Mid-regional pro-adrenomedullin and copeptin to predict short-term prognosis of COPD exacerbations: a multicenter prospective blinded study

Background: Exacerbations of COPD (ECOPD) are a frequent cause of emergency room (ER) visits. Predictors of early outcome could help clinicians in orientation decisions. In the current study, we investigated whether mid-regional pro-adrenomedullin (MR-proADM) and copeptin, in addition to clinical evaluation, could predict short-term outcomes. Patients and methods: This prospective blinded observational study was conducted in 20 French centers. Patients admitted to the ER for an ECOPD were considered for inclusion. A clinical risk score was calculated, and MR-proADM and copeptin levels were determined from a venous blood sample. The composite primary end point comprised 30-day death or transfer to the intensive care unit or a new ER visit. Results: A total of 379 patients were enrolled in the study, of whom 277 were eventually investigated for the primary end point that occurred in 66 (24%) patients. In those patients, the median (interquartile range [IQR]) MR-proADM level was 1.02 nmol/L (0.77-1.48) versus 0.83 nmol/L (0.63-1.07) in patients who did not meet the primary end point (P=0.0009). In contrast, copeptin levels were similar in patients who met or did not meet the primary end point (P=0.23). MR-proADM levels increased with increasing clinical risk score category: 0.74 nmol/L (0.57-0.89), 0.83 nmol/L (0.62-1.12) and 0.95 nmol/L (0.75-1.29) for the low-,intermediate-and high-risk categories, respectively (P<0.001). MR-proADM was independently associated with the primary end point (odds ratio, 1.65; 95% confidence interval[CI], 1.10-2.48; P=0.015). MR-proADM predicted the occurrence of primary end point with a sensitivity of 46% (95% CI, 33%-58%) and a specificity of 79% (95% CI, 74-84). Conclusion: MR-proADM but not copeptin was significantly associated with outcomes at 30 days, even after adjustment for clinical risk category. Overall, MR-proADM, alone or combined with the clinical risk score, was a moderate strong predictor of short-term outcomes.