Amino-Terminal Pro-Brain Natriuretic Peptide, Renal Function, and Outcomes in Acute Heart Failure

Practical algorithms for early diagnosis of heart failure and heart stress using NT-proBNP: A clinical consensus statement from the Heart Failure Association of the ESC

Diagnosing heart failure is often difficult due to the non-specific nature of symptoms, which can be caused by a range of medical conditions. Natriuretic peptides (NPs) have been recognized as important biomarkers for diagnosing heart failure. This document from the Heart Failure Association examines the practical uses of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in various clinical scenarios. The concentrations of NT-proBNP vary according to the patient profile and the clinical scenario, therefore values should be interpreted with caution to ensure appropriate diagnosis. Validated cut-points are provided to rule in or rule out acute heart failure in the emergency department and to diagnose de novo heart failure in the outpatient setting. We also coin the concept of 'heart stress' when NT-proBNP levels are elevated in an asymptomatic patient with risk factors for heart failure (i.e. diabetes, hypertension, coronary artery disease), underlying the development of cardiac dysfunction and further increased risk. We propose a simple acronym for healthcare professionals and patients, FIND-HF, which serves as a prompt to consider heart failure: Fatigue, Increased water accumulation, Natriuretic peptide testing, and Dyspnoea. Use of this acronym would enable the early diagnosis of heart failure. Overall, understanding and utilizing NT-proBNP levels will lead to earlier and more accurate diagnoses of heart failure ultimately improving patient outcomes and reducing healthcare costs.

Copeptin, Natriuretic Peptides, and Cardiovascular Outcomes in Patients With CKD: The German Chronic Kidney Disease (GCKD) Study

Rationale & Objective

Copeptin and Midrange pro-atrial natriuretic peptide (MR-pro-ANP) are associated with outcomes independently of N-terminal pro-brain natriuretic peptide (NT-pro-BNP) in patients with heart failure (HF). The value of these markers in patients with chronic kidney disease (CKD) has not been studied.

Study Design

Prospective cohort study.

Setting & Participants

A total of 4,417 patients enrolled in the German Chronic Kidney Disease (GCKD) study with an estimated glomerular filtration rate of 30-60 mL/min/1.73m2 or overt proteinuria (urinary albumin-creatinine ratio >300mg/g or equivalent).

Exposures

Copeptin, MR-pro-ANP, and NT-pro-BNP levels were measured in baseline samples.

Outcomes

Noncardiovascular death, cardiovascular (CV) death, major adverse CV event (MACE), and hospitalization for HF.

Analytical Approach

HRs for associations of Copeptin, MR-pro-ANP, and NT-pro-BNP with outcomes were estimated using Cox regression analyses adjusted for established risk factors.

Results

During a maximum follow-up of 6.5 years, 413 non-CV deaths, 179 CV deaths, 519 MACE, and 388 hospitalizations for HF were observed. In Cox regression analyses adjusted for established risk factors, each one of the 3 markers were associated with all the 4 outcomes, albeit the highest HRs were found for NT-pro-BNP. When models were extended to include all the 3 markers, NT-pro-BNP remained associated with all 4 outcomes. Conversely, from the 2 novel markers, associations remained only for Copeptin with non-CV death (HR, 1.62; 95% CI, 1.04-2.54 for highest vs lowest quintile) and with hospitalizations for HF (HR, 1.73; 95% CI, 1.08-2.75).

Limitations

Single-point measurements of Copeptin, MR-pro-ANP, and NT-pro-BNP.

Conclusions

In patients with moderately severe CKD, we confirm NT-pro-BNP to be strongly associated with all outcomes examined. As the main finding, the novel marker Copeptin demonstrated independent associations with non-CV death and hospitalizations for HF, and should therefore be evaluated further for risk assessment in CKD.

Plain-Language Summary

A blood sample-based biomarker that indicates high cardiovascular risk in a patient with kidney disease would help to guide interventions and has the potential to improve outcomes. In 4,417 patients of the German Chronic Kidney Disease study, we assessed the relationship of Copeptin, pro-atrial natriuretic peptide, and N-terminal pro-brain natriuretic peptide (NT-pro-BNP) with important outcomes over a follow-up period of 6.5 years. NT-pro-BNP was strongly associated with all of the 4 outcomes, including death unrelated to cardiovascular disease, death because of cardiovascular disease, a major cardiovascular event, and hospitalization for heart failure. Copeptin was associated with death unrelated to cardiovascular disease and hospitalization for heart failure. NT-pro-BNP and Copeptin are, therefore, promising candidates for a blood sample-based strategy to identify patients with kidney disease at high cardiovascular risk.

New Insight in Cardiorenal Syndrome: From Biomarkers to Therapy

Cardiorenal syndrome consists in the coexistence of acute or chronic dysfunction of heart and kidneys resulting in a cascade of feedback mechanisms and causing damage to both organs associated with high morbidity and mortality. In the last few years, different biomarkers have been investigated with the aim to achieve an early and accurate diagnosis of cardiorenal syndrome, to provide a prognostic role and to guide the development of targeted pharmacological and non-pharmacological therapies. In such a context, sodium-glucose cotransporter 2 (SGLT2) inhibitors, recommended as the first-line choice in the management of heart failure, might represent a promising strategy in the management of cardiorenal syndrome due to their efficacy in reducing both cardiac and renal outcomes. In this review, we will discuss the current knowledge on the pathophysiology of cardiorenal syndrome in adults, as well as the utility of biomarkers in cardiac and kidney dysfunction and potential insights into novel therapeutics.

Recent Developments in the Evaluation and Management of Cardiorenal Syndrome: A Comprehensive Review

Cardiorenal syndrome (CRS) is an increasingly recognized diagnostic entity associated with high morbidity and mortality among acutely ill heart failure (HF) patients with acute and/ or chronic kidney diseases (CKD). While traditionally viewed as a state of decline in glomerular filtration rate (GFR) due to decreased renal perfusion, mainly due to therapeutic interventions to relieve congestive in HF, recent insights into the underlying pathophysiologic mechanisms of CRS led to a broader definition and further classification of CRS into 5 distinct types. In this comprehensive review, we discuss the classification of CRS, highlighting the underlying common pathogenetic pathways of heart failure and kidney injury, including increased congestion, neurohormonal dysregulation, oxidative stress as well as inflammation, and cytokine storm that are particularly evident in COVID-19 patients with multiorgan failure and also in those with other disorders including sepsis, systemic lupus erythematosus and amyloidosis. In this review we also present the recent advances in the diagnostic strategies of CRS including cardiac and renal biomarkers as well as advanced cardiac and renal imaging techniques that are available to aid in the diagnosis as well as in the prognostication of this disorder. Finally, we discuss the various therapeutic options available to-date, including fluid optimization, hemofiltration, renal replacement therapy as well as the role of SGLT2 inhibitors in light of recent data from RCTs. It is important to note that, CRS population are either excluded or underrepresented, at best, in major RCTs and therefore, therapeutic recommendations are largely extrapolated from HF and CKD clinical trials.

Integration of imaging and circulating biomarkers in heart failure: a consensus document by the Biomarkers and Imaging Study Groups of the Heart Failure Association of the European Society of Cardiology

Circulating biomarkers and imaging techniques provide independent and complementary information to guide management of heart failure (HF). This consensus document by the Heart Failure Association (HFA) of the European Society of Cardiology (ESC) presents current evidence-based indications relevant to integration of imaging techniques and biomarkers in HF. The document first focuses on application of circulating biomarkers together with imaging findings, in the broad domains of screening, diagnosis, risk stratification, guidance of treatment and monitoring, and then discusses specific challenging settings. In each section we crystallize clinically relevant recommendations and identify directions for future research. The target readership of this document includes cardiologists, internal medicine specialists and other clinicians dealing with HF patients.

Renal and intraglomerular haemodynamics in chronic heart failure with preserved and reduced ejection fraction

AIMS

Congestive heart failure (CHF) and impaired renal function are two often co-existing medical conditions and associated with adverse cardiovascular outcome. The aim of the current study was to assess renal and intraglomerular haemodynamics by constant infusion input clearance technique in subjects with CHF.

METHODS AND RESULTS

The group of subjects with CHF consisted of 27 individuals with HFpEF and 27 individuals with HFrEF and were compared with 31 healthy controls. Subjects underwent renal clearance examination to measure glomerular filtration rate (GFR) and renal blood and plasma flow (RBF and RPF) and to calculate intraglomerular haemodynamics such as resistances of the afferent (RA ) and efferent arterioles (RE ) as well as intraglomerular pressure (Pglom ). Measured GFR was lower in CHF subjects (68.1 ± 10.1 mL/min/1.73 m2 ) compared with controls (83.6 ± 13.4 mL/min/1.73 m2 , Padj  < 0.001) as was Pglom (Padj  < 0.001). Total renal vascular resistance (RVR) was higher in CHF subjects (87.3 ± 20.1 vs. 73.8 ± 17.1 dyn × s/cm5 , Padj  < 0.001) mediated by an increased resistance at the afferent site (3201 ± 1084 vs. 2181 ± 796 dyn × s/cm5 , Padj  < 0.001). Comparing HFpEF and HFrEF subjects, RA was higher in HFrEF subjects. The severity of CHF assessed by NT-proBNP revealed an inverse association with renal perfusion (RPF r = -0.421, P = 0.002, RBF r = -0.414, P = 0.002) and a positive relation with RVR (r = 0.346, P = 0.012) at the post-glomerular site (RE : r = 0.318, P = 0.022).

CONCLUSIONS

Renal function assessed by measured GFR is reduced and renal vascular resistance at the preglomerular, afferent site is increased in HFpEF and, to greater extent, in HFrEF. Our data indicate a close cardiorenal interaction in CHF.

Do Natriuretic Peptide Measurements Provide Insights into Management of End-Stage Renal Disease Patients Undergoing Dialysis?

PURPOSE OF REVIEW

Impaired renal function may affect natriuretic peptide levels through a variety of factors and mechanisms, such as high prevalence of concomitant vascular and myocardial diseases, reduced clearance, increased risk of volume overload, and different types and solute removal techniques in the setting of dialysis. Nevertheless, accumulating evidence suggests that natriuretic peptide testing may provide insights into management of patients with chronic kidney disease (CKD) and end-stage kidney disease (ESRD) on dialysis, as they have been shown to be independently associated with morbidity and mortality.

RECENT FINDINGS

Rising natriuretic peptide levels over time may identify CKD patients more likely to approach ESRD and requiring dialysis initiation. Moreover, serial natriuretic peptide measurements may also be helpful in guiding fluid management in ESRD patients on dialysis. However, since patients with CKD usually have significantly higher and more variable baseline levels of natriuretic peptides than those without CKD, traditional cut-off values may not be applicable, and individualized trajectories should be applied and interpreted in the clinical context. Routine clinical use natriuretic peptide testing in the CKD and ESRD settings still needs to be refined and individualized, yet their diagnostic and prognostic values can provide valuable insights into clinical trajectories and potential treatment responses.

Acute Kidney Injury Induces Remote Cardiac Damage and Dysfunction Through the Galectin-3 Pathway

•

In 2 different mouse models, AKI increased Gal-3 expression and induced cardiac dysfunction, cardiac and systemic inflammation, cardiac macrophage infiltration, and fibrosis.

•

Cardiac consequences of AKI were dependent on the Gal-3 pathway and were prevented using Gal-3 knockout mice or modified citrus pectin as a pharmaceutical inhibitor.

•

Cardiac Gal-3 expression resulted from bone marrow-derived immune cells recruitment after AKI.

•

In critically ill patients, development of AKI is associated with increased plasma Gal-3 levels and increased biomarkers of cardiac injury and damage.

Acute kidney injury is associated with increased risk of heart failure and mortality. This study demonstrates that acute kidney injury induces remote cardiac dysfunction, damage, injury, and fibrosis via a galectin-3 (Gal-3) dependent pathway. Gal-3 originates from bone marrow-derived immune cells. Cardiac damage could be prevented by blocking this pathway.

Predictors of responders for low-dose carperitide monotherapy in patients with acute heart failure

Human atrial natriuretic peptide, known as carperitide, is approved for early relief of dyspnea in patients with acute heart failure (AHF). However, the diuretic effect of carperitide is sometimes insufficient for controlling volume overload. We investigated predictors for the carperitide response in patients with AHF. Forty-seven patients (age: 74 ± 10 years; left ventricular ejection fraction: 42.0% ± 15.9%) with AHF were enrolled and treated with carperitide monotherapy at a dose of 0.0125 μg/kg/min. Patients without sufficient diuresis (< 60 ml/h) or improvement of symptoms by 4 h after carperitide administration, despite increasing to twice the dose of carperitide and adding another agent, were defined as non-responders. Twenty-four (51%) patients were defined as responders and treated with low-dose carperitide monotherapy on the first day. Multiple logistic regression analysis showed that the response to carperitide monotherapy was independently predicted by serum creatinine levels and systolic blood pressure (SBP) on admission. The area under the receiver-operating characteristic curve for predicting the response to carperitide by SBP was 0.808 (95% confidence interval [0.686-0.930], sensitivity: 83.3%, specificity: 65.2%, cutoff value: 135 mmHg). Four (8.5%) patients developed asymptomatic transient hypotension. Worsening renal function occurred within 3 days of admission in three (6.4%) patients who received low-dose carperitide therapy. SBP and serum creatinine levels on admission might be useful for predicting the diuretic response to low-dose carperitide monotherapy in patients with AHF. Initial use of low-dose carperitide therapy does not have adverse effects on renal function.

Cardiorenal status using amino-terminal pro-brain natriuretic peptide and cystatin C on cardiac resynchronization therapy outcomes: From the BIOCRT Study

BACKGROUND

Cardiorenal syndrome comprises a heterogeneous group of disorders characterized by acute or chronic cardiac and renal dysfunction.

OBJECTIVE

The purpose of this study was to determine the effect of cardiorenal status using a dual-marker strategy with amino-terminal pro-brain natriuretic peptide (NT-proBNP) and cystatin C on cardiac resynchronization therapy (CRT) outcomes.

METHODS

In 92 patients (age 66 ± 13 years; 80% male; left ventricular ejection fraction 26% ± 7%), NT-proBNP and cystatin C levels were measured at CRT implantation and at 1 month. NT-proBNP >1000 pg/mL and cystatin C >1 mg/L were considered high. Baseline cardiorenal patients were defined as having high NT-proBNP and cystatin C. At 1 month, CRT patients were categorized as (1) irreversible cardiorenal if cystatin C was persistently high; (2) progressive cardiorenal with transition from low to high cystatin C; (3) reversible cardiorenal with transition from high to low cystatin C; and (4) "normal" with stable low cystatin C. Outcomes were 6-month clinical and echocardiographic CRT response and 2 -year major adverse cardiovascular event (MACE).

RESULTS

Compared to patients with low NT-proBNP and cystatin C, cardiorenal patients had >9-fold increase risk of CRT nonresponse (odds ratio uncompensated 9.0; compensated 36.4; both P ≤.004) and >6-fold risk of MACE (hazard ratio uncompensated 8.5; P = .005). Compared to "normal" and reversible patients (referent), irreversible patients had a 9-fold increase for CRT nonresponse (odds ratio 9.1; P <.001) and had >4-fold risk of MACE (adjusted hazard ratio 5.1; P <.001). Irreversible patients were most likely echocardiographic CRT nonresponders.

CONCLUSION

Cardiorenal status by NT-proBNP and cystatin C can identify high-risk CRT patients, and those with both elevated concentrations have worse prognosis.

The association among biomarkers of renal and heart function in patients with heart failure: the role of NGAL

AIM

The NGAL is a biomarker of renal injury associated with the progression of heart failure (HF). We examine the association of NGAL with galectin-3 in patients with chronic HF.

METHODS

We consecutively enrolled 115 subjects with stable ischemic HF of reduced ejection fraction. Serum levels of galectin-3, b-type natriuretic peptide and NGAL were measured.

RESULTS

NGAL levels were positively correlated with galectin-3 (rho = 0.26; p = 0.04) and b-type natriuretic peptide levels (rho = 0.30; p = 0.005) and inversely correlated with ejection fraction (rho = -0.31; p = 0.02) and creatinine clearance levels. The NGAL was independently associated with galectin-3 levels.

CONCLUSION

A positive correlation between NGAL and galectin-3 in HF patients was found, revealing a potential association between renal injury and myocardial fibrosis and remodeling in HF.

Biomarkers in Cardiorenal Syndromes

There is a consensus that cardiorenal syndromes (CRS) are defined as the disorders of heart and kidney where acute or chronic dysfunction in one organ may induce acute or chronic dysfunction in another. Patients with CRS have increased hospitalization and mortality rates, and thus their identification is of great implication. Biomarkers are not only predictive in heart failure or renal diseases, but also useful in identifying cardiac dysfunction in renal diseases and renal injury in heart failure. Thus, they may be applied in order to identify patients with CRS and even assess prognosis and guide therapy in these patients. However, studies on biomarkers have just begun in CRS. Future studies are essential to observe current biomarkers and find novel biomarkers in CRS so as to improve diagnosis, therapy, and prognosis of CRS.

Predicting new-onset HF in patients undergoing coronary or peripheral angiography: results from the Catheter Sampled Blood Archive in Cardiovascular Diseases (CASABLANCA) study

Aims

Methods to identify patients at risk for incident HF would be welcome as such patients might benefit from earlier interventions.

Methods and results

From a registry of 1251 patients referred for coronary and/or peripheral angiography, we sought to identify independent predictors of incident HF during follow‐up and develop a clinical and biomarker strategy to predict this outcome. There were 991 patients free of prevalent HF at baseline. Cox proportional hazard models were developed to predict adjudicated diagnosis of incident HF. Model discrimination and reclassification were evaluated. At follow‐up, 177 (18%) developed new‐onset HF. Independent predictors of new‐onset HF included five clinical variables (age, male sex, heart rate, history of atrial fibrillation/flutter, and history of hypertension) and two biomarkers (amino‐terminal pro‐B type natriuretic peptide and ST2). The c‐statistic for the model without biomarkers was 0.69; including biomarkers increased the c‐statistic to 0.76 (P < 0.001). A score was developed from the model. Patients in the highest score quintile had shortest time to incident HF compared with lower quintiles (log‐rank P < 0.001). Following 100 bootstrap iterations, internal validation was confirmed with Harrell's c‐statistic of 0.77. Use of angiotensin‐converting enzyme inhibitors, angiotensin receptor blockers, and beta‐blockers at enrollment was associated with substantial attenuation of predictive value of the risk score.

Conclusions

Patients undergoing coronary/peripheral angiographic procedures are a population at high risk for incident HF. We describe an accurate clinical and biomarker strategy for predicting incident HF and possibly intervening in such patients (NCT00842868).

Exploring the relation between changes in NT-proBNP and renal function in patients with suspected heart failure using structural equation modelling

BACKGROUND

The relation between changes in NT-proBNP and renal function has commonly been studied using multiple regressions, which may ignore the complexity of relations between related variables.

METHODS AND RESULTS

Data were collected from patients referred with suspected heart failure (HF) to a community service. Structural equation modelling (SEM) was used to assess the association between changes in NT-proBNP at 1year, and other pre-specified variables including age, sex, BMI, eGFR, loop diuretics and ACE inhibitor. Of 1006 patients with a follow-up NT-proBNP at 1year, 882 (88%) had HF. The baseline median age was 72 (IQR: 63-78) years, 732 (73%) were men, 668 (66%) had left ventricular systolic dysfunction and 769 (76%) had NT-proBNP>400pg/ml. For all patients at 1year, 243 (24%) patients had at least a 50% reduction in NT-proBNP, and 199 (20%) had at least a 50% increase, only 40 (3%) had <3% change. Change in NT-proBNP was strongly associated with baseline NT-proBNP (the standardized coefficient (r)=0.73, p<0.001). The change in NT-proBNP was not associated with changes in eGFR, and was indirectly related with age, BMI, eGFR and loop diuretics (p<0.01 for all).

CONCLUSIONS

Baseline NT-proBNP was the main determinant of change in NT-proBNP at one year.

Improving the diagnostic accuracy of acute myocardial infarction with the use of high-sensitive cardiac troponin T in different chronic kidney disease stages

High-sensitive cardiac troponin T (hs-TnT) is a critical biomarker in diagnosis of acute myocardial infarction (AMI). However, CKD individuals usually have elevated hs-TnT even in the absence of AMI. Our study aimed to explore the optimal cutoff-value of hs-TnT and further to improve diagnostic accuracy of AMI in CKD patients. Clinical data of 489 patients were collected from the maintained database between September 2010 and June 2014. CKD patients with AMI were assigned to CKD+AMI group and CKD patients without AMI were assigned to CKD group. Receiver operating characteristic curves were utilized to derive the optimal cutoff-value. In CKD+STEMI and CKD group, hs-TnT was increased with descending eGFR. In CKD+NSTEMI group, hs-TnT showed an upward trend with increasing SYNTAX Score. In patients with CKD+STEMI, hs-TnT was significantly correlated with SYNTAX Score in CKD stage 2, stage 4 and in total. In CKD patients, the optimal cutoff-value of hs-TnT for diagnosis of AMI was 129.45 ng/l with 75.2% sensitivity and 83.2% specificity. The cutoff-value appeared to be hs-TnT level of 99.55ng/l in CKD stage 3, 129.45 ng/l in CKD stage 4, 105.50 ng/l in CKD stage 5 and 149.35 ng/l in dialysis patients, respectively. In different stages of CKD, eGFR-range-specific optimal cutoff-values should be considered.

Renal dysfunction and chronic mechanical circulatory support: from patient selection to long-term management and prognosis

PURPOSE OF REVIEW

The purpose of this review is to describe the effects of mechanical circulatory support (MCS) on changes in kidney function and their relationship with mortality, with an additional focus on the evaluation and management of both preimplant and post-MCS renal dysfunction.

RECENT FINDINGS

Renal dysfunction is highly prevalent in patients referred for MCS and is associated with significantly increased mortality and postoperative acute kidney injury. Most patients, including those with renal dysfunction, experience marked early improvement in renal function with MCS, likely secondary to correction of the cardiogenic shock, volume overload, and neurohormonal activation characteristic of advanced heart failure. Currently, there are no diagnostic tests to definitively distinguish reversible forms of renal dysfunction likely to improve with MCS from irreversible renal dysfunction. Furthermore, the characteristic improvements in renal function observed in the early months of MCS are often transient, with subsequent recurrence of renal dysfunction with longer durations of support. Venous congestion, right ventricular dysfunction, and reduced pulsatility are potential mechanisms involved in resurgence of renal dysfunction following MCS.

SUMMARY

With the exponential growth of MCS, research endeavors to both improve understanding of the mechanisms behind observed changes in renal function and elucidate the device-related effects on the kidney are imperative.

Interpreting Cardiac Biomarkers in the Setting of Chronic Kidney Disease

BACKGROUND

Chronic kidney disease (CKD) is common, particularly in those of advanced age. Because patients with CKD frequently have cardiac comorbidities and acute or chronic symptoms that may represent heart failure or an acute myocardial infarction (AMI), testing for concentrations of cardiac troponins and natriuretic peptides is frequent. Interpretation of these biomarkers can be challenging when differentiating acute from chronic processes, potentially resulting in missed opportunities to direct appropriate treatment.

CONTENT

This review is designed to provide clinicians and laboratorians a platform to understand cardiac specific biomarker interpretation in patients with CKD by summarizing the extensive literature base that has developed specific to this population. First we review the epidemiology and unique contributions of CKD to cardiac pathophysiology. Next we consider the interpretation of cardiac troponin tests for the diagnosis AMI and the prognostic significance of chronic increases across the spectrum of CKD including those requiring renal replacement therapy. Last, we consider the caveats of interpreting natriuretic peptide results for the diagnosis of acute decompensated heart failure in addition to the short- and long-term prognostic implications of increased natriuretic peptide concentrations and CKD in a patient with heart failure.

SUMMARY

CKD is common and associated with acceleration of cardiovascular disease. Cardiac biomarker concentrations are often increased even in an absence of symptoms; typically reflecting the extent of underlying cardiovascular disease rather than impairment of renal clearance. Thoughtful interpretation of cardiac biomarkers in those with CKD can continue to provide important diagnostic and prognostic information.

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.

Amino-Terminal Pro-B-Type Natriuretic Peptide for Diagnosis and Prognosis in Patients With Renal Dysfunction: A Systematic Review and Meta-Analysis

OBJECTIVES

This study sought to determine if amino-terminal pro-B-type natriuretic peptide (NT-proBNP) has different diagnostic and prognostic utility in patients with renal dysfunction.

BACKGROUND

Patients with renal dysfunction have higher NT-proBNP, which may complicate interpretation for diagnosis of acute decompensated heart failure (ADHF) or prognosis.

METHODS

We searched MEDLINE and EMBASE through August 2014 for studies with a subgroup analysis by renal function of the diagnostic or prognostic ability of NT-proBNP.

RESULTS

For diagnosis, 9 studies were included with 4,287 patients and 1,325 ADHF events. Patients were mostly divided into subgroups with and without renal dysfunction by an estimated glomerular filtration rate of 60 ml/min/1.73 m(2). In patients with renal dysfunction, the area under the curve (AUC) for NT-proBNP ranged from 0.66 to 0.89 with a median cutpoint of 1,980 pg/ml, while the AUC ranged from 0.72 to 0.95 with a cutpoint of 450 pg/ml in patients with preserved renal function. For prognosis, 30 studies with 32,203 patients were included, and mortality in patients with renal dysfunction (25.4%) was twice that of patients with preserved renal function (12.2%). The unadjusted pooled risk ratio for NT-proBNP and mortality was 3.01 (95% confidence interval [CI]: 2.53 to 3.58) in patients with preserved renal function and was similar in patients with renal dysfunction (3.25; 95% CI: 2.45 to 4.30). Upon meta-regression, heterogeneity was partially explained if patients with heart failure or coronary artery disease were enrolled.

CONCLUSIONS

NT-proBNP retains utility for diagnosis of ADHF in patients with renal dysfunction with higher cutpoints. Elevated NT-proBNP confers a worse prognosis regardless of renal function.

The kidney in heart failure: an update

Heart and kidney are closely related in the clinical syndrome of heart failure (HF). It is now sufficiently clear that renal dysfunction occurs frequently in all phenotypes of HF, and when present, it is associated with higher mortality and morbidity. While the pathophysiology is multifactorial, the most important factors are a reduced renal perfusion and venous congestion. Recent interest has focused on worsening renal function (WRF), a situation strongly related to mortality, but seemingly only when HF status deteriorates. Unfortunately, to date clinicians are unable to identify specifically those patients with a grim prognosis following WRF. Although much has been learned on cardiorenal interaction in HF, still more questions have been left unanswered. The coming decade should provide us with more dedicated epidemiologic, mechanistic, and controlled trials in HF patients with reduced renal function. An updated classification of the cardiorenal syndrome that incorporates recent evidence and points towards areas of interest and uncertainties, and areas where progress is needed could facilitate this process. Ultimately, this should lead to preventive and treatment strategies that can preserve renal function and associated outcome in patients with HF.

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.

Novel markers and therapies for patients with acute heart failure and renal dysfunction

BACKGROUND

Acute kidney injury complicates decompensated heart failure in ∼33% of cases and is associated with morbidity and mortality; thus, we sought to systematically review this topic in order to summarize novel diagnostic and therapeutic approaches.

METHODS

Structured PubMed searches on these topics were conducted in February 2014 and relevant literature was identified. The PubMed search identified a total of 192 articles that were individually screened for inclusion in this analysis, and 58 were included.

RESULTS

Acute kidney injury, defined by substantial increases in serum creatinine, is associated consistently with prolonged length of stay, rehospitalization, and mortality. Biomarker studies suggested that natriuretic peptides are prognostic for shorter- and longer-term mortality. Novel proteins indicating kidney damage and albumin in the urine are associated with acute kidney injury. The most promising acute pharmacologic treatment appears to be serelaxin, which has been shown to improve acute heart failure symptoms, hemodynamic parameters, and renal function.

CONCLUSIONS

The presence of acute kidney injury results in worse clinical outcomes for patients with acute heart failure. Novel biomarkers and therapies hold the promise of improving both cardiac and renal outcomes in these patients.

Urinary Angiotensinogen Level Predicts AKI in Acute Decompensated Heart Failure: A Prospective, Two-Stage Study

A major challenge in prevention and early treatment of acute cardiorenal syndrome (CRS) is the lack of high-performance predictors. To test the hypothesis that urinary angiotensinogen (uAGT) is an early predictor for acute CRS and 1-year prognosis in patients with acute decompensated heart failure (ADHF), we performed a prospective, two-stage, multicenter cohort study in patients with ADHF. In stage I (test set), 317 patients were recruited from four centers. In stage II (validation set), 119 patients were enrolled from two other centers. Daily uAGT levels were analyzed consecutively. AKI was defined according to Kidney Disease Improving Global Outcomes (KDIGO) Clinical Practice Guidelines. In stage I, 104 (32.8%) patients developed AKI during hospitalization. Daily uAGT peaked on the first hospital day in patients who subsequently developed AKI. After multivariable adjustment, the highest quartile of uAGT on admission was associated with a 50-fold increased risk of AKI compared with the lowest quartile. For predicting AKI, uAGT (area under the receiver-operating characteristic curve [AUC]=0.84) outperformed urinary neutrophil gelatinase-associated lipocalin (AUC=0.78), the urinary albumin/creatinine ratio (AUC=0.71), and the clinical model (AUC=0.77). Survivors in stage I were followed prospectively for 1 year after hospital discharge. The uAGT level independently predicted the risk of 1-year mortality (adjusted odds ratio, 4.5; 95% confidence interval, 2.1 to 9.5) and rehospitalization (adjusted odds ratio, 3.6; 95% confidence interval, 1.6 to 5.7). The ability of uAGT in predicting AKI was validated in stage II (AUC=0.79). In conclusion, uAGT is a strong predictor for acute CRS and 1-year prognosis in ADHF.

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.

Novel renal biomarkers to assess cardiorenal syndrome

Renal dysfunction (RD) in heart failure portends adverse outcomes and often limits aggressive medical and decongestive therapies. Despite the high prevalence in this population, not all forms of RD are prognostically or mechanistically equivalent: RD can result from irreversible nephron loss secondary to diabetic or hypertensive kidney disease or it can develop secondary to heart failure (HF) itself, i.e., the cardiorenal syndrome. Furthermore, filtration is only one aspect of renal performance such that significant renal impairment secondary to cardiorenal syndrome can exist despite a normal glomerular filtration rate. Renal biomarkers have the potential to inform some of the intricacies involved in accurately assessing cardiorenal interactions. This article discusses novel biomarkers for cardiorenal syndrome and their utility in the prognosis, diagnosis, and targeted treatment of heart failure-induced RD.

Prognostic markers of acute decompensated heart failure: the emerging roles of cardiac biomarkers and prognostic scores

Rapidly assessing outcome in patients with acute decompensated heart failure is important but prognostic factors may differ from those used routinely for stable chronic heart failure. Multiple plasma biomarkers, besides the classic natriuretic peptides, have recently emerged as potential prognosticators. Furthermore, prognostic scores that combine clinical and biochemical data may also be useful. However, compared with the scores used in chronic heart failure, scores for acute decompensated heart failure have not been validated. This article reviews potential biomarkers, with a special focus on biochemical biomarkers, and possible prognostic scores that could be used by the clinician when assessing outcome in patients with acute heart failure.

A combined-biomarker approach to clinical phenotyping renal dysfunction in heart failure

BACKGROUND

Differentiating heart failure (HF) induced renal dysfunction (RD) from intrinsic kidney disease is challenging. It has been demonstrated that biomarkers such as B-type natriuretic peptide (BNP) or the blood urea nitrogen to creatinine ratio (BUN/creat) can identify high- vs low-risk RD. Our objective was to determine if combining these biomarkers could further improve risk stratification and clinical phenotyping of patients with RD and HF.

METHODS AND RESULTS

A total of 908 patients with a discharge diagnosis of HF were included. Median values were used to define elevated BNP (>1296 pg/mL) and BUN/creat (>17). In the group without RD, survival was similar regardless of BNP and BUN/creat (n = 430, adjusted P = .52). Similarly, in patients with both a low BNP and BUN/creat, RD was not associated with mortality (n = 250, adjusted hazard ratio [HR] = 1.0, 95% confidence interval [CI] 0.6-1.6, P = .99). However, in patients with both an elevated BNP and BUN/creat those with RD had a cardiorenal profile characterized by venous congestion, diuretic resistance, hypotension, hyponatremia, longer length of stay, greater inotrope use, and substantially worse survival compared with patients without RD (n = 249, adjusted HR = 1.8, 95% CI 1.2-2.7, P = .008, P interaction = .005).

CONCLUSIONS

In the setting of decompensated HF, the combined use of BNP and BUN/creat stratifies patients with RD into groups with significantly different clinical phenotypes and prognosis.

N-terminal pro-brain natriuretic peptide is a useful prognostic marker in patients with pre-capillary pulmonary hypertension and renal insufficiency

N-terminal pro-brain natriuretic peptide (NT-proBNP) is a routinely used prognostic parameter in patients with pre-capillary pulmonary hypertension (PH). As it accumulates in the presence of impaired renal function, the clinical utility of NT-proBNP in PH patients with concomitant renal insufficiency remains unclear. In a retrospective approach, patients with pre-capillary PH (group I or IV) and concomitant renal insufficiency at time of right heart catheterization (glomerular filtration rate (GFR) ≤60 ml/min/1.73 m²) were identified out of all prevalent pre-capillary PH patients treated at a single center. Forty patients with renal insufficiency (25.8%) were identified and matched regarding hemodynamic parameters with a control group of 56 PH patients with normal renal function (GFR >60 ml/min/1.73 m²). Correlations of NT-proBNP levels with hemodynamic and prognostic parameters (time to clinical worsening and overall survival) were assessed. Overall, GFR correlated inversely with NT-proBNP and had the strongest influence on NT-proBNP levels in a stepwise multiple linear regression model including hemodynamic parameters and age (r² = 0.167). PH patients with renal insufficiency had significant higher levels of NT-proBNP (median: 1935 ng/l vs. 573 ng/l, p = 0.001). Nevertheless, NT-proBNP correlated with invasive hemodynamic parameters in these patients. Using higher cut-off values than in patients with preserved renal function, NT-proBNP levels were significantly associated with time to clinical worsening (>1660 ng/l, p = 0.001) and survival (>2212 ng/l, p = 0.047) in patients with renal insufficiency. Multivariate Cox’s proportional hazards analysis including established prognostic parameters, age and GFR confirmed NT-proBNP as an independent risk factor for clinical worsening in PH patients with renal insufficiency (hazard ratio 4.8, p = 0.007). Thus, in a retrospective analysis we showed that NT-proBNP levels correlated with hemodynamic parameters and outcome regardless of renal function. By using higher cut-off values, NT-proBNP seems to represent a valid clinical marker even in PH patients with renal insufficiency.

Effect of B-type natriuretic peptide-guided treatment of chronic heart failure on total mortality and hospitalization: an individual patient meta-analysis

Aims

Natriuretic peptide-guided (NP-guided) treatment of heart failure has been tested against standard clinically guided care in multiple studies, but findings have been limited by study size. We sought to perform an individual patient data meta-analysis to evaluate the effect of NP-guided treatment of heart failure on all-cause mortality.

Methods and results

Eligible randomized clinical trials were identified from searches of Medline and EMBASE databases and the Cochrane Clinical Trials Register. The primary pre-specified outcome, all-cause mortality was tested using a Cox proportional hazards regression model that included study of origin, age (<75 or ≥75 years), and left ventricular ejection fraction (LVEF, ≤45 or >45%) as covariates. Secondary endpoints included heart failure or cardiovascular hospitalization. Of 11 eligible studies, 9 provided individual patient data and 2 aggregate data. For the primary endpoint individual data from 2000 patients were included, 994 randomized to clinically guided care and 1006 to NP-guided care. All-cause mortality was significantly reduced by NP-guided treatment [hazard ratio = 0.62 (0.45–0.86); P = 0.004] with no heterogeneity between studies or interaction with LVEF. The survival benefit from NP-guided therapy was seen in younger (<75 years) patients [0.62 (0.45–0.85); P = 0.004] but not older (≥75 years) patients [0.98 (0.75–1.27); P = 0.96]. Hospitalization due to heart failure [0.80 (0.67–0.94); P = 0.009] or cardiovascular disease [0.82 (0.67–0.99); P = 0.048] was significantly lower in NP-guided patients with no heterogeneity between studies and no interaction with age or LVEF.

Conclusion

Natriuretic peptide-guided treatment of heart failure reduces all-cause mortality in patients aged <75 years and overall reduces heart failure and cardiovascular hospitalization.

Cardiac biomarkers in heart failure

BACKGROUND

Heart failure is a syndrome characterized by the inability of the heart to meet the body's circulatory demands. Heart failure is a growing health issue worldwide and the prevalence of heart failure is expected to rise as populations age. Therapies and interventions for a variety of cardiac conditions continue to advance and biomarkers will play an increasing role in patient management.

METHODS

This is a review of the clinical research in blood based biomarkers for diagnosis, prognosis and therapeutic guidance of heart failure. The focus of this review is biomarkers that are currently available for clinical measurement, and their current and potential for applications for managing heart failure patients.

RESULTS

The various biologic pathways and physiologic processes of heart failure biomarkers represent a host of different including inflammation, remodeling, strain, neurohormonal activation, metabolism and cardiac myocyte injury. The clinical characteristics and applications of each heart failure biomarker are discussed.

CONCLUSION

As populations age and effective treatments and interventions for coronary artery disease improve, heart failure will increase in incidence and prevalence. Blood biomarkers will play an increasing role in the early diagnosis, therapeutic monitoring and management of heart failure patients in the future.

Clinical features of patients with stress-induced cardiomyopathy associated with renal dysfunction: 7 case series in single center

Background

Stress-induced cardiomyopathy (sCMP) is characterized by transient wall-motion abnormalities involving the left ventricular apex and mid-ventricle that are precipitated by emotional or physical stress. As the heart and kidney influence each other’s function through bidirectional pathways, sCMP can induce renal dysfunction or be induced by renal dysfunction. This study reviewed the clinical characteristics and outcomes of patients with confirmed sCMP associated with renal dysfunction.

Methods

We conducted a retrospective analysis of the medical records of all patients from our institution who were diagnosed with sCMP from March 2010 to April 2012. Each patient’s demographic characteristics, presenting symptoms, triggering events, electrocardiographic characteristics, laboratory data, echocardiographic study findings, cardiac catheterization data, and outcomes were reviewed.

Results

Among 30 patients who were diagnosed with sCMP, 7 patients had associated renal dysfunction. Three patients were on maintenance hemodialysis (HD) and 4 patients had acute kidney injury (AKI). Their mean ejection fraction was 35.2% at initial echocardiography, and 57.2% at follow-up echocardiography. Pericardial effusion was detected in all HD patients initially; these patients were treated with intensive HD for suspected under-dialysis status. In patients with AKI, the mean peak serum creatinine was 4.17 mg/dL. Two patients were treated with continuous renal replacement therapy. One patient required maintenance HD, and 1 patient died. Two patients had full renal recovery to their baseline renal function at 7 and 14 days.

Conclusions

Patients with renal dysfunction including those with AKI and those undergoing HD can develop sCMP, renal function must be closely monitored in patients with sCMP. Additionally, it should be considered that patients on HD who develop sCMP may be under-dialyzed.