Diagnostic Performance of N Terminal-Pro Brain Natriuretic Peptide (NT-ProBNP) in the Assessment of Dyspnea in Heart Failure and Chronic Obstructive Pulmonary Disease in a Group of Patients in Sub–Saharan Africa (SSA): An Analytical Cross-Sectional Study

Background: Heart failure (HF) and Chronic Obstructive Pulmonary Disease (COPD) are two conditions frequently responsible of dyspnea. The clinical distinction between these two etiologies is challenging in clinical practice, particularly in developing countries where access to imagery is limited. Thus, natriopeptides, secreted during the stretching of cardiomyocytes, could be a more accessible method for the etiological diagnosis of dyspnea. Objective: The aim of this cross-sectional study was to evaluate the diagnostic performance of NT-pro BNP in the assessment of dyspnea during heart failure and COPD. Methods: The population consisted of patients with dyspnea caused by heart failure according to Framingham criteria or COPD diagnosed according to GOLD criteria. The NT-pro BNP levels and left ventricular ejection fraction was assessed. The ROC curve and the Youden index was used to determine the diagnostic performance of the test and the threshold of significance was set at 0.05. Results: Of the 45 subjects recruited, 32 had heart failure and 13 had COPD. The NT-pro BNP levels were higher in HF patients (3725.5 [651 – 9945] pg/ml) compared to the COPD patients (316 [32- 1307] pg/ml); p=0.02. The NT-pro BNP levels was correlated to dyspnea in both groups (r=0.75; p<0.001 in HF patients and r=0.91; p<0,001 in COPD patients). The diagnostic threshold obtained was 497 pg/ml with a sensitivity of 81%, a specificity of 69% and a Youden’s index of 0.5. Conclusion: The diagnostic performance of NT-proBNP is acceptable in distinguishing between heart failure and COPD.