The effect of long-term aggressive lipid lowering on ischemic and atherosclerotic burden in patients with chronic kidney disease

Pathophysiological concepts and screening of cardiovascular disease in dialysis patients

Dialysis patients experience 10-20 times higher cardiovascular mortality than the general population. The high burden of both conventional and nontraditional risk factors attributable to loss of renal function can explain higher rates of cardiovascular disease (CVD) morbidity and death among dialysis patients. As renal function declines, uremic toxins accumulate in the blood and disrupt cell function, causing cardiovascular damage. Hemodialysis patients have many cardiovascular complications, including sudden cardiac death. Peritoneal dialysis puts dialysis patients with end-stage renal disease at increased risk of CVD complications and emergency hospitalization. The current standard of care in this population is based on observational data, which has a high potential for bias due to the paucity of dedicated randomized clinical trials. Furthermore, guidelines lack specific guidelines for these patients, often inferring them from non-dialysis patient trials. A crucial step in the prevention and treatment of CVD would be to gain better knowledge of the influence of these predisposing risk factors. This review highlights the current evidence regarding the influence of advanced chronic disease on the cardiovascular system in patients undergoing renal dialysis.

Kidney disease and stroke: epidemiology and potential mechanisms of susceptibility

Patients with chronic kidney disease (CKD) have an increased risk of both ischaemic and haemorrhagic stroke compared with the general population. Both acute and chronic kidney impairment are independently associated with poor outcome after the onset of a stroke, after adjustment for confounders. End-stage kidney disease (ESKD) is associated with a 7- and 9-fold increased incidence of both ischaemic and haemorrhagic strokes, respectively, poorer neurological outcome and a 3-fold higher mortality. Acute kidney injury (AKI) occurs in 12% of patients with stroke and is associated with a 4-fold increased mortality and unfavourable functional outcome. CKD patients seem to have less access to revascularisation techniques like thrombolysis and thrombectomy despite their poorer prognosis. Even if CKD patients could benefit from these specific treatments in acute ischaemic stroke, their prognosis remains poor. After thrombolysis, CKD is associated with a 40% increased risk of intracerebral haemorrhage (ICH), a 20% increase in mortality and poorer functional neurological outcomes. After thrombectomy, CKD is not associated with ICH but is still associated with increased mortality, and AKI with unfavourable outcome and mortality. The beneficial impact of gliflozins on the prevention of stroke is still uncertain. Non-traditional risk factors of stroke, like uraemic toxins, can lead to chronic cerebrovascular disease predisposing to stroke in CKD, notably through an increase in the blood-brain barrier permeability and impaired coagulation and thrombosis mechanisms. Preclinical and clinical studies are needed to specifically assess the impact of these non-traditional risk factors on stroke incidence and outcomes, aiming to optimize and identify potential therapeutic targets.

Narrative Review of Carotid disease and the kidney

Patients with chronic kidney disease (CKD) have an increased cardiovascular (CV) risk that is only in part explained by established risk factors. Carotid arteriosclerosis and atherosclerosis are increased in CKD, play a role in the causation of CV disease in these patients and can affect the progression of renal disease. The arterial stiffening process is evident even in CKD patients with a very mild reduction of glomerular filtration rate (GFR) whereas arterial thickening is evident in more advanced stages. Possible mechanisms include functional and structural alterations of the arterial wall. Arterial stiffness can mediate the effect of CKD on target organs (i.e., brain, kidney and heart). In this review we discuss the arterial phenotype of patients with CKD. This is characterized by increased common carotid artery stiffness and outward remodeling (enlargement and thickening of the arterial wall) and a normal/reduced stiffness paired with an inward remodeling (narrowing of the arterial wall) of muscular arteries. We also discuss the consequences of carotid dysfunction, including the involvement of large elastic arteries stiffness on ventricular-vascular coupling, the mechanisms linking carotid stiffening and increased cardio- and cerebrovascular risk in CKD patients, and the therapeutic options to improve carotid function.

Clinical Studies of Interventions to Mitigate Cardiovascular Risk in Peritoneal Dialysis Patients

Cardiovascular disease (CVD) is highly prevalent in the peritoneal dialysis (PD) population, affecting up to 60% of cohorts. CVD is the primary cause of death in up to 40% of PD patients in Australia, New Zealand, and the United States. Cardiovascular mortality rates are reported to be approximately 14 per 100 patient-years, which are 10- to 20-fold greater than those of age- and sex-matched controls. The excess risk of CVD is related to a combination of traditional risk factors (such as hypertension, dyslipidemia, obesity, smoking, sedentary lifestyle, and insulin resistance), nontraditional (kidney disease-related) risk factors (such as anemia, chronic volume overload, inflammation, malnutrition, hyperuricemia, and mineral and bone disorder), and PD-specific risk factors (such as dialysis solutions, glycation end products, hypokalemia, residual kidney function, and ultrafiltration failure). Interventions targeting these factors may mitigate cardiovascular risk, although high-level clinical evidence is lacking. This review summarizes the evidence relating to cardiovascular interventions targeting modifiable CVD risk factors in PD patients, as well as highlighting the key recommendations of the International Society for Peritoneal Dialysis Cardiovascular and Metabolic Guidelines.

Mitochondrial dysfunction in diabetic kidney disease

Globally, diabetes is the leading cause of chronic kidney disease and end-stage renal disease, which are major risk factors for cardiovascular disease and death. Despite this burden, the factors that precipitate the development and progression of diabetic kidney disease (DKD) remain to be fully elucidated. Mitochondrial dysfunction is associated with kidney disease in nondiabetic contexts, and increasing evidence suggests that dysfunctional renal mitochondria are pathological mediators of DKD. These complex organelles have a broad range of functions, including the generation of ATP. The kidneys are mitochondrially rich, highly metabolic organs that require vast amounts of ATP for their normal function. The delivery of metabolic substrates for ATP production, such as fatty acids and oxygen, is altered by diabetes. Changes in metabolic fuel sources in diabetes to meet ATP demands result in increased oxygen consumption, which contributes to renal hypoxia. Inherited factors including mutations in genes that impact mitochondrial function and/or substrate delivery may also be important risk factors for DKD. Hence, we postulate that the diabetic milieu and inherited factors that underlie abnormalities in mitochondrial function synergistically drive the development and progression of DKD.

Modified Lipids and Lipoproteins in Chronic Kidney Disease: A New Class of Uremic Toxins

Chronic kidney disease (CKD) is associated with an enhanced oxidative stress and deep modifications in lipid and lipoprotein metabolism. First, many oxidized lipids accumulate in CKD and were shown to exert toxic effects on cells and tissues. These lipids are known to interfere with many cell functions and to be pro-apoptotic and pro-inflammatory, especially in the cardiovascular system. Some, like F2-isoprostanes, are directly correlated with CKD progression. Their accumulation, added to their noxious effects, rendered their nomination as uremic toxins credible. Similarly, lipoproteins are deeply altered by CKD modifications, either in their metabolism or composition. These impairments lead to impaired effects of HDL on their normal effectors and may strongly participate in accelerated atherosclerosis and failure of statins in end-stage renal disease patients. This review describes the impact of oxidized lipids and other modifications in the natural history of CKD and its complications. Moreover, this review focuses on the modifications of lipoproteins and their impact on the emergence of cardiovascular diseases in CKD as well as the appropriateness of considering them as actual mediators of uremic toxicity.

Common Carotid Artery Thickness in Chronic Kidney Disease

AIM: Previous studies showed that patients with chronic kidney disease (CKD) > 2 dergee had increased intima-media thickness (IMT).  We evaluate the relationship between IMT and parameters for renal function.METHODS: 130 subjects were examined – 66 with CKD, 44 without CKD, as well as 20 healthy volunteers. The first group- patients with CKD were with creatinine clearance (CrCl) over 20 ml/min and below 90 ml/min. The second group included 44 pts. with normal renal function, CrCl > 90 ml/min. All examined patients with and without CKD had hypertension.   The two groups were streamed into two subgroups: with and without vascular disease. To evaluate the renal function creatinine clearance was calculated in ml/min. IMT was measured in both common carotid artery (CCA) using high resolution sonography in all examined subjects.RESULTS: CCA IMT increased in pts. with CKD and was > 0.75 ( 0.76 ± 0.14 v.s contols 0.59 ± 0.10) Patients with vascular disease (VD) had higher IMT which increased significant when CKD with GFR < 90 ml/min was included (0.77 ± 0.06/0.81 ± 0.10, p < 0.05). Multiple regression analysis proved that renal function deterioration directly affected CCA IMT (R2=0.208, p=0.022).CONCLUSION: Increased IMT is presented in mild renal dysfunction. CKD –GFR< 90 ml/min could be an independent vascular risk factor.

A meta-analysis of the role of statins on renal outcomes in patients with chronic kidney disease. Is the duration of therapy important?

INTRODUCTION

The efficacy of statin treatment in chronic kidney disease (CKD) patients remains controversial. Therefore, we performed a meta-analysis to investigate whether statins modulate renal function in patients with CKD.

METHODS

Data from Scopus, PubMed, Web of Science, and the Cochrane Central Register of randomized controlled trials for years 1966-December 2012 were searched for appropriate studies.

RESULTS

Twenty trials with 6452 CKD subjects randomized to receive either statin or placebo were included. Statin therapy significantly influenced high sensitivity C-reactive protein levels in patients on or off dialysis [-0.28 mg/dl, 95%CI: -0.93 to -0.37; p<0.05 and -0.46 mg/dl, 95%CI: -0.87 to -0.05; p=0.03], respectively], urinary protein (-0.77 g/24 h, 95%CI: -1.24 to -0.29, p<0.02; this effect persisted for treatment ≤12 months), and serum creatinine but only for long-term therapy (3 years) (-0.65 mg/dl, 95%CI: -1.00 to -0.30; p=0.0003). The summary for standardized effect size of mean differences of glomerular filtration rate was 0.29 ml/min/1.73 m(2) (95%CI: 0.01 to 0.58; p=0.04), and depended on treatment duration - a significant increase was observed for between 1 and 3 years of statin therapy (0.50 ml/min/1.73 m(2), 95%CI: 0.40 to 0.60; p<0.0001), with no significant increase for both ≤1 and >3 years of the therapy.

CONCLUSION

Statins might exert significant renoprotective effects in CKD patients; however, benefit may depend on the duration of treatment. This is an issue that warrants more definitive investigation. More studies are necessary in dialysis patients to credibly evaluate the renal effects of statin therapy.

Effects of statins on lipid profile in chronic kidney disease patients: a meta-analysis of randomized controlled trials

OBJECTIVE

The available data on statin effects in chronic kidney disease (CKD) patients are still conflicting. We investigated the impact of short- and long-term statin therapy on lipid profiles in CKD patients requiring or not requiring dialysis.

RESEARCH DESIGN AND METHODS

Data from Scopus, PubMed, Web of Science, and the Cochrane Library from 1966 to May 2012 were searched for studies that investigated this effect. We included all randomized controlled clinical trials that investigated the impact of statin therapy on lipids and lipoproteins.

RESULTS

The final analysis included 16 trials with 3594 subjects. In CKD patients, statin therapy significantly reduced total cholesterol (TC), triglycerides (TG) and low-density lipoprotein cholesterol (LDL-C) (p < 0.003 for all comparisons), and the effect insignificantly intensified with duration of statin therapy (56.3 vs 66.8, 22.5 vs 24.1, and 53 vs 56.1 mg/dl, respectively). Comparing statin therapy for ≤ 3 and >3 months in CKD patients on dialysis, the magnitude of TC and LDL-C decreased (26.3 vs 25.9, and 42.2 vs 29.8 mg/dl, respectively, p > 0.05 for both), while TG increased modestly (4.5 vs 13.4 mg/dl). Short-term statin therapy increased high density lipoprotein cholesterol by a mean 0.7 mg/dl (p = 0.04), and long-term therapy was associated with a mean reduction of 2.4 mg/dL.

CONCLUSIONS

Statin therapy significantly modifies the lipid profile in CKD patients not on dialysis therapy (with the trend to be more effective with longer therapy), and have less beneficial effect in patients on dialysis with the trend to be less effective with longer duration of therapy.

Multimodality vascular imaging in CKD: divergence of risk between measured parameters

BACKGROUND

High cardiovascular risk in chronic kidney disease (CKD) patients appears only partly attributable to atherosclerosis, with much of the remaining risk being ascribed to other vasculature abnormalities, including endothelial dysfunction, arterial stiffness and vascular calcification (VC). To date, these factors have been primarily studied in isolation or in dialysis patients. This study performed a global vascular assessment in moderate CKD and assessed the relationships with both traditional and novel risk factors.

METHODS

This was a prospective cross-sectional analysis of 120 patients (age 60 ± 10 years; estimated glomerular filtration rate 25-60 mL/min/1.73m(2)). Demographic, clinical and biochemical characterization was performed. VC was characterized by lateral lumbar radiograph; arterial stiffness by aortic pulse-wave velocity (PWV); atheroma burden by carotid intima-media thickness (cIMT) and endothelial function by flow-mediated dilation (FMD) of the brachial artery.

RESULTS

VC was highly prevalent (74%), and FMD generally poor (FMDΔ 3.3 ± 3.3%). There were significant correlations between all vascular parameters; although these were predominantly explained by age. cIMT was independently associated with classical risks and also PWV (adjusted standardized β = 0.31, P = 0.001). However, traditional risks showed almost no independent associations with other vascular measurements. In contrast, serum phosphate and 1,25-dihydroxyvitamin D (1,25-OHD) correlated with PWV and the presence of VC, respectively. After adjustment, every 1 pg/mL increase in 1,25-OHD was related to a 3% reduction in the chance of VC (odds ratio 0.97; 95% confidence interval 0.94-1.00, P = 0.03). Medication use, HOMA-IR and C-reactive protein did not correlate with any of the vascular measures.

CONCLUSIONS

This study demonstrates extensive vascular disease across multimodality imaging in moderate CKD. Atherosclerotic burden correlated with traditional risks and PWV, while higher 1,25-OHD was associated with less VC. The lack of association between renal function and imaging indices raises the possibility of a threshold, rather than graded uraemic effect on vascular health that warrants further exploration.

The estimated GFR, but not the stage of diabetic nephropathy graded by the urinary albumin excretion, is associated with the carotid intima-media thickness in patients with type 2 diabetes mellitus: a cross-sectional study

Background

To study the relationship between the intima-media thickness (IMT) of the carotid artery and the stage of chronic kidney disease (CKD) based on the estimated glomerular filtration rate (eGFR) and diabetic nephropathy graded by the urinary albumin excretion (UAE) in the patients with type 2 diabetes mellitus.

Methods

A cross-sectional study was performed in 338 patients with type 2 diabetes mellitus. The carotid IMT was measured using an ultrasonographic examination.

Results

The mean carotid IMT was 1.06 ± 0.27 mm, and 42% of the subjects showed IMT thickening (≥ 1.1 mm). Cerebrovascular disease and coronary heart disease were frequent in the patients with IMT thickening. The carotid IMT elevated significantly with the stage progression of CKD (0.87 ± 0.19 mm in stage 1, 1.02 ± 0.26 mm in stage 2, 1.11 ± 0.26 mm in stage 3, and 1.11 ± 0.27 mm in stage 4+5). However, the IMT was not significantly different among the various stages of diabetic nephropathy. The IMT was significantly greater in the diabetic patients with hypertension compared to those without hypertension. The IMT positively correlated with the age, the duration of diabetes mellitus, and the brachial-ankle pulse wave velocities (baPWV), and negatively correlated with the eGFR. In a stepwise multivariate regression analysis, the eGFR and the baPWV were independently associated with the carotid IMT.

Conclusions

Our study is the first report showing a relationship between the carotid IMT and the renal parameters including eGFR and the stages of diabetic nephropathy with a confirmed association between the IMT and diabetic macroangiopathy. Our study further confirms the importance of intensive examinations for the early detection of atherosclerosis and positive treatments for hypertension, dyslipidaemia, obesity, as well as hyperglycaemia are necessary when a reduced eGFR is found in diabetic patients.

Renal dysfunction potentiates foam cell formation by repressing ABCA1

OBJECTIVE

Patients with chronic kidney disease (CKD) have the highest risk for atherosclerotic cardiovascular disease (CVD). Current interventions have been insufficiently effective in lessening excess incidence and mortality from CVD in CKD patients versus other high-risk groups. The mechanisms underlying the heightened risk remain obscure but may relate to differences in CKD-induced atherogenesis, including perturbation of macrophage cholesterol trafficking.

METHODS AND RESULTS

We examined the impact of renal dysfunction on macrophage cholesterol homeostasis in the apoE(-/-) mouse model of atherosclerosis. Renal impairment induced by uninephrectomy dramatically increased macrophage cholesterol content, linked to striking impairment of macrophage cholesterol efflux. This blunted efflux was associated with downregulation of the cholesterol transporter ATP-binding cassette transporter A1 (ABCA1) and activation of the nuclear factor-kappa B (NF-kappaB). Treatment with the angiotensin receptor blocker (ARB) losartan decreased NF-kappaB and restored cholesterol efflux.

CONCLUSIONS

Our findings show that mild renal dysfunction perturbs macrophage lipid homeostasis by inhibiting cholesterol efflux, mediated by decreased ABCA1 transporter and activation of NF-kappaB, and that ARB can restore cholesterol efflux.

Dyslipidemia of kidney disease

PURPOSE OF REVIEW

Chronic kidney disease is associated with specific alterations of lipoprotein metabolism that may be linked to accelerated atherosclerosis and cardiovascular disease. This review summarizes current knowledge of the pathophysiology of renal dyslipidemia and the therapeutic options.

RECENT FINDINGS

The renal dyslipidemia is characterized by accumulation of intact and partially metabolized triglyceride-rich apoB-containing and apoC-containing lipoproteins. Increased concentrations of atherogenic apoC-III rich lipoproteins, the hallmark of renal dyslipidemia, may result from disturbances of insulin metabolism and action in chronic kidney disease. Novel findings strongly suggest that apoC-III triggers a cascade of pro-inflammatory events, which ultimately can result in endothelial dysfunction and vascular damage. Disappointingly, recently reported intervention trials with statins have failed to show any benefit on cardiovascular disease in patients with advanced renal failure.

SUMMARY

During recent years, our understanding of the character and biological significance of the dyslipidemia of chronic kidney disease, and its link to cardiovascular disease, has increased. However, our knowledge about its proper management is still very limited.

Reducing lipids for CV protection in CKD patients-current evidence

Lipid parameters are altered in the earliest stages of primary kidney disease, some even when measured glomerular filtration rate (GFR) is still normal. The main problem is that routinely measured lipid parameters are deceivingly normal except low high-density lipoprotein (HDL) and moderately elevated triglycerides (TGs) (>150 mg per 100 ml). Behind this unimpressive spectrum, serious anomalies are hidden: increased very low-density lipoprotein (VLDL) and chylomicron remnants, accumulation of delipidated small dense low-density lipoprotein (LDL), post translational modification of lipoproteins, abnormal concentrations of Lp(a) and nonprotective HDL. A routine parameter with some predictive value is the concentration of non-HDL cholesterol. Several of these abnormal lipoprotein particles stimulate cellular free oxygen radical formation which in turn induce inflammation and impact on endothelial function.A bone of contention is the indication for treatment with statins in endstage renal disease. Poor survival is paradoxically predicted by low cholesterol. This appears to be the result of confounding by microinflammation. One controlled interventional study in hemodialysed type 2 diabetics, the 4-D study, failed to show a significant benefit on the primary cardiovascular endpoint. We discuss potential explanations for this 'negative' outcome and the implications for statin treatment.

Atheroma progression in chronic kidney disease

BACKGROUND AND OBJECTIVES

Cardiovascular events are 10 to 100 times more frequent in chronic kidney disease (CKD). We tested the hypothesis that the rate of atherosclerotic plaque growth is faster in severe versus moderate CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We performed a prospective cohort study in 318 prevalent CKD patients with initial creatinine clearance (CCr) between 20 and 50 ml/min/1.73 m(2). Baseline clinical and laboratory data were obtained on all patients. Plaque area was determined every 6 mo using bilateral carotid ultrasonography. Plaque area distribution was normalized using a cube root transformation. Unadjusted and adjusted associations between CCr quintiles and rate of change in the transformed plaque area were assessed using multiple linear regression.

RESULTS

The rate of plaque progression appeared lower in patients with the lowest CCr. Median rate of plaque growth was 0.4 mm(2)/yr in the lowest quintile of CCr (< 23 ml/min/1.73 m(2)) versus 5.0 mm(2)/yr in the highest quintile (> 43 ml/min/1.73 m(2)). This association remained significant after adjustment for potential confounders. A secondary analysis using quintiles of Modification of Diet in Renal Disease (MDRD) GFR confirmed the absence of increased plaque growth at low GFR, although a reduced rate of growth in the lowest quintile of MDRD GFR was not observed.

CONCLUSION

We did not observe accelerated plaque growth at low levels of renal function. We suggest that mechanisms other than plaque growth are responsible for the observed excess of cardiovascular disease in CKD patients.

Stroke in chronic renal failure

Chronic kidney diseases and cardiovascular diseases have several common risk factors like hypertension and diabetes. In chronic renal disease stroke risk is several times higher than in the average population. The combination of classical risk factors and those characteristic of chronic kidney disease might explain this increased risk. Among acute cerebrovascular diseases intracerebral hemorrhages are more frequent than in those with normal kidney function. The outcome of stroke is worse in chronic kidney disease. The treatment of stroke (thrombolysis, antiplatelet and anticoagulant treatment, statins, etc.) is an area of clinical research in this patient group. There are no reliable data on the application of thrombolysis in acute stroke in patients with chronic renal disease. Aspirin might be administered. Carefulness, individual considerations and lower doses might be appropriate when using other treatments. The condition of the kidney as well as other associated diseases should be considered during administration of antihypertensive and lipid lowering medications.

Lipid abnormalities and cardiovascular risk in renal disease

The recent 4D study failed to provide definitive evidence for benefit of statin use in type 2 diabetics on dialysis. This finding stands in stark contrast to a number of other observations in patients with early stages of chronic kidney disease where substantial benefit of statins had been documented. Here we discuss some potential explanations for the unexpected finding of the 4D study and for the negative association between below average total cholesterol and vascular mortality among dialysis patients. Admittedly, in the absence of definite evidence in dialysis patients, we still conclude that the administration of statins is appropriate in patients with manifest coronary disease.

Effects of lipid-lowering therapy with rosuvastatin on atherosclerotic burden in patients with chronic kidney disease

OBJECTIVE

Although previous studies suggest that treatment of dyslipidemia with statins reduces mortality and morbidity that are associated with cardiovascular disease, only a few studies have examined the efficacy of statins on atherosclerotic status in patients with chronic kidney disease (CKD).

MATERIALS AND METHODS

A 12-month, prospective, randomized study was designed to assess the efficacy of rosuvastatin in reducing circulating atherosclerotic parameters and renal function in patients with CKD. Thirty-eight patients with CKD and LDL cholesterol levels > or =100 mg/dL were randomly assigned to receive 2.5 mg/dL rosuvastatin (group A, n=22) or nonrosuavastatin therapy (group B, n=16). Lipid profile, estimated glomerular filtration rate (eGFR), high sensitivity C-reactive protein (hs-CRP), and intima-media thickness (IMT) were measured before and 12 months after rosuvastatin was added to the treatment.

RESULTS

Total cholesterol, low-density lipoprotein cholesterol, remnant-like particle-cholesterol and triglycerides were significantly reduced only in patients who received rosuvastatin. These parameters remained unchanged in patients who were not treated with rosuvastatin. eGFR was significantly increased from 50.7+/-18.7 mL/min/1.73 m(2) to 53.3+/-20.1 mL/min/1.73 m(2) and a significant reduction of U-P was detected in group A patients (0.17+/-0.29 vs. 0.13+/-0.3 g/day; p<0.01). In addition to the hypolipidemic effect, rosuvastatin treatment significantly reduced hs-CRP (p=0.0054). Moreover, maximal IMT at the baseline (1.89+/-0.98 mm) decreased significantly to 1.75+/-0.87 mm at 12 months (p=0.0231).

CONCLUSION

Rosuvastatin treatment, in addition to its beneficial effect on cholesterol levels, reduced maximal IMT and modified the inflammatory state of these patients.

Lipid changes and statins in chronic renal insufficiency

It has been known for a long time that chronic kidney disease (CKD) is associated with dyslipidemia, but the full extent of abnormalities has been appreciated only recently, because routine laboratory tests fail to disclose the entire spectrum of lipid abnormalities. Lipids, particularly HDL cholesterol, are predictive of cardiovascular events, but a paradoxic inverse relation between cholesterol concentration and cardiovascular death has been noted in uremic patients. This currently is thought to be explained by the confounding effect of microinflammation and possibly calcification, but this is not definitely proved. Several retrospective analyses that included patients with mild or moderate CKD documented benefit from lowering of cholesterol by statins. In contrast, the Die Deutsche Diabetes Dialyse (4D) study and a small Scandinavian study failed to show a benefit from lowering of cholesterol by statins in ESRD. Pathomechanistically, it is possible that nonclassical pathomechanisms override statin-sensitive mechanisms as also suggested by the observation that statins fail to reduce carotid intima-media thickening. Although, experimentally, exposure to lipids (particularly oxidized lipids) aggravates progression, data on the effect of statins on progression in patients with CKD are not definite. The most likely explanation is that the impact of numerous confounders obscures their effect on progression. The increase in urinary protein excretion of patients who are treated with statins had been a cause of concern, but the underlying mechanism (i.e. interference with proximal tubular reabsorption of protein) meanwhile has been well documented.

Effects of atorvastatin on inflammatory and fibrinolytic parameters in patients with chronic kidney disease

Although substantial evidence suggests that treatment of dyslipidemia with statins reduces mortality and morbidity that are associated with cardiovascular disease, only a few studies have examined the efficacy of statins on inflammatory and fibrinolytic status in patients with chronic kidney disease (CKD). A 6-mo, prospective, randomized study was designed to assess the efficacy of atorvastatin in reducing circulating inflammatory and fibrinolytic parameters in patients with CKD. Sixty-six patients with CKD (stages 2, 3, and 4) and LDL cholesterol levels > or =100 mg/dl were randomly assigned (2:1) to receive 20 mg/d atorvastatin (n = 44) or nonatorvastatin therapy (n = 22). Lipid profile, renal function, fibrinolytic balance (tissue plasminogen activator [t-PA] and plasminogen activator inhibitor-1), and inflammatory markers (C-reactive protein [CRP], IL-1 beta, IL-6, and TNF-alpha) were measured before and 6 mo after atorvastatin was added to the treatment. Twenty-five age-matched individuals with normal renal function (estimated GFR >90 ml/min) were used as healthy control subjects. Patients with CKD had higher CRP, IL-1 beta, TNF-alpha, and IL-6 levels than age-matched population with normal renal function. t-PA concentration was higher in patients with CKD (P = 0.000). Plasminogen activator inhibitor-1 values were comparable in all patients. Total cholesterol and LDL cholesterol were significantly reduced only in patients who received atorvastatin. In addition to the hypolipidemic effect, atorvastatin treatment significantly reduced inflammatory parameters: CRP (median 4.1 to 2.9; P = 0.015), TNF-alpha (6.0 +/- 2.7 to 4.7 +/- 2.4; P = 0.046), and IL-1 beta levels (1.9 +/- 0.7 to 1.2 +/- 0.7; P = 0.001). These parameters remained unchanged in patients who were not treated with atorvastatin. Fibrinolytic parameters were not modified by atorvastatin treatment. Patients with CKD showed higher levels of inflammatory parameters and t-PA levels than age-matched healthy control subjects. Atorvastatin treatment, in addition to its beneficial effect on cholesterol levels, improved the inflammatory state of these patients without modifying fibrinolytic balance.

A Randomized Trial of the Effect of Statin and Fibrate Therapy on Arterial Function in CKD

BACKGROUND

Although patients with chronic kidney disease (CKD) are at increased risk of cardiovascular disease (CVD), the roles of lipid-modifying therapies in decreasing CVD risk are unclear. Our aim is to compare the effects of statin and fibrate therapy on arterial function as a risk marker of CVD.

STUDY DESIGN

Double-blind, randomized, placebo-controlled, parallel-group study.

SETTING & PARTICIPANTS

Ambulatory patients with stages 3 to 5 CKD.

INTERVENTION

6 weeks of atorvastatin, 40 mg/d, or gemfibrozil, 600 mg twice daily, with placebo.

OUTCOMES & MEASUREMENTS

Primary outcome was arterial function assessed by means of endothelial-dependent flow-mediated dilatation (FMD) and small-artery compliance (C2). Secondary outcomes included endothelial-independent glyceryl trinitrate-mediated dilatation (GTNMD), large-artery compliance (C1), and levels of lipids, lipoproteins, and oxidized low-density lipoprotein, as well as markers of insulin resistance and inflammation.

RESULTS

Compared with placebo, atorvastatin significantly decreased low-density lipoprotein (-52%), triglyceride (-30%), and oxidized low-density lipoprotein levels (-41%; P < 0.0001). Gemfibrozil significantly decreased triglyceride levels (-40%) and increased high-density lipoprotein levels (+20%; P < 0.0001). Neither atorvastatin nor gemfibrozil had a significant effect on markers of insulin resistance or inflammation. There was no significant change in FMD, GTNMD, or C1 with either atorvastatin or gemfibrozil. There was improvement in C2 with atorvastatin (+1.1 mL/mm Hg x 100) compared with placebo (P = 0.024), but not with gemfibrozil compared with placebo.

LIMITATIONS

Small sample size leading to inadequate power, short duration of therapy, and use of a heterogeneous group of patients with CKD and dialysis patients.

CONCLUSION

In patients with advanced CKD, atorvastatin is associated with improvement in dyslipidemia and small-artery stiffness, but not endothelial function. Gemfibrozil improves dyslipidemia, but has no effect on arterial function.

The effect of fluvastatin on cardiac outcomes in patients with moderate to severe renal insufficiency: A pooled analysis of double-blind, randomized trials

BACKGROUND

Individuals with chronic kidney disease are at high risk for cardiovascular disease and have a high prevalence of hyperlipidemia. Lipid-lowering therapy may help patients with renal disease reduce their risk for cardiovascular events.

METHODS

A pooled analysis of 30 completed clinical trials compared the efficacy and safety profiles of fluvastatin in subgroups of patients with moderate to severe renal insufficiency (creatinine clearance < 50 ml/min) and patients with normal renal function or mild renal insufficiency (creatinine clearance > or = 50 ml/min).

RESULTS

Changes in lipid parameters with fluvastatin treatment were similar for the compared patient subgroups. Fluvastatin treatment reduced combined cardiac death and myocardial infarction by 41% compared with placebo among patients with moderate to severe renal insufficiency (hazard ratio, 0.59; p=0.007) and by 30% among patients with normal renal function or mild renal insufficiency (hazard ratio, 0.70; p=0.009). The relative reduction in the risk of major adverse cardiac events, a composite endpoint comprising cardiac death, nonfatal myocardial infarction, and coronary intervention procedures, with fluvastatin treatment was not significant for patients with moderate to severe renal insufficiency (hazard ratio, 0.83; p=0.18); in this patient subgroup, the incidence of coronary intervention procedures was similar between treatment groups. The safety profiles were similar for fluvastatin- and placebo-treated patients.

CONCLUSIONS

The results of this pooled analysis indicate that fluvastatin is safe and effective for reducing cardiac death and nonfatal myocardial infarction in patients with moderate to severe renal insufficiency. Fluvastatin did not reduce the rate of coronary intervention procedures.

Statins and cardiovascular risk reduction in patients with chronic kidney disease and end-stage renal failure

BACKGROUND

Although numerous large-scale trials have firmly established the benefits of statins for primary and secondary prevention of coronary artery disease, the role of this class of agents in patients with impaired renal function remains unclear.

METHODS AND RESULTS

In the following review, we evaluate current evidence regarding the role of statins in patients with both chronic kidney disease (CKD) and end-stage renal disease (ESRD) on hemodialysis. Although statins do appear to reduce cardiovascular risk in patients with CKD, it remains unclear whether such benefit extends to the ESRD population. Thus far, 1 randomized placebo-controlled trial failed to demonstrate a statistically significant reduction in the primary endpoint of cardiovascular death, stroke, and nonfatal myocardial infarction among patients with ESRD on hemodialysis. This finding contrasts with observational analyses suggesting improved outcomes among patients with ESRD taking statins.

CONCLUSIONS

Risk factors unique to the CKD population, which may not be modifiable with statins, could contribute to the increased cardiovascular morbidity among patients with ESRD. These include alterations in mineral metabolism, elevation in serum homocysteine, and increased oxidative stress. Larger prospective studies are needed to elucidate the role of statins in patients with chronic kidney disease, including those with ESRD on dialysis. Pending further data, we currently recommend using statins in patients with CKD.

Insulin Resistance, Inflammation, and Blood Pressure Determine Vascular Dysfunction in CKD

BACKGROUND

Conventional cardiovascular risk equations underestimate the risk for cardiovascular disease (CVD) in patients with chronic kidney disease (CKD), implying a role for novel risk factors. Our aim was to compare vascular function and arterial compliance, known markers of CVD, between patients with CKD and healthy controls and examine their association with traditional and novel CVD risk factors.

METHODS

Vascular function was determined by using high-resolution ultrasonography to measure brachial artery endothelial-dependent flow-mediated dilatation (FMD) and endothelial-independent glyceryl trinitrate (GTN)-mediated dilatation. Arterial compliance was measured by using pulse contour analysis to generate large-artery (C1) and small-artery (C2) compliance. We also examined the relationship between vascular function, arterial compliance and blood pressure, lipid and lipoprotein levels, insulin resistance, inflammation, oxidative stress, and calcium and phosphate levels in 105 patients with CKD and 40 healthy controls.

RESULTS

Vascular function and arterial compliance were significantly impaired in patients with CKD compared with healthy controls: mean FMD, 3.8% +/- 0.3% (SE) versus 5.7% +/- 0.6%; GTN-mediated dilatation, 15.7% +/- 0.9% versus 19.6% +/- 1.0%; C1, geometric mean, 12.1 mL/mm Hg; 95% confidence interval (CI), 11.2 to 13.1 versus 15.1 mL/mm Hg; 95% CI, 13.7 to 16.5; and C2, 3.8 mL/mm Hg; 95% CI, 3.4 to 4.3 versus 5.0 mL/mm Hg; 95% CI, 4.2 to 6.0; all P < 0.05. Patients with CKD had greater waist-hip ratios, systolic blood pressures (SBPs), pulse pressures, triglyceride levels, oxidized low-density lipoprotein levels, high-sensitivity interleukin 6 levels, and Homeostasis Model Assessment (HOMA) scores (all P < 0.05) and lower high-density lipoprotein levels (P < 0.001). In patients with CKD, HOMA score and SBP were associated negatively with FMD (model R(2) = 0.28; P < 0.001), and SBP and waist-hip ratio were associated negatively with GTN-mediated dilatation (model R(2) = 0.25; P < 0.001). Pulse pressure was associated negatively with C1 (R(2) = 0.37; P < 0.001), and pulse pressure and high-sensitivity interleukin 6 level were associated negatively with C2 (model R(2) = 0.36; P < 0.001).

CONCLUSION

Insulin resistance, inflammation, systolic hypertension, and increased pulse pressure, but not dyslipidemia, were associated with vascular dysfunction and may be targets for future interventional strategies to reduce CVD risk in patients with CKD.

Canadian Cardiovascular Society position statement--recommendations for the diagnosis and treatment of dyslipidemia and prevention of cardiovascular disease

Since the last publication of the recommendations for the management and treatment of dyslipidemia, new clinical trial data have emerged that support a more vigorous approach to lipid lowering in specific patient groups. The decision was made to update the lipid guidelines in collaboration with the Canadian Cardiovascular Society. A systematic electronic search of medical literature for original research consisting of blinded, randomized controlled trials was performed. Meta-analyses of studies of the efficacy and safety of lipid-lowering therapies, and of the predictive value of established and emerging risk factors were also reviewed. All recommendations are evidence-based, and have been reviewed in detail by primary and secondary review panels. Major changes include a lower low-density lipoprotein cholesterol (LDL-C) treatment target (lower than 2.0 mmol/L) for high-risk patients, a slightly higher intervention point for the initiation of drug therapy in most low-risk individuals (LDL-C of 5.0 mmol/L or a total cholesterol to high-density lipoprotein cholesterol ratio of 6.0) and recommendations regarding additional investigations of potential use in the further evaluation of coronary artery disease risk in subjects in the moderate-risk category.

The case for disease management in chronic kidney disease

Chronic kidney disease (CKD) is a growing epidemic in the United States and worldwide, with nearly two thirds of CKD patients also having diabetes, hypertension, or both. Morbidity and mortality among patients with CKD are high, as are the costs associated with care, which is highly fragmented. Disease management (DM) programs are designed to coordinate the delivery of care to patients, improve clinical outcomes, and reduce costs along the continuum of care. The goals of DM programs in CKD patients are to fill the gaps in current care by focusing on four key areas: (1) slowing the progression of CKD, (2) identifying and managing the complications of CKD, (3) identifying and managing associated comorbid conditions, and (4) smoothing the transition to renal replacement therapy (RRT). To be successful, this approach requires multidisciplinary collaboration among physicians (eg, primary care physicians, endocrinologists, cardiologists, nephrologists, surgeons) and participating caregivers including nurses, dieticians, social workers, and pharmacists. Patient identification, limited reimbursement, late patient referral, and lack of primary care physician and nephrologist knowledge about the importance and details of CKD management are all barriers that must be overcome for such programs to be successfully implemented. Considering the magnitude of the opportunity, DM applied to CKD is a promising approach to the care of this vulnerable population.

Increased targeting of cardiovascular risk factors in patients with chronic kidney disease does not improve atheroma burden or cardiovascular function

BACKGROUND

Although multiple risk factor intervention (MRFI) is recommended to reduce the increased morbidity and mortality of cardiovascular disease (CVD) in chronic kidney disease (CKD), its efficacy is unknown. We studied the efficacy of a MRFI program in CKD.

METHODS

This randomized controlled study of 200 patients with stage 4 or 5 CKD compared a physician-supervised, nurse-driven MRFI clinic (focused on dyslipidemia, hyperhomocysteinemia, blood pressure [BP], anemia, and hyperphosphatemia) with conventional care in CKD. One hundred eleven subjects completed 2 years of follow-up (median follow-up 674 days [interquartile range {IQR} 348-719 days]). Outcome measures were atheroma burden (carotid intimamedia thickness [IMT]) and endothelial function (brachial artery reactivity [BAR]).

RESULTS

The MRFI group showed significant improvements, compared with usual care, in serum low-density lipoprotein cholesterol (-30.9 mg/dL vs -12.7 mg/dL, P = .001), homocysteine (-6.95 vs -0.67 micromol/L, P < .001), systolic BP (-6.9 vs -0.2 mm Hg, P = .049), and diastolic BP (-4.8 vs -1.0 mm of Hg, P = .043). No significant changes were seen in serum phosphate or hemoglobin level. Despite observed improvements in risk factors, no differences from baseline were demonstrated for IMT (-0.00 vs -0.01 mm, P = .533) or BAR (0.09% vs 0.22%, P = .834). Forty-two patients reached a composite end point of CVD death, acute coronary syndrome, revascularization, nonfatal stroke, and amputation and this was similar between groups (23 vs 19 events, P = .475).

CONCLUSIONS

A MRFI program was not associated with improvement in vascular structure or function in stage 4 or 5 patients with CKD.

Antiatherogenic effects of angiotensin receptor antagonism in mild renal dysfunction

Angiotensin II (Ang II) increases atherosclerotic cardiovascular disease. Renal damage that is characterized by activation of Ang II markedly potentiates the risk for atherosclerosis, even in the setting of subtle renal impairment. Therefore, whether antagonism of Ang II actions can modify atherosclerosis in a model of mild renal impairment was examined. Apolipoprotein E-deficient spontaneously hyperlipidemic mice underwent uninephrectomy (UNx) or sham operation (sham) followed by treatment with Ang II receptor antagonist losartan or hydralazine for 12 wk. While UNx did not increase the serum creatinine levels, BP and lipids were higher in UNx mice than in age-matched sham controls with intact kidneys. UNx caused a dramatic increase in the extent and the number of atherosclerotic lesions together with greater macrophage-positive area and more disruption in the elastin component of the extracellular matrix versus sham. Ang II antagonism dramatically decreased the UNx-induced acceleration in atherosclerosis in association with decreased macrophage content, linked to decreased macrophage migration in vitro with losartan but not with hydralazine. Aortae of mice treated with Ang II antagonism had fewer elastin breaks together with less immunostaining for the powerful elastolytic enzyme cathepsin S. None of these benefits was observed in the hydralazine-treated mice despite equivalent reduction in BP. These findings support an important role for endogenous Ang II in accelerated atherosclerosis in renal dysfunction and offer a therapeutic intervention with particular benefit in this setting through mechanisms that include reduced vascular macrophage infiltration and preservation of the elastin component of extracellular matrix.

Outcomes in patients with chronic kidney disease undergoing cardiac rehabilitation

BACKGROUND

Chronic kidney disease (CKD) is associated with an adverse prognosis in patients with coronary heart disease. Cardiac rehabilitation (CR) improves morbidity and mortality among patients with coronary heart disease, but its impact on patients with concomitant CKD has not been described.

METHODS

We compared baseline characteristics of patients with CKD (calculated glomerular filtration rate <60 mL/min per 1.73 m2) and without CKD who completed CR between 1996 and 2004 using t tests and chi2 tests. CR outcomes were evaluated by comparing the degree of change in clinical and behavioral variables within and between groups with paired and unpaired t testing, respectively, and by comparing the proportion of patients who achieved secondary prevention goals between groups using chi2 testing.

RESULTS

Among 376 patients, CKD was present in 115 (31%). Patients with CKD were older, had more cardiac risk factors and comorbidities, and had lower functional capacity and perceived health status than patients without CKD. Both groups achieved significant improvements in diet scores, body weight, lipid profiles, 6-minute walk distances, physical activity level, and perceived health status. The proportion of patients who achieved secondary prevention goals was also similar, but patients with CKD continued to have lower high-density lipoprotein cholesterol, lower physical component health status summary scores, and lower functional capacity than patients without CKD.

CONCLUSIONS

CKD is common among CR participants. Patients with CKD have a high cardiovascular risk factor and comorbidity burden. CR is as effective in improving coronary risk profiles among patients with CKD as it is among patients with normal renal function.

Managing the Failing Allograft

Managing the failing allograft juxtaposes immunosuppressive management and routine chronic kidney disease care. The complications of immunosuppression can be more pronounced in those with renal failure (infection, anemia, bone disease). The withdrawal of immunosuppression may be associated with acute allograft rejection, arthralgias, and the development of antidonor antibodies. Likewise depression is prevalent. Improving well-being and overall survival necessitates proper titration of immunosuppressive medications and control of blood pressure, anemia, lipids, and glucose along with attention to treatment of depression.

Chronic Kidney Disease: A Risk Factor for Cardiovascular Disease

The goal of risk stratification of CVD inpatients with CKD is to lead to effective and early intervention and to prevent the adverse outcomes associated with this complex multisystem disease that is characteristic of growing number of patients with CKD in the general population and of patients receiving dialysis therapy or kidney transplantation. By 2030, there will be 2.24 million patients with ESRD in the United States, and approximately 1.3 million of these cases of ESRD will be caused by diabetes mellitus. Thus, CVD in this high-risk population presents a challenge for the nephrology and the cardiology community.

Preventing cardiovascular outcome in patients with renal impairment: is there a role for lipid-lowering therapy?

Patients with chronic kidney disease (CKD), ranging from modest renal impairment to dialysis and transplant, have an increased risk for cardiovascular disease (CVD). Patients with CKD have both traditional and non-traditional risk factors for CVD. The role of lipids as risk factors for CVD in these populations has not been firmly established. In a recent prospective controlled trial, it was established that atherogenic lipids are indeed strong risk factors for CVD in renal transplant recipients, and that treatment with a HMG-CoA reductase inhibitor reduced the incidence of cardiac death and myocardial infarction. For patients receiving dialysis, the association between serum lipid levels and cardiovascular outcome is uncertain and there is no evidence from controlled trials that lipid-lowering therapy does have a beneficial effect on cardiovascular outcome in these patients. Atherogenic lipids are probably a risk factor for patients with mild or moderate CKD, and five subgroup analyses have indicated a favorable effect of lipid-lowering therapy on cardiovascular outcome, although we still lack prospective controlled trials in these patients. CVD in patients with CKD has been a neglected area of research.