Biomarker Shown Effective in ED Diagnoses of Pneumonia, Heart Failure
October 6th, 2016
BOSTON – “Doctor, I can’t catch my breath” is a common complaint in emergency departments. The challenge is determining the cause of the dyspnea.
As a result, many EDs are turning to biomarkers to improve diagnostic accuracy and aid with prognostication in patients with breathing complaints.
A study published recently in the American Journal of Medicine examined the clinical utility of serum procalcitonin (PCT) for the diagnosis of pneumonia in patients presenting to the ED with dyspnea. Researchers from Massachusetts General Hospital and Harvard Medical School also sought, as a secondary objective, to evaluate the prognostic value of PCT for death to a single year.
Overall, they found the biomarker a useful tool.
“In emergency department patients with acute dyspnea,” study authors write. “PCT is an accurate diagnostic marker for pneumonia, and adds independent prognostic information for 1-year mortality.”
For the study, researchers pooled the patient populations of two prospective cohorts that previously enrolled patients presenting with dyspnea to two urban EDs, focusing on 453 patients having serum samples available for biomarker analysis. They reviewed clinician certainty for the diagnosis of acutely decompensated heart failure as well as discrimination, calibration, and net reclassification improvement for the diagnosis of pneumonia, taking into account any fatal outcomes.
Results showed that pneumonia alone was diagnosed in 6.6% of patients, heart failure without pneumonia in 47% and both diagnoses in 6.6%. PCT concentrations were higher in subjects with pneumonia.
“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,” study authors note.
Overall, adding PCT results to variables predictive of pneumonia resulted in a net reclassification improvement of 0.54 for both up- and down-reclassifying events. In adjusted analyses, elevated PCT was a predictor of one-year mortality, especially when elevated in conjunction with natriuretic peptides.
