Addition of Novel Biomarkers for Predicting All-Cause and Cardiovascular Mortality in Prevalent Hemodialysis Patients

A high platelet-to-lymphocyte ratio predicts all-cause mortality and cardiovascular mortality in maintenance hemodialysis patients

PURPOSE

The aim of this study was to further assess whether the platelet-to-lymphocyte ratio (PLR) is independently associated with all-cause mortality and cardiovascular mortality in maintenance hemodialysis (MHD) patients.

METHODS

From January 1, 2014, to December 31, 2014, patients undergoing regular hemodialysis in the Blood Purification Center of the General Hospital of Northern Theatre Command were retrospectively selected. A total of 303 MHD patients were enrolled in accordance with the inclusion and exclusion criteria. For each patient, the endpoint of follow-up was either death or December 31, 2021. The primary endpoints were all-cause and cardiovascular death. A receiver operating characteristic (ROC) curve was drawn to detect the predictive ability of PLR, and the optimal critical value of PLR was determined to be 107.57. Kaplan-Meier curves and Cox proportional analysis were used to assess the prognostic value of PLR. We used the same method to evaluate the correlation between the neutrophil-to-lymphocyte ratio (NLR) and the prognosis of MHD patients.

RESULTS

At the end of follow-up, 128 MHD patients had progressed to all-cause death, and 73 MHD patients had progressed to cardiovascular death. In multivariate Cox regression, both the high PLR group and the high NLR group were independently associated with all-cause mortality (HR 2.608, 95% CI 1.579-4.306, p < .001 vs. HR 1.634, 95% CI 1.023-2.610, p = .04). Only high PLR expression was associated with cardiovascular mortality (HR 3.379, 95% CI 1.646-6.936, p = .001).

CONCLUSIONS

High PLR levels can independently predict all-cause and cardiovascular mortality in MHD patients.

Growth differentiation factor-15 predicts major bleeding, major adverse cardiac events and mortality in patients with end-stage kidney disease on haemodialysis: findings from the VIVALDI study

BACKGROUND

Patients with end-stage kidney disease (ESKD) are at high risk of cardiovascular events and bleeding. Optimizing risk assessment of ESKD patients regarding the risk of thromboembolism and bleeding complications in comorbid conditions, including atrial fibrillation and coronary heart disease, is challenging. To improve risk prediction we investigated growth differentiation factor-15 (GDF-15), a promising cardiovascular biomarker, and its relation to adverse outcomes.

METHODS

In this prospective, multicentre, population-based cohort study, GDF-15 was measured in 594 ESKD patients on haemodialysis (median age 66 years, 38% female), who were followed up for a median of 3.5 years. The association of GDF-15 with major bleeding, arterial thromboembolism, major adverse cardiac events (MACE) and death was analysed within a competing risk framework. Further, we evaluated the additive predictive value of GDF-15 to cardiovascular and death risk assessment.

RESULTS

GDF-15 levels were in median 5475 ng/l (25th-75th percentile 3964-7533) and independently associated with major bleeding {subdistribution hazard ratio [SHR] 1.31 per double increase [95% confidence interval (CI) 1.00-1.71]}, MACE [SHR 1.47 (95% CI 1.11-1.94)] and all-cause mortality [SHR 1.58 (95% CI 1.28-1.95)] but not arterial thromboembolism [SHR 0.91 (95% CI 0.61-1.36)]. The addition of GDF-15 to the HAS-BLED score significantly improved discrimination and calibration for predicting major bleeding [C-statistics increased from 0.61 (95% CI 0.52-0.70) to 0.68 (95% CI 0.61-0.78)]. Furthermore, we established an additive predictive value of GDF-15 beyond current risk models for predicting MACE and death.

CONCLUSION

GDF-15 predicts the risk of major bleeding, cardiovascular events and death in ESKD patients on haemodialysis and might be a valuable marker to guide treatment decisions in this challenging patient population.

Prognostic value of beta-2 microglobulin on mortality in chronic kidney disease patients: A systematic review and meta-analysis

The aim of this study was to delve into whether beta-2 microglobulin could assess all-cause mortality in patients with chronic kidney disease. PubMed and Embase were systematically searched. Hazard risk and 95% CI were pooled using random-effect models. A total of eight studies were involved according to the inclusion and exclusion criterions. By meta-analysis, each 1 mg/L increase in beta-2 microglobulin displayed positive relationships to the risk of all-cause mortality (hazard risk 1.03, 95% CI = 1.02-1.03) and cardiovascular events (hazard risk 1.04, 95% CI = 1.00-1.08) in patients with dialysis. However, the relationship between elevated level of serum beta-2 microglobulin as a categorical variable and mortality was not significant. The prognostic value of elevated beta-2 microglobulin might be significant in ESRD patients with dialysis and a proper cutoff value to predict mortality should be determined in the future.

Building clinical risk score systems for predicting the all-cause and expanded cardiovascular-specific mortality of patients with type 2 diabetes

AIM

To develop and validate risk score systems by examining the effects of glycaemic and blood pressure variabilities on the all-cause and expanded cardiovascular-specific mortality of people with type 2 diabetes.

MATERIALS AND METHODS

This retrospective cohort study consisted of 9692 patients aged 30-85 years, diagnosed with type 2 diabetes and enrolled in a managed care programme of a medical centre from 2002 to 2016. All the patients were randomly allocated into two groups, namely, training and validation sets (2:1 ratio), and followed up until death or August 2019. Cox's proportional hazard regression was performed to develop all-cause and expanded cardiovascular-specific mortality prediction models. The performance of the prediction model was assessed by using the area under the receiver operating characteristic curve (AUROC).

RESULTS

Overall, 2036 deaths were identified after a mean of 8.6 years of follow-up. The AUROC-measured prediction accuracies of 3-, 5-, 10- and 15-year all-cause mortalities based on a model containing the identified traditional risk factors, biomarkers and variabilities in fasting plasma glucose, HbA1c and blood pressure in the validation set were 0.79 (0.76-0.83), 0.78 (0.76-0.81), 0.80 (0.78-0.82) and 0.80 (0.78-0.82), respectively. The corresponding values of the expanded cardiovascular-specific mortalities were 0.85 (0.80-0.90), 0.83 (0.79-0.86), 0.80 (0.77-0.83) and 0.79 (0.77-0.82), respectively.

CONCLUSIONS

Our prediction models considering glycaemic and blood pressure variabilities had good prediction accuracy for the expanded cardiovascular-specific and all-cause mortalities of patients with type 2 diabetes.

Association of beta-2-microglobulin and cardiovascular events and mortality: A systematic review and meta-analysis

Background and aims

Beta-2-microglobulin (B2M) has been suggested as an emerging biomarker for cardiovascular diseases (CVD), including coronary heart disease (CHD) and stroke, and mortality.

Methods

Three databases were searched from inception to January 2, 2020, supplemented by scanning reference lists of identified studies. We identified studies that reported associations of baseline serum or plasma B2M and CVD incidence, CVD mortality, or CHD and stroke separately, in either general populations or patients with renal disease. Relative risks (RR) were extracted and harmonized to a comparison of the highest versus lowest third of the distribution of B2M, and the results were aggregated.

Results

Sixteen studies (5 in general populations, and 11 in renal disease populations) were included, involving 30,988 participants and 5391 CVD events. Based on random-effects meta-analysis, the pooled adjusted RRs comparing the highest versus lowest third of the distribution of B2M were 1.71 (95%CI: 1.37–2.13) for CVD, 2.29 (1.51–3.49) for CVD mortality, 1.64 (1.14–2.34) for CHD, and 1.51 (1.28–1.78) for stroke, with little to high heterogeneity between studies (0.0% ≤ I² ≤ 80.0%). The positive associations between B2M and risks of CVD outcomes remained broadly significant across subgroup analyses. Moreover, the pooled adjusted RRs were 2.51 (1.94–3.26; I² = 83.7%) for all-cause mortality and 2.64 (1.34–5.23; I² = 83.1%) for infectious mortality.

Conclusions

Available observational data show that there are moderate positive associations between B2M levels and CVD events and mortality, although few studies have been conducted in general populations.

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Available epidemiological evidence shows that circulating B2M levels are moderately associated with CVD events and mortality.

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Future large-scale general population-based prospective studies and genetic studies are needed to assess the causality.

Fibroblast growth factor 23 (FGF23) level is associated with ultrafiltration rate in patients on hemodialysis

Fibroblast growth factor 23 (FGF23) is a bone-derived hormone that regulates renal phosphate reabsorption and vitamin D synthesis in renal proximal tubules. High circulating FGF23 levels are associated with increased mortality in patients with chronic kidney disease and those on dialysis. Current data also suggest higher circulating levels of FGF23 are associated with cardiovascular mortality, vascular calcification, and left ventricular hypertrophy; however, evidence on the role of FGF23 in patients on dialysis is incomplete, and some of the data, especially those on cardiovascular disease (CVD), are controversial. This study aimed to evaluate factors associated with FGF23 in hemodialysis patients with or without CVD. Randomly selected 76 patients on maintenance hemodialysis at a single hemodialysis center were enrolled. After the exclusion of eight patients with extremely outlying FGF23 levels, 68 patients, including 48 males and 46 patients with a CVD history, were included in the study. The mean age was 64.4 ± 12.1 years, and the mean dialysis duration was 12.7 ± 7.1 years. Dialysis duration, time-averaged concentration of urea (TAC-urea), ultrafiltration rate (UFR), blood pressure during hemodialysis session, laboratory data, and echocardiographic parameters including interventricular septum thickness (IVST), left ventricular mass indices (LVMI), and ejection fraction were included in univariate and multivariate analyses. The median lgFGF23 levels in the overall cohort and in those with and without CVD were 2.14 (interquartile range, IQR − 0.43 to − 4.23), 2.01 (− 0.52 to 4.12), and 2.59 (0.07 to 4.32), respectively, and there was no difference between the patients with and without CVD (p = 0.14). The univariate analysis revealed that FGF23 was significantly associated with age (r =  − 0.12, p < 0.01), duration of hemodialysis (r =  − 0.11, p < 0.01), TAC-urea (r = 0.29, p = 0.01), UFR (r = 0.26, p = 0.04), alkaline phosphatase (ALP; r =  − 0.27, p = 0.03), corrected serum calcium (cCa; r = 0.32, p < 0.01), serum phosphate (iP, r = 0.57, p < 0.01), intact parathyroid hormone (iPTH; r = 0.38, p < 0.01), IVST (r = 0.30, p = 0.01), and LVMI (r = 0.26, p = 0.04). In multivariate regression analysis, FGF23 was significantly associated with cCa (F = 25.6, p < 0.01), iP (F = 22.5, p < 0.01), iPTH (F = 19.2, p < 0.01), ALP (F = 5.34, p = 0.03), and UFR (F = 3.94, p = 0.05). In addition, the univariate analysis after the categorization of patients according to CVD indicated that FGF23 was significantly associated with cCa (r = 0.34, p = 0.02), iP (r = 0.41, p < 0.01), iPTH (r = 0.39, p = 0.01), and TAC-urea (r = 0.45, p < 0.01) in patients with CVD, whereas only IVST (r = 0.53, p = 0.04) was associated with FGF23 in those without CVD. FGF23 levels in hemodialysis patients were extremely high and associated not only with mineral bone disease-related factors but also with UFR. Additionally, dialysis efficacy might be associated with lower FGF23 levels in patients with CVD.

Pathophysiology and significance of natriuretic peptides in patients with end-stage kidney disease

Natriuretic peptides (NP), especially B type (BNP) and its N-terminal pro-B type natriuretic peptide (NT-proBNP), have long been regarded as biomarkers of volume overload and tools to exclude heart failure in the general population. However, their role in end-stage kidney disease (ESKD) is less certain given that BNP and NT-proBNP are excreted by the kidney and so serum concentrations of NPs are nearly universally elevated compared to controls. Nevertheless, the accumulated evidence suggests thatserum concentrations of NPs in patients with ESKD show moderate or strong positive relationships with underlying heart disease, abnormal cardiac structure or function and mortality. Limited evidence also supports the role of BNP including NT-proBNP, ANP in some studies, rather than CNP or DNP in risk stratification among ESKD patients as well as the utility of BNP samplings pre- and post- hemodialysis. However, studies of the cut-off values of NPs have yielded inconsistent results, such that further large-scale studies are needed to clarify these issues. This review summarizes the pathophysiology and significance of NPs in ESKD patients, especially their potential role as risk stratification biomarkers in clinical management.

Fibroblast growth factor 23: are we ready to use it in clinical practice?

Patients with chronic kidney disease (CKD) have a greatly enhanced risk of cardiovascular morbidity and mortality. Over the past decade it has come clear that a disturbed calcium-phosphate metabolism, with Fibroblast Growth Factor-23 as a key hormone, is partly accountable for this enhanced risk. Numerous studies have been performed unravelling FGF23s actions and its association with clinical conditions. As FGF23 is strongly associated with adverse outcome it may be a promising biomarker for risk prediction or, even more important, targeting FGF23 may be a strategy to improve patient outcome. This review elaborates on the clinical usefulness of FGF23 measurement. Firstly it discusses the reliability of the FGF23 measurement. Secondly, it evaluates whether FGF23 measurement may lead to improved patient risk classification. Finally, and possibly most importantly, this review evaluates if lowering of FGF23 should be a target for therapy. For this, the review discusses the current evidence indicating that FGF23 may be in the causal pathway to cardiovascular pathology, provides an overview of strategies to lower FGF23 levels and discusses the current evidence concerning the benefit of lowering FGF23.

Association of NT-proBNP and BNP With Future Clinical Outcomes in Patients With ESKD: A Systematic Review and Meta-analysis

RATIONALE & OBJECTIVE

Use of brain natriuretic peptide (BNP) and N-terminal pro-BNP (NT-proBNP) for cardiovascular (CV) risk assessment in patients with end-stage kidney disease (ESKD) remains unclear. We examined the associations between different threshold elevations of these peptide levels and clinical outcomes in patients with ESKD.

STUDY DESIGN

Systematic review and meta-analysis.

SETTING & STUDY POPULATIONS

We searched MEDLINE and EMBASE (through September 2019) for observational studies of adults with ESKD (estimated glomerular filtration rate≤15mL/min/1.73m² or receiving maintenance dialysis).

SELECTION CRITERIA FOR STUDIES

Studies that reported NT-proBNP or BNP levels and future CV events, CV mortality, or all-cause mortality.

DATA EXTRACTION

Cohort characteristics and measures of risk associated with study-specified peptide thresholds.

ANALYTICAL APPROACH

Hazard ratios (HRs) for clinical outcomes associated with different NT-proBNP and BNP ranges were categorized into common thresholds and pooled using random-effects meta-analysis.

RESULTS

We identified 61 studies for inclusion in our review (19,688 people). 49 provided sufficient detail for inclusion in meta-analysis. Pooled unadjusted HRs for CV mortality were progressively greater for greater thresholds of NT-proBNP, from 1.45 (95% CI, 0.91-2.32) for levels>2,000pg/mL to 5.95 (95% CI, 4.23-8.37) for levels>15,000pg/mL. Risk for all-cause mortality was significantly higher at all NT-proBNP thresholds ranging from> 1,000 to> 20,000pg/mL (HR range, 1.53-4.00). BNP levels>550pg/mL were associated with increased risk for CV mortality (HR, 2.54; 95% CI, 1.49-4.33), while the risks for all-cause mortality were 2.04 (95% CI, 0.82-5.12) at BNP levels>100pg/mL and 2.97 (95% CI, 2.21-3.98) at BNP levels>550pg/mL. Adjusted analyses demonstrated similarly greater risks for CV and all-cause mortality with greater NT-proBNP concentrations.

LIMITATIONS

Incomplete outcome reporting and risk for outcome reporting bias. Estimation of risk for CV events for specific thresholds of both peptides were limited by poor precision.

CONCLUSIONS

ESKD-specific NT-proBNP and BNP level thresholds of elevation are associated with increased risk for CV and all-cause mortality. This information may help guide interpretation of NT-proBNP and BNP levels in patients with ESKD.

Single Measurements of Carboxy-Terminal Fibroblast Growth Factor 23 and Clinical Risk Prediction of Adverse Outcomes in CKD

RATIONALE & OBJECTIVE

An elevated fibroblast growth factor 23 (FGF-23) level is independently associated with adverse outcomes in populations with chronic kidney disease, but it is unknown whether FGF-23 testing can improve clinical risk prediction in individuals.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

Participants in the Chronic Renal Insufficiency Cohort (CRIC) Study (n = 3,789).

EXPOSURE

Baseline carboxy-terminal FGF-23 (cFGF-23) level.

OUTCOMES

All-cause and cardiovascular (CV) mortality, incident end-stage renal disease (ESRD), heart failure (HF) admission, and atherosclerotic events at 3, 5, and 8 years.

ANALYTICAL APPROACH

We assessed changes in model performance by change in area under the receiver operating characteristic curve (ΔAUC), integrated discrimination improvement (IDI), relative IDI, and net reclassification index (NRI) above standard clinical factors. We performed sensitivity analyses, including an additional model comparing the addition of phosphate rather than cFGF-23 level and repeating our analyses using an internal cross-validation cohort.

RESULTS

Addition of a single baseline value of cFGF-23 to a base prediction model improved prediction of all-cause mortality (ΔAUC, 0.017 [95% CI, 0.001-0.033]; IDI, 0.021 [95% CI, 0.006-0.036]; relative IDI, 32.7% [95% CI, 8.5%-56.9%]), and HF admission (ΔAUC, 0.008 [95% CI, 0.0004-0.016]; IDI, 0.019 [95% CI, 0.004-0.034]; relative IDI, 10.0% [95% CI, 1.8%-18.3%]), but not CV mortality, ESRD, or atherosclerotic events at 3 years of follow-up. The NRI did not reach statistical significance for any of the 3-year outcomes. The incremental predictive utility of cFGF-23 level diminished in analyses of the 5- and 8-year outcomes. The cFGF-23 models outperformed the phosphate model for each outcome.

LIMITATIONS

Power to detect increased CV mortality likely limited by low event rate. The NRI is not generalizable without accepted prespecified risk thresholds.

CONCLUSIONS

Among individuals with CKD, single measurements of cFGF-23 improve prediction of risks for all-cause mortality and HF admission but not CV mortality, ESRD, or atherosclerotic events. Future studies should evaluate the predictive utility of repeated cFGF-23 testing.