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Background: Coronary microvascular dysfunction (CMD) is common in end-stage renal disease (ESRD) and is an adverse prognostic marker. Coronary flow velocity reserve (CFVR) is a measure of coronary microvascular function and can be assessed using Doppler echocardiography. Reduced CFVR in ESRD has been attributed to factors such as diabetes, hypertension and left ventricular hypertrophy. The contributory role of other mediators important in the development of cardiovascular disease in ESRD has not been studied. The aim of this study was to examine the prevalence of CMD in a cohort of kidney transplant candidates and to look for associations of CMD with markers of anaemia, bone mineral metabolism and chronic inflammation., Methods: Twenty-two kidney transplant candidates with ESRD were studied with myocardial contrast echocardiography, Doppler CFVR assessment and serum multiplex immunoassay analysis. Individuals with diabetes, uncontrolled hypertension or ischaemic heart disease were excluded., Results: 7/22 subjects had CMD (defined as CFVR < 2). Demographic, laboratory and echocardiographic parameters and serum biomarkers were similar between subjects with and without CMD. Subjects with CMD had significantly lower haemoglobin than subjects without CMD (102 g/L ± 12 vs. 117 g/L ± 11, p = 0.008). There was a positive correlation between haemoglobin and CFVR (r = 0.7, p = 0.001). Similar results were seen for haematocrit. In regression analyses, haemoglobin was an independent predictor of CFVR (β = 0.041 95% confidence interval 0.012-0.071, p = 0.009) and of CFVR < 2 (odds ratio 0.85 95% confidence interval 0.74-0.98, p = 0.022)., Conclusions: Among kidney transplant candidates with ESRD, there is a high prevalence of CMD, despite the absence of traditional risk factors. Anaemia may be a potential driver of microvascular dysfunction in this population and requires further investigation.

For patients awaiting renal transplantation, there is guideline consensus on the need for ischemia testing but no agreement on the frequency of repeat testing. Moreover, there are no data in this population evaluating changes in ischemia assessed with serial myocardial perfusion imaging. Consecutive patients (n = 649) with end-stage renal disease (ESRD) were referred for cardiovascular risk stratification before renal transplantation between 2007 and 2013. Of these, 151 patients (54 ± 9 years) underwent 2 stress-rest technetium-99 m single-photon emission computed tomographic (SPECT) studies with CT attenuation correction in accordance with regional guidelines, which recommend repeat imaging in high-risk subjects who have not undergone renal transplantation within 3 years. An abnormal perfusion result was defined as a summed stress score ≥4. The median interval between imaging was 39 months. At baseline, 28% of patients (42/151) had abnormal SPECT perfusion, half with a fixed defect. Nine subjects (6%) underwent revascularization between SPECT studies after the baseline imaging demonstrated an ischemic perfusion defect size affecting ≥10% of the myocardium. On repeat imaging, 60% (25/42) had abnormal perfusion. In the 72% (109 of 151) with normal baseline SPECT perfusion, 19% (21/109) demonstrated new ischemia at follow-up and 3% (3/109) had an ischemic perfusion defect size ≥10%. The development of new-onset ischemia was associated with systolic hypertension (p = 0.015), serum phosphate (p = 0.043), and Agatston score (p = 0.002), but not diabetes (p = 0.12). In conclusion, there is a high frequency of new-onset ischemia in patients with ESRD awaiting renal transplantation. Further study is needed to define the optimal timing for repeat stress testing., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Chronic kidney disease (CKD) is associated with increased left ventricular (LV) mass and arterial stiffness. In a previous trial, spironolactone improved these end points compared with placebo in subjects with early-stage CKD, but it is not known whether these effects were specific to the drug or secondary to blood pressure lowering., Aim: The aim was to investigate the hypothesis that spironolactone is superior to chlorthalidone in the reduction of LV mass while exerting similar effects on blood pressure., Design: This is a multicenter, prospective, randomized, open-label, blinded end point clinical trial initially designed to compare the effects of 40weeks of treatment with spironolactone 25mg once daily to chlorthalidone 25mg once daily on the co-primary end points of change in pulse wave velocity and change in LV mass in 350 patients with stages 2 and 3 CKD on established treatment with an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Because of slow recruitment rates, it became apparent that it would not be possible to recruit this sample size within the funded time period. The study design was therefore changed to one with a single primary end point of LV mass requiring 150 patients. Recruitment was completed on 31 December 2016, at which time 154 patients had been recruited. Investigations included cardiac magnetic resonance imaging, applanation tonometry, 24-hour ambulatory blood pressure monitoring, and laboratory tests. Subjects are assessed before and after 40weeks of randomly allocated drug therapy and at 46weeks after discontinuation of the study drug., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)

Coronary artery calcium score (CACS) is a strong predictor of adverse cardiovascular events in the general population. Recent data confirm the prognostic utility of single-photon emission computed tomographic (SPECT) imaging in end-stage renal disease, but whether performing CACS as part of hybrid imaging improves risk prediction in this population is unclear. Consecutive patients (n = 284) were identified after referral to a university hospital for cardiovascular risk stratification in assessment for renal transplantation. Participants underwent technetium-99m SPECT imaging after exercise or standard adenosine stress in those unable to achieve 85% maximal heart rate; multislice CACS was also performed (Siemens Symbia T16, Siemens, Erlangen, Germany). Subjects with known coronary artery disease (n = 88) and those who underwent early revascularization (n = 2) were excluded. The primary outcome was a composite of death or first myocardial infarction. An abnormal SPECT perfusion result was seen in 22% (43 of 194) of subjects, whereas 45% (87 of 194) had at least moderate CACS (>100 U). The frequency of abnormal perfusion (summed stress score ≥4) increased with increasing CACS severity (p = 0.049). There were a total of 15 events (8 deaths, and 7 myocardial infarctions) after a median duration of 18 months (maximum follow-up 3.4 years). Univariate analysis showed diabetes mellitus (Hazard ratio [HR] 3.30, 95% CI 1.14 to 9.54; p = 0.028), abnormal perfusion on SPECT (HR 5.32, 95% CI 1.84 to 15.35; p = 0.002), and moderate-to-severe CACS (HR 3.55, 95% CI 1.11 to 11.35; p = 0.032) were all associated with the primary outcome. In a multivariate model, abnormal perfusion on SPECT (HR 4.18, 95% CI 1.43 to 12.27; p = 0.009), but not moderate-to-severe CACS (HR 2.50, 95% CI 0.76 to 8.20; p = 0.130), independently predicted all-cause death or myocardial infarction. The prognostic value of CACS was not incremental to clinical and SPECT perfusion data (global chi-square change = 2.52, p = 0.112). In conclusion, a perfusion defect on SPECT is an independent predictor of adverse outcome in potential renal transplant candidates regardless of the CACS. The use of CACS as an adjunct to SPECT perfusion data does not provide incremental prognostic utility for the prediction of mortality and nonfatal myocardial infarction in end-stage renal disease., (Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.)

Coronary artery calcification (CAC) is a strong predictor of cardiovascular event rates in the general population, and scoring with multislice computed tomography commonly is used to improve risk stratification beyond clinical variables. CAC is accelerated in chronic kidney disease, but this occurs as a result of 2 distinct pathologic processes that result in medial (arteriosclerosis) and intimal (atherosclerosis) deposition. Although there are data that indicate that very high CAC scores may be associated with increased risk of death in hemodialysis, average CAC scores in most patients are elevated at a level at which discriminatory power may be reduced. There is a lack of data to guide management strategies in these patients based on CAC scores. There are even fewer data available for nondialysis patients, and it is uncertain whether CAC score confers an elevated risk of premature cardiovascular morbidity and mortality in such patients. In this article, we review the evidence regarding the utility of CAC score for noninvasive cardiovascular risk assessment in individuals with chronic kidney disease, using a clinical vignette that highlights some of the limitations in using CAC score and considerations in risk stratification., (Copyright © 2015 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

Background: Chronic kidney disease is associated with increased arterial stiffness even in the early stages and this is thought to be a key mediator in the pathophysiology of the increased cardiovascular risk associated with this condition. The use of low-dose spironolactone has previously been shown to improve arterial stiffness and reduce left ventricular mass safely in early-stage chronic kidney disease in the context of careful monitoring at a university hospital. However, the majority of patients with chronic kidney disease are managed by their general practitioners in the community. It is not known whether similar beneficial effects can be achieved safely using spironolactone in the primary care setting. The aim of this study is to determine whether low-dose spironolactone can safely lower arterial stiffness in patients with stage 3 chronic kidney disease in the primary care setting., Methods/design: STOP-CKD is a multicentre, prospective, randomized, double-blind, placebo-controlled pilot trial of 240 adult patients with stage 3 chronic kidney disease recruited from up to 20 general practices in South Birmingham, England. Participants will be randomly allocated using a secured web-based computer randomization system to receive either spironolactone 25 mg once daily or a matching inactive placebo for 40 weeks, followed by a wash-out period of 6 weeks. Investigators, outcome assessors, data analysts and participants will all be blinded to the treatment allocation. The primary endpoint is improved arterial stiffness, as measured by carotid-femoral pulse wave velocity between baseline and 40 weeks. The secondary endpoints are incidence of hyperkalaemia, change in estimated glomerular filtration rate, change in urine albumin:creatinine ratio, change in brachial blood pressure, change in pulse waveform characteristics and overall tolerability of spironolactone. An additional quality control study, aiming to compare the laboratory serum potassium results of samples processed via two methods (utilizing routine transport or centrifugation on site before rapid transport to the laboratory) for 100 participants and a qualitative research study exploring patients' and general practitioners' attitudes to research and the use of spironolactone in chronic kidney disease in the community setting will be embedded in this pilot study., Trial Registration: Current Controlled Trials ISRCTN80658312.

Background: There is strong evidence of an association between chronic kidney disease (CKD) and cardiovascular disease. To date, however, proof that a reduction in glomerular filtration rate (GFR) is a causative factor in cardiovascular disease is lacking. Kidney donors comprise a highly screened population without risk factors such as diabetes and inflammation, which invariably confound the association between CKD and cardiovascular disease. There is strong evidence that increased arterial stiffness and left ventricular hypertrophy and fibrosis, rather than atherosclerotic disease, mediate the adverse cardiovascular effects of CKD. The expanding practice of live kidney donation provides a unique opportunity to study the cardiovascular effects of an isolated reduction in GFR in a prospective fashion. At the same time, the proposed study will address ongoing safety concerns that persist because most longitudinal outcome studies have been undertaken at single centers and compared donor cohorts with an inappropriately selected control group., Hypotheses: The reduction in GFR accompanying uninephrectomy causes (1) a pressure-independent increase in aortic stiffness (aortic pulse wave velocity) and (2) an increase in peripheral and central blood pressure., Methods: This is a prospective, multicenter, longitudinal, parallel group study of 440 living kidney donors and 440 healthy controls. All controls will be eligible for living kidney donation using current UK transplant criteria. Investigations will be performed at baseline and repeated at 12 months in the first instance. These include measurement of arterial stiffness using applanation tonometry to determine pulse wave velocity and pulse wave analysis, office blood pressure, 24-hour ambulatory blood pressure monitoring, and a series of biomarkers for cardiovascular and bone mineral disease., Conclusions: These data will prove valuable by characterizing the direction of causality between cardiovascular and renal disease. This should help inform whether targeting reduced GFR alongside more traditional cardiovascular risk factors is warranted. In addition, this study will contribute important safety data on living kidney donors by providing a longitudinal assessment of well-validated surrogate markers of cardiovascular disease, namely, blood pressure and arterial stiffness. If any adverse effects are detected, these may be potentially reversed with the early introduction of targeted therapy. This should ensure that kidney donors do not come to long-term harm and thereby preserve the ongoing expansion of the living donor transplant program (NCT01769924)., (© 2014.)

Objective: To explore the relationship between serum phosphate, arterial stiffness and left ventricular mass (LVM) in patients with early-stage chronic kidney disease (CKD)., Design: A cross-sectional observational study., Setting: Single centre., Patients: 208 patients with stage 2 to stage 4 non-diabetic CKD., Interventions: Arterial stiffness was determined through measurement of aortic pulse wave velocity (PWV). Cardiac magnetic resonance was used to determine LVM., Main Outcome Measure: Relationship between serum phosphate, aortic PWV and LVM., Results: Mean age was 54 ± 13 years, mean glomerular filtration rate was 50 ± 15 ml/min/1.73 m(2), mean serum phosphate was 1.11 ± 0.21 mmol/l and mean PWV was 8.6 ± 2.1 m/s. When the cohort was divided into quartiles according to serum phosphate, LVM increased across quartiles (p=0.04), with no significant differences in age, kidney function, blood pressure or PWV. Serum phosphate correlated with LVM (r=0.173; p=0.01), but PWV did not (p=0.2). In a regression model containing gender, serum phosphate, office systolic blood pressure, albumin/creatinine ratio and haemoglobin, 30% of the variation in LVM was explained (p<0.0005), with serum phosphate accounting for 5% of the variance., Conclusion: Serum phosphate is independently associated with LVM in patients with CKD. Interventional studies are required to determine whether this association is causative and whether reducing phosphate exposure reduces LVM in this population.

Background: The rate of decline in kidney function is a powerful predictor of cardiovascular risk in patients with chronic kidney disease (CKD). Serum phosphate and increased arterial stiffness are associated with elevated cardiovascular risk in CKD and the general population. We sought to determine whether serum phosphate and markers of arterial stiffness predict progression of renal dysfunction in patients with early CKD., Methods: Two hundred and twenty-five patients with Stage II-IV CKD were prospectively followed up at University Hospital Birmingham. Serum phosphate was measured at baseline and arterial stiffness was determined through measurement of aortic pulse wave velocity (PWV) and augmentation index (AIx). Progression of renal dysfunction was defined as the slope of estimated glomerular filtration rate (eGFR) against time. We determined the associations between possible predictors and rate of progression and also examined a combined end point of start of dialysis or ≥ 25% decline in eGFR., Results: Mean baseline eGFR was 43 ± 19 mL/min/1.73 m(2) and serum phosphate 1.22 ± 0.27 mmol/L. Median follow-up was 924 days. Serum phosphate independently predicted a greater decline in eGFR; a 1 mmol/L increment in serum phosphate was associated with a 0.34 mL/min/month steeper decline (P = 0.02). Brachial and aortic systolic pressure independently predicted the rate of renal function decline but aortic PWV and AIx had no significant influence. Forty-one patients (18%) reached the combined end point; serum phosphate was significantly higher in this group (1.32 ± 0.36 versus 1.19 ± 0.24 mmol/L, P = 0.04) and was an independent predictor for the combined end point., Conclusions: Serum phosphate independently predicts decline in renal function in early CKD. Further studies are required to determine the mechanisms involved and to investigate the potential benefits of phosphate lowering on preserving kidney function.

Chronic kidney disease is a proinflammatory state associated with increased arterial stiffness. We hypothesized that chronic kidney disease patients on long-term immunosuppression would have lower arterial stiffness and require treatment with less antihypertensive medication compared with non-immunosuppressed patients. A total of 254 patients (97 on immunosuppression) with chronic kidney disease were recruited from specialist renal clinics. Brachial blood pressure, central aortic pressure and waveform and pulse wave velocity were measured. Age, peripheral blood pressure and pulse wave velocity increased with worsening renal function but were not different between immunosuppressed and non-immunosuppressed patients. Central systolic (P < 0.001) and pulse pressure (P = 0.003) and the number of antihypertensive medications (P < 0.001) increased with worsening renal function and were higher in non-immunosuppressed patients (P = 0.02, P = 0.004 and P < 0.001, respectively). Age, mean arterial pressure, number of antihypertensive medications and a diagnosis of diabetes were found to be independent predictors of pulse wave velocity (R(2) = 0.375; P < 0.001). In a subgroup of 30 patient pairs without diabetes mellitus and cardiovascular disease and with a proven renal diagnosis, carefully matched for age, gender, renal function and systolic pressure, the prescribed antihypertensive medication remained lower in the immunosuppressed patients compared with non-immunosuppressed patients (P = 0.04). Pulse wave velocity was lower in the immunosuppressed group (7.5 ± 1.8 vs. 8.8 ± 1.9 m s(-1); P = 0.02). This study suggests that immunosuppression might be a method of reducing blood pressure and arterial stiffness in patients with chronic kidney disease.

Background: Validated prediction scores are required to assess the risks of end-stage renal disease (ESRD) and death in individuals with chronic kidney disease (CKD)., Study Design: Prospective cohort study with validation in a separate cohort., Setting & Participants: Cox regression was used to assess the relevance of baseline characteristics to risk of ESRD (mean follow-up, 4.1 years) and death (mean follow-up, 6.0 years) in 382 patients with stages 3-5 CKD not initially on dialysis therapy in the Chronic Renal Impairment in Birmingham (CRIB) Study. Resultant risk prediction equations were tested in a separate cohort of 213 patients with CKD (the East Kent cohort)., Factors: 44 baseline characteristics (including 30 blood and urine assays)., Outcomes: ESRD and all-cause mortality., Results: In the CRIB cohort, 190 patients reached ESRD (12.1%/y) and 150 died (6.5%/y). Each 30% lower baseline estimated glomerular filtration rate was associated with a 3-fold higher ESRD rate and a 1.3-fold higher death rate. After adjustment for each other, only baseline creatinine level, serum phosphate level, urinary albumin-creatinine ratio, and female sex remained strongly (P < 0.01) predictive of ESRD. For death, age, N-terminal pro-brain natriuretic peptide, troponin T level, and cigarette smoking remained strongly predictive of risk. Using these factors to predict outcomes in the East Kent cohort yielded an area under the receiver operating characteristic curve (ie, C statistic) of 0.91 (95% CI, 0.87-0.96) for ESRD and 0.82 (95% CI, 0.75-0.89) for death., Limitations: Other important factors may have been missed because of limited study power., Conclusions: Simple laboratory measures of kidney and cardiac function plus age, sex, and smoking history can be used to help identify patients with CKD at highest risk of ESRD and death. Larger cohort studies are required to further validate these results., (Copyright © 2010 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

Context: Aldosterone has emerged as an important mediator of disease progression and mortality in patients with chronic heart and kidney disease (CKD). Despite the increasing use of mineralocorticoid receptor antagonists in these patients, little is known about the effects on corticosteroid hormone secretion and metabolism., Objective: To assess corticosteroid hormone secretion and metabolism in patients with early stage CKD before and after spironolactone (Spiro)., Design: Randomized, double-blind, placebo-controlled interventional study., Setting: Single tertiary referral centre., Patients: A total of 112 patients with stable stage 2/3 CKD., Interventions: Patients were randomized to receive either Spiro 25 mg once daily or placebo for 36 weeks., Main Outcome Measures: Plasma renin activity (PRA), angiotensin II (AngII) and steroid hormones were analysed by standard assays; urinary corticosteroid hormone metabolites (5α+5β-tetrahydro-cortisol (5α+5β-THF), TH-cortisone (THE), 3α5β-TH-aldosterone (TH-Aldo), 5α+5β-TH-deoxycorticosterone (5α+5β-TH-DOC), TH-11-desoxycortisol (THS)) were analysed by gas chromatography/mass spectrometry., Results: Plasma aldosterone concentration (PAC) was inversely correlated with eGFR (r = -0·331, P < 0·001). Urinary 24-h excretion of TH-Aldo was correlated with PAC (r = 0·214, P < 0·05) and diastolic blood pressure (BP) (r = 0·212, P = <0·05), whereas total 24-h urinary cortisol metabolite excretion was correlated with systolic BP (r = 0·316, P < 0·01). In addition, 11β-hydroxysteroid dehydrogenase (11β-HSD) type 1 activity (urinary 5α+5β-THF)/THE) ratio) was correlated with PRA (r = 0·277, P < 0·01). Spiro treatment significantly reduced BP (123 ± 11/76 ± 7 vs 119 ± 11/73 ± 8 mmHg, P < 0·01) despite renin-angiotensin-aldosterone system induction, reflected by increased urinary 24-h TH-Aldo excretion (17·6 (12, 86) vs 26 (18, 80) μg/24 h, P < 0·05). By contrast, Spiro had no effect on total urinary cortisol metabolite excretion, 11β-hydroxylase, 11β-HSD type 1 and 2 activity., Conclusions: Aldo and cortisol are positively associated with BP suggesting that adrenal hyperactivity may in part explain the increased cardiovascular risk in patients with early end-stage CKD. Addition of Spiro had no effect on glucocorticoid metabolism or total 24-h corticosteroid production., (© 2010 Blackwell Publishing Ltd.)

Chronic kidney disease is associated with elevated cardiovascular risk, and heart failure and arrhythmias are the biggest causes of cardiovascular death in this population. Increased arterial stiffness is a hallmark of chronic kidney disease and is associated with adverse alterations in cardiac structure and function that may predispose to an increased risk of cardiovascular death. These changes are already apparent in early kidney disease, which is highly prevalent in the developed world. The mechanisms underlying increased arterial stiffness in chronic kidney disease are undoubtedly complex, but an understanding is paramount to enable the development of novel therapeutic strategies to prevent or reverse this pathophysiology and therefore reduce the cardiovascular disease burden in this high-risk cohort.

Chronic kidney disease is associated with elevated cardiovascular risk, and heart failure and arrhythmias are the biggest causes of cardiovascular death in this population. Increased arterial stiffness is a hallmark of chronic kidney disease and is associated with adverse alterations in cardiac structure and function that may predispose to an increased risk of cardiovascular death. These changes are already apparent in early kidney disease, which is highly prevalent in the developed world. The mechanisms underlying increased arterial stiffness in chronic kidney disease are undoubtedly complex, but an understanding is paramount to enable the development of novel therapeutic strategies to prevent or reverse this pathophysiology and therefore reduce the cardiovascular disease burden in this high-risk cohort.

Objectives: We sought to determine whether the addition of spironolactone to angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) improves left ventricular mass and arterial stiffness in early-stage chronic kidney disease (CKD)., Background: Chronic kidney disease is associated with a high risk of cardiovascular disease and a high prevalence of left ventricular hypertrophy and arterial stiffness that confer an adverse prognosis. It is believed that these abnormalities are in part a result of activation of the renin-angiotensin-aldosterone system., Methods: After an active run-in phase with spironolactone 25 mg once daily, 112 patients with stage 2 and 3 CKD with good blood pressure control (mean daytime ambulatory blood pressure <130/85 mm Hg) on established treatment with ACE inhibitors or ARBs were randomized to continue spironolactone or to receive a matching placebo. Left ventricular mass (cardiac magnetic resonance) and arterial stiffness (pulse wave velocity/analysis, aortic distensibility) were measured before run in and after 40 weeks of treatment., Results: Compared with placebo, the use of spironolactone resulted in significant improvements in left ventricular mass (-14 +/- 13 g vs. +3 +/- 11 g, p < 0.01), pulse wave velocity (-0.8 +/- 1.0 m/s vs. -0.1 +/- 0.9 m/s, p < 0.01), augmentation index (-5.2 +/- 6.1% vs. -1.4 +/- 5.9%, p < 0.05), and aortic distensibility (0.69 +/- 0.86 x 10(-3) mm Hg vs. 0.04 +/- 1.04 x 10(-3) mm Hg, p < 0.01)., Conclusions: The use of spironolactone reduces left ventricular mass and improves arterial stiffness in early-stage CKD. These effects suggest that aldosterone exerts adverse cardiovascular effects in CKD and that spironolactone is worthy of further study as a treatment that could reduce adverse cardiovascular events. (Is Spironolactone Safe and Effective in the Treatment of Cardiovascular Disease in Mild Chronic Renal Failure; NCT00291720).