[Brain natriuretic peptide. Diagnostic value in heart failure]

The effect of subclinical thyroid dysfunction on B- type natriuretic peptide level

Thyroid hormones (THs) have a significant effect on the cardiovascular system. THs increase myocardium stretch, leading to the release of B-type Natriuretic Peptide (BNP), which is considered a diagnostic biomarker of heart failure (HF). Thyroid dysfunctions (subclinical hypothyroidism; SCH and subclinical hyperthyroidism; SCHyper) stimulate several changes in the heart by causing either diastolic or systolic left ventricular dysfunctions leading to HF. This study aims to measure the changes of B- type NP levels in cases of subclinical hypo and hyperthyroidism. The present study aims to measure the changes in B-type Natriuretic Peptide (BNP) levels in subclinical hypo and hyperthyroidism (SCH and SCHyper). A theoretical study was also conducted using a docking program to find the effectiveness of some drugs in inhibiting or promoting B-type Natriuretic Peptide (BNP). A case study was conducted in a private clinic, Mosul- Iraq, from (April 1st – Sep 1) 2021, with 25 healthy participants with normal functioning thyroids as a control group (EU). A newly diagnosed 25 SCH and 17 SCHyper patients participated in this study, considering that none of them have thyroid dysfunctions taking medicine, hypertension, heart diseases, renal failure, and pregnant women. They all were checked for Thyroid Function Tests (TFTs), Free Triiodothyronine (FT3), Free Thyroxin (FT4) and Thyroid Stimulating Hormone (TSH). The plasma level of BNP was measured in all participants of the three groups. The results showed that the plasma level of BNP was higher in SCHyper patients (10.97 pg/ml) as compared to that of SCH patients (8.09 pg/ml) and EU subjects (8.27 pg/ml). Hereby, we could state that subclinical hyperthyroidism, SCHyper, triggers BNP release. Therefore, it should be kept in mind that any high BNP levels due to SCHyper should be considered a reliable diagnostic biomarker of heart failure (HF). Keywords. Thyroid hormone(TH), Subclinical hypothyroidism(SCH), Subclinical hyperthyroidism(SCHyper), Chronic heart disease(CHD), Heart failure(HF), B-type natriuretic peptide(BNP), Docking Study.

Factors Affecting the B-Type Natriuretic Peptide Levels in Stroke Patients

Introduction: This study aims to evaluate the relationship between increased B-type natriuretic peptide (BNP) levels in stroke patients and clinical parameters such as age, sex, medical history, blood pressure, Glasgow Coma Score (GCS) and National Institutes of Health Stroke Scale (NIHSS). Materials and Methods: This is a prospective study of 123 stroke patients at the Emergency Department. The patients were divided into 3 groups according to the NIHSS scores. The analysis of the mean difference between continuous variables and plasma BNP levels was assessed using the Mann-Whitney and Kruskal-Wallis. Spearman correlation analysis was performed for BNP and other clinical parameters. Results: The BNP levels of patients who had a medical history of hyperlipidaemia, chronic obstructive pulmonary disease, diabetes mellitus and coronary artery disease were significantly higher than in patients without these diseases. Patients who had atrial fibrillation (AF) in their electrocardiography had significantly higher BNP levels than patients with sinus rhythm. A positive correlation was found between plasma BNP levels with age, blood urea nitrogen (BUN) and NIHSS and a negative correlation was found between plasma BNP levels and GCS. There was a significant difference between the BNP levels of NIHSS groups. Conclusion: We consider that plasma BNP levels could help us in interpreting the general clinical severity, functional capacity and clinical progress of stroke patients at the time of admission in the Emergency Department. In evaluating the high BNP levels in stroke patients, we must keep in mind that age, AF, BUN and medical history can affect the BNP levels. Key words: Emergency Department, Progress, Relationship

Prognostic relationship between two serial determinations of B-type natriuretic peptide and medium-long-term events in heart transplantation

BACKGROUND

Persistent elevation of B-type natriuretic peptide (BNP) levels in the first year after transplant appears to be associated with an adverse prognosis. However, there are no data on the prognostic value of two serial determinations of BNP at the end of the first year after transplant in clinically stable patients.

OBJECTIVES

The purpose of this study was to analyze the association between the increase in two serial determinations of BNP at the end of the first year and the subsequent development of events in medium-long-term follow-up.

METHODS

An observational study was conducted in a consecutive series of 71 patients transplanted between January 1999 and January 2001. Patients who were "unstable" or had other conditions that could elevate BNP levels (rejection, elevated pulmonary pressures, renal dysfunction, depressed ventricular function or severe graft vascular disease) were also excluded. The final number of patients included was 51. BNP determinations were performed at 9 and 12 months post-transplant at the same time as biopsies. Three groups were formed depending on the relationship between the two determinations: Group 1 (20 patients), decrease >20%; Group 2 (16 patients), change <20%; and Group 3 (15 patients), increase >20%. The following were considered events: death; late rejection; and ventricular dysfunction associated or not with graft vascular disease.

RESULTS

The baseline clinical profile was similar in the three groups. There was a significant difference in the rate of events (Group 1, 10%; Group 2, 32%; Group 3, 53%; p < 0.017). Event-free survival was statistically different between the groups (p = 0.017), mainly because of the large difference between Groups 1 and 3 (p = 0.003). Thus, cumulative event-free survival at 3,000 days was 89.4% for Group 1, 68.3% for Group 2 and 48.2% for Group 3.

CONCLUSIONS

The increase between two serial determinations of BNP levels at the end of the first year post-transplant could identify a subgroup of patients with poor outcome.

Maximum longitudinal relaxation velocity of the left ventricle: its clinical value and relationship with NT-proBNP plasma levels in heart failure

BACKGROUND

M-mode recordings of the mitral annulus to measure the maximum ascending velocity during early diastole as an expression of maximum longitudinal relaxation velocity of the left ventricle (RVm) can be used as an index of left ventricular (LV) diastolic function. The purpose of this study was to determine the relationship of RVm with LV functional parameters in patients with heart failure, with N-terminal pro-brain natriuretic peptide (NT-proBNP) plasma levels, and with their functional classification.

METHODS AND RESULTS

RVm was recorded in 97 patients by M-mode echocardiography. Patients were classified according to the New York Heart Association (NYHA) and the concentration of NT-proBNP was determined. Patients with ejection fraction (EF)>40 showed a significant correlation between RVm and mitral annulus motion (MAM), mitral flow propagation velocity, E/A, age, deceleration time (DT), and NT-proBNP. In patients with EF<or=40, RVm correlated significantly with MAM, EF, and NT-proBNP. RVm values were higher in NYHA class I compared to II and III, P<0.0001.

CONCLUSIONS

RVm correlates better with functional parameters in patients with EF>40, though its relationship with NT-proBNP both in patients with EF>or<or=40 is to be highlighted. Correlation between RVm and NT-proBNP is influenced by age, EF, and E/A, whereas in patients with EF>40 it is influenced only by age. RVm values showed a significant decrease in NYHA class II and III.

Accuracy of B-type natriuretic peptide levels in the diagnosis of left ventricular dysfunction and heart failure: a systematic review

OBJECTIVES

To evaluate the accuracy of B-type natriuretic peptide levels (BNP) in the diagnosis of heart failure and left ventricular dysfunction.

DATA SOURCES

Electronic search in Medline, Embase, Cochrane Library and Medion database, and hand search of reference lists.

REVIEW METHODS

We have included published studies on the accuracy of BNP which had both sufficient information to construct the 2x2 diagnostic cross table and an appropriate spectrum of patients.

RESULTS

Fifty five studies (16,730 patients) were analyzed. The main determinants of diagnostic accuracy were the reference standard analyzed (clinical heart failure versus left ventricular dysfunction), and the methodological quality of the study. BNP levels were highly accurate for the diagnosis of clinical heart failure (diagnostic OR=41; 95% CI 23-74). The negative likelihood ratios were homogeneous, and useful for excluding the existence of heart failure (pooled negative likelihood ratio=0.11; 95% CI 0.08-0.16). The studies focused on the identification of left ventricular dysfunction were heterogeneous, with indications of publication bias, and showed less overall diagnostic accuracy than studies focused on heart failure.

CONCLUSIONS

BNP levels are useful for ruling out heart failure. The accuracy of BNP for identifying patients with systolic dysfunction is more limited.

Predictive value of brain natriuretic peptide in the diagnosis of heart transplant rejection

AIM

To evaluate the pattern of brain natriuretic peptide (BNP) concentration in heart transplant (HT) recipients and its relation to the degree of graft rejection determined by endomyocardial biopsy specimen.

METHODS

We studied 71 consecutive HT recipients (62 men, 53 +/- 11 years). The patients underwent 383 biopsies. Creatinine and BNP concentrations and hemodynamic parameters were determined along with the degree of graft rejection using endomyocardial biopsy specimens. We considered treatable rejection as International Society for Heart and Lung Transplantation Grade >or=2 in the first 90 days and >or=3A thereafter. We included a control group of 36 healthy individuals.

RESULTS

Brain natriuretic peptide concentration was significantly greater among HT recipients (264 +/- 318 pg/ml) than in controls (17 +/- 16 pg/ml). In the first 90 days, BNP concentration was significantly greater among the patients with graft rejection (510 +/- 470, n = 84, vs 278 +/- 255, n = 87; p < 0.0001), although the corresponding discriminatory capacity was small. After the first 90 days, BNP values were similar in patients with and without graft rejection (170 +/- 297, n = 17, vs 142 +/- 203, n = 195; p = not significant). Creatinine concentration increased with time after transplantation and did not correlate with BNP concentration. We observed significant positive correlation between BNP concentration and hemodynamic parameters.

CONCLUSIONS

Brain natriuretic peptide concentration remains increased after HT, with stabilization after the 4th month. Brain natriuretic peptide concentrations are slightly greater among patients with treatable rejection, particularly in the first 90 days, although BNP concentration lacks discriminatory capacity to serve as a guide to performing biopsy.

N-terminal probrain natriuretic peptide (NT-proBNP) in the emergency diagnosis and in-hospital monitoring of patients with dyspnoea and ventricular dysfunction

OBJECTIVE

To evaluate the utility of NT-proBNP in the emergency diagnosis and in-hospital monitoring of patients with acute dyspnoea and ventricular dysfunction.

BACKGROUND

Misdiagnosis of heart failure (HF) is common in the urgent care setting using clinical diagnostic tests. Reports show that BNP is useful to diagnose HF in patients with acute dyspnoea.

METHODS

Prospective study of 100 patients attending the Emergency Department (ED) for acute dyspnoea. Final diagnosis was determined on the basis of ED data sheets, echocardiography and pulmonary function tests. NT-proBNP levels were obtained on admission, at 24 h and at day 7.

RESULTS

Patients with ventricular dysfunction were sub-classified into decompensated HF and masked HF, defined as HF with concomitant signs of pulmonary disease. Decompensated and masked HF patients had significantly higher NT-proBNP values than patients with non-cardiac dyspnoea (normal ventricular function) (920+/-140 and 978+/-363 vs. 50+/-15 pmol/L; P<0.001 and P<0.01, respectively). The mean area under the ROC curve for NT-proBNP was 0.957 (95% CI, 0.918 to 0.996, P<0.001). In multiple logistic-regression analysis NT-proBNP>115 pmol/l was the strongest independent predictor of ventricular dysfunction (odds ratio 45.4; 95% CI: 4.5-452.3). At day 7, a significant and similar reduction in NT-proBNP was observed in the two groups of patients with ventricular dysfunction (P<0.001 vs. admission values), but complete clinical resolution was less frequent in masked HF patients (P<0.05 vs. decompensated HF).

CONCLUSIONS

NT-proBNP is a new candidate marker for the detection and exclusion of ventricular dysfunction in patients attending the ED for acute dyspnoea. NT-proBNP may also serve to monitor outcome during hospitalization.

Ventricular natriuretic peptide (BNP) in heart transplantation: BNP correlation with endomyocardial biopsy, laboratory and hemodynamic measures

A prospective study of 81 heart transplant (HT) patients was carried out in order to evaluate the evolution of brain natriuretic peptide (BNP) levels in HT patients and compare them with the degree of rejection as determined by endomyocardial biopsy. All patients were subjected to endomyocardial biopsy (532), and determination of BNP and creatinine levels as well as hemodynamic parameters. A control group of 36 volunteers was included. BNP values were significantly greater in HT patients than in healthy volunteers. In the first 3 months, BNP levels in patients with treatable rejection were significantly greater than in patients without graft rejection, although evident overlapping was observed in both distributions and discriminatory potential was low. After the third month, BNP values were similar in patients with and without rejection. Creatinine levels were observed to increase over time after transplantation, but no correlation was observed between the creatinine and BNP levels. A significant positive correlation was observed between BNP and right ventricle and pulmonary arterial pressures.

Radioimmunometric assay of B-type natriuretic peptide (BNP) in heart transplantation: correlation between BNP determinations and biopsy grading of rejection

The aim of this study was to determine whether elevated brain natriuretic peptide (BNP) levels after heart transplantation are correlated with the severity of rejection by using endomyocardial biopsy (EMB) and echocardiographic parameters indicative of ventricular function of the transplanted heart. This was an observational study of 80 orthotopic heart transplant recipients (11 women and 69 men; mean age 53+/-11 years). BNP determinations were performed within 48 h of endomyocardial biopsy. The echocardiographic study and BNP determination were also performed in a group of healthy volunteers. We found significantly higher BNP mean levels in heart transplant patients than in healthy volunteers (volunteers, 16.7+/-16.2 pg.ml-1; transplant, 213.4+/-268.6 pg.ml-1; P<0.001). Transplant recipients with rejection grades 2, 3 and 4 on EMB had significantly higher BNP levels than those with rejection grades 0 and 1 (higher rejection grade, 162.5+/-168.4 pg.ml-1; lower rejection grade, 292+/-361.8 pg.ml-1; P<0.01). BNP values of patients with good left ventricular function (LVF) were significantly lower than in patients with mildly and moderately impaired LVF and patients with severely impaired LVF (good function, 199.76+/-233.6 pg.ml-1; mildly/moderately impaired LVF, 937+/-644.5 pg.ml-1; severely impaired LVF, 1038+/-491.2 pg.ml-1; P<0.001). It is concluded that BNP plasma levels are elevated in heart transplant patients compared to the normal population. The distribution of BNP levels in heart transplanted patients show a wide range. BNP elevation is greater in patients with higher rejection grades on EMB and greater impairment of left ventricular function.

[Value of NTproBNP concentration in an out-of-hospital adult population]

INTRODUCTION

The diagnosis of chronic heart failure (CHF) is based on demonstrating the cardiac origin of clinical manifestations. Echocardiography is the method of choice for the detection of left ventricular systolic dysfunction (LVSD). Brain natriuretic peptide (BNP) rises during LVSD.

OBJECTIVES

To analyze the plasma concentration of N-terminal brain natriuretic propeptide (NTproBNP) in a general adult population in relation to different spontaneous circumstances and to study its capacity for identifying patients with LVSD.Methods. A cardiological examination was made and plasma NTproBNP levels were measured in a randomized group of 203 people (49-81 years old) from the Community of Valencia.

RESULTS

The average NTproBNP concentration was 52.2 98.2 pmol/l. NTproBNP levels varied with age, gender and functional stage (NYHA). The highest NTproBNP values were observed in people who had previously suffered from acute pulmonary edema or who had an ejection fraction (EF) of less than 40%. There was also a significant elevation in patients with nocturnal dyspnea, orthopnea, atrial fibrillation, EF < or = 50%, angina, and ankle edema. The best concentration of NTproBNP for differentiating EF < or = 50% was 37.7 pmol/l, with 92% sensitivity and 68% specificity.

CONCLUSIONS

The elevation of NTproBNP concentration indicates the cardiac origin of clinical manifestations and serves to select patients for echocardiographic examination. Low NTproBNP concentrations help to rule out LVSD.

NT-proBNP y desplazamiento del plano auriculoventricular. Relación e implicaciones diagnósticas

INTRODUCTION AND OBJECTIVES

NT-proBNP is useful in the diagnosis of heart failure and ventricular dysfunction. Left atrioventricular plane displacement (AVPD) is a consolidated index of ventricular function. Our objective was to carry out a multicenter population-based study to establish the relationship between plasma NT-proBNP levels with AVPD values.

PATIENTS AND METHOD

We studied 215 subjects (age 66 9 years; 57.7% women) chosen from a random sample of 432 people from the Community of Valencia, who previously reported suffering from some degree of dyspnea. Doppler echocardiography was done, AVPD was calculated and plasma NT-proBNP concentrations were determined. All studies were completed in 194 patients.

RESULTS

For the whole population NT-proBNP was 88 (0-2,586) pg/ml and AVPD was 11.9 1.6 mm. NT-proBNP concentration correlated well with AVPD (r = 0.44; p < 0.00001), and higher peptide levels were obtained in AVPD quartiles that indicated less displacement (p < 0.05). When NT-proBNP values were grouped according to their association with AVPD lower or higher than the 50th percentile AVPD, the difference was significant at p < 0.01. When AVPD values lower and higher than 10 mm were compared, NT-proBNP values were higher in persons with AVPD lower than 10 mm (p < 0.05).

CONCLUSIONS

This population study found higher NT-proBNP concentrations in subjects with lower AVPD, and illustrates the potential diagnostic usefulness of NT-proBNP in clinical practice.