I am not sure what the specific diet requirements are so I cannot comment. But the AHA and ADA both recommend low fat and cholesterol diets for people at risk of developing heart disease, and certainly for post MI patients.
THe only test that will let us see plaque burden is largely experimental test called an IVUS. This is not practical or indicated in most patients for the diagnosis of plaque burden. A CT angiogram of the chest can also measure plaque burden but this is not as accurate as the IVUS and exposes patients to significant amounts of radiation.
But more importantly nobody has shown that decreasing plaque burden in the coronaries actually decreases heart attacks or prolongs survival. And no diet has ever been shown to do this. But there is a strong placebo effect in some people so why not let them follow strict dietary guidelines? There is really no harm in doing so.
And in fact that is the recommended approach in reducing LDL.
It can take as long or longer then it took to develop the blockage to reverse the disease. Also there is no proof that it can be done. I had a heart attack at the age of 34 and started on a reversal diet that my wife and I have been on for 5 years (less the 20mg Cholesterol and 20 gr fat per day) I have lost weight (about 60 lbs) and now I run every day. My cholesterol is very low and my HDL is slowly rising. I have many tests done every year and so far every thing is looking good. I guess the point is this is worth a try. It is working for me and I have a very agressive disease that almost killed me at 34.
I agree with Ironman2x, I also have been helped by a adopting a strict diet.(vegan) I have followed the advice of Dr Fuhrman who has all you need to know in his book "Eat to Live". If you adhere to the AHA or the ADA you will not get the results you seek, They are not nearly low enough in animal products or fat. I have achieved a weight loss of 40 pounds and am within my body max index. I run 8 miles three days a week and 4 miles every other day. I have through the food I eat and exercise reduced the huge amount of medication I was no on my release from stent surgery. I went from Plavix 75 mg, lipitor 80 mg, lotrel 2o/10, aspirin, zolotf, etc etc. at a cost of $4500 per year. It took just over a year I now only take, lipitor 10mg, lotrel 2,5/5. aspirin. cost $400 per year. (Not Bad for a palcebo effect). I have my cholesterol under 150 ldl under 70 hdl 60 .Blood pressure before my run this morning 109/59 pulse 44. You wil read that for many years Dr Fuhrman has been treating folks that have advanced heart desiese with great results, You will find the folks who stick to the plan turn their lives around, and live to old age because of it.
To answer your original question, You are really making life saving changes that you should take on for life. I dont think one would say eat this way just until the plaque is reduced and then revert to the eating that got you in trouble in the first place?
All the very best to you. Brian.
PS: I would have expected more positive reinforcement from the clinic, except as you will discover for your self not many people can turn away from cheese, milk ,meat, and processed foods. and therefore the statistics rarely show the true gains you can make.