Serum creatine kinase-B activity in patients with chronic lower-limb ischemia and after leg amputation

Serum creatine kinase-B (CK-B) activity was measured and electrocardiograms (ECG) recorded before and after operation in two groups of ten orthopedic patients. Group I underwent lower-limb amputation because of severe, chronic ischemia of the leg and group II (controls) had knee prosthesis implantation or knee ligament surgery. In group I the number of patients with CK-B activities exceeding the discrimination value (0.25 muka-tal/l) for acute myocardial infarction preoperatively and 2, 24, 48, 72 hours, and at 7 days postoperatively were, respectively, three, three, five, three, two and nil. In Group II the serum CK-B activity remained below the myocardial infarction discrimination value in all patients at all times. No ECG abnormalities indicating myocardial infarction appeared in any patient of either group. The study indicates that severe, chronic lower-limb ischemia and amputation of the leg may cause elevation of non-cardiac CK-B activity in serum that can interfere with enzymatic recognition of acute myocardial infarction.