Sunset for statins after AURORA?

The cardiovascular-dialysis nexus: the transition to dialysis is a treacherous time for the heart

Chronic kidney disease (CKD) patients require dialysis to manage the progressive complications of uraemia. Yet, many physicians and patients do not recognize that dialysis initiation, although often necessary, subjects patients to substantial risk for cardiovascular (CV) death. While most recognize CV mortality risk approximately doubles with CKD the new data presented here show that this risk spikes to >20 times higher than the US population average at the initiation of chronic renal replacement therapy, and this elevated CV risk continues through the first 4 months of dialysis. Moreover, this peak reflects how dialysis itself changes the pathophysiology of CV disease and transforms its presentation, progression, and prognosis. This article reviews how dialysis initiation modifies the interpretation of circulating biomarkers, alters the accuracy of CV imaging, and worsens prognosis. We advocate a multidisciplinary approach and outline the issues practitioners should consider to optimize CV care for this unique and vulnerable population during a perilous passage.

Predictors of Arrhythmic Events Detected by Implantable Loop Recorders in Renal Transplant Candidates

BACKGROUND

The recording of arrhythmic events (AE) in renal transplant candidates (RTCs) undergoing dialysis is limited by conventional electrocardiography. However, continuous cardiac rhythm monitoring seems to be more appropriate due to automatic detection of arrhythmia, but this method has not been used.

OBJECTIVE

We aimed to investigate the incidence and predictors of AE in RTCs using an implantable loop recorder (ILR).

METHODS

A prospective observational study conducted from June 2009 to January 2011 included 100 consecutive ambulatory RTCs who underwent ILR and were followed-up for at least 1 year. Multivariate logistic regression was applied to define predictors of AE.

RESULTS

During a mean follow-up of 424 ± 127 days, AE could be detected in 98% of patients, and 92% had more than one type of arrhythmia, with most considered potentially not serious. Sustained atrial tachycardia and atrial fibrillation occurred in 7% and 13% of patients, respectively, and bradyarrhythmia and non-sustained or sustained ventricular tachycardia (VT) occurred in 25% and 57%, respectively. There were 18 deaths, of which 7 were sudden cardiac events: 3 bradyarrhythmias, 1 ventricular fibrillation, 1 myocardial infarction, and 2 undetermined. The presence of a long QTc (odds ratio [OR] = 7.28; 95% confidence interval [CI], 2.01-26.35; p = 0.002), and the duration of the PR interval (OR = 1.05; 95% CI, 1.02-1.08; p < 0.001) were independently associated with bradyarrhythmias. Left ventricular dilatation (LVD) was independently associated with non-sustained VT (OR = 2.83; 95% CI, 1.01-7.96; p = 0.041).

CONCLUSIONS

In medium-term follow-up of RTCs, ILR helped detect a high incidence of AE, most of which did not have clinical relevance. The PR interval and presence of long QTc were predictive of bradyarrhythmias, whereas LVD was predictive of non-sustained VT.

Deeper insight into chronic kidney disease-related atherosclerosis: comparative proteomic studies of blood plasma using 2DE and mass spectrometry

Background

Atherosclerosis is a major cause of cardiac events and mortality in patients suffering from chronic kidney disease (CKD). Moreover, the risk of cardiovascular disease (CVD) development in patients with CKD increases as kidney function declines. Although the close connection between atherosclerosis and kidney dysfunction is undeniable, particular risk factors and specific mechanisms that promote CVD in patients with CKD remain unclear. To gain insight into better recognition of the mechanisms of accelerated atherosclerosis in patients with CKD, we performed a comparative proteomic analysis of blood plasma from patients in various stages of CKD and thus distinct progression of atherosclerosis (n = 90), patients with advanced CVD and normal renal function (n = 30) and healthy volunteers (n = 30).

Methods

Plasma samples were depleted using affinity chromatography and divided into three fractions: high-abundant, low-abundant and low-molecular weight proteins. The first two fractions were analyzed by two-dimensional gel electrophoresis and mass spectrometry, the last one has been subjected to direct MS/MS analysis. A proteomic profiles for high-abundant, low-abundant and low-molecular weight proteins fractions were obtained. Differential accumulated proteins were confirmed by selected reaction monitoring analysis (SRM). The Gene Ontology (GO) function and the interaction networks of differentially expressed proteins were then analyzed.

Results

Forty-nine proteins (13 high- and 36 low-molecular mass) showed differences in accumulation levels. For eleven of them differential expression were confirmed by selected reaction monitoring analysis. Bioinformatic analysis showed that identified differential proteins were related to three different processes: the blood coagulation cascade, the transport, binding and metabolism of lipoproteins and inflammatory processes.

Conclusions

Obtained data provide an additional line of evidence that different molecular mechanisms are involved in the development of CKD- and CVD-related atherosclerosis. The abundance of some anti-atherogenic factors revealed in patients with CKD suggests that these factors are not associated with the reduction of atherosclerosis progression in CKD that is typically observed in “classical” CVD. Moreover, obtained data also suggest that mechanism of CVD acceleration may be different in initial and advanced stages of CKD. Undoubtedly, in advanced stages of CKD inflammation is highly pronounced.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-014-0378-8) contains supplementary material, which is available to authorized users.

Statins in chronic kidney disease and kidney transplantation

HMG-CoA reductase inhibitors (statins) have been shown to improve cardiovascular (CV) outcomes in the general population as well as in patients with cardiovascular disease (CVD). Statins' beneficial effects have been attributed to both cholesterol-lowering and cholesterol-independent "pleiotropic" properties. By their pleiotropic effects statins have been shown to reduce inflammation, alleviate oxidative stress, modify the immunologic responses, improve endothelial function and suppress platelet aggregation. Patients with chronic kidney disease (CKD) exhibit an enormous increase in CVD rates even from early CKD stages. As considerable differences exist in dyslipidemia characteristics and the pathogenesis of CVD in CKD, statins' CV benefits in CKD patients (including those with a kidney graft) should not be considered unequivocal. Indeed, accumulating clinical evidence suggests that statins exert diverse effects on dialysis and non-dialysis CKD patients. Therefore, it seems that statins improve CV outcomes in non-dialysis patients whereas exert little (if any) benefit in the dialysis population. It has also been proposed that dyslipidemia might play a causative role or even accelerate renal injury. Moreover, ample experimental evidence suggests that statins ameliorate renal damage. However, a high quality randomized controlled trial (RCT) and metaanalyses do not support a beneficial role of statins in renal outcomes in terms of proteinuria reduction or retardation of glomerular filtration rate (GFR) decline.

Statins in the management of dyslipidemia associated with chronic kidney disease

The cause of death in the majority of patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD) is accelerated cardiovascular disease and not renal failure per se, suggesting a role for statin therapy in this setting. During the past 6 years three large, randomized, placebo-controlled studies of three different statins have been conducted in the dialysis population-but two of these studies did not demonstrate any benefits of statin therapy, and the third study showed only marginally positive results. To understand why statins have failed to reduce cardiovascular events in patients with ESRD, the basic mechanisms underlying the pathogenesis of dyslipidemia in CKD must be critically examined. The observed negative results in the clinical trials of statin therapy might also reflect the biomarkers and targets that were chosen to be evaluated. The characteristics of dyslipidemia in patients with CKD not yet requiring dialysis treatment differ markedly from those of individuals with established ESRD and form the basis for therapeutic recommendations. The potential adverse effects associated with statin therapy are important to consider in the management of dyslipidemia in patients with CKD.

Glycemic and lipidic profile in diabetic patients undergoing dialysis

OBJECTIVE

The aim of this study is to assess the clinical care pattern and to compare the lipid and glycemic profile in a group of diabetic patients undergoing both hemodialysis (HD) and peritoneal dialysis (PD) and to correlate these data using biomarkers of cardiovascular risk.

SUBJECTS AND METHODS

The first phase consisted in performing a survey on demographic data, questions about the medical team and glycemic control. In the second phase, patients were assessed through laboratorial data on their glycemic and lipid profile at a single center for HD and PD.

RESULTS

91 patients was the total population; 70 patients (77%) answered the survey; 66 patients (94%) considered the nephrologist the physician responsible for caring for their glycemic control. Second phase: 59 patients were assessed, 29 undergoing HD and 30 undergoing PD. Fifty-seven percent of the patients had HbA1c above 7%; the level of glycemic markers in patients undergoing peritoneal dialysis was significantly higher than in patients undergoing hemodialysis: HbA1c (9.37 ± 0.5) vs. (7.37 ± 0.49) p < 0.01; fasting glycemia (170 ± 15) vs. (126 ± 15) mg/dL p < 0.05. We found a positive correlation between HbA1c and hyperfibrinogenemia (r = 0.4437, p < 0.0005).

CONCLUSIONS

The data reveal that glycemic control in diabetic patients undergoing renal replacement therapy (RRT) is neglected. Peritoneal dialysis is related to the worst level of glycemic markers, possibly due to the glucose content in the dialysis solution, and higher levels from HbA1c have a positive correlation with hyperfibrinogenesis in this population.

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.

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.

The diabetic CKD patient--a major cardiovascular challenge

The diabetic patient with chronic kidney disease (CKD) is at very high risk of cardiovascular disease (CVD). Primary and secondary CVD prevention is of major importance and should be targeted at both traditional cardiovascular risk factors and risk factors specific for patients with CKD, such as albuminuria, anaemia and CKD--mineral and bone disorder. However, treatment goals have largely been derived from clinical trials including patients with no or only mild CKD and may not be generalizable to patients with advanced renal disease. Moreover, in patients on renal replacement therapy, the association between traditional CVD risk factors and the incidence of CVD may be reversed, and pharmaceutical interventions that are beneficial in the general population may be ineffective or even harmful in this high-risk population. Those involved in the delivery of care to patients with diabetes and CKD need to be aware of these issues and should adopt an individualised approach to treatment.

Event reduction: revisiting why we treat with statins and harnessing current evidence towards optimal therapy

IMPORTANCE OF THE FIELD

Statins are widely accepted as the drugs of choice for achieving increasingly stringent low-density lipoprotein cholesterol (LDL-C) goals for dyslipidemic patients. However, when making treatment decisions, outcomes data from clinical trials are of greater importance than LDL-C-lowering ability.

AREAS COVERED IN THIS REVIEW

This review will provide an update on current lipid treatment guidelines in the context of statin trial evidence, with particular focus on the incremental benefit of more potent statin therapy compared with lower doses. The discussion will also address combination therapy, statin safety, goal attainment and treatment adherence. MEDLINE searches (1966 to July 2010) were performed.

WHAT THE READER WILL GAIN

The reader will gain a comprehensive review of the evidence base for statin therapy and an appreciation of other issues that affect treatment choice.

TAKE HOME MESSAGE

It is important to remember why we need to partner with our patients: to ensure that they are established on, and continue to adhere to, their appropriate evidence-based statin dose with a goal of achieving lipid targets, but more importantly to prevent cardiovascular disease-related morbidity and mortality. We treat patients to reduce clinical cardiovascular events, not just to control lipids and other important risk factors.

Statins and renal disease: friend or foe?

The role of statins in the treatment and prevention of cardiovascular diseases, such as coronary artery disease, acute coronary syndromes, diabetes, or stroke, is well established. However, there are still some questions regarding the role of statins in patients with chronic kidney disease (CKD). Dyslipidemia is a known cardiovascular risk factor in individuals without CKD. In these patients, however, the relation of dyslipidemia to cardiovascular risk is complex, and the underlying pathobiological mechanisms are complex. Statins have proven to be highly effective in patients with initial stages of CKD; however, their effects in patients with advanced-stage CKD have been neutral despite a low-density lipoprotein cholesterol-lowering effect. In this review, we summarize the findings of the recent clinical trials of statins in renal disease and make recommendations for our patients.

Benefits and harms of phosphate binders in CKD: a systematic review of randomized controlled trials

BACKGROUND

Phosphate binders are widely used to control serum phosphorus levels in patients with chronic kidney disease (CKD). We analyzed the effects of phosphate binders on biochemical and patient-level end points in patients with CKD.

STUDY DESIGN

Systematic review and meta-analysis by searching MEDLINE (1966 to April 2009), EMBASE (1980 to April 2009), and the Cochrane Renal Group Specialised Register and the Cochrane Central Register of Controlled Trials (CENTRAL).

SETTING & POPULATION

Patients with CKD.

SELECTION CRITERIA FOR STUDIES

Randomized controlled trials.

INTERVENTION

Phosphate binders.

OUTCOMES

Serum phosphorus, calcium, and parathyroid hormone levels; incidence of hypercalcemia; all-cause mortality; adverse effects.

RESULTS

40 trials (6,406 patients) were included. There was no significant decrease in all-cause mortality (10 randomized controlled trials; 3,079 patients; relative risk [RR], 0.73; 95% confidence interval [CI], 0.46 to 1.16), hospitalization, or end-of-treatment serum calcium-phosphorus product levels with sevelamer compared with calcium-based agents. There was a significant decrease in end-of-treatment phosphorus and parathyroid hormone levels with calcium salts compared with sevelamer and a significant decrease in risk of hypercalcemia (RR, 0.47; 95% CI, 0.36 to 0.62) with sevelamer compared with calcium-based agents. There was a significant increase in risk of gastrointestinal adverse events with sevelamer in comparison to calcium salts (RR, 1.39; 95% CI, 1.04 to 1.87). Compared with calcium-based agents, lanthanum significantly decreased end-of-treatment serum calcium and calcium-phosphorus product levels, but with similar end-of-treatment phosphorus levels. Effects of calcium acetate on biochemical end points were similar to those of calcium carbonate. Existing data are insufficient to conclude for a differential impact of any phosphate binder on cardiovascular mortality or other patient-level outcome.

LIMITATIONS

Few long-term studies of the efficacy of phosphate binders on mortality and musculoskeletal morbidity, significant heterogeneity for many surrogate outcomes, and suboptimal reporting of study methods to determine trial quality.

CONCLUSION

Currently, there are insufficient data to establish the comparative superiority of non-calcium-binding agents over calcium-containing phosphate binders for such important patient-level outcomes as all-cause mortality and cardiovascular end points. Additional trials are still required to examine the differential effects of phosphate-binding agents on these end points and the mineral homeostasis pathway.

Cardiovascular risk reduction: what do recent trials with rosuvastatin tell us?

Abundant evidence from large-scale clinical trials supports the importance of lowering low-density lipoprotein cholesterol (LDL-C) to decrease the risk of cardiovascular disease (CVD) events. The LDL-C targets in various guidelines remain important treatment goals but, even in trials where statin therapy achieves substantial reduction of LDL-C, a significant number of CVD events still occur and the residual risk remains high. These findings suggest that lipid parameters other than LDL-C, such as high-density lipoprotein cholesterol (HDL-C), triglycerides, and LDL particle size, can influence the risk of CVD. On this basis, other strategies that can alter the lipid profile, in particular raising HDL.C, may provide additional benefits. Other factors such as HDL-C functionality and susceptibility to oxidation and inflammatory factors can also influence cardiovascular risk. In addition to the modifications of the lipid profile, statins have cholesterol-independent beneficial pleiotropic effects. The contribution of these effects to event reduction is not yet fully understood. Recently, the body of evidence has expanded to support the use of intensive statin therapy in broader patient populations. The JUPITER trial has shown the benefit of intensive statin treatment in low-risk subjects with high levels of high-sensitivity C-reactive protein and average levels of LDL-C. Unlike the setting of primary and secondary prevention, the results of statin trials in patients with heart failure have shown no clear benefit in terms of survival. The recently published AURORA trial was carried out to investigate the effect of rosuvastatin in patients with end-stage renal disease undergoing chronic hemodialysis. In this trial no benefit on cardiovascular events was shown with statin therapy. In conclusion, large outcomes trials have clearly shown that statin treatments have a favorable benefit/risk profile in a large range of patients at different levels of risk, with the exception of patients with heart failure and those with renal disease undergoing dialysis. Further evidence is needed on the role of therapeutic strategies on the so-called residual risk.