hello thanks for posting here. Goin by youe description it looks like he has got unstable angina or critical coronary artery disease. Also since he is on maximum medications for the same. So next step would be ideally an intervention like angiogram followed by angioplasty or surgery. But going by his age i would advice you not to go for any intervention as it will be more of a discomfort to him. Yes, he is at the risk of having a heart attack, which you have to accept. If he was my patient I would keep hin on medical management and would adjust his doses/increase doses if necessary. wishing him good health thank you.