Abstract 20: NT-proBNP Elevations in Adult Respiratory Distress Syndrome Strongly Predict Morbidity and Mortality: An Analysis from the Molecular Epidemiology of ARDS Study.
Introduction: Patients with ARDS suffer from a syndrome of marked cardiopulmonary derangement, including right ventricular strain and noncardiogenic pulmonary edema. We hypothesized that N-terminal pro-brain natriuretic peptide (NT-proBNP) levels would be elevated in ARDS, and serve as a marker of prognosis in this setting.
Methods: Patients were diagnosed with ARDS according to the American-European Consensus Committee definition. Blood was taken within the first 72 hours of ARDS onset and assayed for NT-proBNP. Associations between NT-proBNP and presence/severity of sepsis, as well as ICU resource utilization were identified. Patients were followed for the primary outcome of 60-day mortality. Multivariable logistic regression and Cox proportional hazards models were constructed including variables selected using backwards elimination, clinical relevance, and significant interactions.
Results: 177 patients were enrolled and analyzed. There were 70 deaths in the study population. Overall NT-proBNP median was 3181 ng/L (interquartile range=723–9246 ng/L); median NT-proBNP concentrations were relatively higher among those with sepsis plus shock, compared to those with sepsis without shock or neither sepsis nor shock (5015 vs 2131 vs 582 ng/L, P <.001). Patients with marked elevation of NT-proBNP had fewer ventilator free days (5.7 versus 7.5, P <.001). Median NT-proBNP concentrations were significantly higher among decedents versus survivors (6898 versus 2243 ng/L; P <.001). Receiver operating characteristic analysis demonstrated an area under the curve of 0.66 (P <.001) for predicting death; at a cutpoint of 6813 ng/L, NT-proBNP was a significant predictor of death in crude (HR=4.24, 95% CI=2.2– 8.3, P= .001) and adjusted (HR=2.36, 95% CI=1.1–5.0, P = .02) analyses, comparable to the APACHE III score for this indication.
Conclusion: NT-proBNP levels are elevated among patients with ARDS in a range typically considered consistent with heart failure. Importantly, NT-proBNP concentrations are strongly associated with morbidity and mortality in this population, with comparable predictive accuracy as more complex tools such as the APACHE III score. This demonstrates the potential utility of NT-proBNP monitoring for prognosis in ARDS.