What are some of the reasons a cardiologist may tell a person not to attempt quitting smoking cigarettes at the present time?

Not sure: never actually seen that; the only time I have is when I'm asking them to stop the cocaine first. even then.....not so clear.

I could not tell: you. You best bet would be to ask the cardiologist.

Hardly any: If an individual has a very severe anxiety disorder, or has had an exaggerated reaction to quitting smoking in the past, a cardiologist (or any doctor) may recommend some better ways than cold turkey, particularly use of a tapering schedule of nicotine replacement therapy. However, there is virtually NEVER any reason to recommend continuing smoking, and cessation can be done in everyone.