Hi Granny and Skyfall,
I had an unprovoked PE a few years ago and returned to flying after 7 months with an OML. I was placed on warfarin but I believe other forms of anti-coagulant medication is now acceptable.
If I remember correctly the probability of a recurrence without treatment is 5% and with treatment this is reduced to 2%, which seemed to be acceptable to the CAA in my case. At the time I had heard the figure of 1% being quoted too and was pleasantly surprised when I was cleared to return to flying.
The UK CAA protocol is here:
https://www.caa.co.uk/Aeromedical-Ex...e-of-warfarin/
Hope that helps.