Hello Well come to health care magic Dear patient, as you are a known case of coronary artery disease, had MI on 2/1/11 and have multiple stents placed, and now you are experiencing chest pain while going for exercise, you will need to consult a cardiologist to rule out unstable angina or other aspects of acute coronary syndrom, even if your rescent stress test was normal or even if you may be having bronchitis. Bronchitis can cause cough, breathing difficulty but chest pain during exercise is not so common thanks Dr Arshad