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Diagnostic and Prognostic Utility of Procalcitonin in Patients Presenting to the Emergency Department with Dyspnea.
Am J Med. 2015 Jul 10;
Authors: Alba GA, Truong QA, Gaggin HK, Gandhi PU, De Berardinis B, Magrini L, Bajwa EK, Di Somma S, Januzzi JL, Global Research on Acute Conditions Team (GREAT) Network
Abstract
BACKGROUND: Among patients in the emergency department, dyspnea is a common complaint, and can pose a diagnostic challenge. Biomarkers are increasingly utilized to improve diagnostic accuracy and aid with prognostication in dyspneic patients.
OBJECTIVE: To examine the clinical utility of serum procalcitonin (PCT) for the diagnosis of pneumonia in patients presenting to the emergency department with dyspnea. A secondary objective was to evaluate the prognostic value of PCT for death to one year.
METHODS: This study pooled the patient populations of two prospective cohorts that previously enrolled patients presenting to two urban emergency departments with dyspnea. A total of 453 patients had serum samples available for biomarker analysis. Clinician certainty for the diagnosis of acutely decompensated heart failure was reviewed. Discrimination, calibration, and net reclassification improvement for the diagnosis of pneumonia as well as fatal outcomes were considered.
MAIN OUTCOMES: Accuracy of PCT for diagnostic categorization of pneumonia. Prognostic value of PCT for survival to one year was a secondary outcome.
RESULTS: Pneumonia alone was diagnosed in 30 patients (6.6%), heart failure without pneumonia in 212 patients (47%), and both diagnoses in 30 patients (6.6%). PCT concentrations were higher in subjects with pneumonia (0.38 vs 0.06 ng/mL; p <0.001). Area under the receiver operating characteristic curve for the diagnosis of pneumonia based on PCT was 0.84 (95% CI 0.77-0.91, p < 0.001). Across all levels of clinician-based estimates of heart failure, PCT was sensitive and specific; notably, in patients judged with diagnostic uncertainty (n = 70), a PCT value of 0.10 ng/mL had the optimal balance of sensitivity and specificity (80% and 77%, respectively) for pneumonia. Adding PCT results to variables predictive of pneumonia resulted in a net reclassification improvement of 0.54 (95% CI 0.24-0.83, p < 0.001) for both up- and down-reclassifying events. In adjusted analyses, elevated PCT was a predictor of one-year mortality (HR 1.8, 95% CI 1.4-2.3, p < 0.001) and was additive when elevated in conjunction with natriuretic peptides for this application.
CONCLUSION: In emergency department patients with acute dyspnea, PCT is an accurate diagnostic marker for pneumonia, and adds independent prognostic information for one-year mortality.
PMID: 26169892 [PubMed - as supplied by publisher]