lad blockages

i am 73 with 5 blockages on lad 1 as high as 90%, 2@80% and 2 @70%. determined by angiogram
i exercise strenuously 7 days a week. pulse reaches 135.
i have no pain or shortness of breath, 130 col, with excellent ratios, good crp and homocystine levels
my nuclear was negative but stress part without isotope shows an st segment depression which has been present for 35 years.
i have been advised to have 3-5 stents. only doctor who does not agree is a boyhood very close friend whose personality and competence are hard to ignore. i dont believe that he would even offer an opinion if he were uncertain as to the improvement of my chances to stay healthy.
his opinion is based on the statistic that most mi's occur in arteries which are less than 50% occluded and that stents releive symptoms but dont extend life. your opinion would be much appreciated.