The German hospital Universitätsklinikum Hamburg Eppendorf (UKE) performed more than 190 autopsies of patients who died with COVID-19. In a study (where they covered the first 12 cases) they found an unusually high number of of thromboembolic events. Therfore they are now recommending a prophylactic heparin treatment (a commonly uses blood thinner to prevent thrombosis), even for ambulantory care.

Here is the study: https://annals.org/aim/fullarticle/2765934/autopsy-findings-...

And for those who speak German, here is their press conference: https://www.youtube.com/watch?v=VvH3mG-v0Ms