Effect of body mass index on natriuretic peptide levels in patients with acute congestive heart failure: a ProBNP Investigation of Dyspnea in the Emergency Department (PRIDE) substudy

Interaction of Body Mass Index on the Association Between N-Terminal-Pro-b-Type Natriuretic Peptide and Morbidity and Mortality in Patients With Acute Heart Failure: Findings From ASCEND-HF (Acute Study of Clinical Effectiveness of Nesiritide in Decompensated Heart Failure)

BACKGROUND

Higher body mass index (BMI) is associated with lower circulating levels of N-terminal-pro-b-type natriuretic peptide (NT-proBNP). The Interaction between BMI and NT-proBNP with respect to clinical outcomes is not well characterized in patients with acute heart failure.

METHODS AND RESULTS

A total of 686 patients from the biomarker substudy of the ASCEND-HF (Acute Study of Clinical Effectiveness of Nesiritide in Decompensated HF ) clinical trial with documented NT-proBNP levels at baseline were included in the present analysis. Patients were classified by the World Health Organization obesity classification (nonobese: BMI <30 kg/m², Class I obesity: BMI 30-34.9 kg/m², Class II obesity BMI 35-39.9 kg/m², and Class III obesity BMI ≥40 kg/m²). We assessed baseline characteristics and 30- and 180-day outcomes by BMI class and explored the interaction between BMI and NT-proBNP for these outcomes. Study participants had a median age of 67 years (55, 78) and 71% were female. NT-proBNP levels were inversely correlated with BMI (P<0.001). Higher NT-proBNP levels were associated with higher 180-day mortality (adjusted hazard ratio for each doubling of NT-proBNP, 1.40; 95% confidence interval, 1.16, 1.71; P<0.001), but not 30-day outcomes. The effect of NT-proBNP on 180-day death was not modified by BMI class (interaction P=0.24).

CONCLUSIONS

The prognostic value of NT-proBNP was not modified by BMI in this acute heart failure population. NT-proBNP remains a useful prognostic indicator of long-term mortality in acute heart failure even in the obese patient.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00475852.

Regulation of circulating chromogranin B levels in heart failure

BACKGROUND

Chromogranin B (CGB) regulates B-type natriuretic peptide (BNP) production. Circulating CGB levels are elevated in heart failure (HF) animal models and HF patients, but also increase in healthy individuals in response to physical activity. Therefore, CGB seems to integrate information from myocardial stress and systemic neuro-endocrine activation. Substantial gaps remain in our understanding of CGB regulation in HF.

METHODS AND RESULTS

We conducted a retrospective registry study including 372 patients. CGB and N-terminal pro-BNP (NT-proBNP) plasma levels were assessed in acute HF and chronic valvular HF patients and controls. CGB levels were significantly increased in acute HF and chronic valvular HF, but significantly higher in the latter. Patients in chronic valvular HF with severe mitral regurgitation (cHF-MR) showed significantly higher CGB levels than patients in chronic valvular HF with severe aortic stenosis. CGB levels progressively increased with worsening NYHA functional status and were moderately correlated to NT-proBNP, but independent of left ventricular (LV) ejection fraction (LVEF), LV mass, age and body weight. Finally, cHF-MR patients showed significant reductions of CGB levels after interventional mitral valve repair.

CONCLUSION

CGB is a promising emerging biomarker in HF patients with unique potential to integrate information from myocardial stress and neuro-endocrine activation.

Dyspnoea with normal B-type natriuretic peptide level: don't miss cardiac tamponade! A case report

A 78-year-old female patient with a medical history of severe aortic stenosis and metastatic ovarian cancer with liver and right iliac bone metastases was admitted for dyspnoea that started during the same day. Six months ago, she was diagnosed with acute heart failure with a B-type natriuretic peptide (BNP) level at 682 pg/mL. Upon presentation, she was hypotensive (85/55 mmHg) and tachycardic (114 b.p.m.). Her BNP level was 278 pg/mL. A bedside echocardiogram showed a large pericardial effusion that was successfully drained. Ten days later, BNP was repeated and was 1147 pg/mL. The pseudonormalization of BNP level was due to the impaired ventricular stretching caused by the chronic cardiac tamponade.

Joint statement of the European Association for the Study of Obesity and the European Society of Hypertension: obesity and heart failure

Obese individuals are more likely to develop heart failure. Yet, once heart failure is established, the impact of overweight and obesity on prognosis and survival is unclear. The purpose of this joint scientific statement of the European Association for the Study of Obesity and the European Society of Hypertension is to provide an overview on the current scientific literature on obesity and heart failure in terms of prognosis, mechanisms, and clinical management implications. Moreover, the document identifies open questions that ought to be addressed. The need for more tailored weight management recommendations in heart failure will be emphasized and, in line with the emerging evidence, aims to distinguish between primary disease and secondary outcome prevention. In the primary prevention of heart failure, it appears prudent advising obese individuals to lose or achieve a healthy body weight, especially in those with risk factors such as hypertension or type 2 diabetes. However, there is no evidence from clinical trials to guide weight management in overweight or obese patients with established heart failure. Prospective clinical trials are strongly encouraged.

Rationale and design of the ICON-RELOADED study: International Collaborative of N-terminal pro-B-type Natriuretic Peptide Re-evaluation of Acute Diagnostic Cut-Offs in the Emergency Department

OBJECTIVES

The objectives were to reassess use of amino-terminal pro B-type natriuretic peptide (NT-proBNP) concentrations for diagnosis and prognosis of acute heart failure (HF) in patients with acute dyspnea.

BACKGROUND

NT-proBNP facilitates diagnosis, prognosis, and treatment in patients with suspected or proven acute HF. As demographics of such patients are changing, previous diagnostic NT-proBNP thresholds may need updating. Additionally, value of in-hospital NT-proBNP prognostic monitoring for HF is less understood.

METHODS

In a prospective, multicenter study in the United States and Canada, patients presenting to emergency departments with acute dyspnea were enrolled, with demographic, medication, imaging, and clinical course information collected. NT-proBNP analysis will be performed using the Roche Diagnostics Elecsys proBNPII immunoassay in blood samples obtained at baseline and at discharge (if hospitalized). Primary end points include positive predictive value of previously established age-stratified NT-proBNP thresholds for the adjudicated diagnosis of acute HF and its negative predictive value to exclude acute HF. Secondary end points include sensitivity, specificity, and positive and negative likelihood ratios for acute HF and, among those with HF, the prognostic value of baseline and predischarge NT-proBNP for adjudicated clinical end points (including all-cause death and hospitalization) at 30 and 180days.

RESULTS

A total of 1,461 dyspneic subjects have been enrolled and are eligible for analysis. Follow-up for clinical outcome is ongoing.

CONCLUSIONS

The International Collaborative of N-terminal pro-B-type Natriuretic Peptide Re-evaluation of Acute Diagnostic Cut-Offs in the Emergency Department study offers a contemporary opportunity to understand best diagnostic cutoff points for NT-proBNP in acute HF and validate in-hospital monitoring of HF using NT-proBNP.

Organ dysfunction, injury and failure in acute heart failure: from pathophysiology to diagnosis and management. A review on behalf of the Acute Heart Failure Committee of the Heart Failure Association (HFA) of the European Society of Cardiology (ESC)

Organ injury and impairment are commonly observed in patients with acute heart failure (AHF), and congestion is an essential pathophysiological mechanism of impaired organ function. Congestion is the predominant clinical profile in most patients with AHF; a smaller proportion presents with peripheral hypoperfusion or cardiogenic shock. Hypoperfusion further deteriorates organ function. The injury and dysfunction of target organs (i.e. heart, lungs, kidneys, liver, intestine, brain) in the setting of AHF are associated with increased risk for mortality. Improvement in organ function after decongestive therapies has been associated with a lower risk for post-discharge mortality. Thus, the prevention and correction of organ dysfunction represent a therapeutic target of interest in AHF and should be evaluated in clinical trials. Treatment strategies that specifically prevent, reduce or reverse organ dysfunction remain to be identified and evaluated to determine if such interventions impact mortality, morbidity and patient-centred outcomes. This paper reflects current understanding among experts of the presentation and management of organ impairment in AHF and suggests priorities for future research to advance the field.

Role of Biomarkers for the Prevention, Assessment, and Management of Heart Failure: A Scientific Statement From the American Heart Association

BACKGROUND AND PURPOSE

Natriuretic peptides have led the way as a diagnostic and prognostic tool for the diagnosis and management of heart failure (HF). More recent evidence suggests that natriuretic peptides along with the next generation of biomarkers may provide added value to medical management, which could potentially lower risk of mortality and readmissions. The purpose of this scientific statement is to summarize the existing literature and to provide guidance for the utility of currently available biomarkers.

METHODS

The writing group used systematic literature reviews, published translational and clinical studies, clinical practice guidelines, and expert opinion/statements to summarize existing evidence and to identify areas of inadequacy requiring future research. The panel reviewed the most relevant adult medical literature excluding routine laboratory tests using MEDLINE, EMBASE, and Web of Science through December 2016. The document is organized and classified according to the American Heart Association to provide specific suggestions, considerations, or contemporary clinical practice recommendations.

RESULTS

A number of biomarkers associated with HF are well recognized, and measuring their concentrations in circulation can be a convenient and noninvasive approach to provide important information about disease severity and helps in the detection, diagnosis, prognosis, and management of HF. These include natriuretic peptides, soluble suppressor of tumorgenicity 2, highly sensitive troponin, galectin-3, midregional proadrenomedullin, cystatin-C, interleukin-6, procalcitonin, and others. There is a need to further evaluate existing and novel markers for guiding therapy and to summarize their data in a standardized format to improve communication among researchers and practitioners.

CONCLUSIONS

HF is a complex syndrome involving diverse pathways and pathological processes that can manifest in circulation as biomarkers. A number of such biomarkers are now clinically available, and monitoring their concentrations in blood not only can provide the clinician information about the diagnosis and severity of HF but also can improve prognostication and treatment strategies.

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.

The Correlation of Serum Brain Natriuretic Peptide and Interleukin-6 with Quality of Life Using the Chronic Obstructive Pulmonary Disease Assessment Test

OBJECTIVE

The aim of this study was to determine the levels of serum pro-brain natriuretic peptide (pro-BNP) and interleukin (IL)-6 in patients with stable chronic obstructive pulmonary disease (COPD) and to correlate these markers with health-related quality of life using the COPD assessment test (CAT).

MATERIALS AND METHODS

Serum pro-BNP and IL-6 levels were measured in 82 patients with stable COPD. Serum pro-BNP and serum IL-6 levels, pulmonary function, and oxygen saturation (SpO2) were measured according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage and CAT score. Also, the associations of both pro-BNP and IL-6 with the clinical parameters of patients were tested.

RESULTS

The serum levels of IL-6 (7.57 [5-11.16] pg/mL) and pro-BNP (120.55 [92.89-144.20] pg/mL) were higher with enhancing disease severity based on the GOLD classification (p = 0.034 and 0.068, respectively). Also, serum levels of pro-BNP (120.55 [89.50-147.90] pg/mL) and IL-6 (6.68 [4.40-11.97] pg/mL) were increased in patients with high CAT scores (p = 0.004 and 0.017, respectively). There was a significant positive correlation between plasma pro-BNP and IL-6 levels (r = 0.332, p = 0.002).

CONCLUSION

The results demonstrated that with increased severity of obstruction based on the GOLD criteria both IL-6 and pro-BNP were elevated. This increase in inflammatory markers was associated with a reduced quality of life and the severity of hypoxia. These findings indicated that lowering IL-6 and pro-BNP could be useful in the management of COPD patients.

Deep analyses of the associations of a series of biomarkers with insulin resistance, metabolic syndrome, and diabetes risk in nondiabetic middle-aged and elderly individuals: results from a Chinese community-based study

OBJECTIVE

The current study was designed to perform deep analyses of the associations of biomarkers, including high-sensitivity C-reactive protein (hs-CRP), N-terminal prohormone of brain natriuretic peptide (NT-proBNP), and homocysteine (Hcy), with insulin resistance (IR), metabolic syndrome (MetS), and diabetes risk and evaluate the abilities of biomarkers to identify IR, MetS, and diabetes risk in Chinese community-dwelling middle-aged and elderly residents.

PARTICIPANTS AND METHODS

A total of 396 participants older than 45 years underwent physical examinations and laboratory analyses following standardized protocol.

RESULTS

Serum hs-CRP concentrations were able to identify MetS, Chinese diabetes risk score (CDRS) ≥4, high-density lipoprotein-cholesterol (HDL-c) <0.9/1.0 mmol/L, and HDL-c <1.0/1.3 mmol/L (P<0.05 for all). Serum NT-proBNP concentrations were able to identify homeostasis model assessment of IR >1.5, CDRS ≥4, overweight, and blood pressure (BP) ≥140/90 mmHg (P<0.05 for all). Serum Hcy concentrations were able to identify CDRS ≥4, general obesity, overweight, and BP ≥140/90 mmHg (P<0.05 for all). Serum hs-CRP concentrations were independently associated with MetS as well as HDL-c <1.0/1.3 mmol/L and HDL-c <0.9/1.0 mmol/L (P<0.05 for all). Serum NT-proBNP concentrations were independently associated with BP ≥140/90 mmHg (P<0.05). Serum Hcy concentrations were independently associated with CDRS ≥4 (P<0.05).

CONCLUSION

Serum HDL-c levels were the major determinant of the associations between serum hs-CRP levels and MetS and the key link between inflammation and MetS. There was no other association of these biomarkers with IR, MetS, and diabetes risk after full adjustment.

N-terminal pro b-type natriuretic peptide (NT-pro-BNP) -based score can predict in-hospital mortality in patients with heart failure

Serum N-terminal pro b-type natriuretic peptide (NT-pro-BNP) testing is recommended in the patients with heart failure (HF). We hypothesized that NT-pro-BNP, in combination with other clinical factors in terms of a novel NT-pro BNP-based score, may provide even better predictive power for in-hospital mortality among patients with HF. A retrospective study enrolled adult patients with hospitalization-requiring HF who fulfilled the predefined criteria during the period from January 2011 to December 2013. We proposed a novel scoring system consisting of several independent predictors including NT-pro-BNP for predicting in-hospital mortality, and then compared the prognosis-predictive power of the novel NT-pro BNP-based score with other prognosis-predictive scores. A total of 269 patients were enrolled in the current study. Factors such as "serum NT-pro-BNP level above 8100 mg/dl," "age above 79 years," "without taking angiotensin converting enzyme inhibitors/angiotensin receptor blocker," "without taking beta-blocker," "without taking loop diuretics," "with mechanical ventilator support," "with non-invasive ventilator support," "with vasopressors use," and "experience of cardio-pulmonary resuscitation" were found as independent predictors. A novel NT-pro BNP-based score composed of these risk factors was proposed with excellent predictability for in-hospital mortality. The proposed novel NT-pro BNP-based score was extremely effective in predicting in-hospital mortality in HF patients.

Bariatric Surgery and Emergency Department Visits and Hospitalizations for Heart Failure Exacerbation: Population-Based, Self-Controlled Series

BACKGROUND

The United States is battling obesity and heart failure (HF) epidemics. Although studies have suggested relationships between obesity and HF morbidity, little is known regarding the effects of substantial weight reduction in obese patients with HF.

OBJECTIVES

This study investigated whether bariatric surgery is associated with a decreased rate of HF exacerbation.

METHODS

We performed a self-controlled case series study of obese patients with HF who underwent bariatric surgery, using the population-based emergency department (ED) and inpatient sample in California, Florida, and Nebraska. Primary outcome was ED visit or hospitalization for HF exacerbation from 2005 to 2011. We used conditional logistic regression to compare the outcome event rate during sequential 12-month periods, using pre-surgery months 13 to 24 as the reference period.

RESULTS

We identified 524 patients with HF who underwent bariatric surgery. During the reference period, 16.2% of patients had an ED visit or hospitalization for HF exacerbation. The rate remained unchanged in the subsequent 12-month pre-surgery period (15.3%; p = 0.67). In the first 12-month period after bariatric surgery, we observed a nonsignificantly reduced rate (12.0%; p = 0.052). However, the rate was significantly lower in the subsequent 13 to 24 months after bariatric surgery (9.9%; adjusted odds ratio: 0.57; p = 0.003). By contrast, there was no significant reduction in the rate of HF exacerbation among obese patients who underwent nonbariatric surgery (i.e., cholecystectomy, hysterectomy).

CONCLUSIONS

Our findings indicate that bariatric surgery is associated with a decline in the rate of HF exacerbation requiring ED evaluation or hospitalization among obese patients with HF.

The influence of confounders in the analysis of mid-regional pro-atrial natriuretic peptide in patients with chronic heart failure

BACKGROUND

Natriuretic peptides play an important role in the diagnosis and risk stratification of patients with acute and chronic heart failure. Multiple studies have shown that these peptides are liable to the influence of individual factors. For N-terminal-pro-B-type natriuretic peptide (NT-proBNP) some of these confounding factors have been evaluated over the years such as age, gender, New York Heart Association (NYHA) class and body mass index (BMI). The aim of this study was to establish confounding factors of mid-regional pro-atrial natriuretic peptide (MR-proANP) assessment.

METHODS AND RESULTS

We studied 684 patients (94% male, age 61.2±11.2, left ventricular ejection fraction [LVEF]<35%-45%, NYHA class (I/II/III/IV: 8.4/45.8/39.5/6.3%), ischaemic aetiology 71%, body mass index [BMI] 26.5±4.3kg/m(2), mean MR-proANP 296.0±281.0pmol/L, mean NT-proBNP 2792.0±5328.6pg/mL, mean creatinine level 110.2±38.0μmol/L and mean haemoglobin 13.9±1.5g/dL) with clinically stable chronic heart failure. MR-proANP levels increased with increasing NYHA class (p<0.0001) and an increasing BMI category was associated with decreasing values of MR-proANP (p<0.0001). We found MR-proANP to be independently associated with BMI, creatinine, ischaemic aetiology, LVEF and NYHA class. Meanwhile, NT-proBNP was independently associated with BMI, creatinine, haemoglobin, LVEF and NYHA class.

CONCLUSION

MR-proANP is subject to the almost identical influencing factors like NT-proBNP. The effects of anaemia warrant further study.

Recent advances in point-of-care testing for natriuretic peptides: potential impact on heart failure diagnosis and management

Heart failure is a leading cause of morbidity and mortality worldwide. The presenting symptoms of heart failure are often nonspecific. The diagnosis of heart failure has traditionally relied heavily upon clinical exam findings, which are often subjective and have low sensitivity. Efficient and rapid diagnosis of heart failure in the emergency room setting can reduce health care costs, hospital admission and ER visits, and improve patient care. Natriuretic peptides are objective biomarkers that can help with diagnosis, prognosis and management of heart failure. The most extensively studied and clinically utilized natriuretic peptides include brain natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP). Point-of-care testing in the emergency room setting can result in faster triage times. Point-of-care testing can also be utilized in the outpatient setting for real-time management of patients with heart failure.

Brain Natriuretic Peptide in Liver Cirrhosis and Fatty Liver: Correlation with Cardiac Performance

Objective

The aims of the present study were to assess the serum BNP level in patients with post hepatitis C liver cirrhosis and patients with fatty liver and to determine the correlation between BNP and the severity of liver disease and cardiac performance.

Methods

The study was conducted on 140 subjects subdivided into 3 groups: group 1 included 60 patients having post hepatitis C virus (HCV) liver cirrhosis; group 2 included 60 patients with nonalcoholic fatty liver disease (NAFLD); and group 3 included 20 healthy volunteers serving as a control group. All patients and volunteers were subjected to full physical examinations, laboratory evaluation of hemoglobin percent, liver and renal function tests, serum electrolytes, cholesterol, triglyceride, HBs antigen, HCV antibody and serum BNP levels, ECG, abdominal ultrasonography, and echocardiography.

Results

There was a significant increase in the BNP level in cirrhotic patients compared to the other two groups (p = 0.000), and it was correlated with the severity of liver disease assigned as Child’s classification (p = 0.000). Also, there was a significant increase in the BNP level in cirrhotic patients with decompensation components compared to those without decompensation components (p = 0.000), history of hepatic encephalopathy (p = 0.000), history of variceal bleeding (p = 0.000), history of spontaneous bacterial peritonitis (p = 0.000), presence of ascites (p = 0.000) and portal vein diameter > 11 mm in abdominal ultrasound (p = 0.000), and prolonged QTc interval in ECG (p = 0.011). There was a significant increase in serum BNP in patients with cirrhosis with the following echocardiographic findings: IVST > 11 mm, PWT > 11 mm, LA diameter > 40 mm, EF% < 54%, and E/A ratio < 1 compared to those without these echocardiographic findings (p = 0.000).

Conclusion

BNP level increases in post hepatitis C cirrhotic patients and tends to decrease in fatty liver disease patients, and it is correlated with both the severity of liver disease and the morpho-functional cardiac changes. Given the ever-increasing prevalence of liver cirrhosis and fatty liver disease worldwide, it is important to understand the benefits and limitations of BNP as a heart failure biomarker in hepatic patients, where the relationship between BNP level and myocardial function is complex and is altered by the liver disease.

N-Terminal Pro-Brain Natriuretic Peptide and Heart Failure Risk Among Individuals With and Without Obesity: The Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

Obesity is a risk factor for heart failure (HF) but is associated with lower N-terminal pro-brain natriuretic peptide (NT-proBNP) levels. It is unclear whether the prognostic value and implications of NT-proBNP levels for HF risk differ across body mass index (BMI) categories.

METHODS AND RESULTS

We followed up 12 230 ARIC participants free of prior HF at baseline (visit 2, 1990-1992) with BMI ≥18.5 kg/m(2). We quantified and compared the relative and absolute risk associations of NT-proBNP with incident HF across BMI categories. There were 1861 HF events during a median 20.6 years of follow-up. Despite increased HF risk in obesity, a weak inverse association was seen between baseline BMI and NT-proBNP levels (r=-0.10). Nevertheless, higher baseline NT-proBNP was associated with increased HF risk in all BMI categories. NT-proBNP improved HF risk prediction overall, even among those with severe obesity (BMI ≥35 kg/m(2); improvement in C statistic, 0.032; 95% confidence interval, 0.011-0.053). However, given the higher HF rates among those with obesity, at each NT-proBNP level, higher BMI was associated with greater absolute HF risk. Indeed, among those with NT-proBNP of 100 to <200 pg/mL, the average 10-year HF risk was <5% among normal-weight individuals but >10% among the severely obese.

CONCLUSIONS

Despite its inverse relationship with BMI, NT-proBNP provides significant prognostic information on the risk of developing HF even among individuals with obesity. Given the higher baseline HF risk among persons with obesity, even slight elevations in NT-proBNP may have implications for increased absolute HF risk in this population.

An Emerging Role of Natriuretic Peptides: Igniting the Fat Furnace to Fuel and Warm the Heart

Natriuretic peptides are produced in the heart and have been well characterized for their actions in the cardiovascular system to promote diuresis and natriuresis, thereby contributing to maintenance of extracellular fluid volume and vascular tone. For this review, we scanned the literature using PubMed and MEDLINE using the following search terms: beiging, adipose tissue, natriuretic peptides, obesity, and metabolic syndrome. Articles were selected for inclusion if they represented primary data or review articles published from 1980 to 2015 from high-impact journals. With the advent of the newly approved class of drugs that inhibit the breakdown of natriuretic peptides, thereby increasing their circulation, we highlight additional functions for natriuretic peptides that have recently become appreciated, including their ability to drive lipolysis, facilitate beiging of adipose tissues, and promote lipid oxidation and mitochondrial respiration in skeletal muscle. We provide evidence for new roles for natriuretic peptides, emphasizing their ability to participate in body weight regulation and energy homeostasis and discuss how they may lead to novel strategies to treat obesity and the metabolic syndrome.

Diagnosing and managing acute heart failure in the emergency department

Heart failure is a clinical syndrome that results from the impairment of ventricular filling or ejection of blood and affects millions of people worldwide. Diagnosis may not be straightforward and at times may be difficult in an undifferentiated patient. However, rapid evaluation and diagnosis is important for the optimal management of acute heart failure. We review the many aspects of diagnosing and treating acute heart failure in the emergency department.

Clinical value of NT-proBNP assay in the emergency department for the diagnosis of heart failure (HF) in very elderly people

OBJECTIVE

Scanty data are available on the accuracy of NT-proBNP in the diagnosis of HF and effects of comorbidities in very elderly patients.

METHODS

Symptoms, signs, NT-proBNP, eGFR, Ht, CRP and the presence of cardiomegaly and pleuric effusion were assessed in 895 consecutive patients aged 86±4.3 years admitted to Emergency Department and used to define the diagnosis of HF according to Framingham criteria. Receiver operating characteristic curves (ROC) were used to calculate diagnostic performance and cutoff of NT-proBNP. Sensitivity (Sn), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) were computed for all NT-proBNP cutoffs.

RESULTS

Satisfactory diagnostic performance was obtained with a lower threshold of 980pg/mL (Sn 0.95; NPV 0.90) and a higher threshold of 5340 (Sp 0.85; PPV 0.76) but with 42.4% of patients in the uncertainty area. We determined a second couple of cutoffs (1470-4200) that reduced the gray-area to 27.4%, maintaining an acceptable diagnostic performance compared to commonly used cutoffs (300-1800). Ht, CRP and eGFR all correlated with NT-proBNP in groups with and without HF but none affected diagnostic performance.

CONCLUSION

NT-proBNP performs satisfactorily for the diagnosis of HF in very elderly patients. Proposed threshold couple, compared with the most used cutoffs, showed a gain in Sp and PPV with a slightly lower performance in Sn and NPV and with a decrease in the gray-area with the second one. Our data do not support the use of different NT-proBNP cutoffs depending on eGFR, Ht and CRP.

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.

Impact of body mass index on plasma N-terminal ProB-type natriuretic peptides in Chinese atrial fibrillation patients without heart failure

BACKGROUND

An inverse relationship between body mass index (BMI) and circulating levels of N-terminal proB-type natriuretic peptide (NT-proBNP) has been demonstrated in subjects with and without heart failure. Obesity also has been linked with increased incidence of atrial fibrillation (AF), but its influence on NT-proBNP concentrations in AF patients remains unclear. This study aimed to investigate the effect of BMI on NT-proBNP levels in AF patients without heart failure.

METHODS

A total of 239 consecutive patients with AF undergoing catheter ablation were evaluated. Levels of NT-proBNP and clinical characteristics were compared in overweight or obese (BMI≥25 kg/m2) and normal weight (BMI<25 kg/m2) patients.

RESULTS

Of 239 patients, 129 (54%) were overweight or obese. Overweight or obese patients were younger, more likely to have a history of nonparoxysmal AF, hypertension, and diabetes mellitus. Levels of NT-proBNP were significantly lower in overweight or obese than in normal weight subjects (P<0.05). The relationship of obesity and decreased NT-proBNP levels persisted in subgroup of hypertension, both gender and both age levels (≥65 yrs and <65 yrs).Multivariate linear regression identified BMI as an independent negative correlate of LogNT-proBNP level.

CONCLUSIONS

An inverse relationship between BMI and plasma NT-proBNP concentrations have been demonstrated in AF patients without heart failure. Overweight or obese patients with AF appear to have lower NT-proBNP levels than normal weight patients.

Obesity and natriuretic peptides, BNP and NT-proBNP: mechanisms and diagnostic implications for heart failure

Many advances have been made in the diagnosis and management of heart failure (HF) in recent years. Cardiac biomarkers are an essential tool for clinicians: point of care B-type natriuretic peptide (BNP) and its N-terminal counterpart (NT-proBNP) levels help distinguish cardiac from non-cardiac causes of dyspnea and are also useful in the prognosis and monitoring of the efficacy of therapy. One of the major limitations of HF biomarkers is in obese patients where the relationship between BNP and NT-proBNP levels and myocardial stiffness is complex. Recent data suggest an inverse relationship between BNP and NT-proBNP levels and body mass index. Given the ever-increasing prevalence of obesity world-wide, it is important to understand the benefits and limitations of HF biomarkers in this population. This review will explore the biology, physiology, and pathophysiology of these peptides and the cardiac endocrine paradox in HF. We also examine the clinical evidence, mechanisms, and plausible biological explanations for the discord between BNP levels and HF in obese patients.

Clinical criteria replenish high-sensitive troponin and inflammatory markers in the stratification of patients with suspected acute coronary syndrome

OBJECTIVES

In patients with suspected acute coronary syndrome (ACS), rapid triage is essential. The aim of this study was to establish a tool for risk prediction of 30-day cardiac events (CE) on admission. 30-day cardiac events (CE) were defined as early coronary revascularization, subsequent myocardial infarction, or cardiovascular death within 30 days.

METHODS AND RESULTS

This single-centre, prospective cohort study included 377 consecutive patients presenting to the emergency department with suspected ACS and for whom troponin T measurements were requested on clinical grounds. Fifteen biomarkers were analyzed in the admission sample, and clinical parameters were assessed by the TIMI risk score for unstable angina/Non-ST myocardial infarction and the GRACE risk score. Sixty-nine (18%) patients presented with and 308 (82%) without ST-elevations, respectively. Coronary angiography was performed in 165 (44%) patients with subsequent percutaneous coronary intervention--accounting for the majority of CE--in 123 (33%) patients, respectively. Eleven out of 15 biomarkers were elevated in patients with CE compared to those without. High-sensitive troponin T (hs-cTnT) was the best univariate biomarker to predict CE in Non-ST-elevation patients (AUC 0.80), but did not yield incremental information above clinical TIMI risk score (AUC 0.80 vs 0.82, p = 0.69). Equivalence testing of AUCs of risk models and non-inferiority testing demonstrated that the clinical TIMI risk score alone was non-inferior to its combination with hs-cTnT in predicting CE.

CONCLUSIONS

In patients presenting without ST-elevations, identification of those prone to CE is best based on clinical assessment based on TIMI risk score criteria and hs-cTnT.

Amino-terminal pro-brain natriuretic peptide: a biomarker for diagnosis, prognosis and management of heart failure

There is a substantial need for a diagnostic tool to aid in the early diagnosis of heart failure and in the recognition of those at risk for its development, as well as in guidance of therapy. Testing for amino-terminal pro-brain natriuretic peptide (NT-proBNP) has been recognized to have utility in the diagnosis, prognosis and management of heart failure. In addition, numerous other applications for NT-proBNP testing are now recognized, such as evaluation of patients with heart disease in the absence of heart failure, as well as the diagnostic and prognostic evaluation of patients with acute coronary syndromes or pulmonary thromboembolism.

Can low brain-derived neurotrophic factor levels be a marker of the presence of depression in obese women?

OBJECTIVE

Depression is a common condition in obese women that can result in severe impairment of their physical and social functioning. A deficiency of brain-derived neurotrophic factor (BDNF) is involved in the mechanism of depression. The aim of this study is to investigate whether BDNF levels differ between obese female patients and healthy controls and whether BDNF levels alter with affective states in depressive obese women.

METHODS

The study group included 40 obese, 40 preobese, and 40 normal weight women. BDNF levels were measured with an enzyme-linked immunosorbent assay in patient and control groups. For identifying the depression and anxiety status, Beck Depression/Anxiety Inventories were used; and for the evaluation of cognitive functions, the mini-mental state examination was used.

RESULTS

BDNF levels were significantly lower in obese patients compared to the control group (P<0.01). BDNF levels were significantly lower in obese patients with depression compared to the obese patients without depression (P<0.05). The Beck Depression Inventory showed a negative correlation with BDNF (r=-0.044; P<0.01) and a positive correlation with the Beck Anxiety Inventory (r=0.643; P<0.001), vitamin B12 levels (r=0.023; P<0.001), and insulin levels (r=0.257; P<0.05) in obese patients. When receiver operating characteristic curve analysis was used to analyze the suitability of BDNF to identify depression in obese women, the area under the curve for BDNF, 0.756, was found to be significant (P=0.025). BDNF levels lower than 70.2 pg/mL were associated with a higher prevalence of depressive symptoms.

CONCLUSION

The results of our study suggest that the decrease in BDNF levels can be used as a marker for depression diagnosis in obese patients.

Decreased plasma B-type natriuretic peptide levels in obesity are not explained by altered left ventricular hemodynamics

SUMMARY

BACKGROUND

Although obesity has been reported to be associated with decreased plasma B-type natriuretic peptide (BNP) levels, it is unknown whether the reduced BNP levels in obesity results from decreased left ventricular (LV) hemodynamic load.

METHODS

We examined the relationships between body mass index (BMI), plasma BNP levels, and LV systolic and diastolic function (ejection fraction [EF] and end-diastolic pressure [EDP]) in 271 consecutive patients undergoing cardiac catheterization for coronary artery disease. When patients were grouped by tertile of BMI, with increasing tertiles of BMI, there was a progressive increase in EDP (lower, middle, and upper tertiles of BMI, 13.5 ± 5.8, 14.9 ± 5.3, and 16.3 ± 5.4 mmHg, respectively; p for trend <0.01) and a progressive decrease in log BNP levels (lower, middle, and upper tertiles of BMI, 3.52 ± 1.29, 2.96 ± 1.08, and 2.87 ± 1.21 ln[pg/ml], respectively, p for trend < 0.001). There was no clear difference in EF across BMI tertiles (p for trend >0.1). Plasma BNP levels correlated positively with EDP (r = 0.38, p < 0.001). In multivariate linear regression including EDP and known correlates of plasma BNP levels, BMI correlated negatively with BNP levels (standardized β = -0.31, p < 0.001).

CONCLUSIONS

We found that increased BMI was associated with LV diastolic abnormalities without change in systolic function and that patients with increased BMI had reduced plasma BNP levels despite having elevated EDP. These results suggest that the reduced BNP levels in obesity are not explained by altered LV hemodynamics.

Plasma N-terminal pro-brain natriuretic peptide: a prognostic marker in patients with chronic obstructive pulmonary disease

BACKGROUND

Plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) levels are elevated in patients with secondary pulmonary hypertension and chronic lung disease with right ventricular overload. The aim of the present study was to investigate the use of plasma NT-proBNP levels as a prognostic marker of severe COPD with chronic respiratory failure and latent pulmonary hypertension.

METHODS

Plasma NT-proBNP levels were measured in 61 patients with stable COPD. Plasma NT-proBNP levels, pulmonary function, PaO(2), and PaCO(2) levels and systolic pulmonary artery pressure were compared according to COPD severity. In addition, we examined correlations between plasma NT-proBNP levels and pulmonary function, PaO(2), PaCO(2), and systolic pulmonary artery pressure.

RESULTS

The levels of plasma NT-proBNP significantly increased in patients with stage IV and stage III COPD compared to individuals with stage II COPD according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification. The area under the receiver-operating characteristic curve of plasma NT-proBNP for severe to very severe COPD (FEV(1) <50%) was 0.707 (95% confidence interval [CI] 0.566-0.847, P=0.008). Plasma NT-proBNP levels significantly correlated with %FEV(1) (r= -0.557; P < 0.001), arterial blood gas parameters such as PaCO(2) (r = 0.476; P < 0.001) and PaO(2) (r = -0.347; P = 0.031), and systolic pulmonary artery pressure (r = 0.435; P = 0.001).

CONCLUSIONS

Plasma NT-proBNP levels increased significantly with disease severity, progression of chronic respiratory failure, and secondary pulmonary hypertension in patients with stable COPD. These results suggest that plasma NT-proBNP can be a useful prognostic marker to monitor COPD progression and identify cases of secondary pulmonary hypertension in patients with stable COPD.

Influence of age, race, sex, and body mass index on interpretation of midregional pro atrial natriuretic peptide for the diagnosis of acute heart failure: results from the BACH multinational study

AIMS

Midregional pro atrial natriuretic peptide (MR-proANP) is useful for diagnosing acute heart failure (HF) in patients presenting to the Emergency Department with dyspnoea. Optimal interpretation of MR-proANP requires understanding of how various demographic variables influence its levels and performance as a diagnostic marker. We sought to determine how age, race, sex, and body mass index (BMI) affect the levels and interpretation of MR-proANP for the diagnosis of acute HF.

METHODS AND RESULTS

The Biomarkers in Acute Heart Failure (BACH) study was an international 15-centre study of 1641 patients presenting to the Emergency Department with acute dyspnoea. Of these, 1352 had complete information on age, race, sex, and BMI. MR-proANP levels increased with age and were higher in men and in patients with lower BMI. MR-proANP performed better as a diagnostic marker in younger individuals and in blacks compared with whites. Despite this, MR-proANP at the recommended cut-off point of 120 pmol/L was >90 % sensitive in ruling out the diagnosis of acute HF in all subgroups of patients except white subjects <50 years old.

CONCLUSION

Age, race, sex, and BMI affect MR-proANP levels to various degrees. However, the diagnostic performance of the recommended cut-off point of 120 pmol/L to rule out acute HF was robust across most subgroups. Although both sex and BMI affected MR-proANP levels, they did not alter its overall diagnostic performance. Lower cut-off points for MR-proANP could be considered in younger patients and in patients with a higher BMI, to optimize diagnostic sensitivity.

Elevated N-terminal pro-brain natriuretic peptide is associated with mortality in tobacco smokers independent of airflow obstruction

Background

Tobacco use is associated with an increased prevalence of cardiovascular disease. N-terminal pro-brain natiuretic peptide (NT-proBNP), a widely available biomarker that is associated with cardiovascular outcomes in other conditions, has not been investigated as a predictor of mortality in tobacco smokers. We hypothesized that NT-proBNP would be an independent prognostic marker in a cohort of well-characterized tobacco smokers without known cardiovascular disease.

Methods

Clinical data from 796 subjects enrolled in two prospective tobacco exposed cohorts was assessed to determine factors associated with elevated NT-proBNP and the relationship of these factors and NT-proBNP with mortality.

Results

Subjects were followed for a median of 562 (IQR 252 – 826) days. Characteristics associated with a NT-proBNP above the median (≥49 pg/mL) were increased age, female gender, and decreased body mass index. By time-to-event analysis, an NT-proBNP above the median (≥49 pg/mL) was a significant predictor of mortality (log rank p = 0.02). By proportional hazard analysis controlling for age, gender, cohort, and severity of airflow obstruction, an elevated NT-proBNP level (≥49 pg/mL) remained an independent predictor of mortality (HR = 2.19, 95% CI 1.07–4.46, p = 0.031).

Conclusions

Elevated NT-proBNP is an independent predictor of mortality in tobacco smokers without known cardiovascular disease, conferring a 2.2 fold increased risk of death. Future studies should assess the ability of this biomarker to guide further diagnostic testing and to direct specific cardiovascular risk reduction inventions that may positively impact quality of life and survival.

Cardiac natriuretic peptides, obesity, and insulin resistance: evidence from two community-based studies

BACKGROUND

The natriuretic peptides play an important role in salt homeostasis and blood pressure regulation. It has been suggested that obesity promotes a relative natriuretic peptide deficiency, but this has been a variable finding in prior studies and the cause is unknown.

AIM

The aim of this study was to examine the association between obesity and natriuretic peptide levels and evaluate the role of hyperinsulinemia and testosterone as mediators of this interaction.

METHODS

We studied 7770 individuals from the Framingham Heart Study (n = 3833, 54% women) and the Malmö Diet and Cancer study (n = 3918, 60% women). We examined the relation of plasma N-terminal pro-B-type natriuretic peptide levels (N-BNP) with obesity, insulin resistance, and various metabolic subtypes.

RESULTS

Obesity was associated with 6-20% lower levels of N-BNP (P < 0.001 in Framingham, P = 0.001 in Malmö), whereas insulin resistance was associated with 10-30% lower levels of N-BNP (P < 0.001 in both cohorts). Individuals with obesity who were insulin sensitive had only modest reductions in N-BNP compared with nonobese, insulin-sensitive individuals. On the other hand, individuals who were nonobese but insulin resistant had 26% lower N-BNP in Framingham (P < 0.001) and 10% lower N-BNP in Malmö (P < 0.001), compared with nonobese and insulin-sensitive individuals. Adjustment for serum-free testosterone did not alter these associations.

CONCLUSIONS

In both nonobese and obese individuals, insulin resistance is associated with lower natriuretic peptide levels. The relative natriuretic peptide deficiency seen in obesity could be partly attributable to insulin resistance, and could be one mechanism by which insulin resistance promotes hypertension.

Brain natriuretic peptide measurement in pulmonary medicine

Serum levels of natriuretic peptides are well established as important biomarkers in patients with cardiac disease. Less attention has been placed on the role of natriuretic peptides in patients with pulmonary conditions. In several well-defined groups of patients with pulmonary disease natriuretic peptides provide the clinician with clinically valuable information. A limitation of the interpretation of natriuretic peptides in pulmonary disease is the confounding effect of concurrent conditions such as heart failure, hypoxia, sepsis and renal failure. The present paper reviews the role of natriuretic peptides for diagnosis, risk stratification and prognosis of several pulmonary disorders.

Cardiac assessment of patients with late stage Duchenne muscular dystrophy

Background. Duchenne muscular dystrophy (DMD) patients used to die mainly from pulmonary problems. However, as advances in respiratory care increase life expectancy, mortality due to cardiomyopathy rises. Echocardiography remains the standard diagnostic modality for cardiomyopathy in DMD patients, but is hampered by scoliosis and poor echocardiographic acoustic windows in adult DMD patients. Multigated cardiac radionuclide ventriculography (MUGA) does not suffer from these limitations. N-terminal proBNP (NTproBNP) has shown to be a diagnostic factor for heart failure. We present our initial experience with plasma NT-proBNP measurement in the routine screening and diagnosis of cardiomyopathy in adult mechanically ventilated DMD patients.Methods. Retrospective study, 13 patients. Echocardiography classified left ventricular (LV) function as preserved or depressed. NT-proBNP was determined using immunoassay. LV ejection fraction (LVEF) was determined using MUGA.Results. Median (range) NT-proBNP was 73 (25 to 463) ng/l. Six patients had an NT-proBNP >125 ng/l. Seven patients showed an LVEF <45% on MUGA. DMD patients with depressed LV function (n=4) as assessed by echocardiography had significantly higher median NT-proBNP than those (n=9) with preserved LV function: 346 (266 to 463) ng/l versus 69 (25 to 257) ng/l (p=0.003). NT-proBNP significantly correlated with depressed LV function on echocardiogram and with LVEF determined by MUGA.Conclusion. Although image quality of MUGA is superior to echocardiography, the combination of echocardiography and NT-proBNP achieves similar results in the evaluation of left ventricular function and is less time consuming and burdensome for our patients. We advise to add NT-proBNP to echocardiography in the routine cardiac assessment of DMD patients. (Neth Heart J 2009;17:232-7.).

N-terminal pro-B-type natriuretic peptide in early and advanced phases of obesity

BACKGROUND

Increased plasma amino-terminal-cleavage-fragment of NP (NT-proBNP) is an established indicator for heart failure. Moreover, obese adults had low circulating NT-proBNP suggesting an obesity-related dysregulation (natriuretic handicap). Secretion and/or clearance of NT-proBNP were discussed to be impaired in obesity. As only older adults were investigated so far, it remains unclear when during the evolution of obesity the state of a natriuretic handicap develops, and whether NT-proBNP may still serve as a relevant cardiac marker in obese juveniles.

METHODS

We analysed NT-proBNP in juvenile (n=274, 10-18 years) and middle-aged (n=277, 18-50 years) normal weight (n=213) and obese (n=338) probands together with complex anthropometry, carotis sonography, clinical, and laboratory parameters.

RESULTS

NT-proBNP showed a significant gender and age interaction. Adult females had significant higher NT-proBNP than adult males, and higher levels than juvenile females. Adult males had lower levels than juvenile males. Only a weak age and weight interaction was seen with obese juveniles which showed higher NT-proBNP than obese adults. Moreover, normal weight probands had higher NT-proBNP than overweight and obese. In a multiple regression including all probands, gender, creatinine and uric acid were the best predictors for NT-proBNP. In adults, female gender is the strongest driver for increased NT-proBNP.

CONCLUSIONS

These results argue against an essential influence of obesity to B-type cardiac natriuretic hormone system regulation in the absence of heart failure, and suggest NT-proBNP as a useful cardiac marker irrespective of age and obesity.

Body mass index and adverse cardiovascular outcomes in heart failure patients with preserved ejection fraction: results from the Irbesartan in Heart Failure with Preserved Ejection Fraction (I-PRESERVE) trial

BACKGROUND

Obesity is a major risk factor for incident heart failure (HF). Paradoxically, in HF with reduced left ventricular ejection fraction (HFREF), a high body mass index (BMI) appears to be beneficial. Approximately 50% of HF patients have a preserved left ventricular ejection fraction (HFPEF). However, there are few data regarding the relationship between BMI and outcomes in HFPEF.

METHODS AND RESULTS

Baseline characteristics and cardiovascular outcomes were assessed in the 4109 patients (mean age, 72 years; mean follow-up, 49.5 months) in the Irbesartan in HF with Preserved Ejection Fraction (I-PRESERVE) trial. Based on the BMI distribution, 5 BMI categories were defined: <23.5, 23.5 to 26.4, 26.5 to 30.9, 31 to 34.9, and ≥35 kg/m(2). Most patients (71%) had a BMI ≥26.5, 21% had a BMI between 23.5 and 26.4, and 8% had a BMI <23.5 kg/m(2). Patients with higher BMI were younger, more often women, and more likely to have hypertension and diabetes and higher left ventricular ejection fraction. Patients with BMI of 26.5 to 30.9 kg/m(2) had the lowest rate for the primary composite outcome (death or cardiovascular hospitalization) and were used as reference group. After adjustment for 21 risk variables including age, sex, and N-terminal pro-brain natriuretic peptide, the hazard ratio for the primary outcome was increased in patients with BMI <23.5 (hazard ratio, 1.27; 95% confidence interval, 1.04 to 1.56; P=0.019) and in those with BMI ≥35 kg/m(2) (hazard ratio, 1.27; 95% confidence interval, 1.06 to 1.52; P=0.011) compared with the referent group. A similar relationship was found for all-cause mortality and for HF hospitalization.

CONCLUSIONS

Obesity is common in HFPEF patients and is accompanied by multiple differences in clinical characteristics. Independent of other key prognostic variables, there was a U-shaped relationship, with the greatest rate of adverse outcomes in the lowest and highest BMI categories.

CLINICAL TRIAL REGISTRATION- URL

http://www.clinicaltrials.gov. Unique identifier: NCT000095238.

Relationship between N-terminal pro-B-type natriuretic peptide plasma levels and renal function evaluated with different formulae in older adult subjects admitted because of dyspnea

BACKGROUND

N-terminal pro-B-type natriuretic peptide (NT-proBNP) plasma levels are associated with congestive heart failure severity, and are an important diagnostic tool for assessing patients with acute dyspnea. Reduced renal function increases NT-proBNP concentrations, and therefore it might be a confounding factor in chronic kidney disease (CKD) patients.

OBJECTIVE

The aim of the present study was to relate NT-proBNP plasma levels to different stages of renal function assessed with different methods in older adult subjects admitted because of dyspnea.

METHODS

NT-proBNP plasma levels (Roche Diagnostic, Mannheim, Germany) were measured in 134 older adult patients (age: 80 ± 6 years) admitted to hospital because of dyspnea. Anthropometrics, anamnesis, and biochemical data were collected. Glomerular filtration rate (GFR) was evaluated with different equations, the 4 variables MDRD equations (GFR(MDRD186), GFR(MDRD175)), Mayo Clinic Quadratic formula (GFR(MAYO)), and the new CKD-EPI formula (GFR(CKD-EPI)). Patients were classified into the five K/DOQI stages of CKD and median NT-proBNP values were calculated evaluating their relationship with GFR.

RESULTS

Median NT-proBNP values were better stratified into the five K/DOQI stages by GFR(MAYO) (stage 1 (n = 10) 1,640 pg/ml vs. stage 2 (n = 61) 2,371 pg/ml vs. stage 3 (n = 42) 3,815 pg/ml vs. stage 4 (n = 18) 6,320 pg/ml vs. stage 5 (n = 3) 7,256 pg/ml, p = 0.017). However, similar results were obtained with the other formulae. NT-proBNP was negatively correlated with GFR as evaluated with all the different formulae (r -0.25 to -0.29; all p < 0.01). Multiple regression analysis confirmed the independent association between LnNT-proBNP and GFR.

CONCLUSION

NT-proBNP plasma levels progressively increase with worsening of renal function, and appear to be related to the five K/DOQI stages of CKD. For this purpose, GFR assessed with the GFR(MAYO) formula appears to better stratify NT-proBNP in older adult subjects. Renal function should be considered when interpreting NT-proBNP levels in older adult patients admitted for dyspnoea.

Impact of obesity on plasma B-type natriuretic peptide levels in Japanese community-based subjects

The plasma B-type natriuretic peptide (BNP) concentration was recently shown to be inversely correlated with body mass index (BMI). However, very few attempts have been made to associate abdominal obesity and BNP in the Japanese general population. Here, we conducted a cross-sectional study, and examined 339 male and 429 female residents without heart disease in a rural Japanese community who received an annual health checkup in 2006. BNP was inversely associated with both BMI and abdominal circumference (AC) in the age-adjusted regression analysis (p < 0.05). Following adjustment for traditional risk factors, multiple regression analysis revealed that BNP was negatively correlated with AC (p < 0.05), but not BMI. Although metabolic syndrome was not associated with BNP levels, AC had an influence on low BNP levels in the multiple regression analysis using both AC and BMI concurrently (p < 0.05 for AC and p > 0.60 for BMI). These effects were more prominent in men than in women. Collectively, plasma BNP levels are inversely related with obesity, as measured by AC, in Japanese community-based subjects.

Relationship between N-terminal pro-B-type natriuretic peptide levels and metabolic syndrome

INTRODUCTION

Previous studies have shown that obese individuals have reduced natriuretic peptide levels. But conflicting data exist on the relation of natriuretic peptide levels to other metabolic risk factors.

MATERIAL AND METHODS

We investigated the relationship between plasma N-terminal pro-B-type natriuretic peptide levels (NT-proBNP) and metabolic syndrome (MetS) and metabolic risk factors in 469 patients free of heart failure. Two hundred thirty diagnosed MetS cases and 239 non-MetS cases were included in this study. Echocardiography examinations were performed and left ventricular mass index was calculated according to the Devereux correction formula. NT-proBNP was measured by electrochemiluminescence. The log-transformed NT-proBNP levels were used for abnormal distribution. Multiple linear regression analysis was performed to assess the association between levels of NT-proBNP and metabolic factors. Covariance analysis was used for group comparisons.

RESULTS

Log NT-proBNP levels were independently related to age, gender, body mass index, systolic blood pressure, diastolic blood pressure, fasting blood glucose, triglyceride, high density lipoprotein cholesterol, low density lipoprotein cholesterol, left ventricular mass index and left ventricular ejection fraction in multiple linear regression analysis (p < 0.05). Adjusted log NT-proBNP levels were lower in persons with MetS compared with those without MetS (p < 0.05). Individuals with hyperlipidaemia, elevated body mass index, diastolic blood pressure and fasting plasma glucose had lower levels of log NT-proBNP than those without MetS (p < 0.05).

CONCLUSIONS

There is a relationship between metabolic components and lower plasma NT-proBNP concentration. These findings raise the possibility that reduced plasma NT-proBNP levels are a manifestation of MetS, which might possess significant clinical and pathophysiological implications.

Prognostic values of NTpro BNP/BNP ratio in comparison with NTpro BNP or BNP alone in elderly patients with chronic heart failure in a 2-year follow up

BACKGROUND

Plasma BNP and NT-proBNP are often used as interchangeable parameters in heart failure care in clinical practice. In our previous study we have shown that inflammation was able to induce increased NT pro BNP in a hospital cohort with chronic heart failure in the elderly, indicating that NT-proBNP/BNP ratio should be evaluated concomitantly with inflammatory status to avoid overestimation of heart failure severity. The present study was aimed to evaluate the clinical significance of NT-proBNP/BNP ratio in comparison with NTpro BNP or BNP alone as a prognostic indicator in a 2-year follow up of elderly heart failure population.

MATERIALS AND METHODS

One hundred and eight-nine elderly heart failure patients (72 ± 11 years, male 52%, LVEF 46 ± 14%) were enrolled consecutively during 2006 and 2007 and followed up during 2 years. NTpro BNP and BNP were measured routinely.

RESULTS

We have found that NTpro BNP/BNP ratio provides no additional prognostic information during follow up as compared to NTpro BNP or BNP alone in an elderly population with chronic heart failure. By the use of ROC curves, for total mortality predictive accuracy during 2 years, the cut-off values are NTproBNP ≥ 800 pg/ml, BNP > 60 pg/ml and NTpro BNP/BNP ratio>6.4 respectively. In terms of NTpro BNP, as long as its serum level is above 2000 pg/ml it indicates poor prognosis. However there is an overlap between serum concentration range 2000-8000 pg/ml and >8000 pg/ml in terms of prognostic indicator. Similarly for BNP, as long as its serum level is above 100 pg/ml, it indicates poor prognosis. However there is an overlap between serum concentration range 100-800 pg/ml and >800 pg/ml in terms of prognostic indicator. There was significant correlation between survival and NTpro BNP, BNP and Cystatin-C but not with NTpro BNP/BNP ratio. Such correlation exists irrespective of subgroups regardless of less than or older than 70 years old.

CONCLUSIONS

Our results demonstrated that in elderly heart failure population NTpro BNP/BNP ratio may provide diagnostic help in the presence of acute infection but no additional prognostic information in the long run as compared with NTpro BNP or BNP alone. Furthermore, both NTpro BNP and BNP are useful prognostic biomarkers indeed but they need to be interpreted with caution when it is used as a single biomarker and in the meantime concomitant diseases exist because patients may die due to non-cardiac causes.