Evaluation of N-terminal Pro-B-Type Natriuretic Peptide (NT-proBNP) as a Biomarker of Cardiac Dysfunction Across Heart Failure Phenotypes

Background Heart failure (HF) is a global health problem with high morbidity and mortality. N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a secondary data point to left ventricular ejection fraction (LVEF) that captures all the aspects of cardiac dysfunction, which is not included in systolic performance. There is significant clinical value in using NT-proBNP and LVEF together. Objective To ascertain the association between NT-proBNP levels and LVEF in patients with HF and to identify clinical predictors of elevated NT-proBNP concentrations. Methods This retrospective observational study was conducted at Shalamar Hospital, Lahore, Pakistan, from February 2023 to February 2025. This research involved 165 participants who had been diagnosed with HF. Electronic medical records provided demographic, clinical, lab, and echocardiographic data. The patients were grouped into HF with reduced ejection fraction (HFrEF, <40%), mildly reduced ejection fraction (HFmrEF, 41-49%), or preserved ejection fraction (HFpEF, ≥50%). Results Among the 165 patients, 82 (49.7) patients were HFrEF, 37 (22.4) patients were HFmrEF, and 46 (27.9) patients were HFpEF. HFrEF (4,020 pg/mL (interquartile range (IQR): 2,210-6,580)) had the highest median NT-proBNP concentration when compared to HFmrEF (2,350 pg/mL (IQR: 1,180-3,640)) and HFpEF (1,780 pg/mL (IQR: 910-2,950)) (p < 0.001). NT-proBNP had a significant negative relationship with LVEF in the general cohort (r = -0.52, p<0.001), with the highest value of r -0.61, and p -0.001 in HFrEF. Conclusion In HF, NT-proBNP serves as a valuable biomarker that complements echocardiographic assessment by capturing global cardiac stress beyond systolic function alone. In our cohort, NT-proBNP levels demonstrated a significant association with reduced LVEF and correlated with key clinical predictors, reinforcing its role as an accessible and reliable tool for comprehensive cardiac evaluation. Its integration into routine practice may enhance diagnostic accuracy, guide risk stratification, and support individualized treatment planning within our population context.