I would go back and ask more questions and get a second opinion if needed so you are very clear on exactly what is happening and what is preventing you from being able to exercise. Nobody elses experience matters. Perhaps you need another stent. Perhaps ablation. Maybe nothing can be done but the answer isn't in this forum. If your doc gives you anything but a clearly understandable explanation of why you can't exercise hard and why nothing can be done about it, get that second opinion. I've had two heart attacks and am rockin 5 stents and I'm cleared to go full tilt boogey and race as hard as I can although I'm on beta blockers so the odds of getting a contract with Sky remain slim. But like I said, my experience means nothing to you other than in -some- circumstances, heart attacks do not have to be an end to hard riding. Go pin that dr down on what's going on.