Hi There I understand your concern as it s a big decision to make. As you have consulted many cardiologist and they have a different opinion so in this case it s important to see your father s angiogram first so as to see how many blockages are there and how critical they are and it s not wise to give my opinion with reviewing angiogram. However in general I can tell you that if the blockages are at multiple locations and have a diffuse course or if the Left main coronary artery ( also called widow maker)is affected it s advised to go for a bypass surgery. I know it s sounds dangerous to go for a heart surgery but studies have shown that bypass surgery gives slightly better long term survival rates in good surgeon s hands. Hope I have made my point clear that will help you decide. Good Luck