After going through history of your father even 2 stents are there hypokinesia with systolic function is only 20%.When any fluid is lost in loose motion
or vomiting which may be due to infection? dehydration
may be transient cause reduced blood flow to kidney and cause damage to kidney. or systemic infection itself may cause renal failure if acute renal failure
is there with high urea and creatinine
along with your cadiologist should take care. If he responds to drugs and signs of recovery with good urine output,clearance of toxemia,but he may need hemodylasis if no response and electrolytes imbalance of high potassium and Sodium. Also if reqired support to heart by medicines as pumping is poor. Hope for best good luck.