The use of Mid-Regional pro-Adrenomedullin as prognostic biomarker in ICU COVID-19 patients: preliminary data of Italian “second wave” of pandemic

Background:A prognostic biomarker to evaluate disease progression in COVID-19 intensive care unit (ICU) patients’ is still missing. Mid-Regional Pro-Adrenomedullin (MR-proADM) is a well-known endothelium-related peptide previously used in septic shock and respiratory infections1. Since the SARS-CoV-2 seems to induce a severe endothelial dysfunction, the aim of this study is to test the effectiveness of MR-proADM to describe patient’s severity and predicting mortality. A first phase of the study (March-June 2020) showed encouraging results, pending more definitive confirmations2. Methods:All consecutive COVID-19 adult patients admitted between September 2020 and March 2021 to the ICUs of ‘Città della Salute e della Scienza’ Hospital were enrolled. MR-proADM and routine laboratory test were measured within 48 hours from ICU admission, on day 3, 7 and 14.Univariate analysis was conducted, and variables were compared using the Wilcoxon-Mann-Whitney test, t test and Fisher exact test. Results:94 patients were enrolled. ICU and overall mortality were 55,3% and 62,8%, respectively. No differences were found in demographic characteristics or comorbidities between survivors and non- survivors (table 1A). MR-proADM values were found statistically significant between survivors and non-survivors both in the first 48h of ICU admission, both in the subsequent times (table 1B). In contrast, no significant differences emerged in C-reactive protein, D-dimer, NT-proBNP, LDH, lymphocyte count. Although PCT and IL6 showed a statistical significance at arrival, MR-proADM was the only biomarker to maintain a significantly difference during time (p=0.0106). A higher mortality characterized patients with MR- proADM >1.6 nmol/L (p = 0.0189). Conclusions:In COVID-19 ICU-patients, MR-proADM seems to confirm the ability of stratifying disease severity and mortality risk. A higher value of MR-proADM at admission appears to depict patients with a negative outcome. Further studies are needed to better define severity cut-offs and to fully comprehend variables influencing trends over time.