Natriuretic peptides for early prediction of acute kidney injury in community-acquired pneumonia

BackgroundCommunity-acquired pneumonia (CAP) is common and associated with a considerable risk of acute kidney injury (AKI).MethodsWe prospectively enrolled 341 patients presenting to the emergency department with CAP (mean age 72, male 61%). Blinded measurements of three natriuretic peptides (NT-proBNP, MR-proANP and BNP) were performed upon presentation. The primary endpoint was the accuracy of the natriuretic peptides to predict AKI within 48 h.ResultsAKI occurred in 24 patients (7.6%) within the first 48 h. NPs and creatinine were significantly higher in AKI compared with patients without AKI (NT-proBNP 9517 [2042–26,792] vs 1177 [280–4167] pg/ml; MR-proANP 641 [196–1075] vs 182 [99–352] pmol/l; BNP 592 [230–1630] vs 160 [64–463] pg/ml; creatinine 166 [131–289] versus 100 [78–134] μmol/l, P < 0.001 for each). Predictive accuracy as quantified by the area under the receiver operating characteristics curve was moderate to high: NT-proBNP 0.79 (95%CI 0.70–0.88), MR-proANP 0.78 (95%CI 0.67–0.88), BNP 0.74 (95%CI 0.63–0.85), creatinine 0.77 (95%CI 0.66–0.88). In multivariate logistic regression analysis, NPs remained the only independent AKI predictors: NT-proBNP (increase of 200 pg/ml) OR = 1.01, 95%CI 1.00–1.01, P = 0.009; MR-proANP (increase of 100 pg/ml) OR = 1.23, 95%CI 1.09–1.39, P = 0.001; BNP (increase of 100 pg/ml) OR = 1.08, 95%CI 1.03–1.14, P = 0.002.ConclusionsNP levels are significantly elevated in CAP-patients experiencing early AKI. Their potential to predict early AKI is comparable to serum creatinine and might be useful in cases of diagnostic uncertainty.

► Community-acquired pneumonia (CAP) is associated with acute kidney injury (AKI).
► Natriuretic peptides were accurate predictors of early in-hospital AKI.
► The predictive accuracy of the NPs is similar to the accuracy of serum creatinine.