My father is 85 years old he had heart attack and suffers from blockage in four arteries he was diagnosed that he needed open-heart surgery, but doctors refused operation because of anesthesia intolerance concerns, what is the solution for his case?

If surgery is not an option, he should be seen by a cardiologist and his medical regimen should be optimized. This includes medication, diet and exercise that is safe for him to do. Hopefully, these interventions can maintain his comfort and allow him to live as long as possible while maintaining a good quality of life. Good luck to both of you!