Rosuvastatin and cardiovascular events in patients undergoing hemodialysis

Prognostic model for total mortality in patients with haemodialysis from the Assessments of Survival and Cardiovascular Events (AURORA) study

OBJECTIVES

Risk factors of mortality in patients with haemodialysis (HD) have been identified in several studies, but few prognostic models have been developed with assessments of calibration and discrimination abilities. We used the database of the Assessment of Survival and Cardiovascular Events study to develop a prognostic model of mortality over 3-4 years.

METHODS

Five factors (age, albumin, C-reactive protein, history of cardiovascular disease and diabetes) were selected from experience and forced into the regression equation. In a 67% random try-out sample of patients, no further factors amongst 24 candidates added significance (P < 0.01) to mortality outcome as assessed by Cox regression modelling, and individual probabilities of death were estimated in the try-out and test samples. Calibration was explored by calculating the prognostic index with regression coefficients from the try-out sample to patients in the 33% test sample. Discrimination was assessed by receiver operating characteristic (ROC) areas.

RESULTS

The strongest prognostic factor in the try-out sample was age, with small differences between the other four factors. Calibration in the test sample was good when the calculated number of deaths was multiplied by a constant of 1.33. The five-factor model discriminated reasonably well between deceased and surviving patients in both the try-out and test samples with an ROC area of about 0.73.

CONCLUSIONS

A model consisting of five factors can be used to estimate and stratify the probability of death for individuals The model is most useful for long-term prognosis in an HD population with survival prospects of more than 1 year.

Avoiding harm in peritoneal dialysis patients

This review is focused on minimizing complications and avoiding harm in peritoneal dialysis (PD) patients. Issues related to planning for PD are covered first, with emphasis on PD versus hemodialysis outcomes. Catheter types and insertion techniques are described next, including relevant recommendations by the International Society for Peritoneal Dialysis. A brief review of both noninfectious and infectious complications follows, with emphasis on cardiovascular and metabolic complications. Finally, recommendations for preventing PD-related infections are provided. In conclusion, with proper catheter insertion technique, good training, and attention to detail during the tenure in PD, excellent outcomes can be obtained in a well-informed motivated patient.

Systematic review of noncancer presentations with a median survival of 6 months or less

PURPOSE

We report on clinical indicators of 6-month mortality in advanced noncancer illnesses and the effect of treatment on survival.

METHODS

The MEDLINE database was searched comprehensively to find studies evaluating survival for common advanced noncancer illnesses. We retrieved and evaluated studies that reported a median survival of ≤1 year and evaluated prognostic factors or effect of treatment on survival. We extracted data on presentations with median survivals of ≤6 months for heart failure, chronic obstructive pulmonary disease, dementia, geriatric failure to thrive, cirrhosis, and end-stage renal failure. Independent risk factors for survival were combined and included if their combination was associated with a 6-month mortality of ≥50%.

RESULTS

The search identified 1000 potentially relevant studies, of which 475 were retrieved and evaluated, and 74 were included. We report the common clinical presentations that are consistently associated with a 6-month median survival. Even though advanced noncancer syndromes differ clinically, a universal set of prognostic factors signals progression to terminal disease, including poor performance status, advanced age, malnutrition, comorbid illness, organ dysfunction, and hospitalization for acute decompensation. Generally, a 6-month median survival is associated with the presence of 2-4 of these factors. With few exceptions, these terminal presentations are quite refractory to treatment.

CONCLUSION

This systematic review summarizes prognostic factors common to advanced noncancer illness. There is little evidence at present that treatment prolongs survival at these terminal stages.

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

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

Baseline characteristics of subjects enrolled in the Evaluation of Cinacalcet HCl Therapy to Lower Cardiovascular Events (EVOLVE) trial

BACKGROUND

Secondary hyperparathyroidism (sHPT) and other abnormalities associated with chronic kidney disease-mineral bone disorder can contribute to dystrophic (including vascular) calcification. Dietary modification and variety of medications can be used to attenuate the severity of sHPT. However, it is unknown whether any of these approaches can reduce the high risks of death and cardiovascular disease in patients with end-stage renal disease.

METHODS

The Evaluation of Cinacalcet HCl Therapy to Lower Cardiovascular Events (EVOLVE) trial was designed to test the hypothesis that treatment with the calcimimetic agent cinacalcet compared with placebo (on a background of conventional therapy including phosphate binders +/- vitamin D sterols) reduces time to death or non-fatal cardiovascular events (specifically myocardial infarction, unstable angina, heart failure and peripheral arterial disease events) among patients on hemodialysis with sHPT. This report describes baseline characteristics of enrolled subjects with a focus on regional variation.

RESULTS

There were 3883 subjects randomized from 22 countries, including the USA, Canada, Australia, three Latin American nations, Russia and 15 European nations. The burden of overt cardiovascular disease at baseline was high (e.g. myocardial infarction 12.4%, heart failure 23.3%). The median plasma parathyroid hormone concentration at baseline was 692 pg/mL (10%, 90% range, 363-1694 pg/mL). At baseline, 87.2% of subjects were prescribed phosphate binders and 57.5% were prescribed activated vitamin D derivatives. Demographic data, comorbid conditions and baseline laboratory data varied significantly across regions.

CONCLUSIONS

EVOLVE enrolled 3883 subjects on hemodialysis with moderate to severe sHPT. Inclusion of subjects from multiple global regions with varying degrees of disease severity will enhance the external validity of the trial results.

Composition and plaque patterns of coronary culprit lesions and clinical characteristics of patients with chronic kidney disease

Coronary artery disease is a serious complication of chronic kidney disease (CKD); however, there is little information about coronary plaque morphology in these patients. Here we identified the characteristics of coronary culprit plaques and their clinical manifestations in 78 patients with CKD divided into four groups based on their estimated glomerular filtration rate. Patients were examined by Virtual Histology-Intravascular Ultrasound, a tomographic imaging method that can visualize atherosclerotic plaques in vivo using radiofrequency analysis of ultrasound backscatter signals. These ultrasound analyses showed an increase in the relative volumes of both dense calcium and necrotic core with decreasing renal function. The necrotic core/dense calcium ratio was significantly higher in patients with acute myocardial infarction compared to those with stable angina pectoris. Furthermore, the necrotic core/dense calcium ratio decreased in advanced CKD. Thus, the plaque composition of coronary culprit lesions changed from necrotic core-rich to extensively calcium-rich plaques as renal function decreased, suggesting that such coronary culprit composition was associated with stability, particularly in advanced CKD.

Are dialysate sodium levels too high?

Universal lower dialysate [Na+] is often advocated as a means of improving the dire cardiovascular plight of our dialysis patients. However, there is evidence associating lower dialysate [Na+] and increased morbidity and mortality especially in frailer patients, probably as a result of more frequent intra-dialytic hypotension. In this editorial, we summarize arguments for and against lower dialysate [Na+], and provide recommendations around selecting the most appropriate dialysate [Na+] for specific clinical subsets that may benefit from manipulation of salt and water balance. The lack of overall clarity on relative benefits and risks of lower dialysate [Na+] does not support the case for empirical "across the board" change, and experimental testing in clinical trials is required to determine safe and effective use.

[Assessment and characteristics of chronic renal insufficiency in France]

Chronic kidney disease (CKD) is a major public health issue. In France, few studies have evaluated CKD prevalence. The objective of the MONA LISA study was to estimate and to characterize CKD in three representative cross-sectional surveys in subjects aged 35-74.9 years. CKD was defined as subjects having MDRD glomerular filtration rate lower than 60 mL/min/1.73 m(2). Prevalence of CKD in MONA LISA was standardized according to the French population. A multiple logistic regression analysis was performed in order to find independent factors associated to CKD. The French estimate of CKD prevalence was 8.2% (95% confidence interval: 7.4-8.9%), that is 2,454,548 (95% confidence interval: 2,215,080-2,664,082) subjects aged 35-74.9 years. Factors significantly and independently associated to CKD were older age, hypertension and dyslipidemias. In conclusion, the MONA LISA study evaluated for the first time in France CKD prevalence in subjects aged 35-74.9 years. This prevalence probably underestimates the real CKD size due to selection bias present in every representative cross-sectional survey.

Chronic Inflammation and Coronary Atherosclerosis in Patients with End-Stage Renal Disease

The key role of chronic inflammation in the pathogenesis of atherosclerosis has become increasingly apparent in recent years based on the results of experimental, epidemiologic and clinical studies. Coronary artery disease and its complications occur with disproportionately high frequency in patients with end-stage renal disease (ESRD) and contribute substantially to cardiovascular morbidity and mortality in this population. Traditional cardiovascular risk factors occur commonly in patients with ESRD. In addition, a variety of patient-related and dialysis-related factors unique to ESRD predispose to chronic inflammation and by doing so are thought to contribute to coronary atherosclerosis and its complications. These risk factors may serve as therapeutic targets and as such may offer the potential for altering the natural history of coronary atherosclerosis in ESRD.

Statin therapy and hemodialysis vascular access--were we bringing a knife to a gunfight and were hoping to win?

Vascular access dysfunction is a major contributor to end stage renal disease patient morbidity, and the cost of maintaining it is staggering. Any intervention able to improve the vascular access maturation rate and/or patency would be significant progress. Based on the anti-inflammatory and vascular beneficial effects demonstrated in non-end stage renal disease patients, we were hoping that statin use might provide the much needed improvement in the hemodialysis vascular access outcome. The reality proved disappointing. The statins failed to improve every aspect of hemodialysis vascular access studied. The present editorial discusses the current data regarding the effect of statins on vascular access and attempts to explain their lack of success.

Dyslipidemia in children with CKD: should we treat with statins?

Dyslipidemia has been shown to be a risk factor for increased cardiovascular morbidity and mortality in adult patients with chronic kidney disease (CKD) stages 2-4. In patients on dialysis, a paradoxical correlation has been found between low cholesterol values and increased mortality rates. No data exist in children. Treatment with statins has been convincingly shown to both reduce blood lipid levels and mortality rates from cardiovascular disease in adult patients in CKD stages 2-4. There is no strong literature support for treating patients on dialysis or after having had a transplant. Data on benefits of statin therapy do not exist in children with CKD. There are many differences between adult and paediatric kidney patients, and I caution on extrapolating the findings in adult patients to children. Studies are thus needed to evaluate the benefits and potential problems of statin treatment in children with CKD.

APOL1 allelic variants are associated with lower age of dialysis initiation and thereby increased dialysis vintage in African and Hispanic Americans with non-diabetic end-stage kidney disease

BACKGROUND

The APOL1 G1 and G2 genetic variants make a major contribution to the African ancestry risk for a number of common forms of non-diabetic end-stage kidney disease (ESKD). We sought to clarify the relationship of APOL1 variants with age of dialysis initiation and dialysis vintage (defined by the time between dialysis initiation and sample collection) in African and Hispanic Americans, diabetic and non-diabetic ESKD.

METHODS

We examined APOL1 genotypes in 995 African and Hispanic American dialysis patients with diabetic and non-diabetic ESKD.

RESULTS

The mean age of dialysis initiation for non-diabetic African-American patients with two APOL1 risk alleles was 48.1 years, >9 years earlier than those without APOL1 risk alleles (t-test, P=0.0003). Similar results were found in the non-diabetic Hispanic American cohort, but not in the diabetic cohorts. G1 heterozygotes showed a 5.3-year lower mean age of dialysis initiation (t-test, P=0.0452), but G2 heterozygotes did not show such an effect. At the age of 70, 92% of individuals with two APOL1 risk alleles had already initiated dialysis, compared with 76% of the patients without APOL1 risk alleles. Although two APOL1 risk alleles are also associated with ∼2 years increased in dialysis vintage, further analysis showed that this increase is fully explained by earlier age of dialysis initiation.

CONCLUSIONS

Two APOL1 risk alleles significantly predict lower age of dialysis initiation and thereby increased dialysis vintage in non-diabetic ESKD African and Hispanic Americans, but not in diabetic ESKD. A single APOL1 G1, but not G2, risk allele also lowers the age of dialysis initiation, apparently consistent with gain of injury or loss of function mechanisms. Hence, APOL1 mutations produce a distinct category of kidney disease that manifests at younger ages in African ancestry populations.

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.