I too really struggle with these patients.
I usually advise against prostatectomy for high risk patients, but I can see the benefit here if it saves him ADT. I still would probably not favor that route, but that's probably my bias as a rad onc.
If going for XRT in this scenario I usually shoot for at least of 6 months total of ADT (2 months before, 2 months during, 2 months after XRT), then I extend ADT on the basis of tolerance, reliability of follow up with cardiology, and weight gain/diabetes control. I make sure these patients have a cardiologist (not just a PCP managing their HTN, CAD), and go from there. I sometimes even call the cardiologist to get thoughts (ie was their last angio a disaster, are they a ticking time bomb, etc). With underlying CVD, I pretty much never go past 18 months.
Most of the intermittent vs. continuous trials showed more cardiovascular deaths in the continuous arms, so there must be some sort of process going on suggesting long term androgen blockade poses cardiovascular risks. However, this recent
editorial from JCO and it's corresponding study suggests it may not be simply that it's not just the long term ADT is contributing to atherosclerosis - there may even be increased risk for CV events within 1-4 months of initiating ADT.