Coagulation Biomarkers and Mortality in Severe COVID-19: The Prognostic Value of Factor XIII Decline and Elevated D-Dimers.

IntroductionThis study investigated the roles of d-dimers, fibrinogen, activated partial thromboplastin time (aPTT), and Factor XIII (FXIII) in critically ill COVID-19 patients.Methods68 patients were included into the study based on the inclusion criteria. Severe illness was defined as COVID-19 pneumonia leading to acute respiratory failure requiring mechanical ventilation and ICU (Intensive Care Unit) care. Patients who received Extracorporeal Membrane Oxygenation therapy were excluded due to its effects on the coagulation system. Blood samples were collected on day one and days five to seven, to measure coagulation parameters (aPTT, d-dimer, fibrinogen, and FXIII).ResultsIn total, 59% of the patients died during their hospital stay. Coagulation parameters showed elevated d-dimer levels in 95.6% of patients, while FXIII activity significantly decreased during the first week in ICU. A drop in FXIII activity over the first week (FXIII Δ) emerged as a significant predictor of in-hospital mortality (HR = 2.174, P = .031), while d-dimers did not. No significant changes in aPTT, fibrinogen, or d-dimer levels were observed between days one and five to seven.ConclusionThe change in Factor XIII activity during the first week in ICU (FXIII Δ) emerged as an independent predictor of in-hospital mortality. D-dimer levels were elevated in nearly all patients, but did not serve as an independent predictor of in-hospital mortality, possibly due to the homogeneity of the cohort. Overall, the results emphasize the importance of monitoring d-dimers and Factor XIII in predicting disease severity and outcomes in COVID-19 patients.