Oh my that's scary. It's good to know that you have blood mutations where as Im a mystery but still have the same fate by using Eliquis for the rest of my life.
Do you have to do anything else or differently because you have factor 5 or blood mutations?

blood mutations could be the cause, iv had pe and dvt several times and in 2019 found out i have apl (anit phospholipid) disease which is also caused by lupis but the pe's has caused damage to my lungs

Something similar happened to me a couple of weeks ago: collapsed at home, nearly fainting, unable to breathe. Admitted through the ER & found to have a submassive PE in both lungs and the saddle between them. The right ventricle of the heart was twice the size of the left and the tricuspid valves weren’t functioning. Entire femoral/popliteal vein had clot except where it had broken off to the lungs. Had a thrombectomy the next day because heart strain and breathing problems were still severe. Procedure went well but had unexpected complications afterwards including bleeding, blood pressure issues, and developed consolidated pneumonia in the left lower lung. Glad to be alive and home though, since it wasn’t a sure thing when we were on the way to the ER that day. ( I will try to upload a picture of the results of the procedure- clots removed and from where). It was scary but staff were so helpful and calm that I actually wasn’t worried until it was almost time for discharge!