I had my aortic valve replaced (St Jude) on 6/3/93. Been on Warfarin ever since. Blood checked every 6 weeks. After the first couple of weeks the ticking went away and I barely have thought about it. I was born with a defective valve and it became so calcified that it had to be replaced. No heart disease. I am 80 and exercise daily aerobic and resistance. I wonder how much longer can I expect to last with this valve?