Please help our dad live longer

Good day to you all, my dad had a stroke last December 2017 since then he has been in and out of the hospital. My dad is diabetic, he has problems with his lungs, heart, kidneys and his eyes. His Doctors' main concern for now are his heart and eyes. He has a very week heart at the moment and it has affected his lungs and eye sight. Right now he can barely see and it causes him to stumble at times and fluid in his right lung is always accumulating because of his heart. Please help us, he's deteriorating. We still want to see him and be able to take care of him when he grows old. He still has a lot of things he wants to do for us. I hope my brothers will be able to see our dad and be with him while they grow up. My youngest brother is only 4 years old. The Doctor said that he needs bypass operation and eye treatment as soon as possible.