Aspartate aminotransferase as predictor of severity in SARSCoV-2 infection: linear regression model

Abstract

Background and aim: Some patients with SARSCov-2 infection develop severe disease (SARS);however, the factors associated with severity are not yet fully understood. Some reports indicate that liver injury may be a poor prognostic factor. AIM: To identify the biochemical factors related to the development of SARS with mechanical ventilation (MV) requirement in patients with SARSCov-2 and COVID-19. Methods. Type of Study: Observational. Cohort study. Procedure: Data from COVID-19 patients were collected at admission time to a tertiary care center. Differential factors were identified between seriously ill SARS + MV patients versus stable patients without MV. Transformation to the natural logarithm of significant variables was performed and multiple linear regression was applied, then a predictive model of severity called AAD (Age-AST-D dimer) was constructed. Result(s): 166 patients were included, 114(68.7%) men, mean age 50.6 +/- 13.3 years-old, 27(16.3%) developed SARS + MV. In the comparative analysis between those with SARS + MV versus stable patients without MV we found significant raises of ALT (225.4 +/- 341.2 vs. 41.3 +/- 41.1;P = 0.003), AST 325.3 +/- 382.4 vs. 52.8 +/- 47.1;P = 0.001), LDH (764.6 +/- 401.9 vs. 461.0 +/- 185.6;P = 0.001), D dimer (7765 +/- 9109 vs. 1871 +/- 4146;P = 0.003), age (58.6 +/- 12.7 vs. 49.1 +/- 12.8;P = 0-001). The results of the regression are shown in the Table, where model 3 was the one that best explained the development of SARS + MV;with these variables was constructed the model called AAD, where: [AAD = 3.896 + ln(age)x-0.218 + ln(AST)x-0.185 + ln(DD)x0.070], where a value = 2.75 had sensitivity = 0.797 and 1-specificity = 0.391, AUROC = 0.74 (95%CI: 0.62-0.86;P 0.0001), to predict the risk of developing SARS + MV (OR = 5.8, 95%CI: 2.2-15.4;P = 0.001). Conclusion(s): Elevation of AST (probable marker of liver damage) is an important predictor of progression to SARS, together with elevation of D-dimer and age early (at admission) and efficiently predict which patients will potentially require MV. Conflicts of interest: The authors have no conflicts of interest to declare. [Formula presented] [Formula presented] Copyright © 2020