Renal tubular damage and worsening renal function in chronic heart failure: Clinical determinants and relation to prognosis (Bio-SHiFT study)

Associations of Kidney Tubular Biomarkers With Incident Macroalbuminuria and Sustained Low eGFR in DCCT/EDIC

OBJECTIVE

Tubulointerstitial injury contributes to diabetic kidney disease (DKD) progression. We tested tubular biomarker associations with DKD development in type 1 diabetes (T1D).

RESEARCH DESIGN AND METHODS

We performed a case-cohort study examining associations of tubular biomarkers, measured across seven time points spanning ∼30 years, with incident macroalbuminuria ("severely elevated albuminuria," urinary albumin excretion rate [AER] ≥300 mg/day) and sustained low estimated glomerular filtration rate (eGFR) (persistent eGFR <60 mL/min/1.73 m2) in the Diabetes Control and Complications Trial (DCCT)/Epidemiology of Diabetes Interventions and Complications (EDIC) study. Biomarkers included KIM-1 and sTNFR1 in serum/plasma, MCP-1 and EGF in urine, and a composite tubular secretion score reflecting secreted solute clearance. We assessed biomarkers using single values, as mean values from consecutive time points, and as change over consecutive time points, each as time-updated exposures.

RESULTS

At baseline, mean diabetes duration was 5.9 years, with mean HbA1c 8.9%, eGFR 125 mL/min/1.73 m2, and AER 16 mg/day. There were 4.8 and 3.5 cases per 1,000 person-years of macroalbuminuria and low eGFR, respectively. Assessed according to single biomarker values, KIM-1 was associated with risk of subsequent macroalbuminuria and low eGFR (hazard ratio [HR] per 20% higher biomarker 1.11 [95% CI 1.06, 1.16] and 1.12 [1.04, 1.21], respectively) and sTNFR1 was associated with subsequent macroalbuminuria (1.14 [1.03, 1.25]). Mean KIM-1 and EGF-to-MCP-1 ratio were associated with subsequent low eGFR. In slope analyses, increases in KIM-1 and sTNFR1 were associated with subsequent macroalbuminuria (per 20% biomarker increase, HR 1.81 [1.40, 2.34] and 1.95 [1.18, 3.21]) and low eGFR (2.26 [1.65, 3.09] and 2.94 [1.39, 6.23]).

CONCLUSIONS

Serial KIM-1 and sTNFR1 are associated with incident macroalbuminuria and sustained low eGFR in T1D.

Renal Congestion in Heart Failure: Insights in Novel Diagnostic Modalities

Heart failure is increasingly prevalent and is estimated to increase its burden in the following years. A well-reported comorbidity of heart failure is renal dysfunction, where predominantly changes in the patient's volume status, tubular necrosis or other mechanical and neurohormonal mechanisms seem to drive this impairment. Currently, there are established biomarkers evaluating the patient's clinical status solely regarding the cardiovascular or renal system. However, as the coexistence of heart and renal failure is common and related to increased mortality and hospitalization for heart failure, it is of major importance to establish novel diagnostic techniques, which could identify patients with or at risk for cardiorenal syndrome and assist in selecting the appropriate management for these patients. Such techniques include biomarkers and imaging. In regards to biomarkers, several peptides and miRNAs indicative of renal or tubular dysfunction seem to properly identify patients with cardiorenal syndrome early on in the course of the disease, while changes in their serum levels can also be helpful in identifying response to diuretic treatment. Current and novel imaging techniques can also identify heart failure patients with early renal insufficiency and assess the volume status and the effect of treatment of each patient. Furthermore, by assessing the renal morphology, these techniques could also help identify those at risk of kidney impairment. This review aims to present all relevant clinical and trial data available in order to provide an up-to-date summary of the modalities available to properly assess cardiorenal syndrome.

Worsening renal function in hospitalized patients with systolic heart failure: prevalence and risk factors

AIMS

Heart failure (HF) is usually associated with complications of other organs. Renal impairment is seen in a significant proportion of HF patients and is characterized by worsening renal function (WRF). WRF can be used for predicting symptom exacerbation in systolic HF. This study aimed to determine the prevalence and risk factors of WRF among hospitalized patients with systolic HF.

METHODS AND RESULTS

In this cross-sectional study, data from medical records of 347 hospitalized patients diagnosed with HFrEF from 2019 to 2020, admitted to Tabriz Shahid Madani Heart Hospital, who met the predefined inclusion criteria, were retrieved. Patients were divided into two groups based on the in-hospital occurrence of WRF. Laboratory tests and para-clinical findings were collected and analysed using SPSS Version 20.0. Statistical significance was accepted at a P value of <0.05. In this study, 347 hospitalized patients with HFrEF were included. The mean (standard deviation) age was 62.34 (±18.87) years. The mean (SD) length of stay was 6.34 (±4) days. According to our findings, 117 patients (33.71%) had WRF. Following multivariate analysis of potential predictors of WRF occurrence, hyponatremia, haemoglobin concentration, white blood cell count and prior diuretic use were found to be independent predictors for WRF occurrence in patients with systolic heart failure.

CONCLUSIONS

This study revealed that in patients with WRF, mortality rate and length of stay were significantly greater than those of patients without WRF. Initial clinical characteristics of HF patients who developed WRF can help physicians identify patients with a higher risk of WRF.

Prognostic Value of Urinary N-Acetyl-β-d-Glucosaminidase as a Marker of Tubular Damage in Patients with Heart Failure and Mitral Regurgitation

Background

Mitral regurgitation (MR) has a high prevalence and aggravates hypoperfusion and hypoxia in heart failure (HF). Renal tubular epithelial cells are sensitive to hypoxia, and therefore tubulointerstitial damage is quite common in HF. However, the correlation between tubular dysfunction and MR has not been studied. The aim of this work was to evaluate the prognostic significance of urinary N-acetyl- β -d-glucosaminidase (uNAG), a biomarker of renal tubular damage, in patients with HF and MR.

Methods

This was a prospective cohort study of 390 patients (mean age 64 years; 65.6% male) with uNAG measurement on admission (expressed as urinary NAG/urinary creatinine) and at least 1 year of follow-up data. The pre-defined primary endpoint was the composite of all-cause mortality or rehospitalization for HF after discharge. Cox regression analysis, restricted cubic splines, and subgroup analysis were used to investigate the prognostic value of uNAG modeled as a categorical (quartiles) or continuous (per SD increase) variable.

Results

A total of 153 (39.23%) patients reached the composite endpoint over a median follow-up time of 1.2 years. The uNAG level correlated with the severity of HF and with the incidence of adverse events. In a multivariable Cox regression model, each SD (13.80 U/g ⋅ Cr) of increased uNAG was associated with a 17% higher risk of death or HF rehospitalization (95% confidence interval, 2-33%, p = 0.022), and a 19% higher risk of HF rehospitalization (p = 0.027). Subgroup analysis revealed the associations between uNAG and poor prognosis were only significant in younger patients ( ≤ 65 years) and in patients without obvious cardiovascular comorbidities.

Conclusions

uNAG levels at admission were associated with the risk of adverse outcomes in patients with HF and MR. Additional studies are needed to further investigate the heart-kidney interaction.

Biomarkers in Heart Failure with Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous disorder developing from multiple aetiologies with overlapping pathophysiological mechanisms. HFpEF diagnosis may be challenging, as neither cardiac imaging nor physical examination are sensitive in this situation. Here, we review biomarkers of HFpEF, of which the best supported are related to myocardial stretch and injury, including natriuretic peptides and cardiac troponins. An overview of biomarkers of inflammation, extracellular matrix derangements and fibrosis, senescence, vascular dysfunction, anaemia/iron deficiency and obesity is also provided. Finally, novel biomarkers from -omics technologies, including plasma metabolites and circulating microRNAs, are outlined briefly. A cardiac-centred approach to HFpEF diagnosis using natriuretic peptides seems reasonable at present in clinical practice. A holistic approach including biomarkers that provide information on the non-cardiac components of the HFpEF syndrome may enrich our understanding of the disease and may be useful in classifying HFpEF phenotypes or endotypes that may guide patient selection in HFpEF trials.

Acute Kidney Disease After Acute Decompensated Heart Failure

Introduction

Acute kidney disease (AKD) represents a continuum of kidney injury for 7 to 90 days after acute kidney injury (AKI). The incidence and prognosis of AKD after acute decompensated heart failure (ADHF) are currently unclear. The aims of this study were to explore the incidence of AKD and the transition from AKI to AKD, to identify risk factors for AKD and develop a prediction model for any-stage AKD, and to evaluate the prognosis of AKD.

Methods

A total of 7519 patients admitted for ADHF between January 1, 2008, and December 31, 2018, from a multi-institutional database were identified. The composite outcomes after ADHF were stage 3 AKD and all-cause death. The prognosis impact of AKD, including major adverse kidney events (MAKEs), all-cause death, and heart failure hospitalization (HFH), during 5 years of follow-up was analyzed.

Results

The overall incidence of AKI and AKD after ADHF was 9% and 21.2%, respectively; 39.4% of the patients diagnosed with having AKI during ADHF subsequently developed AKD whereas 19.4% of the patients without an identified AKI episode subsequently developed AKD. The predictive scoring models revealed C-statistics of 0.726 (95% CI: 0.712–0.740) for any-stage AKD and 0.807 (95% CI: 0.793–0.821) for the composite of stage 3 AKD and death. Finally, AKD was associated with higher risks of all-cause death, MAKE, and HFH during the 5 years of follow-up (P < 0.001).

Conclusion

AKD after ADHF are associated with adverse outcomes. Our model could help in identification of patients at risk for AKD development, especially in those who did not have an index AKI episode.

Proteomic profiling for detection of early-stage heart failure in the community

Aims

Biomarkers may provide insights into molecular mechanisms underlying heart remodelling and dysfunction. Using a targeted proteomic approach, we aimed to identify circulating biomarkers associated with early stages of heart failure.

Methods and results

A total of 575 community‐based participants (mean age, 57 years; 51.7% women) underwent echocardiography and proteomic profiling (CVD II panel, Olink Proteomics). We applied partial least squares‐discriminant analysis (PLS‐DA) and a machine learning algorithm [eXtreme Gradient Boosting (XGBoost)] to identify key proteins associated with echocardiographic abnormalities. We used Gaussian mixture modelling for unbiased clustering to construct phenogroups based on influential proteins in PLS‐DA and XGBoost. Of 87 proteins, 13 were important in PLS‐DA and XGBoost modelling for detection of left ventricular remodelling, left ventricular diastolic dysfunction, and/or left atrial reservoir dysfunction: placental growth factor, kidney injury molecule‐1, prostasin, angiotensin‐converting enzyme‐2, galectin‐9, cathepsin L1, matrix metalloproteinase‐7, tumour necrosis factor receptor superfamily members 10A, 10B, and 11A, interleukins 6 and 16, and α1‐microglobulin/bikunin precursor. Based on these proteins, the clustering algorithm divided the cohort into two distinct phenogroups, with each cluster grouping individuals with a similar protein profile. Participants belonging to the second cluster (n = 118) were characterized by an unfavourable cardiovascular risk profile and adverse cardiac structure and function. The adjusted risk of presenting echocardiographic abnormalities was higher in this phenogroup than in the other (P < 0.0001).

Conclusions

We identified proteins related to renal function, extracellular matrix remodelling, angiogenesis, and inflammation to be associated with echocardiographic signs of early‐stage heart failure. Proteomic phenomapping discriminated individuals at high risk for cardiac remodelling and dysfunction.

miR-30b-5p Downregulation as a Predictive Biomarker of Coronary In-Stent Restenosis

In-stent restenosis (ISR) is one of the main limitations of percutaneous coronary intervention (PCI) therapy with drug-eluting stents (DES) implantation. The aim of this study was to determine if circulating microRNAs (miRNAs) have diagnostic capability for determining ISR in a cohort of matched patients. Blood samples were collected from 55 patients who underwent previously PCI and were readmitted for a new coronary angiography. Patients were divided into subgroups comprising patients who presented ISR or not (non-ISR). A microarray analysis determined that up to 49 miRNAs were differentially expressed between ISR and non-ISR patients. Of these, 10 miRNAs are related to vascular smooth muscle and endothelial cells proliferation, migration, and differentiation, well-known hallmarks of vascular remodeling. Additionally, we identified that the expression of miR-30b-5p is significantly lower in serum samples of ISR patients, as compared to non-ISR. A further analysis demonstrated that miR-30b-5p provides better values of the receiver operator characteristic curve than other miRNAs and biochemical parameters. Finally, the in-silico analysis suggests that miR-30b-5p is predicted to target 62 genes involved in different signaling pathways involved in vascular remodeling. In conclusion, we determined for the first time that circulating mi-R30b-5p can reliably prognose restenosis in patient with implanted DES, which could be potentially helpful in the establishment of an early diagnosis and therapy of ISR.

Empagliflozin Administration Can Decrease the Dose of Loop Diuretics and Prevent the Exacerbation of Renal Tubular Injury in Patients With Compensated Heart Failure Complicated by Diabetes

Background: Whether the dose of loop diuretics can be decreased by administration of a sodium-glucose cotransporter 2 (SGLT2) inhibitor in diabetic outpatients with compensated heart failure (HF) is unclear. Methods and Results: This study prospectively enrolled 60 diabetic outpatients with compensated HF. Patients were randomly divided into 2 groups: those administered the SGLT2 inhibitor empagliflozin (n=28) and those not (n=30). Changes in the daily dose of loop diuretics, blood sampling data, and urinary renal tubular biomarkers were evaluated 6 months after the intervention. The median (interquartile range) furosemide dose decreased significantly over the 6-month follow-up period in the empagliflozin group (from 40 [20-40] to 20 [10-20] mg), but not in the non-empagliflozin group (from 23 [20-40] to 40 [20-40] mg). Hemoglobin levels increased significantly in the empagliflozin group (from 13.2 [11.9-14.6] to 14.0 [12.7-15.0] g/dL). In addition, excretion of acetyl-β-D-glucosaminidase decreased significantly over the 6-month follow-up in the empagliflozin group (from 4.8 [2.6-11.7] to 3.3 [2.1-5.4] IU/L), especially in the group in which the dose of loop diuretics decreased (from 4.7 [2.5-14.8] to 3.3 [2.1-4.5] IU/L). Conclusions: Empagliflozin administration decreased the dose of loop diuretics and increased the production of erythropoietin, which may help prevent renal tubular injury in diabetic outpatients with HF.

Renal tubular damage and worsening renal function in chronic heart failure: Clinical determinants and relation to prognosis (Bio-SHiFT study)

Background

It is uncertain that chronic heart failure (CHF) patients are susceptible to renal tubular damage with that of worsening renal function (WRF) preceding clinical outcomes.

Hypothesis

Changes in tubular damage biomarkers are stronger predictors of subsequent clinical events than changes in creatinine (Cr), and both have different clinical determinants.

Methods

During 2.2 years, we repeatedly simultaneously collected a median of 9 blood and 8 urine samples per patient in 263 CHF patients. We determined the slopes (rates of change) of the biomarker trajectories for plasma (Cr) and urinary tubular damage biomarkers N‐acetyl‐β‐d‐glucosaminidase (NAG), and kidney‐injury‐molecule (KIM)‐1. The degree of tubular injury was ranked according to NAG and KIM‐1 slopes: increase in neither, increase in either, or increase in both; WRF was defined as increasing Cr slope. The composite endpoint comprised HF‐hospitalization, cardiac death, left ventricular assist device placement, and heart transplantation.

Results

Higher baseline NT‐proBNP and lower eGFR predicted more severe tubular damage (adjusted odds ratio, adj. OR [95%CI, 95% confidence interval] per doubling NT‐proBNP: 1.26 [1.07‐1.49]; per 10 mL/min/1.73 m² eGFR decrease 1.16 [1.03‐1.31]). Higher loop diuretic doses, lower aldosterone antagonist doses, and higher eGFR predicted WRF (furosemide per 40 mg increase: 1.32 [1.08‐1.62]; spironolactone per 25 mg decrease: 1.76 [1.07‐2.89]; per 10 mL/min/1.73 m² eGFR increase: 1.40 [1.20‐1.63]). WRF and higher rank of tubular injury individually entailed higher risk of the composite endpoint (adjusted hazard ratios, adj. HR [95%CI]: WRF 1.9 [1.1‐3.4], tubular 8.4 [2.6‐27.9]; when combined risk was highest 15.0 [2.0‐111.0]).

Conclusion

Slopes of tubular damage and WRF biomarkers had different clinical determinants. Both predicted clinical outcome, but this association was stronger for tubular injury. Prognostic effects of both appeared independent and additive.