B 20 +/- 10 days). Days on HD were different between both groups (group A 208.9 +/- 97.2 vs. group B 583.2 +/- 287.0, p < 0.001) and all patients from group A (n = 12, 100%) and 2 patients from group B (16.7%) died (p = 0.001). Major bleeding events were not reported.

CONCLUSIONS

Clopidogrel significantly decreased thrombotic graft episodes. Patients on clopidogrel had a prolonged vascular access patency, longer time on HD and better survival.

Increased arterial stiffness in children on haemodialysis

BACKGROUND

Measures of aortic stiffness--aortic pulse wave velocity (PWV) and augmentation index (AIx)--have been shown to be powerful predictors of survival in adult haemodialysis (HD) patients. Very few data have been reported regarding arterial stiffness in paediatric renal populations.

METHODS

PWV and aortic AIx were determined from contour analysis of arterial waveforms recorded by applanation tonometry using a SphygmoCor device in 14 children on HD (age = 14.1 years) and in 15 age, height matched children controls.

RESULTS

Pre-HD AIx (29.7 +/- 15.4%) and PWV (6.6 +/- 1.0 m/s) were significantly higher compared with children controls (8.3 +/- 8.0% and 5.4 +/- 0.6 m/s, respectively, P < 0.0001). The only significant difference between normal and HD children was BP level: 103/61 vs 114/72 mmHg, P < 0.05. In children of HD patients, a multiple linear regression model including BP, age, height, weight, Ca and P levels as independent variables accounted for 57% of the variability in AIx. Dialysis had no impact on AIx (post-HD: 28.5 +/- 12.7%) or on PWV (post-HD: 6.7 +/- 0.8 m/s).

CONCLUSIONS

We show, in this first-ever report of increased arterial stiffness in children on dialysis, that end-stage renal disease is associated with abnormalities in arterial wall elastic properties, comparable with adult levels, even in childhood. Most importantly, the absence of a discernible amelioration with dialysis implies that purely structural and not functional alterations lie behind the increased arterial stiffness.

Association between Hyperhomocysteinemia and Ultrasonographic Atherosclerotic Indices of Carotid Arteries in Chronic Hemodialysis Patients

BACKGROUND

Atherosclerotic cardiovascular events are a major cause of morbidity and the main cause of mortality in hemodialysis patients. Hyperhomocysteinemia--which is a consistent finding in uremic patients--is considered an independent risk factor for cardiovascular disease (CVD). However, the relationship between plasma homocysteine (Hcy) concentrations and atherosclerotic CVD has not been extensively investigated.

PATIENTS AND METHODS

37 patients undergoing chronic hemodialysis and 30 healthy individuals (control group), sex- and age-matched, were included in this study. Both healthy controls and hemodialysis patients underwent echo-Doppler carotid artery examination. The right and left carotid arteries were assessed separately. Our observation included measurements of the ultrasound images of the intimal wall thickness, the lumen diameter and the atherosclerotic plaques. We determined plasma Hcy, vitamin B12 and folic acid levels and serum cholesterol, triglycerides, HDL, ApoA-I, ApoB-100, Lp(a), CRP, albumin and creatinine levels in blood samples from both studied groups. We also determined the urea reduction ratio in the patient groups. The epidemiological as well as the biochemical data were correlated with the findings of the carotid artery examination.

RESULTS

Plasma Hcy levels were significantly increased in hemodialysis patients compared to controls (33 +/- 12.3 vs. 12.27 +/- 7.47 micromol/l, p < 0.001). Intimal wall thickness, lumen diameter and number of atherosclerotic plaques of both carotid arteries were significantly higher (p < 0.01 or p < 0.001) in patients compared to controls. There was a significant positive correlation between plasma Hcy levels and the number of the atherosclerotic plaques (r = 0.41, p < 0.01 in the right and r = 0.49, p < 0.001 in the left carotid artery). Lumen diameter was significantly (p < 0.01) associated with age, MAP and CRP levels. Significant correlations (p = 0.05-0.01) were also found between the number of the plaques and age as well as the duration of hemodialysis, while folic acid levels were inversely correlated with the number of the plaques.

CONCLUSIONS

Both hyperhomocysteinemia and atherosclerotic indices of the carotid arteries are more prevalent in hemodialysis patients compared to healthy controls. Elevated plasma Hcy levels were associated with the carotid artery atherosclerotic indices in chronic hemodialysis patients.