leaving office but technology was so new then doctors weren't quite sure what to do with the results. >> they said i had some calcium build-up around my heart that put me basically in the top third of risk. but they said there was no evidence of blockage because i'd done so well on the stress test. for a few months before this happened, i noticed whenever -- not every time, but often when i would do rather strenuous exercise, there are some really hilly areas in the town where i am. i'd climb those hills and have to stop and take a breath. i didn't take it seriously, because every time that happens i just lowered the exercise level, got my breath back, and it was never painful. it was just tight. >> if this isn't good for my heart, i don't know what is. >> by the time he felt the first symptoms, that tightness in his chest, president clinton's heart disease was well advanced. it had been decades in the making. >> you don't die with your first plaque. you develop atherosclerosis blockages really your whole life for many, many years before it causes a heart attack or stroke. >> and what the doctor told me next should ring a bell of hope for that do k have an >> it is the biggest killer of men and women, heart disease in this country. >> it is completely preventable. >> coming up, more tests to gauge my heart attack risk. >> and can you really tell who is a heart attack waiting to happen? >> also, can the right diet make you heart attack proof? we'll meet a woman who's betting her life on it. >> with a family history of heart disease and a lifetime of bad eating habits, president clinton told me he was a heart attack waiting to happen. but what does someone really look like who is about to have heart attack? you probably wouldn't think this guy. tom bare, 53, thin, seemingly healthy, and one step short of a