B-type Natriuretic Peptide Assay in Differentiating Congestive Heart Failure from Lung Disease in Patients Presenting with Dyspnea.

This cross-sectional analytical study was conducted in Cardiology & Medicine Department of Mymensingh Medical College Hospital. After fulfilling the exclusion & inclusion criteria, B-type natriuretic peptide concentrations were measured in a convenience sample of 100 predominantly male (94%) dyspnic patients who got admitted in Cardiology & Medicine Department of Mymensingh Medical College & Hospital from November 2013 to October 2014. The diagnosis of Congestive Heart Failure (CHF) was based on generally accepted Framingham criteria with corroborative information including hospital course (response to diuretics, vasodilators, inotropes or hemodynamic monitoring) and results of further cardiac testing, including echocardiography. Patients with right heart failure from cor pulmonale were classified as having CHF. Pulmonary disease was confirmed by using the following diagnostic tools: i) A chest X-ray without signs of heart enlargement or pulmonary venous hypertension or a chest X-ray with signs of chronic obstructive lung disease, ii) Normal heart function as seen by echocardiography, iii) Abnormal pulmonary function tests or follow-up results and iv) A positive response to treatment with steroids, nebulizers or antibiotics in hospital. Patients with CHF (n=50) had mean BNP level 1146.72pg/ml (range 103 to 5000pg/ml), which is significantly higher than the group of patients with a final diagnosis of pulmonary disease (n=50) whose BNP was 34pg/ml (range 10 to 90pg/ml) (p<0.05). In conclusion, it was found that B-type natriuretic peptide is an important biomarker for differentiating congestive heart failure from lung disease in patients presenting with dyspnea.