How do I permanently keep car keys away from my Dad?

I have my Dad's keys. He has some dementia but most importantly he has a pacemaker and even with that he occasionally drops down to a heart rate of 38 or lower and does not respond for as long as 90 seconds,. He is in a retirement center and his truck is still there too. We took his keys away but he calls and/or yells at me every time we are together. I do his bills,manage his medications, clean his apartment and do his laundry as well as take him to appointments. He tells me he is fine to drive but I believe that he is putting himself and others at danger. His cardiologist told him not to drive as well as his PCP. This Friday he see's his PCP again to go over lab results and he (the PCP) has said he will once again reiterate the no driving. I think it would be best if we just removed his truck from the facility but I do not know the legalities of this. He has, signed but not dated the title as the little truck is to go to his youngest Grandson when he cannot any longer drive.