My husband has been on it forever - well, since his 30th birthday when he had a pulmonary embolism.
I don't know if this will help you, (since he's not on dialysis) but he's been on coumadin (the generic anyway) for almost 13 years now. He gets a protime done every 2-3 months (to check his clotting time) or so.
Now, my MIL is on dialysis and does have A-Fib. They had her on amiorodone & plavix up until her last hospitalization right before Christmas when they thought that they might have both been causing liver/kindey probs. We have a tentative cardio appointment this Thursday though - perhaps coumadin will be an option for her.