Acute dyspnoea is a common clinical finding in the emergency department. A rapid and accurate investigation of acute dyspnoea is vital since treatment of dyspnoea can differ markedly depending on the initial clinical impression. Distinguishing between cardiac and noncardiac causes of dyspnoea is often challenging. Measuring blood, BNP levels rapidly and accurately confirms or excludes the diagnosis of CHF in the urgent care setting making it a valuable clinical tool.
MATERIALS AND METHODS
This observational study was conducted on 100 patients who had presented with acute shortness of breath to the Emergency Department of Acharya Shri Chander College of Medical Science and Hospital with effect from November 2006 to November 2007. 5 mL of sample blood was collected for measurement of Brain Natriuretic Peptide (BNP), which was estimated quantitatively chemiluminescence method.
In this study of 100 patients, final diagnosis of CHF was present in 60 patients, which was based on echocardiographic results. Cutoff of <100 pg/mL, BNP levels was taken to exclude heart failure. It was observed that according to BNP levels alone 62 patients had heart failure (BNP levels of >100 pg/mL). BNP levels for diagnosing CHF had a sensitivity of 90% and a specificity of 80%. It was also found that BNP was helpful in detecting diastolic heart failure in presence of normal left ventricular systolic function. 7 patients had BNP levels at the time of admission higher than 1000 pg/mL and died within a week of hospital stay indicating the correlation of BNP levels with severity of CHF and also its prognostic significance.
The dramatic rise in incidence and prevalence of Congestive Heart Failure (CHF) can be attributed to a drastic increase in cardiovascular risk factors such as obesity and diabetes and improved survival rate after acute myocardial infarction and subsequent development of CHF in the last 25 years. Misdiagnosis can lead to increased mortality. BNP assay is a simple and reliable tool to improve the diagnostic accuracy of CHF.