I Have Been Told I Have A Minimal Blockage In

I have been told I have a minimal blockage in my heart. I completed a stress test, and echo cardiogram and Carotoid Artery scan. All came back with good heart function and I was told I had a healthy heart. I do not have any symptoms, as in chest pain, left arm pain etc. Can I improve or reverse any blockages with diet and exercise? My doctor has told me no need to to a heart cath as all looks well and I am not having any symptoms related to a blockage. I see him in 4 mos and if for any reason I have any problems he will schedule a heart cath but at this time I have been told no need to do stints or heart cath on a healthy functioning heart. So can exercise and diet reverse or improve my minimal blockage???