Utility of Urine Neutrophil Gelatinase-Associated Lipocalin for Worsening Renal Function during Hospitalization for Acute Heart Failure: Primary Findings of the Urine N-gal Acute Kidney Injury N-gal Evaluation of Symptomatic Heart Failure Study (AKINESIS)

Definition, Staging, and Role of Biomarkers in Acute Kidney Injury in the Context of Cardiovascular Interventions

Acute kidney injury (AKI) is a frequently occurring complication of cardiovascular interventions, and associated with adverse outcomes. Therefore, a clear definition of AKI is of paramount importance to enable timely recognition and treatment. Historically, changes in the serum creatinine and urine output have been used to define AKI, and the criteria have evolved over time with better understanding of the impact of AKI on the outcomes. However, the reliance on serum creatinine for these AKI definitions carries numerous limitations including delayed rise, inability to differentiate between hemodynamics versus structural injury and assay variability to name a few.

Representation of time-varying and time-invariant EMR data and its application in modeling outcome prediction for heart failure patients

OBJECTIVE

To represent a patient record with both time-invariant and time-varying features as a single vector using an end-to-end deep learning model, and further to predict the kidney failure (KF) status and mortality of heart failure (HF) patients.

MATERIALS AND METHODS

The time-invariant EMR data included demographic information and comorbidities, and the time-varying EMR data were lab tests. We used a Transformer encoder module to represent the time-invariant data, and refined a long short-term memory (LSTM) with a Transformer encoder attached to the top to represent the time-varying data, taking the original measured values and their corresponding embedding vectors, masking vectors, and two types of time intervals as inputs. The proposed representations of patients with time-invariant and time-varying data were used to predict KF status (949 out of 5268 HF patients diagnosed with KF) and mortality (463 in-hospital deaths) for HF patients. Comparative experiments were conducted between the proposed model and some representative machine learning models. Ablation experiments were also performed around the time-varying data representation, including replacing the refined LSTM with the standard LSTM, GRU-D and T-LSTM, respectively, and removing the Transformer encoder and the time-varying data representation module, respectively. The visualization of the attention weights of the time-invariant and time-varying features was used to clinically interpret the predictive performance. We used the area under the receiver operating characteristic curve (AUROC), the area under the precision-recall curve (AUPRC), and the F1-score to evaluate the predictive performance of the models.

RESULTS

The proposed model achieved superior performance, with average AUROCs, AUPRCs and F1-scores of 0.960, 0.610 and 0.759 for KF prediction and 0.937, 0.353 and 0.537 for mortality prediction, respectively. Predictive performance improved with the addition of time-varying data from longer time periods. The proposed model outperformed the comparison and ablation references in both prediction tasks.

CONCLUSIONS

Both time-invariant and time-varying EMR data of patients could be efficiently represented by the proposed unified deep learning model, which shows higher performance in clinical prediction tasks. The way to use time-varying data in the current study is hopeful to be used in other kinds of time-varying data and other clinical tasks.

Cardiorenal Syndrome: A Literature Review

Cardiorenal syndrome (CRS) is a condition characterized by the intricate two-way relationship between the heart and kidneys, which can lead to acute or chronic dysfunction in these organs. The interplay between cardiorenal connectors and both hemodynamic and non-hemodynamic factors is crucial to understanding this syndrome. The clinical importance of these interactions is evident in the changes observed in hemodynamic factors, neurohormonal markers, and inflammatory processes. Identifying and understanding biomarkers associated with CRS is valuable for early detection and enabling intervention before significant organ dysfunction occurs. This comprehensive review focuses on the clinical significance of biomarkers in the diagnosis, prognosis, and management of CRS. Finally, it highlights the necessity for further advancements in managing this condition.

Implications of worsening renal function before hospitalization for acute heart failure

AIMS

Kidney function changes dynamically during AHF treatment, but risk factors for and consequences of worsening renal function (WRF) at hospital admission are uncertain. We aimed to determine the significance of WRF at admission for acute heart failure (AHF).

METHODS AND RESULTS

We evaluated a subgroup of 406 patients from The Acute Kidney Injury Neutrophil gelatinase-associated lipocalin Evaluation of Symptomatic heart failure Study (AKINESIS) who had serum creatinine measurements available within 3 months before and at the time of admission. Admission WRF was primarily defined as a 0.3 mg/dL or 50% creatinine increase from preadmission. Alternative definitions evaluated were a ≥0.5 mg/dL creatinine increase, ≥25% glomerular filtration rate decrease, and an overall change in creatinine. Predictors of admission WRF were evaluated. Outcomes evaluated were length of hospitalization, a composite of adverse in-hospital events, and the composite of death or HF readmission at 30, 90, and 365 days. Biomarkers' prognostic ability for these outcomes were evaluated in patients with admission WRF. One-hundred six patients (26%) had admission WRF. These patients had features of more severe AHF with lower blood pressure, higher BUN, and lower serum sodium concentrations at admission. Higher BNP (odds ratio [OR] per doubling 1.16-1.28, 95% confidence interval [CI] 1.00-1.55) and lower diastolic blood pressure (OR 0.97-0.98, 95% CI 0.96-0.99) were associated with a higher odds for the three definitions of admission WRF. The primary WRF definition was not associated with a longer hospitalization, but alternative WRF definitions were (1.3 to 1.6 days longer, 95% CI 1.0-2.2). WRF across definitions was not associated with a higher odds of adverse in-hospital events or a higher risk of death or HF readmission. In the subset of patients with WRF, biomarkers were not prognostic for any outcome.

CONCLUSIONS

Admission WRF is common in AHF patients and is associated with an increased length of hospitalization, but not adverse in-hospital events, death, or HF readmission. Among those with admission WRF, biomarkers did not risk stratify for adverse events.

Heart Failure and Cardiorenal Syndrome: A Narrative Review on Pathophysiology, Diagnostic and Therapeutic Regimens-From a Cardiologist's View

In cardiorenal syndrome (CRS), heart failure and renal failure are pathophysiologically closely intertwined by the reciprocal relationship between cardiac and renal injury. Type 1 CRS is most common and associated with acute heart failure. A preexistent chronic kidney disease (CKD) is common and contributes to acute kidney injury (AKI) in CRS type 1 patients (acute cardiorenal syndrome). The remaining CRS types are found in patients with chronic heart failure (type 2), acute and chronic kidney diseases (types 3 and 4), and systemic diseases that affect both the heart and the kidney (type 5). Establishing the diagnosis of CRS requires various tools based on the type of CRS, including non-invasive imaging modalities such as TTE, CT, and MRI, adjuvant volume measurement techniques, invasive hemodynamic monitoring, and biomarkers. Albuminuria and Cystatin C (CysC) are biomarkers of glomerular filtration and integrity in CRS and have a prognostic impact. Comprehensive "all-in-one" magnetic resonance imaging (MRI) approaches, including cardiac magnetic resonance imaging (CMR) combined with functional MRI of the kidneys and with brain MRI are proposed for CRS. Hospitalizations due to CRS and mortality are high. Timely diagnosis and initiation of effective adequate therapy, as well as multidisciplinary care, are pertinent for the improvement of quality of life and survival. In addition to the standard pharmacological heart failure medication, including SGLT2 inhibitors (SGLT2i), renal aspects must be strongly considered in the context of CRS, including control of the volume overload (diuretics) with special caution on diuretic resistance. Devices involved in the improvement of myocardial function (e.g., cardiac resynchronization treatment in left bundle branch block, mechanical circulatory support in advanced heart failure) have also shown beneficial effects on renal function.

Pathophysiology of Acute Kidney Injury in Critical Illness: A Narrative Review

Acute kidney injury (AKI) is a syndrome that entails a rapid decline in kidney function with or without injury. The consequences of AKI among acutely ill patients are dire and lead to higher mortality, morbidity, and healthcare cost. To prevent AKI and its short and long-term repercussions, understanding its pathophysiology is essential. Depending on the baseline kidney histology and function reserves, the number of kidney insults, and the intensity of each insult, the clinical presentation of AKI may differ. While many factors are capable of inducing renal injury, they can be categorized into a few processes. The three primary processes reported in the literature are hemodynamic changes, inflammatory reactions, and nephrotoxicity. The majority of patients with AKI will suffer from more than one during their development and/or progression of AKI. Moreover, the development of one usually leads to the instigation of another. Thus, the interactions and progression between these mechanisms may determine the severity and duration of the AKI. Other factors such as organ crosstalk and how our concurrent therapies interact with these mechanisms complicate the pathophysiology of the progression of the AKI even further. In this narrative review article, we describe these three main pathophysiological processes that lead to the development and progression of AKI. © 2022 American Physiological Society. Compr Physiol 12: 1-14, 2022.

Novel Biomarkers of Renal Dysfunction and Congestion in Heart Failure

Heart failure is a major public health problem and, despite the constantly emerging, new, effective treatments, it remains a leading cause of morbidity and mortality. Reliable tools for early diagnosis and risk stratification are crucial in the management of HF. This explains a growing interest in the development of new biomarkers related to various pathophysiological mechanisms of HF. In the course of this review, we focused on the markers of congestion and renal dysfunction in terms of their interference with cardiovascular homeostasis. Congestion is a hallmark feature of heart failure, contributing to symptoms, morbidity, and hospitalizations of patients with HF and has, therefore, become a therapeutic target in AHF. On the other hand, impaired renal function by altering the volume status contributes to the development and progression of HF and serves as a marker of an adverse clinical outcome. Early detection of congestion and an adequate assessment of renal status are essential for the prompt administration of patient-tailored therapy. This review provides an insight into recent advances in the field of HF biomarkers that could be potentially implemented in diagnosis and risk stratification of patients with HF.

Decongestion, kidney injury and prognosis in patients with acute heart failure

BACKGROUND

In patients with acute heart failure (AHF), the development of worsening renal function with appropriate decongestion is thought to be a benign functional change and not associated with poor prognosis. We investigated whether the benefit of decongestion outweighs the risk of concurrent kidney tubular damage and leads to better outcomes.

METHODS

We retrospectively analyzed data from the AKINESIS study, which enrolled AHF patients requiring intravenous diuretic therapy. Urine neutrophil gelatinase-associated lipocalin (uNGAL) and B-type natriuretic peptide (BNP) were serially measured during the hospitalization. Decongestion was defined as ≥30% BNP decrease at discharge compared to admission. Univariable and multivariable Cox models were assessed for one-year mortality.

RESULTS

Among 736 patients, 53% had ≥30% BNP decrease at discharge. Levels of uNGAL and BNP at each collection time point had positive but weak correlations (r ≤ 0.133). Patients without decongestion and with higher discharge uNGAL values had worse one-year mortality, while those with decongestion had better outcomes regardless of uNGAL values (p for interaction 0.018). This interaction was also significant when the change in BNP was analyzed as a continuous variable (p < 0.001). Although higher peak and discharge uNGAL were associated with mortality in univariable analysis, only ≥30% BNP decrease was a significant predictor after multivariable adjustment.

CONCLUSIONS

Among AHF patients treated with diuretic therapy, decongestion was generally not associated with kidney tubular damage assessed by uNGAL. Kidney tubular damage with adequate decongestion does not impact outcomes; however, kidney injury without adequate decongestion is associated with a worse prognosis.

Insights of Worsening Renal Function in Type 1 Cardiorenal Syndrome: From the Pathogenesis, Biomarkers to Treatment

Type-1 cardiorenal syndrome refers to acute kidney injury induced by acute worsening cardiac function. Worsening renal function is a strong and independent predictive factor for poor prognosis. Currently, several problems of the type-1 cardiorenal syndrome have not been fully elucidated. The pathogenesis mechanism of renal dysfunction is unclear. Besides, the diagnostic efficiency, sensitivity, and specificity of the existing biomarkers are doubtful. Furthermore, the renal safety of the therapeutic strategies for acute heart failure (AHF) is still ambiguous. Based on these issues, we systematically summarized and depicted the research actualities and predicaments of the pathogenesis, diagnostic markers, and therapeutic strategies of worsening renal function in type-1 cardiorenal syndrome.

Predictors of acute kidney injury in patients with acute decompensated heart failure in emergency departments in China

Objective

This retrospective multicentre observational study was performed to assess the predictors of acute kidney injury (AKI) in patients with acute decompensated heart failure (ADHF) in emergency departments in China.

Methods

In total, 1743 consecutive patients with ADHF were recruited from August 2017 to January 2018. Clinical characteristics and outcomes were compared between patients with and without AKI. Predictors of AKI occurrence and underdiagnosis were assessed in multivariate regression analyses.

Results

Of the 1743 patients, 593 (34.0%) had AKI. AKI was partly associated with short-term all-cause mortality and cost. Cardiovascular comorbidities such as coronary heart disease, diabetes mellitus, and hypertension remained significant predictors of AKI in the univariate analysis. AKI was significantly more likely to occur in patients with a lower arterial pH, lower albumin concentration, higher creatinine concentration, and higher N-terminal pro-brain natriuretic peptide (NT-proBNP) concentration. Patients treated with inotropic agents were significantly more likely to develop AKI during their hospital stay.

Conclusion

This study suggests that cardiovascular comorbidities, arterial pH, the albumin concentration, the creatinine concentration, the NT-proBNP concentration, and use of inotropic agents are predictors of AKI in patients with ADHF.

Circulating heart failure biomarkers beyond natriuretic peptides: review from the Biomarker Study Group of the Heart Failure Association (HFA), European Society of Cardiology (ESC)

New biomarkers are being evaluated for their ability to advance the management of patients with heart failure. Despite a large pool of interesting candidate biomarkers, besides natriuretic peptides virtually none have succeeded in being applied into the clinical setting. In this review, we examine the most promising emerging candidates for clinical assessment and management of patients with heart failure. We discuss high-sensitivity cardiac troponins (Tn), procalcitonin, novel kidney markers, soluble suppression of tumorigenicity 2 (sST2), galectin-3, growth differentiation factor-15 (GDF-15), cluster of differentiation 146 (CD146), neprilysin, adrenomedullin (ADM), and also discuss proteomics and genetic-based risk scores. We focused on guidance and assistance with daily clinical care decision-making. For each biomarker, analytical considerations are discussed, as well as performance regarding diagnosis and prognosis. Furthermore, we discuss potential implementation in clinical algorithms and in ongoing clinical trials.

Biomarkers in Cardiorenal Syndrome

Cardiorenal syndrome is a clinical manifestation of the bidirectional interaction between the heart and kidney diseases. Over the last years, in patients with cardiovascular diseases, several biomarkers have been studied in order to better assess renal function as well as to identify patients prone to experiencing chronic or acute worsening of renal function. The aim of this review is to focus on the possible clinical usefulness of the most recent biomarkers in the setting of cardiorenal syndrome.

Potential Utility of Cardiorenal Biomarkers for Prediction and Prognostication of Worsening Renal Function in Acute Heart Failure

BACKGROUND

Multiple different pathophysiologic processes can contribute to worsening renal function (WRF) in acute heart failure.

METHODS AND RESULTS

We retrospectively analyzed 787 patients with acute heart failure for the relationship between changes in serum creatinine and biomarkers including brain natriuretic peptide, high sensitivity cardiac troponin I, galectin 3, serum neutrophil gelatinase-associated lipocalin, and urine neutrophil gelatinase-associated lipocalin. WRF was defined as an increase of greater than or equal to 0.3 mg/dL or 50% in creatinine within first 5 days of hospitalization. WRF was observed in 25% of patients. Changes in biomarkers and creatinine were poorly correlated (r ≤ 0.21) and no biomarker predicted WRF better than creatinine. In the multivariable Cox analysis, brain natriuretic peptide and high sensitivity cardiac troponin I, but not WRF, were significantly associated with the 1-year composite of death or heart failure hospitalization. WRF with an increasing urine neutrophil gelatinase-associated lipocalin predicted an increased risk of heart failure hospitalization.

CONCLUSIONS

Biomarkers were not able to predict WRF better than creatinine. The 1-year outcomes were associated with biomarkers of cardiac stress and injury but not with WRF, whereas a kidney injury biomarker may prognosticate WRF for heart failure hospitalization.

Using lipocalin as a prognostic biomarker in acute kidney injury

Introduction: Human lipocalin-2, known as neutrophil gelatinase-associated lipocalin (NGAL), is a widely studied biomarker of acute kidney injury (AKI).Areas covered: NGAL can serve as a predictor of AKI, disease progression, and mortality and can help in differentiating between AKI etiologies. We conducted a systematic review in the PubMed and Medline databases involving the clinical application of NGAL in patients with AKI.Expert opinion: In this review, we explored the usefulness of NGAL for AKI or clinical outcome prediction. The use of urine or blood NGAL levels alone or in combination with a clinical prediction model may facilitate AKI prediction, severity prediction, AKI etiological differentiation, and mortality prediction. For AKI prediction, urine and plasma NGAL levels have an area under the curve (AUC) ranging from 0.71 to 0.90 and from 0.71 to 0.89, respectively, in different populations. The diagnostic performance of NGAL alone for renal replacement therapy or successful discontinuation prediction is suboptimal (AUC range: 0.65-0.81). Sepsis limits the application of NGAL as a clinical predictor, and the prediction performance of NGAL is affected by baseline renal function, timing of sample collection, and underlying comorbidities. The lack of internationally approved reference material also limits the usefulness of NGAL.

Recommendations on Acute Kidney Injury Biomarkers From the Acute Disease Quality Initiative Consensus Conference: A Consensus Statement

IMPORTANCE

In the last decade, new biomarkers for acute kidney injury (AKI) have been identified and studied in clinical trials. Guidance is needed regarding how best to incorporate them into clinical practice.

OBJECTIVE

To develop recommendations on AKI biomarkers based on existing data and expert consensus for practicing clinicians and researchers.

EVIDENCE REVIEW

At the 23rd Acute Disease Quality Initiative meeting, a meeting of 23 international experts in critical care, nephrology, and related specialties, the panel focused on 4 broad areas, as follows: (1) AKI risk assessment; (2) AKI prediction and prevention; (3) AKI diagnosis, etiology, and management; and (4) AKI progression and kidney recovery. A literature search revealed more than 65 000 articles published between 1965 and May 2019. In a modified Delphi process, recommendations and consensus statements were developed based on existing data, with 90% agreement among panel members required for final adoption. Recommendations were graded using the Grading of Recommendations, Assessment, Development and Evaluations system.

FINDINGS

The panel developed 11 consensus statements for biomarker use and 14 research recommendations. The key suggestions were that a combination of damage and functional biomarkers, along with clinical information, be used to identify high-risk patient groups, improve the diagnostic accuracy of AKI, improve processes of care, and assist the management of AKI.

CONCLUSIONS AND RELEVANCE

Current evidence from clinical studies supports the use of new biomarkers in prevention and management of AKI. Substantial gaps in knowledge remain, and more research is necessary.

Epidemiology and outcomes of acute kidney injury in cardiac intensive care unit patients

PURPOSE

To describe the epidemiology and outcomes of acute kidney injury (AKI) among contemporary non-surgical cardiac intensive care unit (CICU) patients.

MATERIALS AND METHODS

We reviewed adult non-surgical CICU patients admitted from 2007 to 2015. The highest AKI stage during hospitalization was defined using modified Kidney Disease: Improving Global Outcomes (KDIGO) criteria, based on changes in serum creatinine. Hospital and 5-year mortality were examined using logistic regression and Cox proportional-hazards models, respectively.

RESULTS

We included 9311 patients with a mean age of 67.5 years, including 37% females. AKI was present in 51%: stage 1 AKI in 34%, stage 2 AKI in 9%, and stage 3 AKI in 8%. Hospital mortality was associated with AKI stage (adjusted OR for each AKI stage 1.17, 95% CI 1.04-1.31, p = 0.007). Five-year mortality was incrementally associated with AKI stage (adjusted HR per AKI stage 1.13, 95% CI 1.08-1.18; p < 0.001), particularly post-discharge mortality among hospital survivors (adjusted HR per AKI stage 1.20, 95% CI 1.15-1.25, p < 0.001). Patients with stage 3 AKI (especially requiring dialysis) had the highest adjusted hospital and five-year mortality.

CONCLUSION

AKI severity is incrementally associated with higher short-term and long-term mortality in CICU patients, especially severe AKI requiring dialysis.

Cardiorenal syndrome in thalassemia patients

Background

Cardiorenal syndrome (CRS), a serious condition with high morbidity and mortality, is characterized by the coexistence of cardiac abnormality and renal dysfunction. There is limited information about CRS in association thalassemia. This study aimed to investigate the prevalence of CRS in thalassemia patients and also associated risk factors.

Methods

Thalassemia patients who attended the out-patient clinic of a tertiary care university hospital from October 2016 to September 2017 were enrolled onto this cross-sectional study. Clinical and laboratory findings from 2 consecutive visits, 3 months apart, were assessed. The criteria for diagnosis of CRS was based on a system proposed by Ronco and McCullough. Cardiac abnormalities are assessed by clinical presentation, establishment of acute or chronic heart failure using definitions from 2016 ESC guidelines or from structural abnormalities shown in an echocardiogram. Renal dysfunction was defined as chronic kidney disease according to the 2012 KDIGO guidelines.

Results

Out of 90 thalassemia patients, 25 (27.8%) had CRS. The multivariable analysis showed a significant association between CRS and extramedullary hematopoiesis (EMH) (odds ratio (OR) 20.55, p = 0.016); thalassemia type [β⁰/β^E vs β⁰/β⁰ thalassemia (OR 0.005, p = 0.002)]; pulmonary hypertension (OR 178.1, p = 0.001); elevated serum NT-proBNP (OR 1.028, p = 0.022), and elevated 24-h urine magnesium (OR 1.913, p = 0.016). There was no association found between CRS and frequency of blood transfusion, serum ferritin, liver iron concentration, cardiac T2*, type of iron chelating agents, or urine neutrophil gelatinase-associated lipocalin level.

Conclusions

CRS is relatively common in thalassemia patients. Its occurrence is associated with laboratory parameters which are easily measured in clinical practice.

Cardiac biomarkers of heart failure in chronic kidney disease

Heart failure remains a continuing threat to patients with chronic kidney disease (CKD). Although various heart failure biomarkers have been applied for early detection, diagnosis and prognosis in CKD, these are easily affected by renal insufficiency thus limiting use in these patients. In this review, the major four groups of heart failure biomarkers are explored. These include those associated with: myocardial stretch, ie, brain natriuretic peptide (BNP), N-terminal pro-BNP (NT-proBNP) and mid-regional proatrial natriuretic peptide (MR-proANP); myocyte injury, ie, high-sensitivity troponin T (hsTnT), heart-type fatty acid-binding protein (H-FABP); fibrosis, matrix remodelling and inflammation, ie, soluble growth stimulating gene 2 (sST2), galectin-3 (Gal-3), growth differentiation factor-15 (GDF-15); and renal function, ie, neutrophil gelatinase-associated lipocalin (NGAL) kidney injury molecule-1 (KIM-1), cystatin C (CysC), urinary sodium and urinary albumin. This review highlights classic heart failure biomarkers with critical values adjusted to glomerular filtration rate, summarizes research progress of new heart failure biomarkers and future research directions. Because diagnostic and prognostic usefulness of a single time point biomarker is limited, biomarkers should be combined and monitored at multiple times for optimal clinical impact.

Role of the Furosemide Stress Test in Renal Injury Prognosis

Risk stratification and accurate patient prognosis are pending issues in the management of patients with kidney disease. The furosemide stress test (FST) has been proposed as a low-cost, fast, safe, and easy-to-perform test to assess tubular integrity, especially when compared to novel plasma and urinary biomarkers. However, the findings regarding its clinical use published so far provide insufficient evidence to recommend the generalized application of the test in daily clinical routine. Dosage, timing, and clinical outcomes of the FST proposed thus far have been significantly different, which further accentuates the need for standardization in the application of the test in order to facilitate the comparison of results between series. This review will summarize published research regarding the usefulness of the FST in different settings, providing the reader some insights about the possible implications of FST in clinical decision-making in patients with kidney disease and the challenges that research will have to address in the near future before widely applying the FST.

Short-term prognostic implications of serum and urine neutrophil gelatinase-associated lipocalin in acute heart failure: findings from the AKINESIS study

AIMS

Kidney impairment has been associated with worse outcomes in acute heart failure (AHF), although recent studies challenge this association. Neutrophil gelatinase-associated lipocalin (NGAL) is a novel biomarker of kidney tubular injury. Its prognostic role in AHF has not been evaluated in large cohorts. The present study aimed to determine if serum NGAL (sNGAL) or urine NGAL (uNGAL) is superior to creatinine for predicting short-term outcomes in AHF.

METHODS AND RESULTS

The study was conducted in an international, multicentre, prospective cohort consisting of 927 patients with AHF. Admission and peak values of sNGAL, uNGAL and uNGAL/urine creatinine (uCr) ratio were compared to admission and peak serum creatinine (sCr). The composite endpoints were death, initiation of renal replacement therapy, heart failure (HF) readmission and any emergent HF-related outpatient visit within 30 and 60 days, respectively. The mean age of the cohort was 69 years and 62% were male. The median length of stay was 6 days. The composite endpoint occurred in 106 patients and 154 patients within 30 and 60 days, respectively. Serum NGAL was more predictive than uNGAL and the uNGAL/uCr ratio but was not superior to sCr [area under the curve: admission sNGAL 0.61, 95% confidence interval (CI) 0.55-0.67, and 0.59, 95% CI 0.54-0.65; peak sNGAL: 0.60, 95% CI 0.54-0.66, and 0.57, 95% CI 0.52-0.63; admission sCr: 0.60, 95% CI 0.54-0.64, and 0.59, 95% CI 0.53-0.64; peak sCr: 0.61, 95% CI 0.55-0.67, and 0.59, 95% CI 0.54-0.64, at 30 and 60 days, respectively]. NGAL was not predictive of the composite endpoint in multivariate analysis.

CONCLUSIONS

Serum NGAL outperformed uNGAL but neither was superior to admission or peak sCr for predicting adverse events.