MYOSIN LIGHT-CHAIN-I GRADE - A SIMPLE MARKER FOR THE SEVERITY AND PROGNOSIS OF PATIENTS WITH ACUTE MYOCARDIAL-INFARCTION

To establish serum myosin light chain I (MLCI) as a severity and progn ostic marker for patients with acute myocardial infarction (AMI), we m easured the serum levels of MLCI in 71 patients with first AMI daily F or 1 week after the onset and classified them into four groups by the peak LCI: group 1, greater than or equal to 2.5 ng/ml but <10 ng/ml; g roup 2, greater than or equal to 10 ng/ml but <25 ng/ml; group 3, grea ter than or equal to 25 ng/ml but <50 ng/ml; and group 4, greater than or equal to 50 ng/ml (MLCI grade). The patients in group 1 were likel y to show non-Q-wave infarction. The patients in groups 1 and 2 were l ikely to show redistribution on exercise thallium-201 scintigraphy, su ggesting frequent residual ischemia in these groups. The patients in g roup 4 were likely to show higher Forrester's subset and lower cardiac index at admission and lower left ventricular ejection fraction at di scharge. Recurrent angina was equally found in all groups. Severe comp lications or death were found in patients in groups 3 and 4. Thus the MLCI grade can be used as a simple marker for evaluating the severity of patients with AMI.