I am a heart attack survivor and have had bypass surgery, and during the time right before and especially right after the episode, I spent much time and much reading on the whole issue. It is MY humble opinion that saturated fats are a main factor in coronary artery disease. The liver produces 80% of the cholesterol in our bloodstreams FROM saturated fats, so the big thing is that - and NOT that saturated fat contains cholesterol.
It goes without saying that more exercise would help the burning of said fats but MOST Americans who end up having a heart attack and dying do NOT get enough exercise, and DO consume to many saturated fats - add in smoking and you've got a coronary toxic hi ball.
Read the China Study as Lance has. Read Dr Dean Ornish's book on Prevention and Reversal of Coronary artery Disease. There are others. I think adding in the fact that we eat too much processed food, too much "fast" food, along with our "drive in" mentality, from food to banks to prescription windows, etc etc have put us where we are. I believe that a person with MOST American's sedentary lifestyle is way more apt to get coronary artery disease with the addition of saturated fats to the mix.