What procedures were used to determine you have Mitral Valve Prolapse originally? I'm guessing an Echocardiogram and perhaps you had a stress test as well. Have you had the same procedures to see if your Prolapse and mild regurgitation has worsened?
Perhaps the doctors believe because the leakage is 'mild' that you wouldn't be symptomatic... the majority of people on our planet have 'trivial' or 'mild' regurgitation. There are very few perfect hearts! I have 'moderate' regurgitation along with a number of heart problems, but I don't have any symptoms of regurgitation.
You might consider asking for both an Echo and stress test. The Echo could be compared to your test earlier, and the stress test would indicate arterial blockages.
Yes, the Echo and stress test was done when the Mitral Prolapse and mild regurgitation was first found. They have never done the echo since then. The only thing I could ever get them to do was another stress test. The second time they done the chemical stress test. They told me both times if I didn't stop smoking, slow down on the caffiene (I think I spelled that right), and start getting more excersise, I would die at an early age. I don't think they should have told me that though!. But other than that they said nothing was wrong with the stress test.
I'm sure you understand that having asthma and smoking is far more dangerous than a diagnosis of mild regurgitation of a heart valve, and it doesn't stretch my imagination to believe that smoking with asthma could be the cause of chest discomfort. I doubt the doctors told you to eliminate the bad habits with the intent of hurting your feelings, but were being honest and were trying to lengthen your life.
I'd suggest listening to their advice and follow it before doing anything else.