ABSTRACT
BACKGROUND: Amino-terminal fragments of type-A and type-B natriuretic peptide prohormones (NT-proBNP, NT-proANP) are powerful prognostic markers in patients with cardiac disease, and NT-proBNP has been demonstrated to predict outcome in severe sepsis and septic shock. We assessed the prognostic value of NT-proBNP and NT-proANP in a consecutive series of mechanically ventilated intensive care patients and compared their prognostic merit. METHODS: Seventy unselected patients admitted to the intensive care unit (ICU) were included in the study 48 h after start of controlled mechanical ventilation. Venous blood was obtained on inclusion and assayed for NT-proBNP and NT-pro ANP. Univariate and multivariate logistic regression analysis was used to assess the association of NT-proBNP and NT-proANP levels with 30-day mortality. Established risk factors and possible confounders were used as covariates. Discrimination of different prognostic models was assessed calculating the area under the receiver-operating characteristics curve (ROC-AUC). RESULTS: NT-proBNP and NT-proANP levels were higher in non-survivors (n=25) than in 30-day survivors (n=45). Log NT-proBNP [odds ratio (OR) 2.34, 95% CI 1.17-4.66], and log NT-proANP (OR 2.44, 95% CI 1.12-5.30) were independently predictive of increased mortality. A prior diagnosis of chronic obstructive lung disease was predictive of decreased mortality (OR 0.29, 95% CI 0.08-1.00). The relative prognostic values, evaluated by the ROC-AUCs of NT-proBNP (AUC 0.74, 95% CI 0.61-0.86) and NT-proANP (AUC 0.73, 95% CI 0.61-0.86), were nearly identical. CONCLUSIONS: High NT-proANP and NT-proBNP levels associated with decreased short-term survival in unselected, mechanically ventilated ICU patients. NT-proANP performed equally well as a prognostic indicator as NT-proBNP, and may represent a clinically useful alternative to NT-proBNP.
