Coumadin (warfarin) also prevents clotting, but is usually reserved for patients who have more serious conditions that would make them suseceptible to heart attacks. In addition, people on coumadin need to have their blood levels checked about once monthly. Too much coumadin in the blood could cause serious bleeding.
I had been on Plavix for a few years. Last year, I had an aortic valve replacement, together with a single bypass. The doctor put me on coumadin. A year later, when my heart was healed and I had a choice, I opted to stay on the coumadin. It is much cheaper than Plavix, and the blood test is no big deal.