Proadrenomedullin, a useful tool for risk stratification in high Pneumonia Severity Index score community acquired pneumonia

Abstract The aim of the present study was, first, to evaluate the prognostic value of mid-regional proadrenomedullin (proADM) in emergency department (ED) patients with a diagnosis of community acquired pneumonia (CAP) and, second, to analyze the added value of proADM as a risk stratification tool in comparison with other biomarkers and clinical severity scores. We evaluated proADM, C-reactive protein and procalcitonin, along with the Pneumonia Severity Index (PSI) score in consecutive CAP patients. Ability to predict 30-day mortality was assessed using receiver operating characteristic curve analysis, logistic regression, and reclassification metrics for all patients and for patients with high PSI scores. Primary outcome was death within 30 days after ED admission. One hundred nine patients were included (median age [interquartile range] 71 [27] years). Nine patients died within 30 days. A significant correlation between proADM and PSI was found ( ρ = 0.584, P < .001). PSI and proADM levels were significantly predictive of risk of death. In patients with PSI class IV and V (score > 90), proADM levels significantly predicted risk of death (OR [95% CI], 4.681 (1.661-20.221), P = .012) whereas PSI score did not ( P = .122). ROCAUC (area under the receiver operating characteristic curve) was higher for proADM than for PSI score (ROCAUC [95% CI], 0.810 [0.654-0.965] and 0.669 [0.445-0.893] respectively). Reclassification analysis revealed that combination of PSI and proADM allows a better risk assessment than PSI alone ( P = .001). MR-proADM may be helpful in individual risk stratification of CAP patients with a high PSI score in the ED, allowing to a better identification of patients at risk of death.