IN-111 ANTIMYOSIN SCINTIGRAPHY BEFORE AND AFTER CORONARY-BYPASS SURGERY - UNEXPECTED PREOPERATIVE MYOCARDIAL UPTAKES

The present study was designed to evaluate In-111-antimyosin scintigra phy in detecting pre-and post-operative myocardial infarction in patie nts undergoing coronary artery bypass surgery. Fab antimyosin scintigr aphy has been shown to be sensitive and specific in detecting myocardi al necrosis and to be potentially valuable in situations where other c riteria are not reliable. In a previous study, postoperative antimyosi n uptakes occurred in 82% of the studied patients. Sixteen consecutive patients with an indication of coronary artery surgery were assessed by preoperative coronary angiography, serial electrocardiograms, and m yocardial scanning with (111)Indium-labeled antimyosin antibodies perf ormed before and after operation. In four patients, a recent myocardia l infarction (1 to 3 months) was detected with an accurate localizatio n when compared to the classic criteria of myocardial infarction. One more patient with a 21-year old myocardial infarction showed an intens e uptake whereas there was no recent acute coronary event. Four other patients had an unexpected preoperative uptake, since there were no ac ute coronary events in their medical history. All preoperative scintig raphic uptakes were still present on the second scan performed postope ratively in these nine patients. Only one patient showed a new postope rative uptake when compared to the preoperative scan which was normal; this postoperative septal infarct was confirmed by a postoperative co ronary angiography. Extracardiac uptakes (sternum and ribs) were frequ ently observed after operation and might hamper the interpretation of postoperative scintigrams. Unexpected preoperative uptakes may be rela ted to non diagnosed small necrosis. A preoperative reference scan is required for an accurate interpretation of a postoperative In-111-anti myosin uptake. Moreover, extracardiac uptakes may limit the interpreta tion of perioperative cardiac damage. (C) 1997 Elsevier Science Irelan d Ltd.