Background: Acute dyspnea is common in the emergency department (ED) and is associated with mortality. Biomarkers may help stratify risk in this setting.
Methods: Among 577 dyspneic subjects we identified 5 candidate biomarkers with prognostic value: amino terminal B-type natriuretic peptide (NT-proBNP), C-reactive protein (CRP), the interleukin family member ST2, hemoglobin and blood urea nitrogen (BUN); these were assessed using both receiver operating characteristic curve and Cox proportional hazards analyses. Results were validated in a population of dyspneic patients from a distinct cohort.
Results: At 1 y follow up, 93 (16.1%) patients had died. Independent predictive ability was established in an age-adjusted Cox model containing all markers: NT-proBNP (HR=1.89); CRP (HR=1.95); ST2 (HR=7.17); hemoglobin (HR=1.68); BUN (HR=2.06) (all P<.05). Following categorical assessment based on number of abnormal markers, the 1-y risk of death increased in a monotonic fashion with mortality rates of 0%, 2.0%, 7.8%, 22.3%, 29.3%, and 57.6% respectively; similar results were seen in the validation set.
Conclusion: Simultaneous assessment of pathophysiologically diverse markers in acute dyspnea provides powerful, independent and incremental prognostic information.