Hello, the most probable cause of your father s kindey dysfunction (creatinine above normal range) is diabetes. Diabetes is a well-known cause of kidney damage. The heart problems you mentioned imply established vascular damage by diabetes which is common between diabetic patients with kidney problems. The best he can do now is try to keep his blood pressure within normal range, maintain a normal body weight, walk every day for at least 30 minutes, adhere to a healthy diet and keep his blood sugar under control. Some doctors may argue that blood pressure in diabetic patients with kidney problems should be even less than the upper normal range for a healthy individual but this is a matter of scientific debate. In any case a blood pressure around 125-130mmHg/70-80mmHg, fasting blood glucose between 80-120mg/dL and the rest I already mentioned is the way to go. One final note about walking. Mild exercise (when not contraindicated) has proven its benefit over the years. Actually it is as important as medications themselves. It keeps the blood sugar low and helps the blood pressure too. It has to be done every day or at least every other day. I hope I ve clarified your father s situation for you! If you need further guidance, please let me know. Kind Regards!