Effect of rosuvastatin on outcomes in chronic haemodialysis patients - design and rationale of the AURORA study

Automated External Defibrillators and Survival from Cardiac Arrest in the Outpatient Hemodialysis Clinic

Automated external defibrillators (AED) have been recommended for use in outpatient dialysis clinics to improve outcomes from cardiac arrest, the most common cause of death in patients with ESRD. The effectiveness of this policy is unknown. The study cohort consisted of 43,200 hemodialysis patients in the US Gambro Healthcare System from 2002 to 2005. Of these, 729 patients who sustained an in-center cardiac arrest were identified. Baseline characteristics at the time of the event were compared between patients who underwent hemodialysis in clinics with and without an AED on site. Unadjusted survival and survival adjusted for potential confounders was measured using Cox proportional hazards regression models. Unadjusted survival at 30 d was 19 versus 15% (P = 0.12) and 9.5 versus 7.8% at 1 yr (P = 0.39) in the AED-present and AED-absent groups, respectively. AED presence was not associated with outcome in unadjusted analysis (hazard ratio [HR] 0.91; 95% confidence interval [CI] 0.78 to 1.07; P = 0.26). Univariable analysis identified age (HR 1.07 per decade; 95% CI 1.01 to 1.13), serum albumin (HR 0.91 per 0.7-mg/dl increase; 95% CI 0.82 to 1.01), and indwelling dialysis catheters (HR 1.21; 95% CI 1.02 to 1.42) as potential confounders. Medications including angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, beta blockers, calcium channel blockers, other BP medications, aspirin, antibiotics, and antiarrhythmics were associated with survival and considered confounders. After controlling for case mix and confounders, AED presence was not associated with outcome (HR 0.98; 95% CI 0.82 to 1.18; P = 0.83). Presence of AED in the dialysis clinic is not sufficient by itself to improve the abysmal outcome from in-clinic cardiac arrest in hemodialysis patients in the United States.

Dyslipidemia, inflammation and dialysis outcomes: what we know now

PURPOSE OF REVIEW

The limited prognosis of patients with chronic kidney disease starts when renal function begins to decline.

RECENT FINDINGS

Available interventions did not prove their efficacy. Treatment of dyslipidemia and inflammation by statins was shown to be effective in post-hoc subgroup analyses of large-scale randomized controlled trials in patients with chronic kidney disease stages 2 and 3. So far, randomized controlled trials in dialysis patients (HEMO, ADEMEX, 4D study) and after kidney transplantation (ALERT study) have produced so-called 'negative results'. It is most likely that these trials had limited power to prove the primary hypothesis. It is also probable that cardiac disease in renal patients changes its character from a vascular atherosclerotic to a more complex structural heart disease in combination with stiff arteries (arteriosclerosis). Clinically, this leads to a high proportion of sudden cardiac deaths: of 270 cardiac deaths in the 4D trial, 160 were of sudden cardiac origin. A complex pathogenetic process and a number of new emerging cardiovascular disease risk factors in the setting of high-grade inflammation/infection are proposed as being responsible.

SUMMARY

This review focuses on outcome variables in diabetic hemodialysis patients with special focus on risk factors such as inflammation and dyslipidemia.

Statins in the treatment of chronic heart failure: a systematic review

BACKGROUND

The efficacy of statin therapy in patients with established chronic heart failure (CHF) is a subject of much debate.

METHODS AND FINDINGS

We conducted three systematic literature searches to assess the evidence supporting the prescription of statins in CHF. First, we investigated the participation of CHF patients in randomized placebo-controlled clinical trials designed to evaluate the efficacy of statins in reducing major cardiovascular events and mortality. Second, we assessed the association between serum cholesterol and outcome in CHF. Finally, we evaluated the ability of statin treatment to modify surrogate endpoint parameters in CHF. Using validated search strategies, we systematically searched PubMed for our three queries. In addition, we searched the reference lists from eligible studies, used the "see related articles" feature for key publications in PubMed, consulted the Cochrane Library, and searched the ISI Web of Knowledge for papers citing key publications. Search 1 resulted in the retrieval of 47 placebo-controlled clinical statin trials involving more than 100,000 patients. CHF patients had, however, been systematically excluded from these trials. Search 2 resulted in the retrieval of eight studies assessing the relationship between cholesterol levels and outcome in CHF patients. Lower serum cholesterol was consistently associated with increased mortality. Search 3 resulted in the retrieval of 18 studies on the efficacy of statin treatment in CHF. On the whole, these studies reported favorable outcomes for almost all surrogate endpoints.

CONCLUSIONS

Since CHF patients have been systematically excluded from randomized, controlled clinical cholesterol-lowering trials, the effect of statin therapy in these patients remains to be established. Currently, two large, randomized, placebo-controlled statin trials are under way to evaluate the efficacy of statin treatment in terms of reducing clinical endpoints in CHF patients in particular.

Statins: are any questions unanswered?

PURPOSE OF REVIEW

To summarize recent and ongoing randomized trials of statin therapy for the prevention of major vascular events.

RECENT FINDINGS

Four large-scale randomized trials have compared high-dose vs. standard doses of statin therapy among patients with coronary heart disease, and their results suggest that higher doses are more effective for preventing major vascular events, albeit with evidence of increased toxicity. There is now clear evidence that statin therapy is effective among most patients with type 2 diabetes, although uncertainty remains about the benefits in those with advanced nephropathy. Ongoing trials will assess whether statin therapy is beneficial among patients with noncoronary vascular disease (such as congestive heart failure, cerebrovascular disease, or aortic stenosis), and among people with comorbid conditions or risk factors that increase the risk of vascular disease (including chronic kidney disease and raised C-reactive protein with below average low-density lipoprotein cholesterol).

SUMMARY

Statin therapy safely reduces the risk of vascular events in a wide range of patients. Uncertainties persist about the effects of higher statin doses and the role of statins among patients with specific conditions or risk factors.

Prevention of cardiovascular events in end-stage renal disease: results of a randomized trial of fosinopril and implications for future studies

Cardiovascular events (CVEs) are the leading cause of death in chronic hemodialysis patients. Results of trials in non-end-stage renal disease (ESRD) patients cannot be extrapolated to patients with ESRD. It is critical to test cardiovascular therapies in these high-risk patients who are usually excluded from major cardiovascular trials. The study objective was to evaluate the effect of fosinopril on CVEs in patients with ESRD. Eligible patients were randomized to fosinopril 5 mg titrated to 20 mg daily (n=196) or placebo (n=201) plus conventional therapy for 24 months. The primary end point was combined fatal and nonfatal first major CVEs (cardiovascular death, resuscitated death, nonfatal stroke, heart failure, myocardial infarction, or revascularization). No significant benefit for fosinopril was observed in the intent to treat analysis (n=397) after adjusting for independent predictors of CVEs (RR=0.93, 95% confidence interval (CI) 0.68-1.26, P=0.35). The per protocol secondary supportive analysis (n=380) found a trend towards benefit for fosinopril (adjusted RR=0.79 (95% CI 0.59-1.1, P=0.099)). In the patients who were hypertensive at baseline, systolic and diastolic blood pressures were significantly decreased in the fosinopril as compared to the placebo group. After adjustment for risk factors, trends were observed suggesting fosinopril may be associated with a lower risk of CVEs. These trends may have become statistically significant had the sample size been larger, and these findings warrant further study.

Prognostic Associations Between Lipid Markers and Outcomes in Kidney Transplant Recipients

BACKGROUND

Hyperlipidemia is highly prevalent in kidney transplant recipients, but the prognostic significance for mortality and allograft survival in these patients has not been established sufficiently.

METHODS

We prospectively enrolled 733 kidney transplant recipients between 1996 and 1998. Clinical information was collected and blood was drawn for laboratory evaluation. Information on the previous transplantation procedures and organ donor were obtained from the Eurotransplant Foundation database. We used the Austrian Dialysis and Transplantation Registry for follow-up. Using multivariate proportional hazard regression, independent relations of fasting plasma triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol levels to risk for death from any cause and risk for kidney allograft loss were examined.

RESULTS

During a median follow-up of 6.1 years, 154 patients died and 260 kidney allografts were lost. After careful multivariate adjustment, there were no significant associations between TG and TC levels and patient mortality. Patients in the highest quartile of TG and TC levels had no difference in risks for mortality compared with patients in the lowest quartile of these parameters (hazards ratio, 0.81; 95% confidence interval, 0.51 to 1.28; hazards ratio, 0.68; 95% confidence interval, 0.42 to 1.10, respectively). Similarly, no associations were found with allograft loss. Further analysis of associations between high-density lipoprotein cholesterol or low-density lipoprotein cholesterol categories and patient mortality or kidney allograft loss did not show associations.

CONCLUSION

Elevated levels of TC or its subfractions and elevated TG levels are not associated with increased risk for patient mortality or allograft loss in these kidney transplant recipients.

Statin therapy for prevention and treatment of acute and chronic cardiovascular disease: update on recent trials and metaanalyses

PURPOSE OF REVIEW

To summarize the evidence from recent clinical trials and metaanalyses on the efficacy of statin therapy to reduce death, myocardial infarction and stroke, and to review the effects of statins in patients with low LDL cholesterol, diabetes, end-stage renal disease, and acute coronary syndrome.

RECENT FINDINGS

In large metaanalyses of randomized controlled trials relative risk reductions from statins compared with placebo for patients with manifest or with risk factors for coronary artery disease were 13% for overall mortality, 26% for fatal and nonfatal myocardial infarction, and 18% for fatal and nonfatal stroke. Evidence from large trials suggests that patients with type II diabetes compared with patients without diabetes have similar risk reductions from statins for cardiovascular events, but this benefit is not seen in patients with diabetes and end-stage renal disease. In patients with acute coronary syndrome, early treatment with high-dose atorvastatin reduces cardiovascular morbidity after the first 4 months following the event, but the impact on mortality endpoints remains less clear. Results from recent trials in patients with stable coronary artery disease or type II diabetes suggest that statins provide benefit at considerable low LDL cholesterol levels. Therefore, target values for LDL cholesterol of less than 1.8 mmol/l (<70 mg/dl) should be considered for all patients with coronary artery disease or equivalent coronary risk.

SUMMARY

For patients at high risk of coronary artery disease there is growing evidence for the concept of 'the lower, the better' regarding LDL cholesterol levels. Ongoing trials are further investigating the safety of lower target values in patients at various risk of coronary artery disease.

In vivo and in vitro effects of simvastatin on inflammatory markers in pre-dialysis patients

BACKGROUND

The beneficial effects of statins in reducing cardiovascular events have been attributed predominantly to their lipid-lowering effects, recent studies suggest that these effects might be due to their anti-inflammatory properties. We here investigate the in vivo and in vitro effects of simvastatin on cytokine production in pre-dialysis chronic renal failure patients.

METHODS

Our clinical study has been designed as a randomized double-blind placebo controlled study. A total of 55 chronic kidney disease (CKD) patients at stages 3 and 4 (mean creatinine clearance 45 ml/min, range 15-60) were randomly assigned to receive simvastatin 40 mg/day or placebo, added to their ongoing treatment, for 6 months. Blood samples were obtained at baseline, and after 3 and 6 months of observation for the determination of lipids, inflammatory markers and renal function. For the in vitro studies, the effect of increasing doses of simvastatin on cytokine production [namely interleukin (IL)-6 and IL-8] in human cultured monocytes from 10 healthy subjects (HS) and 15 CKD patients stimulated by lipopolysaccharide (LPS) was investigated.

RESULTS

A significant reduction in total cholesterol from 221+/-44 mg/dl to 184+/-41 mg/dl (3 months) and to 186+/-39 mg/dl (6 months) (P<0.02) and low-density lipoprotein cholesterol from 139+/-40 mg/dl to 104+/-29 mg/dl (3 months) and to 100+/-31 mg/dl (6 months) (P<0.001) was observed in the 28 patients treated with simvastatin. In this group, C-reactive protein (CRP) levels significantly decreased from 2.6 mg/l [interquartile range (IQR 4.9)] to 2.0 mg/l (IQR 1.9) (P = 0.03) at 6 months (P<0.05). A parallel reduction of IL-6 levels from 5.1 pg/ml (IQR 3.8) to 3.5 pg/ml (IQR 3.1) (P = 0.001) at 6 months was also observed. No significant reduction in inflammatory markers [CRP from 5.1 mg/l (IQR 1.9) to 5.4 mg/l (IQR 1.3) (P = NS) at 6 months] or plasma lipids [LDL-cholesterol from 127+/-32 mg/dl to 131+/-21 mg/dl (6 months)] was observed in the 27 patients of the placebo group. In the in vitro studies, the average value for cell-associated IL-6 and IL-8 was higher in CKD (155+/-95 pg/ml monocytes for IL-6 and 722+/-921 pg/ml monocytes for IL-8) vs HS (137+/-87 pg/ml monocytes and 186+/-125 pg/ml monocytes) (P<0.01) and was not affected by simvastatin alone. LPS resulted in a significant increase in cytokine production (IL-6: 1954+/-321 pg/ml monocytes for CKD and 1451+/-237 pg/ml monocytes for HS; P<0.001); the simultaneous addition of increasing doses of simvastatin to these cultures induced a dose-dependent inhibition of IL-6 and IL-8 production in stimulated peripheral blood mononuclear cells in all groups.

CONCLUSIONS

These results indicate that simvastatin in commonly used doses has an in vitro and in vivo anti-inflammatory effect in CKD patients, and may play an important role in counteracting the mechanisms involved on the pathogenesis of cardiovascular disease.