Diagnostic and Prognostic Utilities of Insulin-Like Growth Factor Binding Protein-7 in Patients With Dyspnea

Large scale plasma proteomics identifies novel proteins and protein networks associated with heart failure development

Heart failure (HF) causes substantial morbidity and mortality but its pathobiology is incompletely understood. The proteome is a promising intermediate phenotype for discovery of novel mechanisms. We measured 4877 plasma proteins in 13,900 HF-free individuals across three analysis sets with diverse age, geography, and HF ascertainment to identify circulating proteins and protein networks associated with HF development. Parallel analyses in Atherosclerosis Risk in Communities study participants in mid-life and late-life and in Trøndelag Health Study participants identified 37 proteins consistently associated with incident HF independent of traditional risk factors. Mendelian randomization supported causal effects of 10 on HF, HF risk factors, or left ventricular size and function, including matricellular (e.g. SPON1, MFAP4), senescence-associated (FSTL3, IGFBP7), and inflammatory (SVEP1, CCL15, ITIH3) proteins. Protein co-regulation network analyses identified 5 modules associated with HF risk, two of which were influenced by genetic variants that implicated trans hotspots within the VTN and CFH genes.

Do Heart Failure Biomarkers Influence Heart Failure Treatment Response?

PURPOSE OF REVIEW

Heart failure (HF) is one of the leading causes of cardiac morbidity and mortality around the world. Our evolving understanding of the cellular and molecular pathways of HF has led to the identification and evaluation of a growing number of HF biomarkers. Natriuretic peptides remain the best studied and understood HF biomarkers, with demonstrated clinical utility in the diagnosis and prognostication of HF. Less commonly understood is the utility of HF biomarkers for guiding and monitoring treatment response. In this review, we outline the current HF biomarker landscape and identify novel biomarkers that have potential to influence HF treatment response.

RECENT FINDINGS

An increasing number of biomarkers have been identified through the study of HF mechanisms. While these biomarkers hold promise, they have not yet been proven to be effective in guiding HF therapy. A more developed understanding of HF mechanisms has resulted in an increased number of available pharmacologic HF therapies. In the past, biomarkers have been useful for the diagnosis and prognostication of HF. Future evaluation on their use to guide pharmacologic therapy is ongoing, and there is promise that biomarker-guided therapy will allow clinicians to begin personalizing treatment for their HF patients.

Auto- and paracrine rewiring of NIX-mediated mitophagy by insulin-like growth factor-binding protein 7 in septic AKI escalates inflammation-coupling tubular damage

AIMS

Inflammation-coupling tubular damage (ICTD) contributes to pathogenesis of septic acute kidney injury (AKI), in which insulin-like growth factor-binding protein 7 (IGFBP-7) serves as a biomarker for risk stratification. The current study aims to discern how IGFBP-7 signalling influences ICTD, the mechanisms that underlie this process and whether blockade of the IGFBP-7-dependent ICTD might have therapeutic value for septic AKI.

MATERIALS AND METHODS

In vivo characterization was carried out in B6/JGpt-Igfbp7^em1Cd1165/Gpt mice subjected to cecal ligation and puncture (CLP). Transmission electron microscopy, immunofluorescence, flow cytometry, immunoblotting, ELISA, RT-qPCR and dual-luciferase reporter assays were used to determine mitochondrial functions, cell apoptosis, cytokine secretion and gene transcription.

KEY FINDINGS

ICTD augments the transcriptional activity and protein secretion of tubular IGFBP-7, which enables an auto- and paracrine signalling via deactivation of IGF-1 receptor (IGF-1R). Genetic knockout (KO) of IGFBP-7 provides renal protection, improves survival and resolves inflammation in murine models of cecal ligation and puncture (CLP), while administering recombinant IGFBP-7 aggravates ICTD and inflammatory invasion. IGFBP-7 perpetuates ICTD in a NIX/BNIP3-indispensable fashion through dampening mitophagy that restricts redox robustness and preserves mitochondrial clearance programs. Adeno-associated viral vector 9 (AAV9)-NIX short hairpin RNA (shRNA) delivery ameliorates the anti-septic AKI phenotypes of IGFBP-7 KO. Activation of BNIP3-mediated mitophagy by mitochonic acid-5 (MA-5) effectively attenuates the IGFBP-7-dependent ICTD and septic AKI in CLP mice.

SIGNIFICANCE

Our findings identify IGFBP-7 is an auto- and paracrine manipulator of NIX-mediated mitophagy for ICTD escalation and propose that targeting the IGFBP-7-dependent ICTD represents a novel therapeutic strategy against septic AKI.

Insulin-like growth factor-binding protein-7 (IGFBP7) links senescence to heart failure

Heart failure (HF) is a rising global cardiovascular epidemic driven by aging and chronic inflammation. As elderly populations continue to increase, precision treatments for age-related cardiac decline are urgently needed. Here we report that cardiac and blood expression of IGFBP7 is robustly increased in patients with chronic HF and in an HF mouse model. In a pressure overload mouse HF model, Igfbp7 deficiency attenuated cardiac dysfunction by reducing cardiac inflammatory injury, tissue fibrosis and cellular senescence. IGFBP7 promoted cardiac senescence by stimulating IGF-1R/IRS/AKT-dependent suppression of FOXO3a, preventing DNA repair and reactive oxygen species (ROS) detoxification, thereby accelerating the progression of HF. In vivo, AAV9-shRNA-mediated cardiac myocyte Igfbp7 knockdown indicated that myocardial IGFBP7 directly regulates pathological cardiac remodeling. Moreover, antibody-mediated IGFBP7 neutralization in vivo reversed IGFBP7-induced suppression of FOXO3a, restored DNA repair and ROS detoxification signals and attenuated pressure-overload-induced HF in mice. Consequently, selectively targeting IGFBP7-regulated senescence pathways may have broad therapeutic potential for HF.

Insulin-like growth factor binding protein 7 (IGFBP7), a link between heart failure and senescence

AIMS

Insulin like growth factor binding protein 7 (IGFBP7) is a marker of senescence secretome and a novel biomarker in patients with heart failure (HF). We evaluated the prognostic value of IGFBP7 in patients with heart failure and examined associations to uncover potential new pathophysiological pathways related to increased plasma IGFBP7 concentrations.

METHODS AND RESULTS

We have measured plasma IGFBP7 concentrations in 2250 subjects with new-onset or worsening heart failure (BIOSTAT-CHF cohort). Higher IGFBP7 plasma concentrations were found in older subjects, those with worse kidney function, history of atrial fibrillation, and diabetes mellitus type 2, and in subjects with higher number of HF hospitalizations. Higher IGFBP7 levels also correlate with the levels of several circulating biomarkers, including higher NT-proBNP, hsTnT, and urea levels. Cox regression analyses showed that higher plasma IGFBP7 concentrations were strongly associated with increased risk of all three main endpoints (hospitalization, all-cause mortality, and combined hospitalization and mortality) (HR 1.75, 95% CI 1.25-2.46; HR 1.71, 95% CI 1.39-2.11; and HR 1.44, 95% CI 1.23-1.70, respectively). IGFBP7 remained a significant predictor of these endpoints in patients with both reduced and preserved ejection fraction. Likelihood ratio test showed significant improvement of all three risk prediction models, after adding IGFBP7 (P < 0.001). A biomarker network analysis showed that IGFBP7 levels activate different pathways involved in the regulation of the immune system. Results were externally validated in BIOSTAT-CHF validation cohort.

CONCLUSIONS

IGFPB7 presents as an independent and robust prognostic biomarker in patients with HF, with both reduced and preserved ejection fraction. We validate the previously published data showing IGFBP7 has correlations with a number of echocardiographic markers. Lastly, IGFBP7 pathways are involved in different stages of immune system regulation, linking heart failure to senescence pathways.

Blood-Based Biomarkers to Search for Atrial Fibrillation in High-Risk Asymptomatic Individuals and Cryptogenic Stroke Patients

Background

Atrial fibrillation (AF) increases the risk of ischemic stroke in asymptomatic individuals and may be the underlying cause of many cryptogenic strokes. We aimed to test the usefulness of candidate blood-biomarkers related to AF pathophysiology in two prospective cohorts representative of those populations.

Methods

Two hundred seventy-four subjects aged 65–75 years with hypertension and diabetes from the AFRICAT cohort, and 218 cryptogenic stroke patients aged >55 years from the CRYPTO-AF cohort were analyzed. AF was assessed by 4 weeks of monitoring with a wearable Holter device (NuuboTM™). Blood was collected immediately before monitoring started. 10 candidate biomarkers were measured by automated immunoassays (Roche, Penzberg) in the plasma of all patients. Univariate and logistic regression analyses were performed in each cohort separately.

Results

Atrial fibrillation detection rate was 12.4% (AFRICAT cohort) and 22.9% (CRYPTO-AF cohort). 4 biomarkers were significantly increased in asymptomatic individuals with AF [Troponin-T, Angiopoietin-2 (Ang-2), Endocan, and total N-terminal pro-B type natriuretic peptide (NT-proBNP)] and 7 biomarkers showed significantly higher concentrations in cryptogenic stroke patients with AF detection [growth differentiation factor 15, interleukin 6, Troponin-T, Ang-2, Bone morphogenic protein 10, Dickkopf-related protein 3 (DKK-3), and total NT-proBNP]. The models including Ang-2 and total NT-proBNP [AUC 0.764 (0.665–0.863)], and Ang-2 and DKK-3 [AUC = 0.733 (0.654–0.813)], together with age and sex, showed the best performance to detect AF in high-risk asymptomatic individuals, and in cryptogenic stroke patients, respectively.

Conclusion

Blood-biomarkers, in particular, total NT-proBNP, DKK-3, and Ang-2, were associated with AF reflecting two mechanistically different pathways involved in AF pathophysiology (AF stretch and vascular changes). The combination of these biomarkers could be useful in AF screening strategies in the primary care setting and also for searching AF after cryptogenic stroke.

IGFBP7 Concentration May Reflect Subclinical Myocardial Damage and Kidney Function in Patients with Stable Ischemic Heart Disease

The objective of this study was to determine the associations between insulin-like growth-factor-binding protein 7(IGFBP7) concentrations and concentrations of troponin T(TnT), N-terminal pro-B-type natriuretic peptide(NT-proBNP) and the parameters of kidney function in patients with stable ischemic heart disease(IHD). The IHD group consisted of 88 patients, and the population group comprised 66 subjects without a history of IHD. IGFBP7, TnT and NTproBNP concentrations were measured. The IGFBP7 value was considerably higher in the IHD group (1.76 ± 1 ng/mL vs. 1.43 ± 0.44 ng/mL, respectively, p = 0.019). Additionally, IHD subjects had a significantly higher concentration of TnT and NTproBNP. In both groups there was a significant correlation between IGFBP7 and serum parameters of kidney function (creatinine concentration: population gr. r = 0.45, p < 0.001, IHD gr. r = 0.86, p < 0.0001; urea concentration: population gr. r = 0.51, p < 0.0001, IHD gr. r = 0.71, p < 0.00001). No correlation between IGFBP7 and microalbuminuria or the albumin to creatinine ratio in urine was found. Moreover, there was a significant correlation between IGFBP7 concentration and markers of heart injury/overload-TnT and NT-BNP(r = 0.76, p < 0.001 and r = 0.72, p < 0.001, respectively). Multivariate regression analysis in joint both revealed that the IGFBP7 concentration is independently associated with urea, creatinine and TnT concentrations (R2 for the model 0.76). IHD patients presented significantly higher IGFBP7 concentrations than the population group. Elevated IGFBP7 levels are associated predominantly with markers of kidney function and myocardial damage or overload.

Multiple Cardiac Biomarker Testing Among Patients With Acute Dyspnea From the ICON-RELOADED Study

BACKGROUND

Among patients with acute dyspnea, concentrations of N-terminal pro-B-type natriuretic peptide (NT-proBNP), high-sensitivity cardiac troponin T, and insulin-like growth factor binding protein-7 predict cardiovascular outcomes and death. Understanding the optimal means to interpret these elevated biomarkers in patients presenting with acute dyspnea remains unknown.

METHODS AND RESULTS

Concentrations of NT-proBNP, high-sensitivity cardiac troponin T, and insulin-like growth factor binding protein-7 were analyzed in 1448 patients presenting with acute dyspnea from the prospective, multicenter International Collaborative of NT-proBNP-Re-evaluation of Acute Diagnostic Cut-Offs in the Emergency Department (ICON-RELOADED) Study. Eight biogroups were derived based upon patterns in biomarker elevation at presentation and compared for differences in baseline characteristics. Of 441 patients with elevations in all 3 biomarkers, 218 (49.4%) were diagnosed with acute heart failure (HF). The frequency of acute HF diagnosis in this biogroup was higher than those with elevations in 2 biomarkers (18.8%, 44 of 234), 1 biomarker (3.8%, 10 of 260), or no elevated biomarkers (0.4%, 2 of 513). The absolute number of elevated biomarkers on admission was prognostic of the composite end point of mortality and HF rehospitalization. In adjusted models, patients with one, 2, and 3 elevated biomarkers had 3.74 (95% confidence interval [CI], 1.26-11.1, P = .017), 12.3 (95% CI, 4.60-32.9, P < .001), and 12.6 (95% CI, 4.54-35.0, P < .001) fold increased risk of 180-day mortality or HF rehospitalization.

CONCLUSIONS

A multimarker panel of NT-proBNP, hsTnT, and IGBFP7 provides unique clinical, diagnostic, and prognostic information in patients presenting with acute dyspnea. Differences in the number of elevated biomarkers at presentation may allow for more efficient clinical risk stratification of short-term mortality and HF rehospitalization.

IGFBP7 and GDF-15, but not P1NP, are associated with cardiac alterations and 10-year outcome in an elderly community-based study

Background

Little is known about the clinical value of Insulin-like growth factor-binding protein-7 (IGFBP7), a cellular senescence marker, in an elderly general population with multiple co-morbidities and high prevalence of asymptomatic cardiovascular ventricular dysfunction. Inflammation and fibrosis are hallmarks of cardiac aging and remodelling. Therefore, we assessed the clinical performance of IGFBP7 and two other biomarkers reflecting these pathogenic pathways, the growth differentiation factor-15 (GFD-15) and amino-terminal propeptide of type I procollagen (P1NP), for their association with cardiac phenotypes and outcomes in the PREDICTOR study.

Methods

2001 community-dwelling subjects aged 65–84 years who had undergone centrally-read echocardiography, were selected through administrative registries. Atrial fibrillation (AF) and 4 echocardiographic patterns were assessed: E/e’ (> 8), enlarged left atrial area, left ventricular hypertrophy (LVH) and reduced midwall circumference shortening (MFS). All-cause and cardiovascular mortality and hospitalization were recorded over a median follow-up of 10.6 years.

Results

IGFBP7 and GDF-15, but not P1NP, were independently associated with prevalent AF and echocardiographic variables after adjusting for age and sex. After adjustment for clinical risk factors and cardiac patterns or NT-proBNP and hsTnT, both IGFBP7 and GDF-15 independently predicted all-cause mortality, hazard ratios 2.13[1.08–4.22] and 2.03[1.62–2.56] per unit increase of Ln-transformed markers, respectively.

Conclusions

In a community-based elderly cohort, IGFBP7 and GDF-15 appear associated to cardiac alterations as well as to 10-year risk of all-cause mortality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02138-8.

Economic Evaluation of an N-terminal Pro B-type Natriuretic Peptide-Supported Diagnostic Strategy Among Dyspneic Patients Suspected of Acute Heart Failure in the Emergency Department

Our objective was to perform an economic evaluation of an N-terminal pro B-type natriuretic peptide (NT-proBNP)-supported diagnostic strategy in dyspneic patients suspected of acute heart failure in the emergency department (ED). A decision-tree model was developed to evaluate clinical outcomes and costs for NT-proBNP-supported assessment compared with clinical assessment alone over 6 months from the United States (US) Medicare perspective. The model considered rule-in/rule-out cutoffs identified in the ICON and ICON-RELOADED studies. Acute heart failure prevalence, diagnostic accuracies, and medical resource use conditional on disease status and test results were derived from ICON-RELOADED. Several assumptions based on previous studies of NT-proBNP acute dyspnea and verified with clinicians were applied to medical resource use and assessed in sensitivity analyses. Compared with clinical assessment alone, NT-proBNP-supported assessment improved overall probability of correct diagnosis by a relative 7% (18% for true-positive and 5% for true-negative). This led to relative reductions in medical resource use in ED and hospital, including fewer initial hospitalizations (-14%), required echocardiograms (-31%), cardiology admissions (-16%), intensive care unit admissions (-12%), ED readmissions (-3%), and hospital readmissions (-22%). NT-proBNP use decreased average inpatient management costs by a relative 10%, yielding cost savings of US$2,337 per patient ED visit. These findings were robust in sensitivity analyses. In conclusion, based on a contemporary trial of patients with acute dyspnea, this analysis reaffirmed that using NT-proBNP as a diagnostic tool may improve the management of patients with dyspnea presenting to EDs and is likely to be cost-saving from the US Medicare perspective.

Biomarkers in Acute Heart Failure: Diagnosis, Prognosis, and Treatment

Heart failure is a global health problem. An episode of acute heart failure (AHF) is a period of substantial morbidity and mortality with few advances in the management of an episode that have improved outcomes. The measurement of multiple biomarkers has become an integral adjunctive tool for the management of AHF. Many biomarkers are now well established in their ability to assist with diagnosis and prognostication of an AHF patient. There are also emerging biomarkers that are showing significant promise in the areas of diagnosis and prognosis. For improving the management of AHF, both established and novel biomarkers may assist in guiding medical therapy and subsequently improving outcomes. Thus, it is important to understand the different abilities and limitations of established and emerging biomarkers in AHF so that they may be correctly interpreted and integrated into clinical practice for AHF. This knowledge may improve the care of AHF patients. This review will summarize the evidence of both established and novel biomarkers for diagnosis, prognosis and management in AHF so that the treating clinician may become more comfortable incorporating these biomarkers into clinical practice in an evidence-based manner.

Insulin-Like Growth Factor Binding Protein 7 Predicts Renal and Cardiovascular Outcomes in the Canagliflozin Cardiovascular Assessment Study

OBJECTIVE

To analyze the association between concentrations of plasma insulin-like growth factor binding protein 7 (IGFBP7) with renal and cardiac outcomes among participants with type 2 diabetes and high cardiovascular risk.

RESEARCH DESIGN AND METHODS

Associations between IGFBP7 levels and clinical outcomes were assessed among participants in the Canagliflozin Cardiovascular Assessment Study (CANVAS) with type 2 diabetes and high cardiovascular risk.

RESULTS

Among CANVAS participants, 3,577 and 2,898 had IGFBP7 measured at baseline and 1 year, respectively. Per log-unit higher concentration, baseline IGFBP7 was significantly associated with the composite renal end point of sustained 40% reduction in estimated glomerular filtration rate, need for renal replacement therapy, or renal death (hazard ratio [HR] 3.51; P < 0.001) and the composite renal end point plus cardiovascular death (HR 4.90; P < 0.001). Other outcomes, including development or progression of albuminuria, were also predicted by baseline IGFBP7. Most outcomes were improved by canagliflozin regardless of baseline IGFBP7; however, those with baseline concentrations ≥96.5 ng/mL appeared to benefit more from canagliflozin relative to the first progression of albuminuria compared with those with lower baseline IGFBP7 (HR 0.64 vs. 0.95; P _interaction = 0.003). Canagliflozin did not lower IGFBP7 concentrations by 1 year; however, at 1 year, higher IGFBP7 concentrations more strongly predicted the composite renal end point (HR 15.7; P < 0.001). Patients with rising IGFBP7 between baseline and 1 year had the highest number of composite renal events.

CONCLUSIONS

Plasma IGFBP7 concentrations predicted renal and cardiac events among participants with type 2 diabetes and high cardiovascular risk. More data are needed regarding circulating IGFBP7 and progression of diabetic kidney disease and its complications.