CLINICAL AND ANGIOGRAPHIC CORRELATES OF NORMAL CREATINE-KINASE WITH INCREASED MB ISOENZYMES IN POSSIBLE ACUTE MYOCARDIAL-INFARCTION

A retrospective study of patients with possible acute myocardial infarction was conducted over a P-year period to evaluate the clinical characteristics, angiographic findings, and in-hospital prognosis in patients with normal total creatine kinase (CK) activity and increased MB isoenzyme activity (CK-MB). Thirty-nine cases were identified (study group) and compared with cases of Q-wave (n=77) and non-Q-wave (n=60) infarctions. Compared with the Q-wave group, study group patients were older (67.5+/-9.0 vs 60.8+/-11.5 years; p<0.01) and more often had previous diagnoses of coronary disease (52.6% vs 18.2%; p<0.01) and peripheral vascular disease (28.9% vs 10.4%; p=0.02). Angina (92.2% vs 65.8%; p<0.01) and ST elevation (81.8% vs 13.2%; p<0.01) were more common in the Q-wave group. Nearly identical clinical profiles and electrocardiographic findings were observed in the study and non-Q-wave groups. Angiographic analysis revealed a higher frequency of multivessel disease in the study group (89.6%) than in the Q-wave group (48.6%, p<0.01) but no difference between the study group and the non-Q-wave group (79.6%; p not statistically significant). Left ventricular function and in-hospital complications were similar among groups. It is concluded that patients with normal total CK activity and increased CK-MB concentration represent a subgroup of patients with non-Q-wave infarction with a high prevalence of multivessel coronary disease.