Rosuvastatin and cardiovascular events in patients undergoing hemodialysis

Rosuvastatin in diabetic hemodialysis patients

A randomized, placebo-controlled trial in diabetic patients receiving hemodialysis showed no effect of atorvastatin on a composite cardiovascular endpoint, but analysis of the component cardiac endpoints suggested that atorvastatin may significantly reduce risk. Because the AURORA (A Study to Evaluate the Use of Rosuvastatin in Subjects on Regular Hemodialysis: An Assessment of Survival and Cardiovascular Events) trial included patients with and without diabetes, we conducted a post hoc analysis to determine whether rosuvastatin might reduce the risk of cardiac events in diabetic patients receiving hemodialysis. Among the 731 participants with diabetes, traditional risk factors such as LDL-C, smoking, and BP did not associate with cardiac events (cardiac death and nonfatal myocardial infarction). At baseline, only age and high-sensitivity C-reactive protein were independent risk factors for cardiac events. Assignment to rosuvastatin associated with a nonsignificant 16.2% reduction in risk for the AURORA trial's composite primary endpoint of cardiac death, nonfatal MI, or fatal or nonfatal stroke (HR 0.84; 95% CI 0.65 to 1.07). There was no difference in overall stroke, but the rosuvastatin group had more hemorrhagic strokes than the placebo group (12 versus two strokes, respectively; HR, 5.21; 95% CI 1.17 to 23.27). Rosuvastatin treatment significantly reduced the rates of cardiac events by 32% among patients with diabetes (HR 0.68; 95% CI 0.51 to 0.90). In conclusion, among hemodialysis patients with diabetes mellitus, rosuvastatin might reduce the risk of fatal and nonfatal cardiac events.

Place of pitavastatin in the statin armamentarium: promising evidence for a role in diabetes mellitus

Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, known as statins, have revolutionized the treatment of hypercholesterolemia and coronary artery disease prevention. However, there are considerable issues regarding statin safety and further development of residual risk control, particularly for diabetic and metabolic syndrome patients. Pitavastatin is a potent statin with low-density lipoprotein (LDL) cholesterol-lowering effects comparable to those of atorvastatin or rosuvastatin. Pitavastatin has a high-density lipoprotein (HDL) cholesterol raising effect, may improve insulin resistance, and has little influence on glucose metabolism. Considering these factors along with its unique pharmacokinetic properties, which suggest minimal drug–drug interaction, pitavastatin could provide an alternative treatment choice, especially in patients with glucose intolerance or diabetes mellitus. Many clinical trials are now underway to test the clinical efficacy of pitavastatin in various settings and are expected to provide further information.

Clinical Trials: Minimising source data queries to streamline endpoint adjudication in a large multi-national trial

BACKGROUND

The UK Clinical Trial Regulations and Good Clinical Practice guidelines specify that the study sponsor must ensure clinical trial data are accurately reported, recorded and verified to ensure patient safety and scientific integrity. The methods that are utilised to assess data quality and the results of any reviews undertaken are rarely reported in the literature. We have recently undertaken a quality review of trial data submitted to a Clinical Endpoint Committee for adjudication. The purpose of the review was to identify areas that could be improved for future clinical trials. The results are reported in this paper.

METHODS

Throughout the course of the study, all data queries were logged. Following study close out, queries were coded and categorised. A descriptive and comparative analysis was conducted to determine the frequency of occurrence for each category by country of origin.

RESULTS

From 1595 endpoint packages reviewed, 782 queries were generated. No source data queries were generated for countries with ≤ 25 recruited subjects, but both low recruiting and high recruiting countries had a high number of queries relating to subject identifiers.

CONCLUSIONS

The implementation of some simple measures could help improve data quality and lead to significant savings.

Inflammatory markers and risk of cerebrovascular events in patients initiating dialysis

BACKGROUND AND OBJECTIVES

Stroke remains a leading cause of morbidity and mortality for patients on dialysis; however, its risk factors in this population and measures to prevent it are not well understood.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We investigated whether inflammation was associated with cerebrovascular events in a national US cohort of 1041 incident dialysis patients enrolled from October 1995 to June 1998 and followed until January 31, 2004. Incident cerebrovascular events were defined as nonfatal (hospitalized stroke, carotid endarterectomy) and fatal (stroke death) events after dialysis initiation. With Cox proportional hazards regression analysis accounting for the competing risk of nonstroke death, we assessed the independent event risk associated with baseline levels of multiple inflammatory markers (high-sensitivity C-reactive protein [hsCRP], interleukin-6 (IL-6), matrix metalloproteinase-3 [MMP-3], and P-selectin) and hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor (statin) use, which may have pleiotropic inflammatory effects.

RESULTS

165 patients experienced a cerebrovascular event during 3548 person-years of follow-up; overall incidence rate was 4.9/100 person-years. None of the inflammatory markers were associated with cerebrovascular event risk (adjusted hazard ratios [HRs] per log unit [95% confidence interval]: hsCRP, 0.97 [0.85 to 1.11]; IL-6, 1.04 [0.85 to 1.26]; MMP-3, 1.02 [0.70 to 1.48]; P-selectin, 0.98 [0.57 to 1.68]). Statin use was also not associated with significant risk of events in unadjusted (HR 1.07 [0.69 to 1.68]) or propensity-score adjusted analyses (HR 0.98 [0.61 to 1.56]).

CONCLUSIONS

In conclusion, neither inflammatory markers nor statin use was associated with risk of cerebrovascular events. Further studies are needed to understand the pathophysiology and prevention of stroke in patients on dialysis.

New insights into lipid metabolism in chronic kidney disease

Disorders in lipid levels in kidney disease consist of alterations both in the levels of the differing lipoprotein classes as well as alteration in their structures. Triglycerides (TGs) are increased, and both high density lipoprotein (HDL) and low density lipoprotein (LDL) levels are reduced. HDL fails to mature normally primarily as a consequence of decreased activity of lecithin cholesterol ester transfer protein (LCAT), and HDL levels are reduced because of increase clearance. The HDL that is present consist of small pre-β discoid HDL that fails to function as an antioxidant. All of the apo B containing lipoproteins exhibit decreased clearance in part because of increased levels of the lipoprotein lipase inhibitory apolipoproteins apo C I and apo C III. The concentration of oxidized LD, an athorgenic risk factor, is increased, in part because of the inability of the HDL that is present to reduce oxidized LDL and in part because of the increased LDL residence time effected by decreased clearance.

Atorvastatin Reduces High Glucose Toxicity in Rat Peritoneal Mesothelial Cells

Objective

Continuous exposure of the peritoneal membrane to high glucose dialysis solutions can produce functional alterations in this membrane. We studied the toxic effects of high glucose (50 mmol/L and 83 mmol/L) and its reversal by atorvastatin (0.5 – 5 μmol/L) on cultures of rat peritoneal mesothelial cells (PMCs).

Methods

Rat PMCs were harvested from the peritonea of male Sprague–Dawley rats and grown in M199 medium supplemented with 10% fetal bovine serum. The effects of high glucose (50 mmol/L and 83 mmol/L) on levels of reactive oxygen species (ROS), on caspase 3 activity, and on phospho-p38 mitogen-activated protein kinase (MAPK) in the cultures were evaluated.

Results

Exposure to high glucose (for 4, 8, and 24 hours) increased intracellular levels of ROS and phospho-p38 MAPK (indices of cellular toxicity). Atorvastatin blocked these toxic effects of high glucose, being more effective against 50 mmol/L glucose (protective effects were observed above 0.5 μmol/L) than against 83 mmol/L (protective effects were observed above 2.5 μmol/L). Atorvastatin was also able to prevent glucose-induced increase in caspase 3 activity.

Conclusions

The present study shows that high glucose may promote oxidative stress and may activate apoptotic pathways in rat PMCs. These toxic effects could be reversed by atorvastatin.

Insulin resistance, inflammation, and vascular disease in nondiabetic predialysis chronic kidney disease patients

BACKGROUND

Chronic kidney disease (CKD) is associated with high cardiovascular morbidity and mortality, which is not fully explained by traditional risk factors; hence, the interest in nontraditional risk factors such as inflammation and insulin resistance (IR). Though IR is shown in nondiabetic CKD, its association with vascular disease and inflammation in this population is unknown, and is what this study aims to investigate.

HYPOTHESIS

IR and inflammation are related to vascular disease in nondiabetic predialysis CKD patients.

METHODS

We studied carotid-artery intima-media thickness (IMT) and endothelial function (brachial artery flow mediated dilation [FMD]) in 35 nondiabetic predialysis patients with stage 3-5 CKD and 35 age- and gender-matched controls. Insulin resistance was measured using the homeostasis model assessment for insulin resistance score (HOMA-IR), inflammation by high-sensitivity CRP (hsCRP), and their relationship with FMD and IMT.

RESULTS

Patients with CKD showed reduced FMD (3.34 ± 2.14% vs. 5.27 ± 1.78%, P<0.001) and increased IMT (0.78 ± 0.22 mm vs. 0.64 ± 0.16 mm, P = 0.003) compared with controls. The CKD patients had a higher HOMA-IR (2.20 ± 1.08 vs. 1.13 ± 0.64, P<0.001) and hsCRP (3.25 ± 5.47 mg/L vs. 1.10 ± 1.85 mg/L [median ± interquartile range], P = 0.02). In the study population, HOMA-IR was directly related to hsCRP. After adjusting for traditional risk factors, high HOMA-IR and hsCRP were significantly related to decreased FMD (adjusted β = -0.44, 95% confidence interval [CI]: -1.55 to -0.08, P = 0.003 and adjusted β = -0.51, 95% CI: -0.51 to -0.15, P = 0.001) and increased IMT (adjusted β = 0.62, 95% CI: 0.54-1.90, P = 0.001 and adjusted β = 0.43, 95% CI: 0.08-0.57, P = 0.011), respectively.

CONCLUSIONS

Subjects with systemic inflammation were more insulin-resistant, and in nondiabetic predialysis CKD, IR and systemic inflammation were independently associated with endothelial dysfunction and atherosclerosis.

Effect of intravenous omega-3 fatty acid infusion and hemodialysis on fatty acid composition of free fatty acids and phospholipids in patients with end-stage renal disease

BACKGROUND

Patients treated with hemodialysis (HD) have been reported to have decreased levels of ω-3 polyunsaturated fatty acids (PUFAs) in plasma and cells. The aim of this study was to investigate the effect of ω-3 PUFAs administered intravenously during HD, as well as the effect of HD treatment, on the fatty acid composition of plasma free fatty acids (FFAs), plasma phospholipids, and platelet phospholipids.

METHODS

Forty-four HD patients were randomized to groups receiving either a single dose of a lipid emulsion containing 4.1 g of ω-3 PUFAs or placebo (saline) administered intravenously during HD. Blood was drawn immediately before (baseline) and after (4 hours) HD and before the next HD session (48 hours). Fatty acid composition was measured using gas chromatography.

RESULTS

The increase in ω-3 FFAs was greater in the ω-3 PUFA group compared with the placebo group, whereas the increase in total FFAs was similar between the 2 groups. In the ω-3 PUFA group, ω-3 PUFAs in plasma phospholipids were higher after 48 hours than at baseline, and in platelet phospholipids, ω-3 PUFAs increased after 4 hours. In the placebo group, no changes were observed in ω-3 PUFAs in plasma and platelet phospholipids.

CONCLUSIONS

Intravenous ω-3 PUFAs administered during HD caused a transient selective increase in ω-3 FFA concentration. Furthermore, ω-3 PUFAs were rapidly incorporated into platelets, and the content of ω-3 PUFAs in plasma phospholipids increased after 48 hours.

Elevated non-high-density lipoprotein cholesterol (non-HDL-C) predicts atherosclerotic cardiovascular events in hemodialysis patients

BACKGROUND AND OBJECTIVES

Dialysis patients show "reverse causality" between serum cholesterol and mortality. No previous studies clearly separated the risk of incident cardiovascular disease (CVD) and the risk of death or fatality after such events. We tested a hypothesis that dyslipidemia increases the risk of incident atherosclerotic CVD and that protein energy wasting (PEW) increases the risk of fatality after CVD events in hemodialysis patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was an observational cohort study in 45,390 hemodialysis patients without previous history of myocardial infarction (MI), cerebral infarction (CI), or cerebral bleeding (CB) at the end of 2003, extracted from a nationwide dialysis registry in Japan. Outcome measures were new onsets of MI, CI, CB, and death in 1 year.

RESULTS

The incidence rates of MI, CI, and CB were 1.43, 2.53, and 1.01 per 100 person-years, and death rates after these events were 0.23, 0.21, and 0.29 per 100 person-years, respectively. By multivariate logistic regression analysis, incident MI was positively associated with non-HDL cholesterol (non-HDL-C) and inversely with HDL cholesterol (HDL-C). Incident CI was positively associated with non-HDL-C, whereas CB was not significantly associated with these lipid parameters. Among the patients who had new MI, CI, and/or CB, death risk was not associated with HDL-C or non-HDL-C, but with higher age, lower body mass index, and higher C-reactive protein levels.

CONCLUSIONS

In this hemodialysis cohort, dyslipidemia was associated with increased risk of incident atherosclerotic CVD, and protein energy wasting/inflammation with increased risk of death after CVD events.

Inflammation-associated graft loss in renal transplant recipients

BACKGROUND

Although short-term graft survival has improved substantially in renal transplant recipients, long-term graft survival has not improved over the last decades. The lack of knowledge of specific causes and risk factors has hampered improvements in long-term allograft survival. There is an uncertainty if inflammation is associated with late graft loss.

METHODS

We examined, in a large prospective trial, the inflammation markers high-sensitivity C-reactive protein (hsCRP) and interleukin-6 (IL-6) and their association with chronic graft dysfunction. We collected data from the Assessment of Lescol in Renal Transplant trial, which recruited 2102 maintenance renal transplant recipients.

RESULTS

Baseline values were hsCRP 3.8 ± 6.7 mg/L and IL-6 2.9 ± 1.9 pg/mL. Adjusted for traditional risk factors, hsCRP and IL-6 were independently associated with death-censored graft loss, the composite end points graft loss or death and doubling of serum creatinine, graft loss or death.

CONCLUSION

The inflammation markers hsCRP and IL-6 are associated with long-term graft outcomes in renal transplant recipients.

Statin use is associated with lower inflammation and erythropoietin responsiveness index in hemodialysis patients

Patients with end-stage renal disease are prone to inflammation and inflammation is related to erythropoietin-stimulating agent hyporesponsiveness and mortality in this population. Statins have been demonstrated to reduce cardiovascular mortality in selected populations of end-stage renal disease patients. These drugs have pleiotrophic effects such as anti-inflammation. In this retrospective analysis, we determined whether the use of statins improves inflammation and inflammation-related anemia in a cohort of hemodialysis patients. Data were analyzed from Fresenius Medical Care Dialysis Clinics in Turkey between 2005 and 2007. Seventy prevalent hemodialysis patients who were on statins at the start of the study and have been on statins during follow-up (statin users) and 1293 patients who were not on statin at the start of the study and had never been prescribed any lipid-modifying drugs during follow-up (statin nonusers) were included in the study. High-sensitive C-reactive protein levels were significantly decreased in statin users (1.50±1.49 vs. 1.33±1.11 mg/L, P=0.05) compared with nonusers (1.93±3.22 vs. 2.05±2.77 mg/L). Hemoglobin levels and the rate of erythropoietin-stimulating agent users were similar. However, the prescribed erythropoietin-stimulating agent dose (31.6±27.5 vs. 47.3±45.2 U/kg/week, P<0.05) and the erythropoietin response index (2.90±2.73 vs. 4.51±4.48 U/kg/week/Hb, P=0.001) were lower in statin users compared with statin nonusers. On stepwise multiple regression analysis, gender, high-sensitive C-reactive protein, duration of hemodialysis, serum ferritin, and statin use were independent determinants of the erythropoietin responsiveness index. Our results suggest that statin treatment leads to lower inflammation and improves hematopoiesis in hemodialysis patients.

Sudden cardiac death in hemodialysis patients: an in-depth review

Sudden cardiac death (SCD) is the leading cause of death in hemodialysis patients, accounting for death in up to one-quarter of this population. Unlike in the general population, coronary artery disease and heart failure often are not the underlying pathologic processes for SCD; accordingly, current risk stratification tools are inadequate when assessing these patients. Factors assuming greater importance in hemodialysis patients may include left ventricular hypertrophy, electrolyte shift, and vascular calcification. Knowledge regarding SCD in hemodialysis patients is insufficient, in part reflecting the lack of an agreed-on definition of SCD in this population, although epidemiologic studies suggest the most common times for SCD to occur are toward the end of the long 72-hour weekend interval between dialysis sessions and in the 12 hours immediately after hemodialysis. Accordingly, it is hypothesized that the dialysis procedure itself may have important implications for SCD. Supporting this is recognition that hemodialysis is associated with both ventricular arrhythmias and dynamic electrocardiographic changes. Importantly, echocardiography and electrocardiography may show changes that are modifiable by alterations to dialysis prescription. The most effective preventative strategy in the general population, implanted cardioverter-defibrillator devices, are less effective in the presence of chronic kidney disease and have not been studied adequately in dialysis patients. Last, many dialysis patients experience SCD despite not fulfilling current criteria for implantation, making appropriate allocation of defibrillators uncertain.

Secular trends in cardiovascular mortality rates of patients receiving dialysis compared with the general population

BACKGROUND

Cardiovascular mortality rates in the general population have decreased over time. We hypothesized that cardiovascular mortality rates in dialysis patients, which are higher than in the general population, have not decreased as much as those in the general population.

STUDY DESIGN

Comparison of registry data with population data.

SETTING & PARTICIPANTS

Data for prevalent Australian patients for whom dialysis was the first renal replacement therapy were obtained from the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry for 1992-2005. Data for a comparable Australian general population were obtained from the Australian Bureau of Statistics.

OUTCOME

Cardiovascular mortality rates per 100 person-years were calculated from ANZDATA Registry data, and age-specific relative risks were calculated relative to cardiovascular mortality rates in the general population.

RESULTS

Included in this cohort were 34,741 dialysis patients with 93,112 person-years of follow-up and 7,267 cardiovascular deaths. Cardiovascular mortality rates decreased over time in the general population and in dialysis patients older than 55 years. In patients aged 55-64 years, cardiovascular mortality rates were 9.0 (95% CI, 7.8-10.3) per 100 person-years in 1992-1994 and 6.4 (95% CI, 5.5-7.3) in 2004-2005; corresponding relative risks were 32.4 (95% CI, 28.2-37.2) and 52.0 (95% CI, 45.2-59.9), respectively. The corresponding cardiovascular mortality rates for dialysis patients aged 65-74 years were 11.6 (95% CI, 10.4-13.0) and 8.3 (95% CI, 7.4-9.3); relative risks were 12.9 (95% CI, 11.6-14.5) and 20.8 (95% CI, 18.7-23.2). Using negative binomial regression, the relative risk associated with dialysis compared with the general population increased over time (P for interaction = 0.001).

LIMITATIONS

Causes of death used to define cardiovascular mortality were not coded using identical systems in the ANZDATA Registry and the Australian population.

CONCLUSIONS

Despite decreasing cardiovascular mortality rates in some dialysis patients, the excess cardiovascular risk compared with the general population is increasing.

Lipid control in patients with diabetes mellitus

Patients with diabetes mellitus are at increased risk of cardiovascular disease (CVD). Dyslipidemia, an important component of the insulin resistance syndrome and type 2 diabetes, is strongly related to CVD risk and is open to therapeutic intervention. Statins have proved to be safe, very-well tolerated, and highly effective in reducing the levels of LDL cholesterol and apolipoprotein B. Primary and secondary CVD prevention trials have shown that use of statins leads to highly significant reductions in the incidence of major CVD events. A wealth of data on the outcomes of statin therapy is now available to guide clinical practice in the population of patients with type 2 diabetes. Statin therapy in patients with type 1 diabetes seems to have a similar benefit to that seen in patients with type 2 diabetes. However, despite statin therapy, high CVD risk persists in these populations. More-intensive statin therapy produces greater reduction in the incidence of CVD events, but a more-global approach to lipid management is likely to result in further risk reduction. After reductions in the levels of LDL cholesterol and apolipoprotein B, the next target of lipid-lowering therapy is to increase HDL-cholesterol levels, which tend to be low in patients with type 2 diabetes. The most effective HDL-cholesterol-raising agent currently available for use in clinical practice is niacin. Trials with surrogate end points have pointed to the cardiovascular benefit of adding niacin to statin therapy. Large CVD end point trials, which include many patients with diabetes, are underway to test the combination of a statin and niacin versus a statin alone.

Chronic kidney disease as a coronary disease equivalent--a comparison with diabetes over a decade

BACKGROUND AND OBJECTIVES

Whether chronic kidney disease (CKD) should also be considered a coronary disease equivalent like diabetes is not clear.

DESIGN, SETTING, PARTICIPANTS, & METHODS

Veterans with and without diabetes and with and without CKD were prospectively recruited. A competing Cox regression model was used to describe the risk of myocardial infarction (MI) in the two groups (CKD and diabetes) over a decade of follow-up.

RESULTS

The incidence rate of MI in those without CKD was 0.047/yr and in those with CKD was 0.206/yr. Multivariate adjustment revealed the incident rate ratio for MI in CKD as 3.5 and for diabetes mellitus as 2.5. The cumulative incidence for MI was influenced by CKD and diabetes. CKD was associated with a subhazard ratio for MI of 3.74; in contrast, diabetes was associated with a subhazard ratio for MI of 2.6. For the outcome of all-cause mortality, after multivariate adjustment, CKD was associated with a hazard ratio (HR) of 1.86, which was similar to the HR of 2.27 for prevalent coronary artery disease. The HR for diabetes was NS at 1.35.

CONCLUSIONS

CKD is associated with a risk of death similar to that of established coronary artery disease and higher than that of diabetes mellitus. CKD is associated with a risk of MI that is at least as much as that from diabetes mellitus. Among veterans, CKD appears to be a coronary disease equivalent.

Inefficacy interim monitoring procedures in randomized clinical trials: the need to report

If definitive evidence concerning treatment effectiveness becomes available from an ongoing randomized clinical trial, then the trial could be stopped early, with the public release of results benefiting current and future patients. However, stopping an ongoing trial based on accruing outcome data requires methodological rigor to preserve validity of the trial conclusions. This has led to the use of formal interim monitoring procedures, which include inefficacy monitoring that will stop a trial early when the experimental treatment appears not to be working. For participants, inefficacy monitoring is especially important as it ensures that they are not being treated worse than if they had not enrolled on the trial. We discuss the importance of reporting with trial results the formal interim inefficacy monitoring guidelines that were utilized, and, if none were used, the reasons for their absence. A survey of two leading medical journals suggests that this is not current practice.

Role of statins in preventing adverse cardiovascular outcomes in patients with chronic kidney disease

PURPOSE OF REVIEW

Cardiovascular disease accounts for the majority of deaths in chronic kidney disease (CKD). Dyslipidemia is a well established cardiovascular risk factor. We summarize key aspects of available evidence relating to beneficial effects of statins in nondialysis-dependent CKD, dialysis-dependent CKD and renal transplant recipients.

RECENT FINDINGS

Previous trials and their meta-analyses suggested that statins reduce lipid levels, the risk of cardiovascular disease and all-cause mortality in nondialysis-dependent CKD. The Study of Heart and Renal Protection (SHARP) study that enrolled both dialysis-dependent and nondialysis-dependent CKD patients showed a 17% decrease in major atherosclerotic events with statins or ezetimibe. Similar cardiovascular benefits are observed in renal transplant recipients. However, such positive effects were not found in two recent clinical trials that enrolled hemodialysis patients alone. This lack of benefit might be attributed to differences in the cause of cardiovascular death seen in dialysis patients and smaller sample size. The overall benefits-harms tradeoff may benefit from meta-analysis and individual patient data meta-analysis in hemodialysis patients including the SHARP data.

SUMMARY

Nondialysis-dependent CKD patients and renal transplant recipients benefit from statins. Statins have also been found to be beneficial in one of the three large trials in hemodialysis patients, a matter which may be further explored.

The efficacy and safety of the 3-hydroxy-3-methylglutaryl-CoA reductase inhibitors in chronic kidney disease, dialysis, and transplant patients

Coronary heart disease (CHD) is the leading cause of death in Western civilizations, in particular in chronic kidney disease (CKD) patients. Serum total cholesterol and LDL have been linked to the development of atherosclerosis and progression to CHD in the general population. However, the reductions of total and LDL cholesterol in the dialysis population have not demonstrated the ability to reduce the morbidity, mortality, and cost burden associated with CHD. The patients at greatest risk include those with pre-existing CHD, a CHD-risk equivalent, or multiple risk factors. However, data in the dialysis population are much less impressive, and the relationship between plasma cholesterol, cholesterol reduction, use of 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase, and reduction in incidence of CHD or effect on progression of renal disease have not been proven. Adverse event information from published trials indicates that agents within this class share similar tolerability and adverse event profiles. Hepatic transaminase elevations may occur in 1 to 2% of patients and is dose related. Myalgia, myopathy, and rhabodmyolysis occur infrequently and are more common in kidney transplant patients and patients with CKD. This effect appears to be dose related and may be precipitated by administration with agents that inhibit cytochrome P-450 isoenzymes. Caution should be exercised when coadministering any statin with drugs that metabolize through cytochrome P-450 IIIA-4 in particular fibrates, cyclosporine, and azole antifungals. Elderly patients with CKD are at greater risk of adverse drug reactions, and therefore the lowest possible dose of statins should be used for the treatment of hyperlipidemia.

Abdominal obesity is the most significant metabolic syndrome component predictive of cardiovascular events in chronic hemodialysis patients

BACKGROUND

Five components of metabolic syndrome (MetS) have been identified as predictive of cardiovascular events (CVEs) in the general population: impaired fasting glucose, abdominal obesity, hypertriglyceridemia, hypertension and low high-density lipoprotein cholesterol. Whether MetS and its components are also predictive of CVEs in chronic hemodialysis (HD) patients remains unclear. We therefore investigated the role of MetS and its components in patients on chronic HD.

METHODS

MetS at baseline was diagnosed in 91 HD patients based on the American Heart Association/National Heart, Lung and Blood Institute (AHA/NHLBI) and the International Diabetes Federation (IDF) definitions. During a 3-year period, all hospitalizations, CVEs and deaths were recorded and analyzed using Kaplan-Meier survival analysis and Cox regression.

RESULTS

There were no differences in the number of CVEs, hospitalizations or deaths between patients with and without AHA/NHLBI-defined MetS; however, patients with IDF-defined MetS were found to be at a higher risk for CVEs (P = 0.006). Cox regression analysis showed that, of the MetS components, abdominal obesity was the single most significant predictor of CVEs (hazard ratio 6.25; 95% confidence interval: 1.65-23.6; P = 0.007).

CONCLUSIONS

IDF-defined MetS was more predictive of CVEs than AHA/NHLBI-defined MetS. Of the MetS components, abdominal obesity was the single most significant predictor of CVEs in chronic HD patients.

Dyslipidemia associated with chronic kidney disease

Cardiovascular disease is a major cause of morbidity and mortality in patients with impaired renal function. Dyslipidemia has been established as a well-known traditional risk factor for cardiovascular disease (CVD) in the general population and it is well known that patients with chronic kidney disease (CKD) exhibit significant alterations in lipoprotein metabolism. In this review, the pathogenesis and treatment of CKD-induced dyslipidemia are discussed. Studies on lipid abnormalities in predialysis, hemodialysis and peritoneal dialysis patients are analyzed. In addition, the results of the studies that tested the effects of the hypolipidemic drugs on cardiovascular morbidity and mortality in patients with CKD are reported.

Phosphate binders for preventing and treating bone disease in chronic kidney disease patients

BACKGROUND

Phosphate binders are widely used to lower serum phosphorus levels in people with chronic kidney disease (CKD) but their impact in CKD remains controversial.

OBJECTIVES

To review the effects of various phosphate binders on biochemical and patient-level end-points in CKD stages 3 to 5D.

SEARCH STRATEGY

In March 2010 we searched MEDLINE, EMBASE, the Cochrane Renal Group's Specialised Register and CENTRAL for relevant studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-RCTs that assessed the effects of various phosphate binders in adults with CKD.

DATA COLLECTION AND ANALYSIS

Two authors independently reviewed search results and extracted data. Results were expressed as mean differences (MD) for continuous outcomes and risk ratios (RR) for dichotomous outcomes with 95% confidence intervals (CI) using a random-effects model.

MAIN RESULTS

Sixty studies (7631 participants) were included. There was no significant reduction in all-cause mortality (10 studies, 3079 participants: RR 0.73, 95% CI 0.46 to 1.16), or serum calcium by phosphorus (Ca x P) product with sevelamer hydrochloride compared to calcium-based agents. There was a significant reduction in serum phosphorus (16 studies, 3126 participants: MD 0.23 mg/dL, 95% CI 0.04 to 0.42) and parathyroid hormone (PTH) (12 studies, 2551 participants; MD 56 pg/mL, 95% CI 26 to 84) but a significant increase in the risk of hypercalcaemia (12 studies, 1144 participants: RR 0.45, 95% CI 0.35 to 0.59) with calcium-based agents compared to sevelamer hydrochloride. There was a significant increase in the risk of adverse gastrointestinal events with sevelamer hydrochloride in comparison to calcium salts (5 studies, 498 participants: RR 1.58, 95% CI 1.11 to 2.25). Compared with calcium-based agents, lanthanum significantly reduced serum calcium (2 studies, 122 participants: MD -0.30 mg/dL, 95% CI -0.64 to -0.25) and the Ca x P product, but not serum phosphorus levels. The effects of calcium acetate on biochemical end-points were similar to those of calcium carbonate. The phosphorus lowering effects of novel agents such as ferric citrate, colestilan and niacinamide were only reported in a few studies.

AUTHORS' CONCLUSIONS

Available phosphate-binding agents have been shown to reduce phosphorus levels in comparison to placebo. However, there are insufficient data to establish the comparative superiority of novel non-calcium binding agents over calcium-containing phosphate binders for patient-level outcomes such as all-cause mortality and cardiovascular end-points in CKD.

Sevelamer carbonate for the treatment of hyperphosphatemia in patients with kidney failure (CKD III - V)

IMPORTANCE OF THE FIELD

Altered mineral metabolism in chronic kidney disease (CKD) is associated with increased morbidity, mortality, hospitalization, cost of care and reduced quality of life. Phosphorus control, one component of CKD metabolic derangements, is potentially related to impaired outcomes and has significant room for improvement.

AREAS COVERED IN THIS REVIEW

Historical, present and future aspects of treatment of hyperphosphatemia focusing on sevelamer hydrochloride and sevelamer carbonate.

WHAT THE READER WILL GAIN

Comprehensive insight into the background and controversies regarding phosphate binders.

TAKE HOME MESSAGE

While calcium-free phosphate binders with a sevelamer backbone may offer therapeutic advantages for CKD patients at risk, more studies comprising significant patient numbers are warranted to answer compelling clinical questions.

Cardiorenal syndrome type 4-cardiovascular disease in patients with chronic kidney disease: epidemiology, pathogenesis, and management

The term cardiorenal syndrome refers to the interaction between the heart and the kidney in disease and encompasses five distinct types according to the initial site affected and the acute or chronic nature of the injury. Type 4, or chronic renocardiac syndrome, involves the features of chronic renal disease (CKD) leading to cardiovascular injury. There is sufficient epidemiologic evidence linking CKD with increased cardiovascular morbidity and mortality. The underlying pathophysiology goes beyond the highly prevalent traditional cardiovascular risk burden affecting renal patients. It involves CKD-related factors, which lead to cardiac and vascular pathology, mainly left ventricular hypertrophy, myocardial fibrosis, and vascular calcification. Risk management should consider both traditional and CKD-related factors, while therapeutic interventions, apart from appearing underutilized, still await further confirmation from large trials.

Large artery calcification on dialysis patients is located in the intima and related to atherosclerosis

BACKGROUND AND OBJECTIVES

Vascular calcification (VC) has a significant effect in cardiovascular diseases on dialysis patients. However, VC is assessed with x-ray-based techniques, which do not inform about calcium localization (intima, media, atherosclerosis-related). The aim of this work is to study VC and its related factors using arterial ultrasound to report the exact location of calcium.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was an observational, cross-sectional, case-control study that included 232 patients in dialysis and 208 age- and sex-matched controls with normal kidney function. Demographic data and laboratory values were collated. Carotid, femoral, and brachial ultrasounds were performed to assess VC and atherosclerosis burden using a standardized protocol.

RESULTS

Cardiovascular risk factors were predominantly found in controls, although the burden of atherosclerosis was higher in the dialysis group. VC was significantly more prevalent in the group of patients on dialysis than control subjects, and in both groups the most prevalent pattern of VC was linear calcification located in the intima of the artery wall. Age and undergoing dialysis (with or without previous cardiovascular diseases) were positively and significantly associated with linear calcification. Conversely, the absence of atherosclerosis and low levels of C-reactive protein and phosphorus significantly impeded the development of linear calcification.

CONCLUSIONS

VC in large, conduit arteries is more prevalent in patients on dialysis than controls and is predominantly located in a linear fashion in the intima of the arteries.

Efficacy and safety of statin treatment for cardiovascular disease: a network meta-analysis of 170,255 patients from 76 randomized trials

BACKGROUND

Statins represent the largest selling class of cardiovascular drug in the world. Previous randomized trials (RCTs) have demonstrated important clinical benefits with statin therapy.

AIM

We combined evidence from all RCTs comparing a statin with placebo or usual care among patients with and without prior coronary heart disease (CHD) to determine clinical outcomes.

DESIGN

We searched independently, in duplicate, 12 electronic databases (from inception to August 2010), including full text journal content databases, to identify all statin versus inert control RCTs. We included RCTs of any statin versus any non-drug control in any populations. We abstracted data in duplicate on reported major clinical events and adverse events. We performed a random-effects meta-analysis and meta-regression. We performed a mixed treatment comparison using Bayesian methods.

RESULTS

We included a total of 76 RCTs involving 170,255 participants. There were a total of 14,878 deaths. Statin therapy reduced all-cause mortality, Relative Risk (RR) 0.90 [95% confidence interval (CI) 0.86-0.94, P ≤ 0.0001, I(2)=17%]; cardiovascular disease (CVD) mortality (RR 0.80, 95% CI 0.74-0.87, P<0.0001, I(2)=27%); fatal myocardial infarction (MI) (RR 0.82, 95% CI 0.75-0.91, P<0.0001, I(2)=21%); non-fatal MI (RR 0.74, 95% CI 0.67-0.81, P ≤ 0.001, I(2)=45%); revascularization (RR 0.76, 95% CI 0.70-0.81, P ≤ 0.0001); and a composite of fatal and non-fatal strokes (0.86, 95% CI 0.78-0.95, P=0.004, I(2)=41%). Adverse events were generally mild, but 17 RCTs reported on increased risk of development of incident diabetes [Odds Ratio (OR) 1.09; 95% CI 1.02-1.17, P=0.001, I(2)=11%]. Studies did not yield important differences across populations. We did not find any differing treatment effects between statins.

DISCUSSION

Statin therapies offer clear benefits across broad populations. As generic formulations become more available efforts to expand access should be a priority.

Prevention of dialysis catheter malfunction with recombinant tissue plasminogen activator

BACKGROUND

The effectiveness of various solutions instilled into the central venous catheter lumens after each hemodialysis session (catheter locking solutions) to decrease the risk of catheter malfunction and bacteremia in patients undergoing hemodialysis is unknown.

METHODS

We randomly assigned 225 patients undergoing long-term hemodialysis in whom a central venous catheter had been newly inserted to a catheter-locking regimen of heparin (5000 U per milliliter) three times per week or recombinant tissue plasminogen activator (rt-PA) (1 mg in each lumen) substituted for heparin at the midweek session (with heparin used in the other two sessions). The primary outcome was catheter malfunction, and the secondary outcome was catheter-related bacteremia. The treatment period was 6 months; treatment assignments were concealed from the patients, investigators, and trial personnel.

RESULTS

A catheter malfunction occurred in 40 of the 115 patients assigned to heparin only (34.8%) and 22 of the 110 patients assigned to rt-PA (20.0%)--an increase in the risk of catheter malfunction by a factor of almost 2 among patients treated with heparin only as compared with those treated with rt-PA once weekly (hazard ratio, 1.91; 95% confidence interval [CI], 1.13 to 3.22; P = 0.02). Catheter-related bacteremia occurred in 15 patients (13.0%) assigned to heparin only, as compared with 5 (4.5%) assigned to rt-PA (corresponding to 1.37 and 0.40 episodes per 1000 patient-days in the heparin and rt-PA groups, respectively; P = 0.02). The risk of bacteremia from any cause was higher in the heparin group than in the rt-PA group by a factor of 3 (hazard ratio, 3.30; 95% CI, 1.18 to 9.22; P = 0.02). The risk of adverse events, including bleeding, was similar in the two groups.

CONCLUSIONS

The use of rt-PA instead of heparin once weekly, as compared with the use of heparin three times a week, as a locking solution for central venous catheters significantly reduced the incidence of catheter malfunction and bacteremia. (Current Controlled Trials number, ISRCTN35253449.).

Pre-procedural atorvastatin mobilizes endothelial progenitor cells: clues to the salutary effects of statins on healing of stented human arteries

Objectives

Recent clinical trials suggest an LDL-independent superiority of intensive statin therapy in reducing target vessel revascularization and peri-procedural myocardial infarctions in patients who undergo percutaneous coronary interventions (PCI). While animal studies demonstrate that statins mobilize endothelial progenitor cells (EPCs) which can enhance arterial repair and attenuate neointimal formation, the precise explanation for the clinical PCI benefits of high dose statin therapy remain elusive. Thus we serially assessed patients undergoing PCI to test the hypothesis that high dose Atorvastatin therapy initiated prior to PCI mobilizes EPCs that may be capable of enhancing arterial repair.

Methods and Results

Statin naïve male patients undergoing angiography for stent placement were randomized to standard therapy without Atorvastatin (n = 10) or treatment with Atorvastatin 80 mg (n = 10) beginning three days prior to stent implantation. EPCs were defined by flow cytometry (e.g., surface marker profile of CD45dim/34+/133+/117+). As well, we also enumerated cultured angiogenic cells (CACs) by standard in vitro culture assay. While EPC levels did not fluctuate over time for the patients free of Atorvastatin, there was a 3.5-fold increase in EPC levels with high dose Atorvastatin beginning within 3 days of the first dose (and immediately pre-PCI) which persisted at 4 and 24 hours post-PCI (p<0.05). There was a similar rise in CAC levels as assessed by in vitro culture. CACs cultured in the presence of Atorvastatin failed to show augmented survival or VEGF secretion but displayed a 2-fold increase in adhesion to stent struts (p<0.05).

Conclusions

High dose Atorvastatin therapy pre-PCI improves EPC number and CAC number and function in humans which may in part explain the benefit in clinical outcomes seen in patients undergoing coronary interventions.

Oral activated charcoal adsorbent (AST-120) ameliorates extent and instability of atherosclerosis accelerated by kidney disease in apolipoprotein E-deficient mice

BACKGROUND

Accelerated atherosclerosis and increased cardiovascular events are not only more common in chronic kidney disease (CKD) but are more resistant to therapeutic interventions effective in the general population. The oral charcoal adsorbent, AST-120, currently used to delay start of dialysis, reduces circulating and tissue uremic toxins, which may contribute to vasculopathy, including atherosclerosis. We, therefore, investigated whether AST-120 affects CKD-induced atherosclerosis.

METHODS

Apolipoprotein E-deficient mice, a model of atherosclerosis, underwent uninephrectomy, subtotal nephrectomy or sham operation at 8 weeks of age and were treated with AST-120 after renal ablation. Atherosclerosis and its characteristics were assessed at 25 weeks of age.

RESULTS

Uninephrectomy and subtotal nephrectomised mice had significantly increased acceleration of atherosclerosis. AST-120 treatment dramatically reduced the atherosclerotic burden in mice with kidney damage, while there was no beneficial effect in sham-operated mice. The benefit was independent of blood pressure, serum total cholesterol or creatinine clearance. AST-120 significantly decreased necrotic areas and lessened aortic deposition of the uremic toxin indoxyl sulfate without affecting lesional macrophage or collagen content. Furthermore, AST-120 lessened aortic expression of monocyte chemoattractant protein-1, tumor necrosis factor-α and interleukin-1β messenger RNA.

CONCLUSIONS

AST-120 lessens the extent of atherosclerosis induced by kidney injury and alters lesion characteristics in apolipoprotein E-deficient mice, resulting in plaques with a more stable phenotype with less necrosis and reduced inflammation.

Lipotoxicity and impaired high density lipoprotein-mediated reverse cholesterol transport in chronic kidney disease

Chronic kidney disease (CKD) is associated with a high risk of death from cardiovascular disease. Inflammation, oxidative stress, and dyslipidemia, which are common consequences of CKD, contribute to the pathogenesis of atherosclerosis and cardiovascular disease in this population. Dyslipidemia of CKD is characterized by diminished plasma high density lipoprotein (HDL) concentration, impaired HDL anti-oxidant and anti-inflammatory activities, and elevated plasma triglyceride, very low density lipoprotein (VLDL), intermediate density lipoprotein, chylomicron remnants, and oxidized lipids and lipoproteins. The constellation of inflammation, HDL deficiency, and oxidative modification of lipoproteins can cause atherosclerosis and progression of renal disease. We have recently found lipid accumulation in the remnant kidney and the wall of aorta in rats with CKD induced by 5/6 nephrectomy. This was mediated by up-regulation of scavenger receptors involved in the influx of oxidized lipids or lipoproteins, tubular reabsorption of lipid binding proteins through megalin-cubilin complexes, upregulation of fatty acid synthesis, and downregulation of fatty acid oxidation pathways. The combination of increased lipid influx, elevated production and reduced catabolism of lipids, and impaired HDL-mediated reverse cholesterol transport can promote atherosclerosis, glomerulosclerosis, and tubulointerstitial damage. Although statins can be effective in slowing CKD progression in patients with mild-to-moderate CKD, they have consistently failed to mitigate oxidative stress, inflammation, HDL deficiency, or cardiovascular mortality in the end-stage renal disease populations. Similarly, high doses of antioxidant vitamins have failed to either ameliorate oxidative stress, inflammation, or improve overall mortality in end-stage renal disease. This article is intended to provide a brief review of the effects of CKD on HDL structure and function and pathways of lipid influx, efflux, synthesis, and catabolism in the artery wall and the diseased kidney.