Open heart surgery for aorta valve replacement

Still hoping to hear from more people who have had this done with this condition. I have heard from one and the surgery was successful but the person thru a blood clot and had a stroke 16 days later. That’s exactly what I fear. Is there any one out there that can give me some positive thought and done dos and don’t s The doctors don’t seem to realize the fear we have of clotting and if the bridging isn’t done correctly there can be serious problems. Plus even before the surgery I need to have a heart catherization which means coming off my Coumadin for 5-6 days prior. Please help I’m very scared