Comparison of risk prediction with the CKD-EPI and MDRD equations in acute decompensated heart failure

Clinical Implications of Estimating Glomerular Filtration Rate with Different Equations in Heart Failure Patients with Preserved Ejection Fraction

INTRODUCTION

The prognostic values of estimated glomerular filtration rate (eGFR) calculated by different formulas have not been adequately compared in patients with heart failure with preserved ejection fraction (HFpEF).

AIM

We compared the predictive values of serum creatinine-based eGFRs calculated by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) 2009 equation, Modification of Diet in Renal Disease Study (MDRD) formula, and full-age-spectrum creatinine (FAS Cr) equation in 1751 HFpEF patients.

METHODS

The area under the receiver-operating characteristic curve (AUC), integrated discrimination improvement (IDI) and net reclassification improvement (NRI) were employed.

RESULTS

eGFR values were lowest calculated with FAS Cr equation (p < 0.001). When patients were classified into 4 subgroups (eGFR ≥ 90, 89-60, 59-30, and  < 30 ml/min/1.73 m2) or only 2 subgroups (≥ 60 or  < 60 ml/min/1.73 m2), the 3 formulas correlated significantly, with the best correlation found between the MDRD and CKD-EPI formulas (kappa = 0.871 and 0.963, respectively). The 3 formulas conveyed independent prognostic information. After adjusting for potential cofounders, risk prediction for all-cause mortality was more accurate (p = 0.001) using the CKD-EPI equation than MDRD formula as assessed by AUC. Compared with MDRD formula, CKD-EPI equation exhibited superior predictive ability assessed by IDI and NRI of 0.32% (p < 0.001)/10.4% (p = 0.010) for primary endpoint and 0.37% (p = 0.010)/10.8% (p = 0.010) for HF hospitalization. The risk prediction for deterioration of renal function was more accurate (p ≤ 0.040) using the CKD-EPI equation than FAS Cr equation as assessed by AUC, IDI, and NRI.

CONCLUSION

The CKD-EPI formula might be the preferred creatinine-based equation in clinical risk stratification in HFpEF patients.

The Difference Between Cystatin C- and Creatinine-Based Estimated GFR in Heart Failure With Reduced Ejection Fraction: Insights From PARADIGM-HF

RATIONALE & OBJECTIVE

The clinical implications of the discrepancy between cystatin C (cysC)- and serum creatinine (Scr)-estimated glomerular filtration rate (eGFR) in patients with heart failure (HF) and reduced ejection fraction (HFrEF) are unknown.

STUDY DESIGN

Post-hoc analysis of randomized trial data.

SETTING & PARTICIPANTS

1,970 patients with HFrEF enrolled in PARADIGM-HF with available baseline cysC and Scr measurements.

EXPOSURE

Intraindividual differences between eGFR based on cysC (eGFRcysC) and Scr (eGFRScr; eGFRdiffcysC-Scr).

OUTCOMES

Clinical outcomes included the PARADIGM-HF primary end point (composite of cardiovascular [CV] mortality or HF hospitalization), CV mortality, all-cause mortality, and worsening kidney function. We also examined poor health-related quality of life (HRQoL), frailty, and worsening HF (WHF), defined as HF hospitalization, emergency department visit, or outpatient intensification of therapy between baseline and 8-month follow-up.

ANALYTICAL APPROACH

Fine-Gray subdistribution hazard models and Cox proportional hazards models were used to regress clinical outcomes on baseline eGFRdiffcysC-Scr. Logistic regression was used to investigate the association of baseline eGFRdiffcysC-Scr with poor HRQoL and frailty. Linear regression models were used to assess the association of WHF with eGFRcysC, eGFRScr, and eGFRdiffcysC-Scr at 8-month follow-up.

RESULTS

Baseline eGFRdiffcysC-Scr was higher than +10 and lower than-10mL/min/1.73m2 in 13.0% and 35.7% of patients, respectively. More negative values of eGFRdiffcysC-Scr were associated with worse outcomes ([sub]hazard ratio per standard deviation: PARADIGM-HF primary end point, 1.18; P=0.008; CV mortality, 1.34; P=0.001; all-cause mortality, 1.39; P<0.001; worsening kidney function, 1.31; P=0.05). For a 1-standard-deviation decrease in eGFRdiffcysC-Scr, the prevalences of poor HRQoL and frailty increased by 29% and 17%, respectively (P≤0.008). WHF was associated with a more pronounced decrease in eGFRcysC than in eGFRScr, resulting in a change in 8-month eGFRdiffcysC-Scr of-4.67mL/min/1.73m2 (P<0.001).

LIMITATIONS

Lack of gold-standard assessment of kidney function.

CONCLUSIONS

In patients with HFrEF, discrepancies between eGFRcysC and eGFRScr are common and are associated with clinical outcomes, HRQoL, and frailty. The decline in kidney function associated with WHF is more marked when assessed with eGFRcysC than with eGFRScr.

PLAIN-LANGUAGE SUMMARY

Kidney function assessment traditionally relies on serum creatinine (Scr) to establish an estimated glomerular filtration rate (eGFR). However, this has been challenged with the introduction of an alternative marker, cystatin C (cysC). Muscle mass and nutritional status have differential effects on eGFR based on cysC (eGFRcysC) and Scr (eGFRScr). Among ambulatory patients with heart failure enrolled in PARADIGM-HF, we investigated the clinical significance of the difference between eGFRcysC and eGFRScr. More negative values (ie, eGFRScr>eGFRcysC) were associated with worse clinical outcomes (including mortality), poor quality of life, and frailty. In patients with progressive heart failure, which is characterized by muscle loss and poor nutritional status, the decline in kidney function was more pronounced when eGFR was estimated using cysC rather than Scr.

The difference between cystatin C- and creatinine-based assessment of kidney function in acute heart failure

AIMS

Acute heart failure (HF) is associated with muscle mass loss, potentially leading to overestimation of kidney function using serum creatinine-based estimated glomerular filtration rate (eGFR_sCr ). Cystatin C-based eGFR (eGFR_CysC ) is less muscle mass dependent. Changes in the difference between eGFR_CysC and eGFR_sCr may reflect muscle mass loss. We investigated the difference between eGFR_CysC and eGFR_sCr and its association with clinical outcomes in acute HF patients.

METHODS AND RESULTS

A post hoc analysis was performed in 841 patients enrolled in three trials: Diuretic Optimization Strategy Evaluation (DOSE), Renal Optimization Strategies Evaluation (ROSE), and Cardiorenal Rescue Study in Acute Decompensated Heart Failure (CARRESS-HF). Intra-individual differences between eGFRs (eGFR_diff ) were calculated as eGFR_CysC -eGFR_sCr at serial time points during HF admission. We investigated associations of (i) change in eGFR_diff between baseline and day 3 or 4 with readmission-free survival up to day 60; (ii) index hospitalization length of stay (LOS) and readmission with eGFR_diff at day 60. eGFR_CysC reclassified 40% of samples to more advanced kidney dysfunction. Median eGFR_diff was -4 [-11 to 1.5] mL/min/1.73 m² at baseline, became more negative during admission and remained significantly different at day 60. The change in eGFR_diff between baseline and day 3 or 4 was associated with readmission-free survival (adjusted hazard ratio per standard deviation decrease in eGFR_diff : 1.14, P = 0.035). Longer index hospitalization LOS and readmission were associated with more negative eGFR_diff at day 60 (both P ≤ 0.026 in adjusted models).

CONCLUSIONS

In acute HF, a marked difference between eGFR_CysC and eGFR_sCr is present at baseline, becomes more pronounced during hospitalization, and is sustained at 60 day follow-up. The change in eGFR_diff during HF admission and eGFR_diff at day 60 are associated with clinical outcomes.

CALL-K score: predicting the need for renal replacement therapy in cardiogenic shock

AIMS

The clinical predictors and outcomes of patients with cardiogenic shock (CS) requiring renal replacement therapy (RRT) have not been studied previously. This study assesses the impact of RRT on mortality in patients with CS and aims to identify clinical factors that contribute to the need of RRT.

METHODS AND RESULTS

Consecutive patients presenting with CS were included from a prospective registry of cardiac intensive care unit admissions at a single institution between 2014 and 2020. Of the 1030 patients admitted with CS, 123 (11.9%) received RRT. RRT was associated with higher 1-year mortality [adjusted hazard ratio = 1.62, 95% confidence interval (CI) 1.02-2.14], and a higher in-hospital incidence of sepsis [risk ratio = 2.76, P < 0.001], and pneumonia (risk ratio = 2.9, P = 0.001). Those who received RRT were less likely to receive guideline-directed medical treatment at time of discharge, undergo heart transplantation (2.4% vs. 11.5%, P = 0.002) or receive a durable left ventricular assist device (0.0% vs. 11.6%, P < 0.001). Five variables at admission best predicted the need for RRT (age, lactate, haemoglobin, use of pre-admission loop diuretics, and admission estimated glomerular filtration rate) and were used to generate the CALL-K 9-point risk score, with better discrimination than creatinine alone (P = 0.008). The score was internally validated (area under the curve = 0.815, 95% CI 0.739-0.835) with good calibration (Hosmer-Lemeshow P = 0.827).

CONCLUSIONS

RRT is associated with worse outcomes, including a lower likelihood to receive advanced heart failure therapies in patients with CS. A risk score comprising five variables routinely collected at admission can accurately estimate the risk of needing RRT.

The Prognostic Impact of Estimated Creatinine Clearance by Bioelectrical Impedance Analysis in Heart Failure: Comparison of Different eGFR Formulas

The estimation of glomerular filtration rate (eGFR) provides prognostic information in patients with heart failure (HF). Bioelectrical impedance analysis may calculate eGFR (Donadio formula). The aim of this study was to evaluate the impact of the Donadio formula in predicting all-cause mortality in patients with HF as compared to Cockroft-Gault, MDRD-4 (Modification of Diet in renal Disease Study), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formulas. Four-hundred thirty-six subjects with HF (52% men; mean age 75 ± 11 years; 42% acute HF) were enrolled. Ninety-two patients (21%) died during the follow-up (median 463 days, IQR 287-669). The area under the receiver operator characteristic curve for eGFR, as estimated by Cockroft-Gault formula (AUC = 0.75), was significantly higher than those derived from Donadio (AUC = 0.72), MDRD-4 (AUC = 0.68), and CKD-EPI (AUC = 0.71) formulas. At multivariate analysis, all eGFR formulas were independent predictors of death; 1 mL/min/1.73 m2 increase in eGFR-as measured by Cockroft-Gault, Donadio, MDRD-4, and CKD-EPI formulas-provided a 2.6%, 1.5%, 1.2%, and 1.6% increase, respectively, in mortality rate. Conclusions. eGFR, as calculated with the Donadio formula, was an independent predictor of mortality in patients with HF as well as the measurements derived from MDRD4 and CKD-EPI formulas, but less accurate than Cockroft-Gault.

Sex-specific cut-off values for soluble suppression of tumorigenicity 2 (ST2) biomarker increase its cardiovascular prognostic value in the community

BACKGROUND

Suppression of tumorigenicity 2 (ST2) has important cardiovascular prognostic value in community patients; however, previous analyses have utilized non-sex specific cut-off values. We assessed whether sex-specific ST2 cut-off values would improve the prognostic utility of ST2 in the asymptomatic community.

METHODS

A total of 2042 participants underwent clinical assessment and echocardiographic evaluation. Baseline measurements of high sensitivity troponin, natriuretic peptides and ST2 were obtained in 1681 individuals. ST2, cardiac biomarkers and associated co-morbidities were evaluated by sex-specific ST2 quartile analysis. ST2 concentrations were also analysed as dichotomous variables defined as being above the sex-specific cut-off for each the outcomes of heart failure (HF), major adverse cardiac event (MACE) and mortality.

RESULTS

Median ST2 concentration was 29.4 ng/mL in male subjects and 24.1 ng/mL in female subjects. Higher ST2 concentrations were associated with incident HF (p<0.001; preserved ejection fraction (EF) p<0.001, reduced EF p=0.23), MACE (p=0.003) and mortality (p<0.001) across sex-specific quartiles. Event-based, hazard ratio (HR) analysis revealed sex-specific ST2 cut-offs were significantly more predictive of incident HF, MACE and mortality compared to non-sex-specific analysis even following adjustment for cardiac co-morbidities and traditional biomarkers.

CONCLUSIONS

These data suggest that sex-specific cut-offs, greater than non-sex specific cut-offs, significantly impact the prognostic value of the biomarker ST2 in the asymptomatic community cohort.Clinical SignificanceSuppression of tumorigenicity 2 (ST2) is a biomarker which has known associations with heart failure (HF), major adverse cardiac events (MACEs) and mortality in the general population.Recent data support the concept of sex-specific cut off values and individualized approaches based on sex to predict cardiovascular disease. Given the difference in pathobiology between the sexes, the fact that such approaches improve risk stratification is understandable. Thus, when sex-specific treatments are developed, this may similarly lead to improved outcomes.The use of sex-specific ST2 cut-off values significantly improved the prognostic value in predicting HF, MACE, and mortality in an asymptomatic community. This prognostication was particularly strong for HF with preserved ejection fraction and remained clinically significant following adjustment for cardiac co-morbidities and other traditional cardiac biomarkers (NTproBNP and hscTnI).

Cystatin C-based CKD-EPI estimated glomerular filtration rate equations as a better strategy for mortality stratification in acute heart failure: A STROBE-compliant prospective observational study

An increasing number of studies outline renal function as an important risk marker for mortality in acute heart failure (AHF). However, routine estimation of glomerular filtration rate (eGFR) based on serum creatinine is imprecise.This study aims to compare the prognostic impact of CKD-EPI creatinine based equation (eGFRcr), cystatin C based equation (eGFRcyst), and creatinine-cystatin C equation (eGFRcrcyst) for the mortality stratification in AHF.A total of 354 Patients with AHF were prospectively included between January 2012 and June 2016. Creatinine and cystatin C were measured using the same blood sample tube on admission. We quantified eGFR by the eGFRcr, eGFRcyst, and eGFRcrcyst equations. The continuous net reclassification improvement (cNRI) and integrated discrimination improvement (IDI) were calculated to compare the discriminative prognostic value of different CKD-EPI formula.After a median follow-up of 35 months, 161 patients (45.5%) died. Reduced eGFRcyst and eGFRcrcyst remained significant association with death after adjustment. eGFRcyst showed the best area under the curve value (0.706) for the prediction of all-cause mortality. Considering mortality reclassification, both eGFRcyst (IDI = 7.3%, P < .001; cNRI = 19.6%, P = .012) and eGFRcrcyst (IDI = 4.3%, P < .001; cNRI = 8.7%, P = .138) showed its tendency in improving risk prediction compared to eGFRcr. Compared to eGFRcrcyst showed, eGFRcyst further improved mortality stratification (IDI = 3%, P = .049; cNRI = 11.1%, P = .036).In patients with AHF, our study demonstrates the eGFR calculated by CKD-EPI cystatin C-based equation improved the risk stratification of mortality over both creatinine-based and creatinine/cystatin C-based equations.

Cystatin C and Muscle Mass in Patients With Heart Failure

BACKGROUND

The estimated glomerular filtration rate (eGFR) from cystatin C (eGFRcys) is often considered a more accurate method to assess GFR compared with an eGFR from creatinine (eGFRcr) in the setting of heart failure (HF) and sarcopenia, because cystatin C is hypothesized to be less affected by muscle mass than creatinine. We evaluated (1) the association of muscle mass with cystatin C, (2) the accuracy of eGFRcys, and (3) the association of eGFRcys with mortality given muscle mass.

METHODS AND RESULTS

We included 293 patients admitted with HF. Muscle mass was estimated with a validated creatinine excretion-based equation. Accuracy of eGFRcys and eGFRcr was compared with measured creatinine clearance. Cystatin C and creatinine were 31.7% and 59.9% higher per 14 kg higher muscle mass at multivariable analysis (both P < .001). At lower muscle mass, eGFRcys and eGFRcr overestimated the measured creatinine clearance. At higher muscle mass, eGFRcys underestimated the measured creatinine clearance, but eGFRcr did not. After adjusting for muscle mass, neither eGFRcys nor eGFRcr were associated with mortality (both P > .19).

CONCLUSIONS

Cystatin C levels were associated with muscle mass in patients with HF, which could potentially decrease the accuracy of eGFRcys. In HF where aberrations in body composition are common, eGFRcys, like eGFRcr, may not provide accurate GFR estimations and results should be interpreted cautiously.

Acute Kidney Function Declines in the Context of Decongestion in Acute Decompensated Heart Failure

OBJECTIVES

This study aimed to examine whether incorporation of a comprehensive set of measures of decongestion modifies the association of acute declines in kidney function with outcomes.

BACKGROUND

In-hospital acute declines in kidney function occur in approximately 20% to 30% of patients admitted with acute decompensated heart failure (ADHF) and may be associated with adverse outcomes.

METHODS

Using data from EVEREST (Efficacy of Vasopressin Antagonism in Heart Failure Outcome Study With Tolvaptan), we used multivariable Cox regression models to evaluate the association between in-hospital changes in estimated glomerular filtration rate (eGFR) with death and a composite outcome of cardiovascular death and hospitalization for heart failure. We evaluated eGFR declines within the context of changes in markers of volume overload including b-type natriuretic peptide (BNP), N-terminal prohormone of B-type natriuretic peptide (NT-proBNP), and weight, as well as changes in measures of hemoconcentration including hematocrit, albumin, and total protein.

RESULTS

Among 3,715 patients over a median follow-up of 9.9 months, every 30% decline in eGFR was associated with higher risk of both death (hazard ratio [HR]: 1.19; 95% confidence interval [CI]: 1.07 to 1.31) and the composite outcome (HR: 1.09; 95% CI: 1.01 to 1.18) in adjusted models. The acute decline in eGFR was no longer associated with higher risk of either outcome as long as there was evidence of decongestion, either by declines in BNP, NT-proBNP, or weight or by increases in hematocrit, albumin or total protein. Interaction testing between decline in eGFR and changes in hematocrit, albumin, and total protein was statistically significant (p interaction of <0.01 for death and p interaction of ≤0.01 for composite for all 3 biomarkers). Interaction between change in eGFR and changes in BNP (p interaction = 0.07 for death; p interaction = 0.08 for composite), NT-proBNP (p interaction = 0.15 for death; p interaction = 0.18 for composite) and weight (p interaction = 0.13 for death; p interaction = 0.19 for composite) did not meet statistical significance.

CONCLUSIONS

Overall, acute declines in eGFR are associated with adverse outcomes, with evidence of modification by changes in markers of decongestion, suggesting that they are no longer associated with adverse outcomes if these markers are concomitantly improving.

Relation of Kidney Function Decline and NT-proBNP With Risk of Mortality and Readmission in Acute Decompensated Heart Failure

BACKGROUND

Acute declines in kidney function occur in approximately 20%-30% of patients with acute decompensated heart failure, but its significance is unclear, and the importance of its context is not known. This study aimed to determine the prognostic value of a decline in kidney function in the context of decongestion among patients admitted with acute decompensated heart failure.

METHODS

Using data from patients enrolled in the Ultrafiltration in Decompensated Heart Failure with Cardiorenal Syndrome Study (CARRESS) and Diuretic Optimization Strategies Evaluation (DOSE) trials, we used multivariable Cox regression models to evaluate the association between decline in estimated glomerular filtration rate (eGFR) and change in N-terminal pro-b-type natriuretic peptide (NT-proBNP) with a composite outcome of death and rehospitalization, as well as testing for an interaction between the two.

RESULTS

Among 435 patients, in-hospital decline in eGFR was not significantly associated with death and rehospitalization (hazard ratio [HR] = 0.89 per 30% decline, 95% confidence interval [CI] 0.74, 1.07), whereas decline in NT-proBNP was associated with lower risk (HR = 0.69 per halving, 95% CI 0.58, 0.83). There was a significant interaction (P = 0.002 unadjusted; P = 0.03 adjusted) between decline in eGFR and change in NT-proBNP where a decline in eGFR was associated with better outcomes when NT-proBNP declined (HR = 0.78 per 30% decline in eGFR, 95% CI 0.61, 0.99), but not when NT-proBNP increased (HR = 0.99, 95% CI 0.76, 1.30).

CONCLUSIONS

Decline in kidney function during therapy for acute decompensated heart failure is associated with improved outcomes as long as NT-proBNP levels are decreasing as well, suggesting that incorporation of congestion biomarkers may aid clinical interpretation of eGFR declines.

Cardiac Biomarkers in Advanced Heart Failure: How Can They Impact Our Pre-transplant or Pre-LVAD Decision-making

PURPOSE OF REVIEW

Decision-making in advanced heart failure (HF) is a complex process that involves careful consideration of competing tradeoffs of risks and benefits in regard to heart transplantation (HT) or left ventricular assist device (LVAD) placement. The purpose of this review is to discuss how biomarkers may affect decision-making for HT or LVAD implantation.

RECENT FINDINGS

N-Terminal probrain natriuretic peptide, soluble suppression of tumorigenicity-2, galectin-3, copeptin, and troponin T levels are associated with HF survival and can help identify the appropriate timing for advanced HF therapies. Patients at risk of right ventricular failure after LVAD implantation can be identified with preimplant biomarkers of extracellular matrix turnover, neurohormonal activation, and inflammation. There is limited data on the adoption of biomarker measurement for decision-making in the allocation of advanced HF therapies. Nonetheless, biomarkers can improve risk stratification and prognostication thereby optimizing patient selection for HT and LVAD implantation.

Established and Emerging Roles of Biomarkers in Heart Failure

Heart failure (HF) is a complex syndrome with an enormous societal burden in terms of cost, morbidity, and mortality. Natriuretic peptide testing is now widely used to support diagnosis, prognostication, and management of patients with HF and are incorporated into HF clinical practice guidelines. Beyond the natriuretic peptides, novel biomarkers may supplement traditional clinical and laboratory testing to improve understanding of the complex disease process of HF and possibly to personalize care for those affected through better individual phenotyping. In this review, we will discuss natriuretic peptides and the more novel biomarkers by dividing them into categories based on the major pathophysiologic pathways they represent. Given the complex physiology in HF, it is reasonable to expect that the future of biomarker testing lies in the application of multimarker testing panels, precision medicine to improve HF care delivery, and the use of biomarkers in proteomics and metabolomics to further improve HF care.

Trends in Kidney Function Outcomes Following RAAS Inhibition in Patients With Heart Failure With Reduced Ejection Fraction

RATIONALE & OBJECTIVE

Angiotensin-converting enzyme (ACE) inhibitors are beneficial in heart failure with reduced ejection fraction (HFrEF). We sought to describe longitudinal trends in estimated glomerular filtration rate (eGFR) in HFrEF and how ACE-inhibitor therapy influences these changes.

STUDY DESIGN

Post hoc analysis of trial data.

SETTINGS & PARTICIPANTS

Symptomatic (Treatment Trial, n=2,423) and asymptomatic (Prevention Trial, n=4,094) patients from the Studies of Left Ventricular Dysfunction (SOLVD).

EXPOSURE

Enalapril versus placebo.

OUTCOMES

Early and long-term eGFR slope (ie, within and after the first 6 weeks) and 4 kidney end points: (1) serum creatinine level increase by≥0.3mg/dL, (2)>30% eGFR decline, (3)>40% eGFR decline, and (4) incident eGFR<30mL/min/1.73m².

ANALYTICAL APPROACH

Shared parameter models, multivariable Cox regression models.

RESULTS

Baseline mean eGFR was lower in the Treatment Trial than in the Prevention Trial, 69.5±19.8 (SD) versus 76.2±18.6mL/min/1.73m². Following randomization, an early eGFR decline occurred in the enalapril group; however, slopes during the median 3-year follow-up were not statistically different by randomization arm in either the Treatment Trial (-0.84 in enalapril vs-1.36mL/min/1.73m² per year in placebo; P=0.08) or Prevention Trial (-1.27 in enalapril vs-1.36mL/min/1.73m² per year in placebo; P=0.7). Random assignment to enalapril treatment increased the risk for all 4 outcomes in the Treatment Trial in the first 6-week period (HRs were 1.48 [95% CI, 1.10-1.99] for creatinine increase by≥0.3mg/dL; 1.38 [95% CI, 0.98-1.94] for eGFR decline> 30%; 2.60 [95% CI, 1.30-5.21] for eGFR decline> 40%; and 4.71 [95% CI, 1.78-12.50] for eGFR<30mL/min/1.73m²), but after the first year was not significantly associated with increased risk. A similar albeit less pronounced pattern was observed in the Prevention Trial, with risks present only in the early period.

LIMITATIONS

Creatinine results were not blinded, making it possible that ACE-inhibitor/placebo dosing was influenced by creatinine level.

CONCLUSION

Kidney function decline is slow in HFrEF. Although random assignment to enalapril treatment results in a statistically increased risk for kidney surrogates, the risk is limited to the early phase and late eGFR slopes and risks are not different by randomly assigned group.

Prognostic Comparison of the Estimations of Renal Function in Patients With Acute Heart Failure

BACKGROUND

The prognostic significance of the eGFR calculated by either the four-level Race Chronic Kidney Disease-Epidemiology Collaboration study equation (CKD-EPI4R) or the Chinese-modified Modification of Diet in Renal Disease equation (cMDRD) has not been compared in Asian populations with acute heart failure (AHF).Methods and Results:A total of 3,044 patients hospitalized for AHF were enrolled. The National Death Registry was linked to identify deaths within a 5-year follow-up. Net reclassification improvement (NRI) was calculated to compare the prognostic value of either eGFR equation. During a median follow-up of 23.3 months, 1,424 (47%) patients died. Both eGFR_cMDRDand eGFR_CKD-EPI4Rwere independently predictive of death in the total study population (hazard ratio and 95% confidence intervals per 1-SD: 0.76, 0.71-0.81 and 0.74, 0.70-0.79, respectively), and in the subgroups of either reduced (HFrEF) or preserved (HFpEF) ejection fraction, after accounting for important confounders. With reference to eGFR_cMDRD, eGFR_CKD-EPI4Rmay improve the NRI by 2.0% (0.8-3.2%) for the prediction of death. The prognostic value of the CKD stages categorized by eGFR_CKD-EPI4Rsignificantly outperformed eGFR_cMDRDwith a categorical NRI of 9.5% (4.7-14.3%) in the total study population, 11.5% in HFrEF, and 8.3% in HFpEF.

CONCLUSIONS

Both eGFR_cMDRDand eGFR_CKD-EPI4Rwere independently associated with long-term survival in patients with AHF. However, the CKD stages derived from eGFR_CKD-EPI4Rimproved the risk stratification of death, compared with eGFR_cMDRD.

Renal function and acute heart failure outcome

The interaction between acute heart failure (AHF) and renal dysfunction is complex. Several studies have evaluated the prognostic value of this syndrome. The aim of this systematic review, which includes non-selected samples, was to investigate the impact of different renal function variables on the AHF prognosis. The categories included in the studies reviewed included: creatinine, blood urea nitrogen (BUN), the BUN/creatinine quotient, chronic kidney disease, the formula to estimate the glomerular filtration rate, criteria of acute renal injury and new biomarkers of renal damage such as neutrophil gelatinase-associated lipocalin (NGAL and cystatin c). The basal alterations of the renal function, as well as the acute alterations, transient or not, are related to a worse prognosis in AHF, it is therefore necessary to always have baseline, acute and evolutive renal function parameters.

Establishing the presence or absence of chronic kidney disease: Uses and limitations of formulas estimating the glomerular filtration rate

The development of formulas estimating glomerular filtration rate (eGFR) from serum creatinine and cystatin C and accounting for certain variables affecting the production rate of these biomarkers, including ethnicity, gender and age, has led to the current scheme of diagnosing and staging chronic kidney disease (CKD), which is based on eGFR values and albuminuria. This scheme has been applied extensively in various populations and has led to the current estimates of prevalence of CKD. In addition, this scheme is applied in clinical studies evaluating the risks of CKD and the efficacy of various interventions directed towards improving its course. Disagreements between creatinine-based and cystatin-based eGFR values and between eGFR values and measured GFR have been reported in various cohorts. These disagreements are the consequence of variations in the rate of production and in factors, other than GFR, affecting the rate of removal of creatinine and cystatin C. The disagreements create limitations for all eGFR formulas developed so far. The main limitations are low sensitivity in detecting early CKD in several subjects, e.g., those with hyperfiltration, and poor prediction of the course of CKD. Research efforts in CKD are currently directed towards identification of biomarkers that are better indices of GFR than the current biomarkers and, particularly, biomarkers of early renal tissue injury.

Estimated Glomerular Filtration Rate and 6-Minute Walk Distance in African Americans with Mild to Moderate Heart Failure

BACKGROUND/AIMS

The 6-minute walk test is a measure of functional capacity in patients with heart failure (HF) or chronic kidney disease (CKD). The association between estimated glomerular filtration rate (eGFR) and 6-minute walk distance (6MWD) has not been investigated in African-Americans (AA), despite them having a higher incidence of CKD and chronic HF. Thus, our aim was to determine if eGFR was an independent predictor of 6MWD in AA >50 years of age with HF.

METHODS

In this cross-sectional study, we examined the relationship between eGFR and 6MWD in 45 AA patients with HF from an urban outpatient HF clinic, using logistic regression with bootstrapping.

RESULTS

The sample consisted of 53% females; mean age = 64.8 ± 9 years, mean eGFR = 61.6 ± 20 mL/min/1.73 m², and mean 6MWD = 222 ± 78 m. A decrease in eGFR by 10 mL/min/1.73 m² was associated with 46% higher odds (p = 0.02) of a 6MWD ≤200 m in an unadjusted model and 39-41% higher odds (p = 0.03) of a 6MWD ≤200 m in adjusted models.

CONCLUSION

A decrease in eGFR significantly predicted a shorter 6MWD in AA patients with HF. Therefore, a reduction in eGFR may be used as an early marker to identify and manage declining functional capacity in these patients.

Renal function assessment in heart failure

Renal function is one of the most consistent prognostic determinants in heart failure. The prognostic information it provides is independent of the ejection fraction and functional status. This article reviews the various renal function assessment measures, with special emphasis on the fact that the patient's clinical situation and response to the heart failure treatment should be considered for the correct interpretation of the results. Finally, we review the literature on the performance of tubular damage biomarkers.

Beyond Natriuretic Peptides for Diagnosis and Management of Heart Failure

BACKGROUND

Heart failure (HF) is a complex syndrome with an enormous societal burden in terms of cost and morbidity and mortality. Natriuretic peptide (NP) testing is now widely used to support diagnosis, prognostication, and management of patients with HF, but NPs come with limitations, including vulnerability to the presence of obesity, atrial fibrillation, and renal dysfunction, for example. Beyond the NPs, novel biomarkers may supplement traditional clinical and laboratory testing to improve understanding of the complex disease process of HF, and possibly to personalize care for those affected through better individual phenotyping.

CONTENT

In this review we discuss novel biomarkers by dividing them into categories based on major pathophysiologic pathways they represent including myocardial stretch/stress, cardiac extracellular matrix remodeling, cardiomyocyte injury/death, oxidative stress, inflammation, neurohumoral activation, and renal dysfunction.

SUMMARY

Given the limitations of NPs, along with the complex physiology in HF, it is logical to consider utilization of novel biomarkers providing orthogonal biological and clinical information. Several novel HF biomarkers have shown promise but have substantial expectations to meet before being used clinically. Nonetheless, it is reasonable to expect the future lies in the application of multibiomarker panels for the improvement in management of HF and the personalization of care.

A Clinical Approach to the Acute Cardiorenal Syndrome

Acute kidney injury is a frequent complication of acute heart failure syndromes, portending an adverse prognosis. Acute cardiorenal syndrome represents a unique form of acute kidney injury specific to acute heart failure syndromes. The pathophysiology of acute cardiorenal syndrome involves renal venous congestion, ineffective forward flow, and impaired renal autoregulation caused by neurohormonal activation. Biomarkers reflecting different aspects of acute cardiorenal syndrome pathophysiology may allow patient phenotyping to inform prognosis and treatment. Adjunctive vasoactive, neurohormonal, and diuretic therapies may relieve congestive symptoms and/or improve renal function, but no single therapy has been proved to reduce mortality in acute cardiorenal syndrome.

The predictive value of different equations for estimation of glomerular filtration rate in patients with coronary artery disease - Results from the AtheroGene study

BACKGROUND

Impaired renal function leads to dramatically increased risk for the development and progression of coronary artery disease (CAD). Therefore we aimed to assess the predictive value of different equations for estimated glomerular filtration rate (eGFR) in CAD-patients.

METHODS

From the AtheroGene study 2135 patients were included. eGFR was calculated using the 4-variable Modification of Diet in Renal Disease (4MDRD) equation for serum creatinine (sCr), the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation for sCr and cystatin C (CysC) each alone, and in combination (CysC/sCr). eGFR was assessed regarding the combined outcome of cardiovascular death and non-fatal myocardial infarction and regarding complex CAD represented by a SYNTAX score ≥23. Median follow-up was 4.3years.

RESULTS

Only the CKD-EPI equation using CysC could differentiate between eGFR >90ml/min/1.73m(2) vs. eGFR 60-90ml/min/1.73m(2) according to the occurrence of an endpoint event (log-rank test p=0.009). In the Cox regression analysis only eGFR calculated by CKD-EPI equation for CysC (Hazard ratio per 1 standard deviation (HR) 1.27 (95% CI 1.07-1.50); p=0.007) and for CysC/sCr (HR 1.22 (95% CI 1.02-1.46); p=0.026) were predictive regarding the outcome after adjustment for cardiovascular risk factors and Nt-proBNP. Furthermore, only eGFR calculated by CKD-EPI equation for CysC (odds ratio (OR) 1.57 (95% CI 1.36-1.78); p<0.001) and for CysC/sCr (OR 1.32 (95% CI 1.13-1.53); p<0.001) were significantly associated with a SYNTAX score ≥23.

CONCLUSION

In patients with CAD the CKD-EPI equation for CysC and for CysC/sCr provided the best predictive value regarding the prognosis and the severity of CAD.

Comparison of Risk Prediction With the CKD-EPI and MDRD Equations in Non-ST-Segment Elevation Acute Coronary Syndrome

BACKGROUND

Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations estimate glomerular filtration rate (GFR) more accurately than the Modification of Diet in Renal Disease (MDRD) equation.

HYPOTHESIS

New CKD-EPI equations improve risk stratification in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) and provide complementary information to the Global Registry of Acute Coronary Events (GRACE) risk score.

METHODS

We studied 350 subjects (mean age, 68 ± 12 years; 70% male) with NSTE-ACS. Estimated GFR was calculated using the MDRD and new CKD-EPI equations based on serum creatinine (SCr) and/or cystatin C (CysC) concentrations obtained within 48 hours of hospital admission. The primary endpoint was all-cause death during follow-up.

RESULTS

Over the study period (median, 648 days [interquartile range, 236-1042 days]), 31 patients died (0.05% events per person-year). Decedents had poorer renal-function parameters (P < 0.001). Both CysC-based CKD-EPI equations had the highest areas under the receiver operating characteristic curve for the prediction of all-cause mortality. After multivariate adjustment, only CysC-based CKD-EPI equations were independent predictors of all-cause mortality (CKD-EPISCr - CysC , per mL/min/1.73 m(2) : hazard ratio: 0.975, 95% confidence interval: 0.956-0.994, P = 0.009; CKD-EPICysC , per mL/min/1.73 m(2) : hazard ratio: 0.976, 95% confidence interval: 0.959-0.993, P = 0.005). Reclassification analyses showed that only CysC-based CKD-EPI equations improved predictive accuracy of the GRACE risk score.

CONCLUSIONS

In patients with NSTE-ACS, CysC-based CKD-EPI equations improved clinical risk stratification for mortality and added complementary prognostic information to the GRACE risk score.

Absence of cystatin C involvement in ventricular remodelling and heart failure

Cystatin C (CysC) is a protease encoded by housekeeping genes. Although its prognostic value in heart failure (HF) is well known, it is debatable whether this value is due to the greater accuracy of CysC in calculating the glomerular filtration rate or to its involvement in pathological ventricular remodelling. The aim of this study was to determine whether CysC expression changes in the myocardium of foetuses of different ages and in the myocardium of adults with various cardiovascular diseases, as well as to analyse the correlation between its serum concentrations and cardiac structure and morphology in a patient group with HF.

PATIENTS AND METHODS

We analysed the correlations (Pearson's r and Spearman's test) between the serum CysC levels and echocardiographic parameters of 351 patients with HF. We also performed immunohistochemical staining for CysC, metalloproteinase-9 (MMP-9) and desmin in 9 cardiac tissue samples from autopsies of 4 foetuses of different gestational ages and 5 healthy adults or adults with cardiovascular disease.

RESULTS

For the patients with HF, there was no correlation between the CysC concentrations and the cardiac parameters measured by 2D echocardiography. The immunohistochemistry showed a weak background staining for CysC in all samples, regardless of age and the presence or absence of cardiovascular diseases.

CONCLUSIONS

Our results suggest that CysC does not have a significant role in the pathological remodelling of the left ventricle in HF.

Prediction of mortality using quantification of renal function in acute heart failure

BACKGROUND

Renal function, as quantified by the estimated glomerular filtration rate (eGFR), is a predictor of death in acute heart failure (AHF). It is unknown whether one of the clinically-available serum creatinine-based formulas to calculate eGFR is superior to the others for predicting mortality.

METHODS AND RESULTS

We quantified renal function using five different formulas (Cockroft-Gault, MDRD-4, MDRD-6, CKD-EPI in patients<70 years, and BIS-1 in patients≥70 years) in 1104 unselected AHF patients presenting to the emergency department and enrolled in a multicenter study. Two independent cardiologists adjudicated the diagnosis of AHF. The primary endpoint was the accuracy of the five eGFR equations to predict death as quantified by the time-dependent area under the receiver-operating characteristics curve (AUC). The secondary endpoint was the accuracy to predict all-cause readmissions and readmissions due to AHF. In a median follow-up of 374 days (IQR: 221 to 687 days), 445 patients (40.3%) died. eGFR as calculated by all equations was an independent predictor of mortality. The Cockcroft-Gault formula showed the highest prognostic accuracy (AUC 0.70 versus 0.65 for MDRD-4, 0.55 for MDRD-6, and 0.67 for the combined formula CKD-EPI/BIS-1, p<0.05). These findings were confirmed in patients with varying degrees of renal function and in three vulnerable subgroups: women, patients with severe left ventricular dysfunction, and the elderly. The prognostic accuracy for readmission was poor for all equations, with an AUC around 0.5.

CONCLUSIONS

Calculating eGFR using the Cockcroft-Gault formula assesses the risk of mortality in patients with AHF more accurately than other commonly used formulas.

Prognostic value of glomerular filtration rate estimation equations in acute heart failure with preserved versus reduced ejection fraction

AIMS

Renal function is an important prognostic factor in heart failure. The aim of this study was to compare the predictive value of estimated renal function calculated by the Chronic Kidney Disease-Epidemiology Collaboration equation (CKD-EPI) and the abbreviated Modification of Diet in Renal Disease (MDRD-4) equation for long-term all-cause mortality in patients admitted for acute decompensated heart failure (ADHF) with both preserved ejection fraction (HF-PEF) and reduced ejection fraction (HF-REF).

METHODS AND RESULTS

We evaluated patients included in the Spanish National Registry of Heart Failure (RICA). RICA is a multicentre, prospective, cohort study that included patients admitted to the Internal Medicine units with ADHF. Estimated glomerular filtration rate (eGFR) was calculated with CKD-EPI and MDRD-4 equations. A total of 1805 patients admitted for ADHF were studied (52% women; median age 80 years, interquartile range 73.9-84.6 years); of these, 1044 (58%) had HF-PEF. eGFR values were lower with the CKD-EPI formula than with the MDRD-4 formula (51 ml/min/1.73 m(2) vs. 55.7 ml/min/1.73 m(2) ; p < 0.001). The two formulas provided independent prognostic information over long-term follow-up, in both HF-PEF and HF-REF patients. However, in HF-PEF patients, CKD-EPI equation was associated with a significant improvement in reclassification analyses (net reclassification improvement 6.78%; p = 0.009).

CONCLUSIONS

In this clinical cohort of ADHF patients, eGFR as calculated by both the CKD-EPI and the MDRD-4 formulas offered similar prognostic information, irrespective of ejection fraction status, but in HF-PEF patients specifically, the CKD-EPI formula seems to improve clinical risk stratification as compared with MDRD-4.

Biomarkers in acute heart failure

The care of patients with acutely decompensated heart failure is being reshaped by the availability and understanding of several novel and emerging heart failure biomarkers. The gold standard biomarkers in heart failure are B-type natriuretic peptide and N-terminal pro-B-type natriuretic peptide, which play an important role in the diagnosis, prognosis, and management of acute decompensated heart failure. Novel biomarkers that are increasingly involved in the processes of myocardial injury, neurohormonal activation, and ventricular remodeling are showing promise in improving diagnosis and prognosis among patients with acute decompensated heart failure. These include midregional proatrial natriuretic peptide, soluble ST2, galectin-3, highly-sensitive troponin, and midregional proadrenomedullin. There has also been an emergence of biomarkers for evaluation of acute decompensated heart failure that assist in the differential diagnosis of dyspnea, such as procalcitonin (for identification of acute pneumonia), as well as markers that predict complications of acute decompensated heart failure, such as renal injury markers. In this article, we will review the pathophysiology and usefulness of established and emerging biomarkers for the clinical diagnosis, prognosis, and management of acute decompensated heart failure.

Cystatin C-based CKD-EPI equations and N-terminal pro-B-type natriuretic peptide for predicting outcomes in acutely decompensated heart failure

BACKGROUND

In patients with acute decompensated heart failure (ADHF), both natriuretic peptides and renal impairment predict adverse outcomes. Our aim was to evaluate the complementary prognosis role of N-terminal pro-B-type natriuretic peptide (NT-proBNP) and the newly developed Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations based on cystatin C (CysC) for glomerular filtration rate (GFR) estimation in ADHF patients.

HYPOTHESIS

Renal impairment assessed by CysC-based CKD-EPI equations and natriuretic peptides have complementary prognostic value in ADHF patients.

METHODS

The study included 613 consecutive patients presenting with ADHF. At admission, plasma levels of NT-proBNP and CysC were determined. The GFR was estimated using CysC-based CKD-EPI equations. The primary endpoint was death from any cause and heart failure readmission.

RESULTS

During the median follow-up of 365 days (interquartile range, 227-441 days), 323 patients (0.65 %patient-year) died or were readmitted for heart failure. After multivariate adjustment, estimated GFR <60 mL/min/1.73 m(2) and NT-proBNP >3251 pg/mL were independent predictors of adverse outcomes (P < 0.01). The combination of GFR <60 mL/min/1.73 m(2) and NT-proBNP >3251 pg/mL was associated with the highest risk of adverse outcomes. Furthermore, reclassification analyses demonstrated that use of both NT-proBNP and CysC-based CKD-EPI equations resulted in improving the accuracy for adverse outcomes prediction.

CONCLUSIONS

In patients with ADHF, the combination of NT-proBNP with estimated GFR using CysC-based CKD-EPI equations better predicts outcomes than either parameter alone and adds valuable complementary prognosis information to other established risk factors.

Association between type-2 diabetes mellitus and post-discharge outcomes in heart failure patients: findings from the RICA registry

AIMS

Heart failure (HF) and diabetes are common clinical conditions that may coexist. The main objective was to analyze the association of type-2 diabetes mellitus (T2DM) on prognosis in hospitalized patients with HF.

METHODS

We evaluated the association between T2DM with all-cause mortality and readmissions in the Spanish National Registry on Heart Failure-"Registro Nacional de Insuficiencia Cardiaca" (RICA). This is a multi-center and prospective cohort study that includes patients admitted for decompensated HF from 2008 to 2011. Study endpoints were all-cause mortality and hospital readmission. We determined the adjusted hazard ratio (HR) by a multivariable Cox regression model.

RESULTS

A total of 1082 patients (mean age 77.6±8.5) were included of whom 490 (45.3%) had diabetes and 592 patients (54.7%) had preserved left ventricular ejection fraction (LVEF). During one-year follow-up, 287 patients died (151 patients with diabetes) and 383 patients were readmitted (197 patients with diabetes). After adjusting for baseline characteristics T2DM was significantly associated with all-cause mortality (HR 1.54; 95%CI 1.20-1.97, p=0.001) and readmissions (HR 1.46; 95%CI 1.18-1.80, p<0.001). Age, dementia, peripheral vascular disease, NYHA class, renal insufficiency, hyponatremia and anemia were also independently associated with outcomes. There were no differences in mortality (p=0.415) and readmissions (p=0.514) according to preserved or reduced LVEF.

CONCLUSION

T2DM is very common in patients hospitalized for HF. This condition is a strong and independent co-morbidity of all-cause mortality and readmission for both HF with preserved and reduced LVEF.