Serum myocardial creatine kinase (CK-MB) after coronary arterial bypass surgery

Abstract

Serum myocardial creatine kinase, MB isoenzyme (CK−MB) was measured at 6 hour intervals for 36 hours after surgery by ion exchange column chromatography for detection of perioperative myocardial infarction and was compared with serial electrocardiograms, serum glutamic oxaloacetic transaminase (SGOT) and lactate dehydrogenase (LDH) isoenzyme determination and technetium-99m pyrophosphate myocardial scintigraphy in 100 consecutive patients undergoing coronary artery bypass surgery. Results were compared with those in a control group of 10 patients with normal coronary arteries after closure of an atrial septal defect or mitral valvotomy. Total CK-MB release was estimated by calculating the concentration time integral for 36 hours after surgery. In 77 of 87 patients with a peak CK-MB and total CK-MB release lower than the highest control value (or mean + 2 standard deviations), all other tests were also negative for perioperative myocardial infarction. The other 10 patients had an isolated positive laboratory test (5 patients showed ischemic electrocardiographic changes, 3 patients an SGOT level of more than 90 IU/liter and 2 patients LDH 1 equal to or greater than LDH 2). All 13 patients with CK-MB values higher than the highest control value (or mean ± 2 standard deviations) had at least two additional positive laboratory tests indicating perioperative myocardial infarction (8 patients had new Q waves, 3 patients ischemic electrocardiographic changes, 11 patients LDH 1 equal to or greater than LDH 2, 11 patients SGOT greater than 90 IU/liter and 8 of 10 patients a positive myocardial scintigram). Thus, CK-MB by column chromatography is a reliable test for recognition of perioperative myocardial infarction and appears to be more sensitive than electrocardiography or scintigraphy for detection of myocardial necrosis. Reliability may be strengthened by the association of elevated CK-MB with additional positive tests.