Father's Recent Heart Attack and Behavioral Changes - Seeking Advice

Hello doctor, my father had a mini heart attack in September. He was experiencing asthma and jhanjhanahat (I don't know what else can I call it) in shoulders and hands . His hands would get tight all of a sudden and it would pain a lot. Also, he is very physically active. He used to go to a pulmonologist for asthma but he overlooked all of these and suggested to put volini spray on it. So when he got the heartattack his left body got paralysed for a while and after that he was fine. The doctor said that there was blockage in artery so he got a surgery done where the stunt was placed near waist. We maintained a good diet after that but when he got back to his house my brother's wife would not care much about the diet and fed him oils and refined oil as much as she could. Now it has been 7 month now he has been experiencing tightness in hands and legs again. Please suggest doctor. I fear that he might get heart attack once again. And sir please suggest on one more thing that he used to be a very strict and sophisticated person. But now he has completed changed. Now he is not as strict as before but some weird behaviour is something that I have been noticing over few months. He is highly forgetfully. Like he will ask you for something and then forget about it just after few minutes and then scold you for it. He keeps repeating what he says during a conversation. Sometimes he reacts violently without understanding the situation well which was not the case before. I fear he might have some psychological problems as my mother in law as severe dementia that she cannot even eat or walk. I fear the same.