My Father In Law Is 78 Years Old. Had CABG

My father in law is 78 years old. Had CABG 3 months back, at that time GFR WAS 45. After bronac it improved to 50. 3 days back he had few episodes of involuntary urination. So we went for USG, which says small mid pole calcification in left kidney. BPH. creatine 2 BUN. 80 PSA. 2.8. Can you help me for line of action stage and prognosis. Regards.