Renal failure after two myocardial infarctions

A 60-year-old man was admitted to the hospital for elective cardiac catheterization. He had had two myocardial infarctions (MI) one and two months earlier. After the second MI, he had been treated with tissue plasminogen activator and heparin. Since then, his blood urea nitrogen concentration had increased from 20 to 63 mg/dL and his blood creatinine concentration from 1.2 to 9.2 mg/dL.