Role of B-type natriuretic peptide as a marker of mortality in acute kidney injury patients treated with continuous renal replacement therapy

Brain natriuretic peptide as a predictive marker of mortality in sepsis: an updated systematic review and meta-analysis

INTRODUCTION

Early identification of patients with sepsis at high risk of death remains a challenge, and whether brain natriuretic peptide (BNP) or N-terminal pro-B-type natriuretic peptide (NT-proBNP) has a prognostic effect on patients with sepsis is controversial. Here, we clarified the prognostic value of BNP and NT-proBNP and sought to establish suitable cutoff values and intervals.

METHODS

We searched five databases to identify studies that met the inclusion criteria. The primary outcomes were the pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), area under the curve (AUC), and corresponding 95% credible interval (95% CI) of BNP and NT-proBNP. The secondary outcomes were the sensitivity and specificity of BNP or NT-proBNP in subgroup analyses.

RESULTS

Forty-seven studies were included in our meta-analysis. The pooled sensitivity of NT-proBNP (0.77 [0.68, 0.84]) was weaker than that of BNP (0.82 [0.76, 0.87]), the pooled specificity of NT-proBNP (0.70 [0.60, 0.77]) was less than that of BNP (0.77 [0.71, 0.82]), and the AUC of BNP (0.87 [0.83-0.89]) was greater than that of NT-proBNP (0.80 (0.76-0.83]). The results of the subgroup analysis showed that the cutoff range of 400-800 pg/mL for BNP had high sensitivity (0.86 [0.74-0.98]) and specificity (0.87 [0.81-0.93]) and was probably the most appropriate cutoff range.

CONCLUSIONS

Elevated levels of BNP and NT-proBNP were significantly related to the mortality of patients with sepsis and had a moderate prognostic value in predicting the mortality of patients with sepsis. In addition, our meta-analysis preliminarily established appropriate cutoff values for BNP and NT-proBNP.

Natriuretic peptide testing strategies in heart failure: A 2023 update

Natriuretic peptides (NPs), including B-type natriuretic peptide (BNP) and N-terminal pro-BNP (NT-proBNP), have been recommended as standard biomarkers for diagnosing heart failure (HF), and one of the strongest risk predictors for mortality and HF hospitalization regardless of ejection fraction (EF) and etiology of HF. BNP is an active neurohormone opposing renin-angiotensin-aldosterone and sympathetic nervous system overactivated in HF, whereas NT-proBNP is an inactive prohormone released from cardiomyocytes in response to wall stress. Despite substantial advances in the development of guideline-directed medical therapy (GDMT) for HF with reduced EF, studies demonstrating direct benefits of NP-guided chronic HF therapy on mortality, HF hospitalization, and GDMT optimization have yielded conflicting results. However, accumulating evidence shows that achieving prespecified BNP or NT-proBNP target over time is significantly associated with favorable outcomes, suggesting that benefits of serially measured NPs may be limited to particular groups of HF patients, such as those with extreme levels of baseline BNP or NT-proBNP, which could represent severe phenotypes of HF associated with natriuretic peptide resistance or cardiorenal syndrome. Over the past decade, clinical utilization of BNP and NT-proBNP has been expanded, especially using serial NP measurements for guiding HF therapy, optimizing GDMT and identifying at-risk patients with HF phenotypes who may be minimally symptomatic or asymptomatic.

Prognostic Value of Natriuretic Peptide Levels for Adverse Renal Outcomes in Patients With Moderate to Severe Acute Kidney Injury With or Without Heart Failure

Background Natriuretic peptides have been recommended as biomarkers for the diagnosis and prognosis of patients with heart failure and are often elevated in the setting of acute kidney injury. We sought to demonstrate the associations between increased baseline NT-proBNP (N-terminal pro-B-type natriuretic peptide) and adverse renal outcomes in patients with moderate-to-severe acute kidney injury. Methods and Results We reviewed electronic medical records of consecutive patients with acute kidney injury stage 2 and 3 admitted to the Cleveland Clinic between September 2011 and December 2021. Patients with NT-proBNP levels collected before renal consultation or dialysis initiation were included. Adverse renal outcomes included dialysis requirement and dialysis dependence defined as patients undergoing dialysis within 72 hours before hospital discharge or in-hospital mortality. In our study cohort (n=3811), 2521 (66%) patients underwent dialysis, 1619 (42%) patients became dialysis dependent, and 1325 (35%) patients had in-hospital mortality. After adjusting for cardiorenal risk factors, compared with the lowest quartile, the highest quartile of NT-proBNP (≥18 215 pg/mL) was associated with increased likelihood of dialysis requirement (adjusted odds ratio [OR], 2.36 [95% CI, 1.87-2.99]), dialysis dependence (adjusted OR, 1.89 [95% CI, 2.53-1.34]), and in-hospital mortality (adjusted OR, 1.34 [95% CI, 1.01-1.34]). Conclusions Increased NT-proBNP was associated with an increased risk of dialysis requirement, becoming dialysis dependent, and in-hospital mortality in patients with moderate-to-severe acute kidney injury.

Brain consequences of acute kidney injury: Focusing on the hippocampus

The high mortality rates associated with acute kidney injury are mainly due to extra-renal complications that occur following distant-organ involvement. Damage to these organs, which is commonly referred to as multiple organ dysfunction syndrome, has more severe and persistent effects. The brain and its sub-structures, such as the hippocampus, are vulnerable organs that can be adversely affected. Acute kidney injury may be associated with numerous brain and hippocampal complications, as it may alter the permeability of the blood-brain barrier. Although the pathogenesis of acute uremic encephalopathy is poorly understood, some of the underlying mechanisms that may contribute to hippocampal involvement include the release of multiple inflammatory mediators that coincide with hippocampus inflammation and cytotoxicity, neurotransmitter derangement, transcriptional dysregulation, and changes in the expression of apoptotic genes. Impairment of brain function, especially of a structure that has vital activity in learning and memory and is very sensitive to renal ischemic injury, can ultimately lead to cognitive and functional complications in patients with acute kidney injury. The objective of this review was to assess these complications in the brain following acute kidney injury, with a focus on the hippocampus as a critical region for learning and memory.

Fluid overload at start of continuous renal replacement therapy is associated with poorer clinical condition and outcome: a prospective observational study on the combined use of bioimpedance vector analysis and serum N-terminal pro-B-type natriuretic peptide measurement

Introduction

It is unclear whether the fluid status, as determined by bioimpedance vector analysis (BIVA) combined with serum N-terminal pro-B-type natriuretic peptides (NT-pro-BNP) measurement, is associated with treatment outcome among patients receiving continuous renal replacement therapy (CRRT). Our objective was to answer this question.

Methods

Patients who were in the intensive care units of a university teaching hospital and who required CRRT were screened for enrollment. For the enrolled patients, BIVA and serum NT-pro BNP measurement were performed just before the start of CRRT and 3 days afterward. According to the BIVA and NT-pro BNP measurement results, the patients were divided into four groups according to fluid status type: type 1, both normal; type 2, normal BIVA results and abnormal NT-pro BNP levels; type 3, abnormal BIVA results and normal NT-pro BNP levels; and type 4, both abnormal. The associations between fluid status and outcome were analyzed.

Results

Eighty-nine patients were enrolled, 58 were males, and the mean age was 49.0 ± 17.2 years. The mean score of Acute Physiology and Chronic Health Evaluation II (APACHE II) was 18.8 ± 8.6. The fluid status before CRRT start was as follows: type 1, 21.3% (19 out of 89); type 2, 16.9% (15 out of 89); type 3, 11.2% (10 out of 89); and type 4, 50.6% (45 out of 89). There were significant differences between fluid status types before starting CRRT on baseline values for APACHE II scores, serum creatinine, hemoglobin, platelet count, urine volume, and incidences of oliguria and acute kidney injury (P <0.05). There were significant differences between patients with different fluid status before CRRT start on hospital mortality—type 1, 26.3% (5 out of 19); type 2, 33.3% (5 out of 15); type 3, 40% (4 out of 10); and type 4, 64.4% (29 out of 45) (P = 0.019)—as well as renal function recovery rates: type 1, 57.1% (4 out of 7); type 2, 67.7% (6 out of 9); type 3, 50% (3 out of 6); and type 4, 23.7% (9 out of 38) (P = 0.051).

Conclusions

Fluid status abnormalities were common among patients receiving CRRT. Different types of fluid status distinguished by BIVA combined with serum NT-pro BNP measurements corresponded to different clinical conditions and treatment outcomes, which implies a value of this method for evaluation of fluid status among patients receiving CRRT.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-015-0871-3) contains supplementary material, which is available to authorized users.

Plasma B-type natriuretic peptide (BNP) in acute Puumala hantavirus infection

BACKGROUND

Nephropathia epidemica (NE) is a haemorrhagic fever with renal syndrome (HFRS) caused by Puumala hantavirus (PUUV). Acute infection causes transient kidney injury, permeability disorder, and fluid retention, for example.

METHODS

B-type natriuretic peptide (BNP) and N-terminal peptide (NT-proBNP) during NE were investigated; disease severity and development of clinical symptoms were considered.

RESULTS

Mean concentrations were 80.2 pg/mL and 55.2 pg/mL for BNP, and 2362.5 pg/mL and 1057.0 pg/mL for NT-proBNP in males and females, respectively. Hospitalization was 6.3 versus 5.2 days (P = 0.01) and 5.9 versus 4.4 days (P = 0.01) for patients with elevated BNP (> 100 pg/mL) or NT-proBNP (> 300 pg/mL), respectively, compared to those with normal peptide concentrations. Weight change during hospitalization was -2.8 or -0.3 kg (P <0.05) in patients with elevated or normal BNP, respectively. Heart rate (r = -0.46, P = 0.001 and r = -0.37, P = 0.01), creatinine clearance (r = -0.46, P = 0.001 and r = -0.56, P = 0.000), blood haemoglobin concentration (r = -0.55, P = 0.000 and r = -0.52, P = 0.000), and C-reactive protein (r = -0.47, P = 0.001 and r = -0.36, P = 0.01) measured when the peptide samples were collected correlated with BNP and NT-proBNP, respectively. In addition, anterior chamber depth of eye and plasma BNP (r = -0.39, P < 0.05) displayed a correlation.

CONCLUSIONS

BNP and NT-proBNP levels are associated with severity of several clinical features of acute NE.