The association of sudden cardiac death with inflammation and other traditional risk factors. Kidney Int. 2008;74:1335-1342. [PMID: 18769368 DOI: 10.1038/ki.2008.449]

C-reactive protein and prediction of 1-year mortality in prevalent hemodialysis patients

BACKGROUND AND OBJECTIVES

Measurement of C-reactive protein (CRP) levels remains uncommon in North America, although it is now routine in many countries. Using Dialysis Outcomes and Practice Patterns Study data, our primary aim was to evaluate the value of CRP for predicting mortality when measured along with other common inflammatory biomarkers.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We studied 5061 prevalent hemodialysis patients from 2005 to 2008 in 140 facilities routinely measuring CRP in 10 countries. The association of CRP with mortality was evaluated using Cox regression. Prediction of 1-year mortality was assessed in logistic regression models with differing adjustment variables.

RESULTS

Median baseline CRP was lower in Japan (1.0 mg/L) than other countries (6.0 mg/L). CRP was positively, monotonically associated with mortality. No threshold below which mortality rate leveled off was identified. In prediction models, CRP performance was comparable with albumin and exceeded ferritin and white blood cell (WBC) count based on measures of model discrimination (c-statistics, net reclassification improvement [NRI]) and global model fit (generalized R(2)). The primary analysis included age, gender, diabetes, catheter use, and the four inflammatory markers (omitting one at a time). Specifying NRI ≥5% as appropriate reclassification of predicted mortality risk, NRI for CRP was 12.8% compared with 10.3% for albumin, 0.8% for ferritin, and <0.1% for WBC.

CONCLUSIONS

These findings demonstrate the value of measuring CRP in addition to standard inflammatory biomarkers to improve mortality prediction in hemodialysis patients. Future studies are indicated to identify interventions that lower CRP and to identify whether they improve clinical outcomes.

Wasting and sudden cardiac death in hemodialysis patients: a post hoc analysis of 4D (Die Deutsche Diabetes Dialyse Studie)

BACKGROUND

Wasting is common in hemodialysis patients and often is accompanied by cardiovascular disease and inflammation. The cardiovascular risk profile meaningfully changes with the progression of kidney disease, and little is known about the impact of wasting on specific clinical outcomes. This study examined the effects of wasting on the various components of cardiovascular outcome and deaths caused by infection in hemodialysis patients.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

1,255 hemodialysis patients from 178 centers participating in Die Deutsche Diabetes Dialyse Studie (4D) in 1998-2004.

PREDICTOR

Moderate wasting was defined as body mass index, albumin, and creatinine values less than the median (26.7 kg/m(2), 3.8 g/dL, and 6.8 mg/dL, respectively) and C-reactive protein level less than the median (5 mg/L) at baseline. Severe wasting was defined as body mass index, albumin, and creatinine levels less than the median and C-reactive protein level greater than the median at baseline.

OUTCOMES & MEASUREMENTS

Risks of sudden cardiac death (SCD), myocardial infarction (MI), stroke, combined cardiovascular events, deaths due to infection, and all-cause mortality were determined using Cox regression analyses during a median of 4 years of follow-up.

RESULTS

196 patients had wasting (severe, n = 109; and moderate, n = 87). Overall, 617 patients died (160 of SCD and 128 of infectious deaths). Furthermore, 469 patients experienced a cardiovascular event, with MI and stroke occurring in 200 and 103 patients, respectively. Compared with patients without wasting (n = 1,059), patients with severe wasting had significantly increased risks of SCD (adjusted HR, 1.8; 95% CI, 1.1-3.1), all-cause mortality (adjusted HR, 1.8; 95% CI, 1.4-2.4), and deaths due to infection (adjusted HR, 2.3; 95% CI, 1.2-4.3). In contrast, MI was not affected. The increased risk of cardiovascular events (adjusted HR, 1.5; 95% CI, 1.0-2.1) was explained mainly by the effect of wasting on SCD.

LIMITATIONS

Selective patient cohort.

CONCLUSIONS

Wasting was associated strongly with SCD, but not MI, in diabetic hemodialysis patients. Nonatherosclerotic cardiac disease potentially has a major role to account for the increased cardiovascular events in patients with wasting, suggesting the need for novel treatment strategies.

Macrophage cholesterol homeostasis and metabolic diseases: critical role of cholesteryl ester mobilization

Atherogenic dyslipidemia, including low HDL levels, is the major contributor of residual risk of cardiovascular disease that remains even after aggressive statin therapy to reduce LDL-cholesterol. Currently, distinction is not made between HDL-cholesterol and HDL, which is a lipoprotein consisting of several proteins and a core containing cholesteryl esters (CEs). The importance of assessing HDL functionality, specifically its role in facilitating cholesterol efflux from foam cells, is relevant to atherogenesis. Since HDLs can only remove unesterified cholesterol from macrophages while cholesterol is stored as CEs within foam cells, intracellular CE hydrolysis by CE hydrolase is vital. Reduction in macrophage lipid burden not only attenuates atherosclerosis but also reduces inflammation and linked pathologies such as Type 2 diabetes and chronic kidney disease. Targeting reduction in macrophage CE levels and focusing on enhancing cholesterol flux from peripheral tissues to liver for final elimination is proposed.

Cardiovascular disease in chronic kidney disease. A clinical update from Kidney Disease: Improving Global Outcomes (KDIGO)

Cardiovascular morbidity and mortality in patients with chronic kidney disease (CKD) is high, and the presence of CKD worsens outcomes of cardiovascular disease (CVD). CKD is associated with specific risk factors. Emerging evidence indicates that the pathology and manifestation of CVD differ in the presence of CKD. During a clinical update conference convened by the Kidney Disease: Improving Global Outcomes (KDIGO), an international group of experts defined the current state of knowledge and the implications for patient care in important topic areas, including coronary artery disease and myocardial infarction, congestive heart failure, cerebrovascular disease, atrial fibrillation, peripheral arterial disease, and sudden cardiac death. Although optimal strategies for prevention, diagnosis, and management of these complications likely should be modified in the presence of CKD, the evidence base for decision making is limited. Trials targeting CVD in patients with CKD have a large potential to improve outcomes.

Sudden cardiac death in patients with chronic kidney disease: prevention is the sine qua non

Despite developments in the technology of dialysis procedures and improvements in the understanding of systemic derangements related to chronic kidney disease (CKD), cardiovascular disease is the major cause of death. Unfortunately, the leading subset of cardiovascular disease death is sudden cardiac death (SCD). To date much effort has been exerted to figure out the clues pointing to the risk of future development of SCD in patients with CKD. However, none of these factors satisfactorily detects a truly vulnerable dialysis patient. Thus, recently, it has been advocated that a combination of noninvasive risk assessment methods, carefully chosen to reflect the different aspects of the underlying pathology and changes in the myocardial substrate in CKD, could help to identify patients at high risk of SCD within the CKD. In this review, we aimed to summarize what is known about risk stratification of patients with CKD and appropriate prevention strategies with a special emphasis on recent developments and the use of complimentary tests perhaps as a risk prediction rule.

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.

Prevention of sudden cardiac arrest in dialysis patients: can we do more to improve outcomes?

Sudden cardiac arrest (SCA) is a leading cause of cardiac-associated mortality in dialysis patients. Risk factors unique to hemodialysis patients include abnormal electrolytes, large-volume ultrafiltration, and prior history of cardiac disease. Few randomized controlled trials of standard cardiac interventions have been completed in dialysis patients. Observational studies suggest that modification of the dialysis prescription may be one place to intervene. Prospective research is needed to determine mechanisms of SCA 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.

Soluble P-selectin levels are associated with cardiovascular mortality and sudden cardiac death in male dialysis patients

BACKGROUND/AIMS

P-selectin is released by activated platelets and endothelium contributing to inflammation and thrombosis. We evaluated the association between soluble P-selectin and atherosclerotic cardiovascular disease (ASCVD) in dialysis patients.

METHODS

We measured soluble P-selectin in serum from 824 incident dialysis patients. Using Cox proportional hazards models, we modeled the association of P-selectin levels with ASCVD events, cardiovascular mortality and sudden cardiac death.

RESULTS

After adjustment for demographics, comorbidity and traditional cardiovascular risk factors, higher P-selectin levels were associated with increased risk of ASCVD and cardiovascular mortality among males (p = 0.02 and p = 0.01, respectively), but not females (p = 0.52 and p = 0.31, respectively; p interaction = 0.003), over a median of 38.2 months. Higher P-selectin was associated with a greater risk of sudden cardiac death among males (p = 0.05). The associations between increasing P-selectin and cardiovascular mortality as well as sudden cardiac death in males persisted after adjustment for C-reactive protein, interleukin-6, serum albumin and platelet count (p = 0.01 and p = 0.03, respectively). The risk for sudden cardiac death was more than 3 times greater for males in the highest tertile of soluble P-selectin compared with the lowest tertile after adjustment (HR: 3.19; 95% CI: 1.18 - 8.62; p = 0.02).

CONCLUSION

P-selectin is associated with ASCVD, cardiovascular mortality and sudden cardiac death among male dialysis patients.

Sudden cardiac death in chronic kidney disease: epidemiology and prevention

Annual cardiovascular mortality in patients with chronic kidney disease (CKD) is much higher than in the general population. The rate of sudden cardiac death increases as the stage of CKD increases and could be responsible for 60% of cardiac deaths in patients undergoing dialysis. In hemodialysis units treating patients with CKD, cardiac arrest occurs at a rate of seven arrests per 100,000 hemodialysis sessions. Important risk factors for sudden cardiac death in patients with CKD include hospitalization within the past 30 days, a drop of 30 mmHg in systolic blood pressure during hemodialysis, duration of life on hemodialysis, time since the previous dialysis session, and the presence of concomitant diabetes mellitus. As a result of the adverse cardiomyopathic and vasculopathic milieu in CKD, the occurrence of arrhythmias, conduction abnormalities, and sudden cardiac death could be exacerbated by electrolyte shifts, divalent ion abnormalities, diabetes, sympathetic overactivity, in addition to inflammation and perhaps iron deposition. Impaired baroreflex effectiveness and sensitivity, as well as obstructive sleep apnea, might also contribute to the risk of sudden death in CKD. The likelihood of survival following cardiac arrest is very low in dialysis patients. Primary and secondary prevention of cardiac arrest could reduce cardiovascular mortality in patients with CKD. Cardioverter-defibrillator implantation decreases the risk of sudden death in patients with CKD. The decision to implant a cardioverter-defibrillator should be influenced by the patient's age and stage of CKD.

Plasma S100A12 level is associated with cardiovascular disease in hemodialysis patients

BACKGROUND AND OBJECTIVES

S100A12 is an endogenous receptor ligand for advanced glycation end products. Cardiovascular disease remains a major cause of morbidity and mortality in patients with chronic kidney disease. In this study, we report cross-sectional data on 550 hemodialysis patients and assess the relationship between plasma S100A12 level and cardiovascular disease.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A cross-sectional study of 550 maintenance hemodialysis patients was conducted. We investigated the past history of cardiovascular disease and quantified the plasma level of S100A12 protein in all participants.

RESULTS

Plasma S100A12 level was higher in hemodialysis patients with cardiovascular disease (n=197; 33.8 ± 28.1 ng/ml) than in those without it (n=353; 20.2 ± 16.1 ng/ml; P<0.001). In multivariate logistic regression analysis, the plasma S100A12 level (odds ratio [OR], 1.28; 95% confidence interval [CI], 1.13 to 1.44; P<0.001) was identified as an independent factor associated with the prevalence of cardiovascular disease. The other factors associated with the prevalence of cardiovascular diseases were the presence of diabetes mellitus (OR, 2.81; 95% CI, 1.79 to 4.41; P < 0.001) and high-sensitivity CRP level (OR, 1.02; 95% CI, 1.00 to 1.05; P=0.046). Furthermore, the plasma S100A12 level (OR, 1.30; 95% CI, 1.09 to 1.54; P=0.004) was significantly associated with cardiovascular disease even in hemodialysis patients without diabetes mellitus (n=348).

CONCLUSIONS

These results suggest that the plasma S100A12 protein level is strongly associated with the prevalence of cardiovascular disease in hemodialysis patients.

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.

Increased risk of death in pediatric and adult patients with ESRD secondary to lupus

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease that can cause significant kidney disease. Our goal was to assess the relative mortality risk associated with SLE in pediatric and adult populations with end-stage renal disease (ESRD) maintained on hemodialysis (HD). We performed Kaplan-Meier survival analysis from data collected by the United States Renal Data System (USRDS) in strata of pediatric and adult patients. This file includes data on all Medicare-reimbursed renal replacement patients. Cox proportional hazard models were used to assess mortality after adjusting for race and gender. Subjects were censored at transplantation or at end of follow-up. Pediatric patients with ESRD secondary to SLE had a 2-fold increased risk of death compared with other pediatric patients with ESRD (hazard ratio [HR]: 2.4, 95% confidence interval [CI]: 1.5-3.7). Adult patients with ESRD secondary to SLE were also at increased risk of death compared with other adult patients (HR: 1.7, 95% CI: 1.2-2.7). The most common causes of death in both pediatric and adult patients with SLE were cardiovascular disease and cardiac arrest. Our study demonstrates that there is a significant increase in mortality secondary to cardiovascular disease in pediatric and adult patients with ESRD secondary to SLE. Patients with ESRD secondary to SLE may need aggressive monitoring for traditional risk factors for atherosclerosis and the diagnosis of SLE alone may be an independent risk factor for death in patients with ESRD.

Inflammation as a target for improving health in chronic kidney disease

Since the first reports in the late 1990s connecting elevated circulating levels of C-reactive protein in patients with end-stage renal disease with an atherogenic, wasted phenotype and poor outcome, more than 3600 publications related to the subject have appeared on the Medline bibliographic database. This reflects the exponential interest that this topic has evoked in the field of nephrology, and the possibility of treating this common uremic complication has been much discussed. Several small studies have implied that various nutritional and pharmacological treatment strategies have beneficial effects on surrogate markers of inflammation. However, no randomized controlled trials on anti-inflammatory treatment have yet been performed to test the hypothesis that persistent low-grade inflammation contributes to uremic morbidity and mortality.

Association between estimated glomerular filtration rate at initiation of dialysis and mortality

BACKGROUND

Recent studies have reported a trend toward earlier initiation of dialysis (i.e., at higher levels of glomerular filtration rate) and an association between early initiation and increased risk of death. We examined trends in initiation of hemodialysis within Canada and compared the risk of death between patients with early and late initiation of dialysis.

METHODS

The analytic cohort consisted of 25 910 patients at least 18 years of age who initiated hemodialysis, as identified from the Canadian Organ Replacement Register (2001-2007). We defined the initiation of dialysis as early if the estimated glomerular filtration rate was greater than 10.5 mL/min per 1.73 m². We fitted time-dependent proportional-hazards Cox models to compare the risk of death between patients with early and late initiation of dialysis.

RESULTS

Between 2001 and 2007, mean estimated glomerular filtration rate at initiation of dialysis increased from 9.3 (standard deviation [SD] 5.2) to 10.2 (SD 7.1) (p < 0.001), and the proportion of early starts rose from 28% (95% confidence interval [CI] 27%-30%) to 36% (95% CI 34%-37%). Mean glomerular filtration rate was 15.5 (SD 7.7) mL/min per 1.73 m² among those with early initiation and 7.1 (SD 2.0) mL/min per 1.73 m² among those with late initiation. The unadjusted hazard ratio (HR) for mortality with early relative to late initiation was 1.48 (95% CI 1.43-1.54). The HR decreased to 1.18 (95% CI 1.13-1.23) after adjustment for demographic characteristics, serum albumin, primary cause of end-stage renal disease, vascular access type, comorbidities, late referral and transplant status. The mortality differential between early and late initiation per 1000 patient-years narrowed after one year of follow-up, but never crossed and began widening again after 24 months of follow-up. The differences were significant at 6, 12, 30 and 36 months.

INTERPRETATION

In Canada, dialysis is being initiated at increasingly higher levels of glomerular filtration rate. A higher glomerular filtration rate at initiation of dialysis is associated with an increased risk of death that is not fully explained by differences in baseline characteristics.

C-reactive protein, interleukin 6, fibrinogen and risk of sudden death in European middle-aged men: the PRIME study

OBJECTIVE

To examine prospectively the association of high-sensitivity C-reactive protein, interleukin 6, and fibrinogen with sudden death in asymptomatic European men.

METHODS AND RESULTS

Among the 9771 men from the Etude PRospective de l'Infarctus du Myocarde (PRIME) Study, 664 had a first coronary heart disease over 10 years, including 50 sudden deaths, 34 nonsudden coronary deaths, and 580 nonfatal coronary heart disease events. For each outcome, 2 matched controls, who were free of coronary heart disease at the index date, were randomly selected from the initial cohort (nested case control study design). There was a 3-fold increased risk (95% CI, 1.20 to 7.81) of sudden death between the upper and the lower third of interleukin 6 after adjustment for baseline confounders in conditional logistic regression analysis. Neither high-sensitivity C-reactive protein (hazard ratio(third versus first tertile)=1.27; 95% CI, 0.51 to 3.17) nor fibrinogen (hazard ratio(third versus first tertile)=1.90; 95% CI, 0.76 to 4.75) was associated with sudden death. For comparison, there was a 6-fold increased risk of nonsudden coronary death from the highest compared with the lowest tertile of fibrinogen and a trend toward an association with higher C-reactive protein and higher interleukin 6. All 3 inflammatory biomarkers were moderately, but significantly, associated with nonfatal coronary heart disease.

CONCLUSIONS

Interleukin 6, but not high-sensitivity C-reactive protein or fibrinogen, is an independent predictor of sudden death in asymptomatic European men.

One-year serum albumin is an independent predictor of outcomes in kidney transplant recipients

OBJECTIVE

This research study was conducted to investigate whether serum albumin levels predict allograft/patient outcomes in the new era of transplant medicine and immunology.

METHODS

The association of 1-year post-transplant serum albumin, and patient and graft outcomes was retrospectively analyzed in 500 kidney transplant recipients between 1998 and 2005. Albumin was used as a categorical and a continuous variable in univariate and multivariate Cox regression and Kaplan-Meier survival analyses.

RESULTS

The average (±SE) age at transplant was 47 ± 12 years. Patients were followed up for 63.4 ± 28 months after transplant. There were 56 graft losses and 38 patient deaths. In univariate analysis, the following variables were associated with the composite endpoint of patient death or allograft loss: 1-year serum albumin (hazard ratio [HR] = 0.52, P = .0009), 1-year serum albumin <4.0 g/dL (HR = 1.81, P = .02), 1-year serum creatinine (HR = 3.55, P < .00001), angiotensin converting enzyme inhibitors or angiotensin receptor blockers use (HR = 1.61, P = .03), a history of previous transplant (HR = 1.54, P = .04), months of dialysis before transplant (HR = 1.01, P = .00003), type of transplant (deceased donor HR = 1.64, P = .02), and acute rejection (HR = 1.52, P = .0000003). Of these, multivariable Cox regression analyses retained 1-year serum albumin (HR = 1.4, P < .0001), serum creatinine (HR = 2.7, P < .0001), and acute rejection (HR = 1.7, P = .02) as significant predictors of patient/graft loss.

CONCLUSION

One-year serum albumin is an independent predictor of poor outcomes in the contemporary era of transplant medicine and immunosuppression. Further studies are needed to separate the role of this biomarker in inflammation and nutrition in kidney transplant recipients.

Left ventricular hypertrophy in new hemodialysis patients without symptomatic cardiac disease

BACKGROUND AND OBJECTIVES

Although left ventricular hypertrophy (LVH) is a characteristic finding in hemodialysis (HD) populations, few risk factors for progressive LVH have been identified.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

As part of a multinational, blinded, randomized, controlled trial that demonstrated no effect of hemoglobin targets on LV size, 596 incident HD patients, without symptomatic cardiac disease or cardiac dilation, had baseline echocardiograms within 18 months of starting dialysis and subsequently at 24, 48, and 96 weeks later. A wide array of baseline risk factors were assessed, as were BP and hemoglobin levels during the trial.

RESULTS

The median age and duration of dialysis were 51.5 years and 9 months, respectively. LV mass index (LVMI) rose substantially during follow-up (114.2 g/m(2) at baseline, 121 at week 48, 123.4 at week 48, and 128.3 at week 96), as did fractional shortening, whereas LV volume (68.7, 70.1, 68.7, and 68.1 ml/m(2)) and E/A ratio remained unchanged. At baseline, the only multivariate associations of LVMI were gender and N terminal pro-B type natriuretic peptide. Comparing first and last echocardiograms in those without LVH at baseline, independent predictors of increase in LVMI were higher time-integrated systolic BP and cause of ESRD. An unadjusted association between baseline LVMI and subsequent cardiovascular events or death was eliminated by adjusting for age, diabetes, systolic BP, and N terminal pro-B type natriuretic peptide.

CONCLUSIONS

Progressive concentric LVH and hyperkinesis occur in HD patients, which is partly explained by hypertension but not by a wide array of potential risk factors, including anemia.

Persistent inflammation as a catalyst for other risk factors in chronic kidney disease: a hypothesis proposal

Because inflammation by now is a "traditional" finding that predicts poor outcome and cardiovascular events in the vast majority of patients with ESRD, it could be argued that inflammatory biomarkers should not longer be considered "novel" risk factors. In this review, we forward the hypothesis that, in addition to putative direct proatherogenic effects, persistent inflammation may serve as a catalyst and, in the toxic uremic milieu, modulate the effects of other concurrent vascular and nutritional risk factors. We discuss some recent observational studies, suggesting that the presence of persistent inflammation magnifies the risk for poor outcome via mechanisms related to self-enhancement of the inflammatory cascade and exacerbation of both the wasting and the vascular calcification processes. Because persistent inflammation may be the silent culprit of other commonly observed pathophysiologic alterations in chronic kidney disease, it is imperative that inflammatory markers be regularly monitored and therapeutic attempts be made to target persistent low-grade inflammation in this patient group.

Peritonitis-free survival in peritoneal dialysis: an update taking competing risks into account

BACKGROUND

Peritonitis-free survival is commonly reported in the peritoneal dialysis (PD) literature. The Kaplan-Meier method appears to be the only technique used to date, although it has known limitations for cohorts with multiple outcomes, as in PD. In the presence of these 'competing risks' outcomes, the Kaplan-Meier estimate is interpretable only under restrictive assumptions. In contrast, methods which take competing risks into account provide unbiased estimates of probabilities of outcomes as actually experienced by patients.

METHODS

We analysed peritonitis-free survival in a cohort of 8711 incident patients from the 'Registre de Dialyse Péritonéale de Langue Française' between 1 January 2000 and 31 December 2007 by calculating the cumulative incidence (CI) of the first episode of peritonitis using the Kaplan-Meier method and a method accounting for competing risks. We compared the CI in different patient groups by the log-rank test and a test developed for competing risk data, Gray's test.

RESULTS

After 5 years of PD, the CI of at least one peritonitis episode was 0.4, and the probability of any outcome was 0.96. The Kaplan-Meier method overestimated the CI by a large amount. Compared with the log-rank test, Gray's test led to different conclusions in three out of seven comparisons.

CONCLUSIONS

The competing risk approach shows that the CI of at least one peritonitis episode was lower than reported by the Kaplan-Meier method but that survival peritonitis-free and still on PD was overall low. The competing risk approach provides estimates which have a clearer interpretation than Kaplan-Meier methods and could be more widely used in PD research.

Mineral metabolism and inflammation in chronic kidney disease patients: a cross-sectional study

BACKGROUND AND OBJECTIVES

Mineral metabolism abnormalities and inflammation are concerns in chronic kidney disease (CKD). Interrelationships among these parameters have not been analyzed.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

The study included 133 patients with CKD not on dialysis and not receiving calcium (Ca) supplements, phosphate binders, or vitamin D. Estimated GFR (eGFR) was 34.1 +/- 6.8 ml/min/1.73 m(2); 107 participants had stage 3 CKD, and 26 had stage 4.

RESULTS

Patients were classified by tertiles of Ca, phosphorus (P), Ca-P product (Ca x P), and parathyroid hormone (PTH). After adjustment for age, gender, and eGFR, the levels of C-reactive protein (CRP) and IL-6 (IL-6) of the third tertile of P, Ca x P, and PTH were significantly higher than those of the first and second tertiles. Serum P and Ca x P directly correlated with CRP and IL-6, whereas HDL-cholesterol and eGFR inversely correlated with the levels of the inflammatory parameters. After partial correlation analysis, the previous associations between CRP and eGFR, and serum P, as well as the relationship between IL-6 and eGFR, and serum P, remained significant. Multiple regression analysis demonstrated that eGFR and serum P were independently associated with CRP and IL-6. Finally, logistic regression analysis using the presence/absence of an inflammatory state as the dependent variable showed that eGFR was a protective factor, whereas serum P was an independent risk factor for the presence of an inflammatory state.

CONCLUSIONS

Elevated serum P might play a role in the development of inflammation in CKD.

Does timing of dialysis in patients with ESRD and acute myocardial infarcts affect morbidity or mortality?

BACKGROUND AND OBJECTIVES

Patients with ESRD have an increased incidence of coronary events with a relatively higher risk for mortality after acute myocardial infarction (AMI). We evaluated whether it is safer to delay dialysis in AMI or if delay poses separate risks.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted a retrospective review of 131 long-term hemodialysis patients who had AMI and were admitted between 1997 and 2005 at three New York City municipal hospitals. Patients were separated into three groups on the basis of time between cardiac symptoms and first dialysis (<24 h, 24 to 48 h, and >48 h).

RESULTS

A total of 17 (13%) patients died, 10 (59%) of whom had either hypotension or an arrhythmia during their first cardiac care unit dialysis. Although these groups were comparable in acuity and cardiac status, there were no findings of increased morbidity (26, 36, and 20%, respectively) or mortality (11, 18, and 13%, respectively), despite differences in the timing of each group's dialysis. We found that previous cardiac disease, predialysis K+, DeltaK+ after dialysis, and APACHE scores were significantly higher in patients with peridialysis morbidity.

CONCLUSIONS

We conclude that there is no increased morbidity with early dialysis in AMI, but rather close attention needs to be paid to the rate of decrease in serum potassium in patients with ESRD and their level of acuity when undergoing dialysis.

The scope of coronary heart disease in patients with chronic kidney disease

Chronic kidney disease (CKD) affects approximately 13% of the U.S. population and is associated with increased risk of cardiovascular complications. Once renal replacement therapy became available, it became apparent that the mode of death of patients with advanced CKD was more likely than not related to cardiovascular compromise. Further observation revealed that such compromise was related to myocardial disease (related to hypertension, stiff vessels, coronary heart disease, or uremic toxins). Early on, the excess of cardiovascular events was attributed to accelerated atherosclerosis, inadequate control of blood pressure, lipids, or inflammatory cytokines, or perhaps poor glycemia control. In more recent times, outcome research has given us further information that relates even lesser degrees of renal compromise to an excess of cardiovascular events in the general population and in those with already present atherosclerotic disease. As renal function deteriorates, certain physiologic changes occur (perhaps due to hemodynamic, inflammatory, or metabolic changes) that decrease oxygen-carrying capacity of the blood by virtue of anemia, make blood vessels stiffer by altering collagen or through medial calcinosis, raise the blood pressure, increase shearing stresses, or alter the constituents of atherosclerotic plaque or the balance of thrombogenesis and thrombolysis. At further levels of renal dysfunction, tangible metabolic perturbations are recognized as requiring specific therapy to reduce complications (such as for anemia and hyperparathyroidism), although outcome research to support some of our current guidelines is sorely lacking. Understanding the process by which renal dysfunction alters the prognosis of cardiac disease might lead to further methods of treatment. This review will outline the relationship of CKD to coronary heart disease with respect to the current understanding of the traditional and nontraditional risk factors, the role of various imaging modalities, and the impact of coronary revascularization on outcome.

Mechanisms for increased cardiovascular disease in chronic kidney dysfunction

PURPOSE OF REVIEW

Patients with chronic kidney disease (CKD) have the highest risk for atherosclerotic cardiovascular disease (CVD). Current interventions have been insufficiently effective in lessening excess incidence and mortality from CVD in patients with CKD versus other high-risk groups. This review focuses on traditional and CKD-related risks as well as key mechanisms of macrophage foam cell formation that underlie the excess CVD in the setting of CKD.

RECENT FINDINGS

Hyperlipidemia, particularly increased low-density lipoprotein (LDL) cholesterol, is the key factor in atherogenesis in the general population, but has not been found to be the overriding risk for greater CVD in CKD, especially as renal damage progresses. Although higher incidence of CVD in CKD is not due to higher serum lipids per se, CKD is associated with abnormal lipid metabolism that is proatherogenic. CKD-related risks, including inflammation and disturbances in mineral metabolism, have been implicated. In addition, perturbations of the macrophage, a cell that is central in atherogenesis, may be important.

SUMMARY

The mechanisms underlying the heightened risk for CVD in CKD have been the focus of intense study and may relate to the combined effects of traditional and CKD-specific risks involving inflammation and lipid metabolism, especially perturbation of macrophage cholesterol homeostasis.

Sudden death and associated factors in a historical cohort of chronic haemodialysis patients

BACKGROUND

In haemodialysis patients, deaths due to cardiovascular causes constitute a large proportion of total mortality and sudden cardiac deaths account for approximately 22% of all deaths. The aim of this study was to evaluate the incidence of sudden cardiac death and associated risk factors in a cohort of haemodialysis patients.

METHODS AND RESULTS

The 3-year cumulative incidence of death in a cohort of 476 patients on chronic haemodialysis treatment was 34.3% (SE 2.3). Sudden death had a 6.9% (SE 1.2) cumulative incidence, with 32 events representing 19.2% of all deaths, while cardiovascular not sudden death and noncardiovascular death accounted for a 3-year cumulative incidence of 7.3% (SE 1.2) and 20.1% (SE 1.9), respectively. According to Cox multivariate analysis, significant risk factors for sudden death were the presence of atrial fibrillation, diabetes mellitus, predialytic hyperkalaemia, haemodialysis mode and C-reactive protein level, which were associated with a 2.9 (CI(95%) 1.3-6.4), 3.0 (CI(95%) 1.3-7.2), 2.7 (CI(95%) 1.3-5.8), 4.5 (CI(95%) 1.3-15.5) and 3.3 (CI(95%) 1.2-8.8)-fold increase in the risk of sudden death, respectively. Sudden death was significantly more frequent during the first 24 h of the first short interdialytic interval and during the last 24 h of the long interval, i.e. immediately before and immediately after the first weekly haemodialysis session (P = 0.02).

CONCLUSIONS

Our data show that the incidence of sudden death in haemodialysis patients is high and that atrial fibrillation, diabetes, hyperkalaemia, haemodialysis mode and C-reactive protein play an important role in developing fatal arrhythmia. Further studies will be necessary to define which interventions could be helpful in reducing this cause of mortality.

Metabolic abnormalities in chronic kidney disease that contribute to cardiovascular disease, and nutritional initiatives that may diminish the risk

PURPOSE OF REVIEW

Chronic kidney disease (CKD) is associated with a wide range of severe metabolic and nutritional disturbances that directly or indirectly contribute to left ventricular hypertrophy, ischemic heart disease, vascular calcification, heart failure and other manifestations of cardiovascular disease (CVD). The CVD mortality rate in CKD patients is far higher than in the general population, and CKD is today recognized as one of the most important risk factors for CVD. In this review, we discuss the links between metabolic abnormalities and CVD in CKD patients and nutritional initiatives that may reduce this risk.

RECENT FINDINGS

Certain nontraditional risk factors, such as protein-energy wasting, inflammation, and biomarkers reflecting bone and mineral disorders, are strong predictors of CVD mortality in CKD patients. Although several small nutritional intervention studies have been performed and nutritional guidelines have been introduced in order to minimize metabolic disorders and improve nutritional status, they have so far not been proven to reduce morbidity nor mortality.

SUMMARY

Although the pathophysiological mechanisms involved in the markedly increased CVD risk of CKD patients are becoming more evident, still few nutritional randomized controlled studies have been conducted in this high-risk patient group.