ABSTRACT
Introduction: B-type natriuretic peptide (BNP) and Nterminal pro-B-type natriuretic peptide (NT-proBNP) are usually considered as equal diagnostic tools for heart failure. Increased concentrations of BNP and NT-proBNP in COVID-19 patients have already been reported. The aim of this study was to evaluate the usefulness of these markers and any potential difference between them in predicting COVID-19 prognosis.Materials and Methods: We retrospectively collected and analyzed data about 174 consecutive adult patients affected with COVID-19. The clinical course of COVID-19 before hospitalization and its related complications were also acquired. In particular, the presence of pre-existing diseases related to cardiac and pulmonary functions was recorded, alongside with diabetes and hypertension. BNP and NTproBNP of each patients were collected at admission in hospital. BNP plasma concentrations were measured by chemiluminescent microparticle immunoassay on the ARCHITECT i2000SR system (Abbott Laboratories, Wiesbaden, Germany). NT-proBNP was also measured on the ARCHITECT i2000SR system by using the Alere assay (Roche Diagnostics GmbH, Mannheim, Germany). Results: BNP and NT-proBNP values were higher in in-hospital non-surviving patients (p<0.001). Despite a high correlation obtained by Spearman's rank correlation coefficient between these two variables (rho =0.716, p<0.001), receiver operating characteristics (ROC) curve analysis showed that NT-proBNP (AUC =0.951) performed better (p=0.01) than BNP (AUC =0.777). Kaplan-Meier analysis was performed by dividing the population into groups, based on whether NT-proBNP and BNP concentrations at admission were higher than the cut-offs resulting from ROC curves. Both log rank tests resulted significant (p<0.001), in the group of patients with NT-proBNP admission values lower than the cutoff showing an absence of fatal outcome, whereas the subgroup of patients with BNP admission values lower than cut-off included 53.84% of all non-survivors of this study. Conclusion: NT-proBNP proved to be a better prognostic tool than BNP for fatal outcome in COVID-19 patients. In particular, our study highlighted that a value of NT-proBNP below the cut-off of 511 ng/L at admission led to no inhospital mortality in our population.