A few years ago, I had severe chest pains and was so short of breath I could barely talk. An MRI and other tests revealed that my lungs were full of small clots that had traveled from clots in my calf and thigh. Also, I apparently suffered from a mild heart attack related to the clots. With treatment (heparin, coumadin and oxigen, I was able to leave the hospital after 8 days. I had to remain on coumadin for more than 2 years, with frequent checks of my bleeding time.
I do not have mds. If your father has low platelets or some other related problem, he may require different treatments to get rid of the clots.
Sorry that I have no information about possible side effects from vidaza.
All the best, bety