The Watchman does not stop a stroke from happening. It is used only to plug the opening in the LLA. This stops blood from entering the LLA and forming a blood clot. The only jjob of the Watchman is to stop a blood clot from forming in the LLA and then entering the blood stream. Bloodclots CAN form in other parts of the heart or other areas of the body.
I have a Watchamn installed and have had no problems with the device at all. You won't even know it is in there as you will not be able to feel it.

Yes, Eliquis is VERY expensive. I am so lucky I have good insurance and paid a very small price for mine. I am now off Eliquis and sure don't miss taking it twice a day.