Utility of NT-proBNP in Patients Presenting to the Emergency Department with Breathlessness to Differentiate between Cardiac and Non-cardiac Diseases

Introduction:Breathlessness is a common emergency department presentation with diverse underlying causes, making rapid differentiation between cardiac and non-cardiac aetiologies crucial.NT-proBNP, a biomarker associated with cardiac dysfunction, has emerged as a potential diagnostic tool in such cases.Aim: To assess the diagnostic utility of NT-proBNP levels in distinguishing cardiac from non-cardiac causes of breathlessness and to evaluate its correlation with clinical outcomes.Materials and methods: A descriptive observational study was conducted on 119 patients presenting with breathlessness.Data on demographics, clinical presentation, oxygen saturation, comorbidities, New York Heart Association (NYHA) grading, chest X-ray findings, left ventricular ejection fraction (LVEF), NT-proBNP levels, diuretic requirement, and patient outcomes were analysed.NT-proBNP levels were categorised and correlated with diagnostic and prognostic parameters.Sensitivity and specificity were calculated for cardiac and non-cardiac conditions.Results and Observations: The mean age was 69.61 years, with a near-equal gender distribution.NT-proBNP levels ranged from 9 to 3,32,800 pg/mL, with 69.70% of patients having values >967 pg/mL.Sensitivity and specificity for cardiac diseases were 84.15 and 64.86%, respectively.NT-proBNP levels showed a significant correlation with NYHA grading, requirement for diuretics, heart failure category, and hospital stay duration.However, no significant association was found with hypertension or oxygen therapy needs.Conclusion: NT-proBNP is a valuable biomarker for differentiating cardiac from non-cardiac causes of breathlessness, aiding in early diagnosis and management.Higher NT-proBNP levels were associated with greater disease severity and ICU admission.Patients with heart failure with reduced ejection fraction (HFrEF) have higher NT-proBNP values compared to those with heart failure with preserved ejection fraction (HFpEF).