Does mid-regional pro-adrenomedullin (MR-proADM) improve the sequential organ failure assessment-score (SOFA score) for mortality-prediction in patients with acute infections? Results of a prospective observational study

OBJECTIVES: Risk stratification in patients with infection is usually based on the Sequential Organ Failure Assessment-Score (SOFA score). Our aim was to investigate whether the vasoactive peptide mid-regional pro-adrenomedullin (MR-proADM) improves the predictive value of the SOFA score for 30-day mortality in patients with acute infection presenting to the emergency department (ED). METHODS: This secondary analysis of the prospective observational TRIAGE study included 657 patients with infection. The SOFA score, MR-proADM, and traditional inflammation markers were all measured at time of admission. Associations of admission parameters and 30-day mortality were investigated by measures of logistic regression, discrimination analyses, net reclassification index (NRI), and integrated discrimination index (IDI). RESULTS: MR-proADM values were higher in non-survivors compared with survivors (4.5±3.5 nmol/L vs. 1.7 ± 1.8 nmol/L) with an adjusted odds ratio of 26.6 (95% CI 3.92 to 180.61, p=0.001) per 1 nmol/L increase in admission MR-proADM levels and an area under the receiver operator curve (AUC) of 0.86. While the SOFA score alone revealed an AUC of 0.81, adding MR-proADM further improved discrimination (AUC 0.87) and classification within predefined risk categories (NRI 0.075, p-value <0.05). An admission MR-proADM threshold of 1.75 nmol/L provided the best prognostic accuracy for 30-day mortality; with a sensitivity of 81% and a specificity of 75%, and a negative predictive value of 98%. CONCLUSIONS: MR-proADM improved the mortality risk stratification in patients with infection presenting to the ED beyond SOFA score alone and may further improve initial therapeutic site-of-care decisions. TRIAL REGISTRATION: ClinicalTrials.gov NCT01768494. Registered January 15, 2013.