Several hospitals and researchers have reported links between thrombosis and anticoagulation quite regularly for COVID-19 patients.
This pathways combines this information, including biological mechanisms involved, in one graphical overview. The D-dimer is one of the protein fragments produced when a blood clot dissolves within the (human) body; when not properly degraded could lead to thrombosis.
The graphical visualisation of (crosslinked) fibrin mesh leading to D-dimers is inspired by [https://en.wikipedia.org/wiki/D-dimer Wikipedia].