Clinical effect of renal dysfunction on diagnostic and prognostic accuracy of B-type Natriuretic Peptide and N-terminal Pro-B-type Natriuretic Peptide for acute heart failure

Abstract Background Acute heart failure (AHF) continues to have unacceptable high rates of mortality and morbidity. Therefore, accurate and rapid diagnosis of AHF is crucial for the early initiation of effective treatment. Previous studies have shown that plasma concentrations of B-type natriuretic peptide (BNP) and N-terminal pro-BNP (NT-proBNP) increase with declining renal function and that renal dysfunction seems to decrease the accuracy of BNP and NT-proBNP in the diagnosis of AHF. Purpose We aimed to directly compare the diagnostic and prognostic accuracy of BNP and NT-proBNP in patients presenting with acute dyspnea, including the effect of renal function. Methods This prospective diagnostic study enrolled unselected patients presenting with acute dyspnea to the emergency department. The final diagnosis was centrally adjudicated by two independent cardiologists using all information including imaging and follow-up. BNP and NT-proBNP plasma levels were determined at presentation. 360 days all-cause mortality was the primary prognostic end point. Results Among 1579 patients, acute heart failure (AHF) was the adjudicated final diagnosis in 865 patients (54.8%). Plasma concentrations of both BNP and NT-proBNP were significantly higher in AHF as compared to other causes of acute dyspnea (both p<0.001). Diagnostic accuracy as quantified by the area under the receiver-operating-characteristics curve (AUC) was 0.948 (95% CI 0.938-0.958) for BNP as compared to 0.921 (95% CI 0.908-0.935) for NT-proBNP, p<0.001. The diagnostic superiority of BNP was consistent among predefined subgroups according to renal function and increased with the extent of renal dysfunction (Figure 1: all patients (A), patients with eGFR≥ 60 ml/min/1,73 m² (B), patients with eGFR 30-59 ml/min/1,73 m² (C), patients with eGFR <30ml/min/1,73 m² (D)). In contrast, prognostic accuracy for the prediction of death at 360 days was higher for NT-proBNP (AUC 0.731, 95% CI 0.702-0.760 versus 0.706, 95%CI 0.676-0.736 for BNP; p<0.001). The diagnostic superiority of NTproBNP was consistent among predefined subgroups according to renal function but decreased with the extent of renal dysfunction. Conclusion In patients with acute dyspnea, BNP and NT-proBNP at presentation both have very high diagnostic accuracy for AHF and moderate prognostic accuracy for death. There is a numerically small, but statistically and possibly also clinically significant diagnostic superiority of BNP and prognostic superiority of NT-proBNP.Diagnostic accuracy for AHF