Clinical Impact of N-Terminal Prohormone of Brain Natriuretic Peptide on Patients Hospitalized with Community-Acquired Pneumonia

Background: Risk stratification is important for the management of community-acquired pneumonia (CAP). The present study aimed to investigate the clinical impact of N-terminal prohormone of brain natriuretic peptide (NT-proBNP) on prognosis and to identify clinical characteristics associated with NT-proBNP elevation in CAP patients. Methods: This retrospective study included patients hospitalized for CAP at a tertiary referral center and who underwent measurement plasma NT-proBNP levels. Based on 30-day mortality, patients (n = 1,821) were divided into 2 groups, survivors (n = 150) and nonsurvivors (n = 1,671), and clinical and laboratory findings were compared. Results: In multivariate analysis, blood levels of NT-proBNP (>942.5 pg/mL), albumin (<3.3 g/dL), and troponin I (>0.018 ng/mL) independently predicted 30-day mortality. Of these blood biomarkers, NT-proBNP exhibited the highest C-statistic, followed by albumin. NT-proBNP level/CURB-65 score and NT-proBNP level/pneumonia severity index (PSI) class exhibited significantly higher C-statistics than CURB-65 score and PSI class alone, respectively. The 3-test combinations of CURB-65 score/NT-proBNP level/albumin level and PSI class/NT-proBNP level/albumin level exhibited significantly higher C-statistics than the 2-test combinations. NT-proBNP elevation was associated with increased age, heart disease and chronic kidney disease and NT-proBNP levels only weakly or moderately correlated with other blood biomarkers. Conclusions: NT-proBNP level was a useful marker for the prediction of 30-day mortality in patients hospitalized with CAP, and provided additional prognostic value to PSI or CURB-65 alone.