Unrecognized liver injury assessed by fibrosis indexes is associated with mortality in critically ill COVID-19 patients

Background: Coronavirus disease (COVID-19) with acute respiratory distress syndrome is a life-threatening condition. A previous diagnosis of chronic liver disease is associated with poorer outcomes. Nevertheless, the impact of silent liver injury has not been investigated. We aimed to explore the association of pre-admission liver fibrosis indexes with the prognosis of critically ill COVID-19 patients. Methods: Observational study in 214 patients with COVID-19 consecutively admitted to the ICU. Pre-admission liver fibrosis indexes were calculated. In-hospital mortality and predictive factors were explored with Kaplan-Meier and Cox regression analysis. Results: The mean age was 59.58 (13.79) years. Sixteen patients (7.48%) had previously recognized chronic liver disease. Up to 78.84% of patients according to Forns, and 45.76% according to FIB-4, had more than minimal fibrosis. Fibrosis indexes were higher in non-survivors [Forns: 6.04 (1.42) vs 4.99 (1.58), p < 0.001; FIB-4: 1.77 (1.17) vs 1.41 (0.91), p = 0.020)], but no differences were found in liver biochemistry parameters. Patients with any degree of fibrosis either by Forns or FIB-4 had a higher mortality, which increased according to the severity of fibrosis (p < 0.05 for both indexes). Both Forns [HR 1.41 (1.11-1.81); p = 0.006] and FIB-4 [HR 1.31 (0.99-1.72); p = 0.051] were independently related to survival after adjusting for the Charlson Comorbidity Index, APACHE II and ferritin. Conclusion: Unrecognized liver fibrosis, assessed by serological tests prior to admission, is independently associated with a higher risk of death in patients with severe COVID-19 admitted to the ICU.