ABSTRACT

Background

Heart failure is a clinical condition in which a deviation in normal cardiac structure or function is accountable for the incapability of the heart to eject or fill with blood at a proportion proportionate to the requirements of the metabolizing tissues. The detection of heart failure is based on clinical symptoms, signs, chest x rays and reaction to the treatment. BNPs are released by the heart ventricles in reaction to volume load or pressure load physiologically and they function to counteract rennin angiotensin system, cause vasodilatation and natriuresis. The BNP evaluation has gained approval already in the recommendations of European Society of Cardiology for the detection of heart failure. We wanted to study the potential of a new unconventional assay plasma N-Terminal pro BNP in detecting cardiac failure, and correlate the levels of plasma N-Terminal pro BNP with the severity of the cardiac failure and levels of plasma N-Terminal Pro BNP with systolic and diastolic dysfunction.

Methods

It was an analytical cross-sectional study conducted among 50 patients with clinical features of cardiac failure attending medicine OPD and emergency department of the hospital for the duration of 18 months and an equal number of age and sex equivalent fit controls. In subjects with clinical features of heart failure, and in healthy controls, 2 mL of blood sample is drawn for assay of plasma N-Terminal pro BNP within half an hour of presentation. Using biomedical kit plasma N-T pro BNP concentration was measured. The entire period of the assay is 18 min. Detectability range by this method of N-T proBNP is 5 pg/mL to 35,000 pg/mL.

Results

Cases comprised of 28 males and 22 females with a mean age 50.80 (13.11) years while controls comprised of 28 males and 22 females with a mean age 50.86 (12.7) years. There was a statistically noteworthy difference in Mean N-T pro BNP between case and control groups, NYHA Class, and age group. Mean N-T pro-BNP is not significantly different at discharge and on 2^nd follow-up. For the rest of the diagnoses, there is a notable difference in Mean N-T pro BNP at discharge and on 2^nd follow-up.

Conclusions

Plasma N-Terminal pro BNP levels are useful from therapeutic point of view (aggressive therapy if needed e.g. Heart transplantation / bilateral pacemaker or invasive therapy may be planned by N-T pro BNP levels).

Key words

Brain Natriuretic Peptide, Cardiac Failure, Diagnostic Value

BACKGROUND

Heart failure is a usual and very morbid disease. It is an increasing worldwide epidemic. The Economic burden innovated by Heart failure is quite enormous and is expected to grow dramatically in light of current clinical and demographic trends, particularly with the recent improvement in survival rate after myocardial infarction due to early thrombolysis and revascularization surgery. Thus, it is predicted that the disease load of Heart Failure will nearly increase two fold over the next thirty to forty years.¹

Heart failure is a clinical condition in which a deviation in normal cardiac structure or function is liable for the incapability of the heart to eject or fill with blood at a rate proportionate with the necessities of the metabolizing tissues.²

The detection of Heart failure is based on clinical symptoms, signs, chest X rays and reaction to the treatment. Echocardiography detects the particular structural and functional deformities seen in the syndrome but do not solely decide the detection of Heart failure. The severity of clinical manifestations is commonly described according to criteria developed by the New York Heart Association.³

The signs and symptoms may be challenging to identify in patients with acute respiratory distress particularly in cases where quick diagnosis and treatment are desired. The echocardiogram is useful to diagnose the existence of systolic defect. However, studies have indicated that a 50% of patients with well-established clinical Heart failure have an absolutely normal systolic work (diastolic heart failure). In addition to it, nearly half of patients with systolic defect have no changes of Heart failure (asymptomatic ventricle defect).⁴

Hence a decreased ejection fraction does not ascertain the diagnosis of Heart failure. Moreover, the availability of echocardiography is less in critical care settings. Therefore, there has been a sudden rise in the interest of physicians in a cheap, commonly available, easily accessible diagnostic test that indicates the physiology similar to patients with systolic Heart failure and diastolic Heart failure.⁵

BNPs are released from the heart ventricles in reaction to volume load or pressure load physiologically and they function to counteract rennin angiotensin system, cause vasodilatation and natriuresis.^6,7,8 Detection of plasma levels of N-Terminal Pro BNP is sanctioned by the FDA as a test to support in the detection of Heart failure. Approval of this diagnostic assessment was centred on many research studies that explored the efficacy of Brain Natriuretic peptide in assessing patients coming with symptoms like dyspnoea. These studies have indicated that BNP differentiates correctly among Heart failure and non-Cardiac dyspnoea in various critical care hospitals and primary care centres.^9,10,11,12

The BNP test has been approved already in the European Society of Cardiology recommendations for the detection of Heart failure.¹³ This study has been performed to study the role of plasma N-Terminal Pro BNP in the detection of Heart failure and evaluating plasma N-Terminal Pro BNP levels in various forms of systolic and diastolic Heart failure.

We wanted to study the potential of new unconventional assay plasma N-terminal pro BNP in detecting the cardiac failure, and correlate the levels of plasma N-Terminal pro BNP with the severity of the cardiac failure and levels of plasma N-Terminal Pro BNP with systolic and diastolic dysfunction.

METHODS

It was an analytical cross-sectional study comprised of 50 patients with clinical features of cardiac failure attending medical OPD and emergency department of the hospital for the duration of 18 months and the equal number of age and sex-matched healthy controls.

A detailed clinical history was recorded regarding age, duration of symptoms, ischemic heart disorders, rheumatic heart disorders, hypertension, diabetes, dyslipidaemias, smoking, alcoholism. All patients undertook a comprehensive clinical examination comprising examination of pulse, blood pressure, respiratory, cardiovascular and central nervous systems.

Biochemical tests like random blood glucose, blood urea, complete blood picture, serum creatinine and electrolytes were done. ECG, chest x-ray, 2D echocardiogram and ultrasound abdomen were done for every case of a control subject. Follow up of patient is done over one and half month monitoring readmission of the patient for the same complaints or worsening of symptoms or regular follow up. N Terminal-pro BNP levels are measured during the second admission.

Sample Size

The sample size for the study was found out by using the formula as per the guidelines from Statistician from Community Medicine department:

Sample size

Inclusion Criteria

• Patients with breathlessness because of heart failure as per.
• Framingham’s criteria.

Exclusion Criteria

• Age <15 years.
• Sepsis.
• Pulmonary disease.
• Renal failure.

Study Protocol

In subjects with clinical presentation of heart failure and in healthy controls, 2 mL of blood sample is drawn for assay of plasma N-Terminal Pro BNP within half an hour of presentation. Blood is immediately centrifuged after collecting in EDTA bottle and plasma assay is carried out by Electrochemoluminescent Immunoassay (ECLIA). Blood was gathered in a ice-cold sample tube and rotated in a centrifuge instantaneously. The plasma is kept at -80 degrees until N-T pro BNP assay is carried out. Using biomedical kit plasma N-T pro BNP concentration is measured. The kit is a competitive ELISA destined to detect the immune reactive N-T pro-BNP. The principle of this ECLIA is principled on detection of two polyclonal antibodies: a biotinylated and a ruthenium derivative-labelled antibody. The entire period of the assay is 18 min. Detectability Range by this method of N-T proBNP is 5 pg/mL to 35,000 pg/mL.

Statistical Analysis

Quantitative data was represented as Mean ± SD. Statistical analysis was done using SPSS software version 17. P < 0.05 was considered statistically significant.

RESULTS

DISCLOSURE AND FUNDING

Disclosure forms provided by the authors are available with the full text of this article at jemds.com

ICMJE Forms

( 5-COI Dr Ashish Prakash Anjankar.pdf )

Financial or Other Competing Interests: None

COPYRIGHT

Copyright © 2020 JEMDS. This is an open access article distributed under Creative Commons Attribution License [Attribution 4.0 International (CC BY 4.0)]

How to cite this article

Anjankar AP, Lambe SD, Lambe KS. Diagnostic and prognostic value of n-terminal brain natriuretic peptide in patients of heart failure. J Evolution Med Dent Sci 2020;9(31):2176-2180, DOI: 10.14260/jemds/2020/474