Had a complete obstruction of the right main coronary artery. It was treated very quickly with stents. By an incredible stroke of luck, my cardiac enzymes barely showed a blip, and follow-up echo-cardiograms and thallium stress tests are negative for any significant anatomical or physiology abnormalities. I do have a low grade obstructions on the left anterior descending and another on the circumflex, but those are actually receding. My cardiologist tells me if and only if I stick with the major life-style changes I've made since then, including getting back into cycling big time, I can expect to live out a normal life span with normal quality of life. My intent is to prove him wrong by doing better than "normal" on both counts.
That's my story... I mention it only to point out what's possible. Right now, I'm doing about 50 miles/week, including maybe 1000 feet of climbing every other ride. Pretty wimpy, I know, but I am getting stronger. The Plavix & statins I'm on don't interfere with my riding. Neither did the ACE-inhibitor I was on for hypertension, but I'm weaned off that now.
That said, each case is entirely unique to the person affected, though, so your doctor is your best source of information. Talk to him about what you'd like to do and see what he has to say. You might be pleasantly surprised.
-Bert