COPD is progressive in nature from what I understand. It does effect your heart too tho, and will cause complications with heart conditions and congestive heart failure. Since you had a heart attack in the past, I would get that checked out sooner rather than later. Stopping smoking will slow down the progression of the disease and in some people it has stopped after quitting. However, your lungs do not go back to being healthy. Only a PFT test can truly predict how well your lungs are functioning. You need to see a pulmonologist asap.
Please quit smoking - when I got diagnosed with COPD a month ago I put down the cigarettes totally. Has your doctor ordered at CT scan of your lungs? You would get better information on the progression of your COPD with a CT scan.
I got a copy of my CT scan - moderate emphasema with scattered ground-glass opticities (still not sure what the ground glass means). As soon as I saw a copy of my report - I had 4 cigarettes on me - smokes them one a day and then quit smoking with the help of nicorette gum.
Please quit smoking and see a pulmonary specialist.
Also, all my chest X-Rays were normal - that is why I did not give up the cigarette before I got my CT Scan results.
Julie in SoCalif.