Rosuvastatin and cardiovascular events in patients undergoing hemodialysis

Statins as anti-inflammatory agents in atherogenesis: molecular mechanisms and lessons from the recent clinical trials

Ample evidence exists in support of the potent anti-inflammatory properties of statins. In cell studies and animal models statins exert beneficial cardiovascular effects. By inhibiting intracellular isoprenoids formation, statins suppress vascular and myocardial inflammation, favorably modulate vascular and myocardial redox state and improve nitric oxide bioavailability. Randomized clinical trials have demonstrated that further to their lipid lowering effects, statins are useful in the primary and secondary prevention of coronary heart disease (CHD) due to their anti-inflammatory potential. The landmark JUPITER trial suggested that in subjects without CHD, suppression of low-grade inflammation by statins improves clinical outcome. However, recent trials have failed to document any clinical benefit with statins in high risk groups, such in heart failure or chronic kidney disease patients. In this review, we aim to summarize the existing evidence on statins as an anti-inflammatory agent in atherogenesis. We describe the molecular mechanisms responsible for the anti-inflammatory effects of statins, as well as clinical data on the non lipid-lowering, anti-inflammatory effects of statins on cardiovascular outcomes. Lastly, the controversy of the recent large randomized clinical trials and the issue of statin withdrawal are also discussed.

Exploring the association between macroeconomic indicators and dialysis mortality

BACKGROUND AND OBJECTIVES

Mortality on dialysis varies greatly worldwide, with patient-level factors explaining only a small part of this variation. The aim of this study was to examine the association of national-level macroeconomic indicators with the mortality of incident dialysis populations and explore potential explanations through renal service indicators, incidence of dialysis, and characteristics of the dialysis population.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Aggregated unadjusted survival probabilities were obtained from 22 renal registries worldwide for patients starting dialysis in 2003-2005. General population age and health, macroeconomic indices, and renal service organization data were collected from secondary sources and questionnaires. Linear modeling with log-log transformation of the outcome variable was applied to establish factors associated with survival on dialysis.

RESULTS

Two-year survival on dialysis ranged from 62.3% in Iceland to 89.8% in Romania. A higher gross domestic product per capita (hazard ratio=1.02 per 1000 US dollar increase), a higher percentage of gross domestic product spent on healthcare (1.10 per percent increase), and a higher intrinsic mortality of the dialysis population (i.e., general population-derived mortality risk of the dialysis population in that country standardized for age and sex; hazard ratio=1.04 per death per 10,000 person years) were associated with a higher mortality of the dialysis population. The incidence of dialysis and renal service indicators were not associated with mortality on dialysis.

CONCLUSIONS

Macroeconomic factors and the intrinsic mortality of the dialysis population are associated with international differences in the mortality on dialysis. Renal service organizational factors and incidence of dialysis seem less important.

Instrumental variable analysis

The main advantage of the randomized controlled trial (RCT) is the random assignment of treatment that prevents selection by prognosis. Nevertheless, only few RCTs can be performed given their high cost and the difficulties in conducting such studies. Therefore, several analytical methods for removing the effects of selection bias in observational studies have been proposed. The first aim of this paper is to compare three of those methods: the multivariable risk adjustment method, the propensity score risk adjustment method, and the instrumental variable method. The second aim is to compare the results from observational studies using the instrumental variable method with those from RCTs aiming to answer the same study question.

Value and level of circulating endothelial progenitor cells, angiogenesis factors and mononuclear cell apoptosis in patients with chronic kidney disease

BACKGROUND

Chronic renal failure on dialysis can reduce the number of circulating endothelial progenitor cells (EPCs), but this biomarker has not been fully investigated in patients with chronic kidney disease (CKD). A link between CKD and increased mononuclear cell apoptosis (MCA) in circulation has been reported but the effect of vascular endothelial growth factor (VEGF) and stromal cell-derived factor (SDF)-1α, two angiogenesis factors, on circulating EPC levels in CKD has not been clarified. This study examined the relationships between the numbers of circulating EPCs and the severity of CKD, degree of MCA and serum levels of VEGF and SDF-1α in CKD patients.

METHODS

The numbers of circulating EPCs (CD31/CD34+, CD62E/CD34+, KDR/CD34+, CXCR4/CD34+) were measured in 166 patients with varying degrees of CKD under regular treatment at an outpatient department and in 30 volunteer control subjects.

RESULTS

CKD patients had significantly lower numbers of EPCs (p < 0.007), higher MCA in circulation and higher serum levels of VEGF and SDF-1 compared with the control subjects (all p < 0.001). Compared with patients with early CKD (stages I-III), patients with late CKD [stage IV-V or end-stage renal disease (ESRD)] had significantly lower numbers of EPCs (CXCR4/CD34+), higher MCA, and elevated serum levels of VEGF and SDF-1α (all p < 0.01). Serum VEGF level but not MCA or SDF-1α was strongly correlated with increased numbers of circulating EPCs. Multivariate analysis showed that ESRD along with lower serum albumin was independently predictive of lower numbers of circulating EPCs (p < 0.04).

CONCLUSION

Circulating EPCs were markedly reduced in CKD patients. ESRD was strongly and independently predictive of decreased numbers of circulating EPCs.

Ezetimibe therapy: mechanism of action and clinical update

The lowering of low-density lipoprotein cholesterol (LDL-C) is the primary target of therapy in the primary and secondary prevention of cardiovascular events. Although statin therapy is the mainstay for LDL-C lowering, a significant percentage of patients prescribed these agents either do not achieve targets with statin therapy alone or have partial or complete intolerance to them. For such patients, the use of adjuvant therapy capable of providing incremental LDL-C reduction is advised. One such agent is ezetimibe, a cholesterol absorption inhibitor that targets uptake at the jejunal enterocyte brush border. Its primary target of action is the cholesterol transport protein Nieman Pick C1 like 1 protein. Ezetimibe is an effective LDL-C lowering agent and is safe and well tolerated. In response to significant controversy surrounding the use and therapeutic effectiveness of this drug, we provide an update on the biochemical mechanism of action for ezetimibe, its safety and efficacy, as well as the results of recent randomized studies that support its use in a variety of clinical scenarios.

Lipoprotein-associated phospholipase A2 and outcome in patients with type 2 diabetes on haemodialysis

BACKGROUND

  Lipoprotein-associated phospholipase A2 (LpPLA2) is a lipoprotein-bound enzyme involved in inflammation and atherosclerosis. In a post hoc analysis of a controlled trial with atorvastatin in patients with type 2 diabetes (T2D) on haemodialysis, we examined the association between baseline and change by measuring baseline LpPLA2 activity on cardiovascular events (CVE) and mortality.

METHODS AND RESULTS

  LpPLA2 activity was available of 1202 patients at baseline and 6 months after randomisation from 1255 patients in the German Diabetes Dialysis Study. During the 4-year follow-up, 445 patients (37%) suffered from CVE and 583 patients (49%) died. The highest quartile of LpPLA2 activity (≥615 U/L) was associated with elevated risk for CVE [HR 1·35 (1·02-1·87); P = 0·035]. This association was mainly driven by the placebo group [HR 1·51 (1·01-2·25); P = 0·046]. Receiver-operating characteristics analysis revealed that including LpPLA2 activity in an already adjusted model increased the area under the curve (AUC) for CVE from 0·586 (0·553-0·620) to 0·632 (0·599-0·664; P = 0·020) and for death from 0·704 (0·674-0·733) to 0·708 (0·679-0·737; P = 0·026). In atorvastatin-treated patients, the decrease in LpPLA2 was associated with reduced fatal risk [HR per standard deviation 0·74 (0·62-0·90); P = 0·002], an effect not seen in the placebo group. In contrast, those patients in the placebo group presenting a > 25% decrease in LpPLA2 activity (n = 33) had a more than doubled risk of dying [HR 2·48 (1·56-3·95); P < 0·001].

CONCLUSION

  LpPLA2 activity is predictive for cardiovascular outcome and total mortality. Reducing LpPLA2 by atorvastatin was associated with reduced mortality in patients with T2D on haemodialysis.

Dissociation between progression of coronary artery calcification and endothelial function in hemodialysis patients: a prospective pilot study

Chronic kidney disease profoundly disturbs calcium-phosphate metabolism and predisposes to premature atherosclerosis. Both coronary artery calcification (CAC) and endothelial dysfunction are common in hemodialysis (HD) patients. We hypothesized that a calcium-free phosphate binder would improve endothelial function and delay progression of vascular calcification in HD patients.

METHODS

This was a randomized parallel-group trial in HD patients comparing lanthanum carbonate (LC) with a non-LC phosphorus binders control group (non-LC) at a 1 : 1 randomization. CAC was obtained at baseline, 6, and 12 months, and endothelial function (brachial artery flow-mediated dilation - FMD) at baseline and 6 months.

RESULTS

13 patients were randomized (LC n = 7 and non-LC n = 6). CAC scores (Log ± SE) at baseline were 7.21 ± 0.62 (LC) and 6.07 ± 0.73 (control). CAC increased in the non-LC group (33 ± 17% and 77 ± 22% at 6 and 12 months), but tended to decrease in the LC group (-10 ± 11% and -2 ± 11% at 6 and 12 months). There was statistically less progression in CAC in the LC group compared to control at 6 (p = 0.002) and 12 months (p = 0.003). There was no difference between groups in FMD (p = 0.7). Markers of inflammation did not change significantly.

CONCLUSION

A slower rate of progression of CAC occurred in the LC group, independent of changes in FMD. This is the first study showing dissociation between progression of CAC and FMD in HD patients. Larger studies are warranted to elucidate the impact of different phosphate sequestration therapies on atherosclerosis in HD patients.

Association of race with cumulative exposure to statins in dialysis

BACKGROUND

Patients on dialysis have high rates of cardiovascular disease and are frequently treated with HMG-CoA reductase inhibitors. Given that these patients have insurance coverage for medications as well as regular contact with health care providers, differences by race in exposure to statins over time should be minimal among patients who are candidates for the drug.

METHODS

We created a cohort of incident dialysis patients who were dually eligible for Medicare and Medicaid services. We determined the proportion of days covered (or PDC, a marker of cumulative medication exposure) by a statin prescription over a mean of 2.0 ± 1.4 years. Ordinary least squares regression was used to determine the factors associated with cumulative drug exposure.

RESULTS

Of the 18,727 patients who filled at least one prescription for a statin, mean PDC was 0.57 ± 0.32. The unadjusted PDC was higher for Caucasians (0.63 ± 0.31) than for African-Americans (0.51 ± 0.32), Hispanics (0.54 ± 0.31), and individuals of other race/ethnicity (0.58 ± 0.32). In multivariable modeling, Caucasian race was independently associated with greater exposure to statins. Relative to Caucasians, the adjusted odds ratios for the PDC for African-Americans was 0.47 (95% confidence interval, CI, 0.43-0.50), for Hispanics 0.52 (0.48-0.56) and for others, 0.72 (0.64-0.81).

CONCLUSIONS

Despite insurance coverage, regular contact with health care providers, and at least one prescription for a statin, there are large differences by race in statin exposure over time. The provider- and patient-associated factors related to this phenomenon should be further examined.

Effects of statins on cardiorenal syndrome

Cardiovascular disease and renal disease have a close relationship that forms a vicious cycle as a cardiorenal syndrome (CRS). Oxidative stress, endothelial dysfunction, and vascular inflammation could be therapeutic targets when the renin-angiotensin-aldosterone system is activated by accumulation of conventional cardiovascular risk factors; however, a strategy for management of CRS has not been established yet. Statins, HMG-CoA reductase inhibitors, have not only cholesterol-lowering effects but also pleiotropic effects on cardiovascular systems, including anti-inflammatory and antioxidant effects and improvement of nitric oxide bioavailability. Since recent studies have indicated that statins have beneficial effects on chronic kidney disease and heart failure as well as coronary artery disease in cholesterol-lowering-dependent/independent manners, treatment with statins might be a successful strategy for preventing deterioration of CRS.

Accuracy and limitations of the diagnosis of malnutrition in dialysis patients

Uremic malnutrition, also known as protein-energy wasting (PEW), is a common phenomenon in maintenance dialysis patients and a risk factor for poor clinical outcomes including worse quality of life and increased hospitalization and mortality. The paradoxical association between traditional cardiovascular risk factors and better outcomes in dialysis patients also referred to as "reverse epidemiology," is a good example of the powerful effect-modifying impact of the nutritional status in this population. Measures of food intake, body composition tools, nutritional scoring systems, and laboratory values such as serum albumin are used to diagnose PEW and to assess the degree of severity of PEW without clearly validated diagnostic criteria. Some observational studies suggest that inflammation is a missing link between the PEW and poor clinical outcomes in dialysis patients, although PEW per se may also predispose to illness and inflammation. Ongoing debate as to whether such surrogates as serum albumin or prealbumin concentrations are markers of nutritional status, inflammation, comorbidity, or other conditions has led to confusion and diagnostic and therapeutic nihilism. Irrespective of the cause of hypoalbuminemia in dialysis patients, evidence suggests that nutritional interventions can increase serum albumin in dialysis patients. Hence, we should continue assessing serum albumin and other surrogates of nutritional status to risk-stratify patients and to allocate nutritional therapy, while well-designed, large-scale, randomized, controlled trials of the effects of nutritional intake on clinical outcomes are awaited.

Cardio-renal syndrome type 4: epidemiology, pathophysiology and treatment

Cardiovascular diseases such as coronary artery disease, congestive heart failure, arrhythmia, and sudden cardiac death represent the leading causes of morbidity and mortality in patients with CKD, increasing sharply as patients approach end-stage renal disease. The pathogenesis includes a complex, bidirectional interaction between the heart and kidneys that encompasses traditional and nontraditional risk factors, and has been termed cardio-renal syndrome type 4. In this review, an overview of the epidemiology and scope of this problem is provided, some suggested mechanisms for the pathophysiology of this disorder are discussed, and some of the key treatment strategies are described, with particular focus on recent clinical trials, both negative and positive.

Statins and kidney disease: is the study of heart and renal protection at the cutting edge of evidence?

PURPOSE OF REVIEW

Dyslipidaemias are noted in all stages of chronic kidney disease (CKD). Currently most evidence for their treatment comes from secondary retrospective analyses of patient subgroups with CKD recruited into clinical trials powered of hypertensive and dyslipideamic cohorts powered for cardiovascular endpoints.These analyses suggest a number of different beneficial effects of statins (3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors) on renal, cardiovascular and mortality outcomes. However, there is disagreement on the impact of interventions at different CKD stages, and on treatment targets.

RECENT FINDINGS

The Study of Heart and Renal Protection (SHARP) trial published in June 2011 was the first trial specifically powered to investigate atherosclerotic outcomes in CKD patients. It found a 17% overall reduction in major adverse cardiac events in the statin-treated group compared with placebo, yet no effect on any renal outcomes of proteinuria and progressive decline of glomerular filtration rate. Furthermore, the Swedish Web-system for Enhancement and Development of Evidencebased care in Heart disease Evaluated According to Recommended Therapies (SWEDEHEART) investigators provided further important observational data on the beneficial effect of statins in CKD stages I-IV.

SUMMARY

The evidence that statins have a cardiovascular and mortality benefit in CKD stages I-IV has been reinforced by SHARP, which also definitively shows that there are no special safety concerns for their administration in CKD. However, the utility of the use of statins in patients on dialysis is far from clear, at least in our opinion. The effect of statins on renal outcomes is unconvincing and the evidence does not presently support their use for these indications alone.

Effect on short- and long-term major adverse cardiac events of statin treatment in patients with acute myocardial infarction and renal dysfunction

The 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins) reduce major adverse cardiac events (MACE) and mortality in patients with acute coronary syndrome. We investigated the effectiveness of statin therapy in reducing MACE in patients with acute myocardial infarction (AMI) and renal dysfunction (RD). In the present retrospective study of 12,853 patients with AMI, the patients were categorized into 4 groups: group I, statin therapy and no RD (estimated glomerular filtration rate ≥60 ml/min/1.73 m(2)); group II, neither statin therapy nor RD; group III, statin therapy and RD; group IV, no statin therapy but RD. The primary end points were death and complications during the hospital course. The secondary end points were MACE during 1 year of follow-up after AMI. Significant differences in the composite MACE during 12 months of follow-up were observed among the 4 groups (group I, 11.7%; group II, 19.0%; group III, 26.7%; and group IV, 45.5%; p <0.001). In a Cox proportional hazards model, mortality at 12 months increased stepwise from group II to IV compared to group I. Moreover, MACE-free survival in the severe RD group (estimated glomerular filtration rate <30 mL/min/1.73 m(2)) was also greater in the statin-treated group. In conclusion, statin therapy reduced MACE at 1 year of follow-up in patients with AMI regardless of RD.

Statin therapy and the risk of intracerebral hemorrhage: a meta-analysis of 31 randomized controlled trials

BACKGROUND AND PURPOSE

Statin therapy decreases the risk of ischemic stroke. An increased risk of intracerebral hemorrhage (ICH) has been observed in some studies. To investigate this issue, we performed a meta-analysis of randomized controlled trials using statins that reported ICH.

METHODS

We performed a literature search of Medline, Web of Science, and The Cochrane Library through January 25, 2012, and identified additional randomized controlled trials by reviewing reference lists of retrieved studies and prior meta-analyses. All randomized controlled trials of statin therapy that reported ICH or hemorrhagic stroke were included. The primary outcome variable was ICH. Thirty-one randomized controlled trials were included. All analyses used random effects models and heterogeneity was not observed in any of the analyses.

RESULTS

A total of 91,588 subjects were included in the active group and 91,215 in the control group. There was no significant difference in incidence of ICH observed in the active treatment group versus control (OR, 1.08; 95% CI, 0.88-1.32; P=0.47). ICH risk was not related to the degree of low-density lipoprotein reduction or achieved low-density lipoprotein cholesterol. Total stroke (OR, 0.84; 95% CI, 0.78-0.91; P<0.0001) and all-cause mortality (OR, 0.92; CI, 0.87-0.96; P=0.0007) were significantly reduced in the active therapy group. There was no evidence of publication bias.

CONCLUSIONS

Active statin therapy was not associated with significant increase in ICH in this meta-analysis of 31 randomized controlled trials of statin therapy. A significant reduction in all stroke and all-cause mortality was observed with statin therapy.

Effect of erythropoietin-stimulating agent on uremic inflammation

BACKGROUND

The goal of the present study was to explore the effect of medications that are commonly prescribed for CKD patients on uremic state.

METHODS

This was a cross-sectional study. From January 2006 to October 2009, 1,623 patients with end-stage kidney disease (ESKD) commenced hemodialysis (HD) at the 9 participating hospitals. The criteria for exclusion from the database were 1) serum C-reactive protein (CRP) > 3 mg/dL, 2) WBC count > 9,000/mm3 or <4,000/mm3, and 3) patients with cancer, immune complex disease, or vasculitis. A total of 900 patients were entered into the final database. We explored the association of serum CRP just before the first HD session with clinical characteristics, laboratory data, and medications for CKD in the predialysis period.

RESULTS

On univariate analysis, age, CTR, eGFR, and WBC were significantly correlated with CRP. Systolic and diastolic blood pressure, serum albumin, LDL-C, HDL-C, Hb, Cr, and Ca were inversely associated with CRP. Use of erythropoietin-stimulating agents (ESA) using (r = -0.111, p = 0.0015), renin-angiotensin-aldosterone system inhibitors (r = -0.083, p = 0.0154), and calcium channel blockers (r = -0.1, p = 0.0039) was also negatively correlated with CRP. However, only use of ESA showed a significant negative correlation with CRP that was independent of other clinical factors and CKD medications on multiple regression analysis.

CONCLUSION

ESA may strongly reduce uremic inflammation in addition to improving anemia. To confirm this potential effect, a large-scale longitudinal study would be required.

Effects of sevelamer hydrochloride on mortality, lipid abnormality and arterial stiffness in hemodialyzed patients: a propensity-matched observational study

BACKGROUND

Cause-and-effect associations between sevelamer hydrochloride (HCl) and mortality have yet to be clarified. The effects of sevelamer HCl on mortality, lipid abnormality and arterial stiffness were examined in patients with chronic kidney disease stage 5D.

METHODS

The effects of sevelamer HCl were studied by a single-center cohort study that was conducted from January 1, 2005 to December 31, 2008 (n = 483). By the end of the study, 172 patients (Sevelamer group) had succeeded in continuing sevelamer HCl for >6 months (median 37 months), and 300 patients (Control group) had received calcium carbonate (n = 264) or no phosphate binder (n = 36). The mortality and other outcomes were compared between these two groups after matching by a propensity score calculated using age, gender, diabetes prevalence, and dialysis vintage.

RESULTS

All-cause [hazard ratio (HR) 0.4, P = 0.02] and cardiovascular (CV)-cause [HR 0.29, P = 0.03] cumulative mortality were significantly lower in the matched Sevelamer group than in the matched Control group. The matched Sevelamer group showed increased high-density lipoprotein cholesterol (P = 0.003) and no change in pulse wave velocity (PWV) and ankle-brachial index (ABI), whereas the matched Control group showed increased serum low-density lipoprotein (LDL) cholesterol (P = 0.003), increased PWV (P = 0.03), and decreased ABI (P = 0.0009). Change in serum LDL cholesterol level correlated inversely with sevelamer HCl dosage (P = 0.02).

CONCLUSIONS

Reduced mortality in patients with sevelamer HCl may, at least in part, be explained by an improvement in dyslipidemia and arterial stiffness by sevelamer HCl.