[The Italian Group for the Study of Streptokinase in Myocardial Infarct: Evaluation of the enzymatic curve of creatine kinase].

Within the multicentre trial of the Italian Group for the Study of Streptokinase in Infarct (G.I.S.S.I.), a particular study was planned for the analysis of plasma creatine kinase curves (CK). Serial measurements of total plasma CK from 11,806 pts (5.905 treated with Streptokinase (SK) and 5,901 control pts (C)) were evaluated by the compartment method (Fig. 7), which is commonly used in pharmacological studies. By this method, the plasma enzyme curve is interpreted on the basis of the following kinetic parameters: the fractional rate of input (Ki) and of disappearance (Kd) of enzyme into and from the blood; the plasma cumulative CK activity (Dp); the time interval between the onset of symptoms and the beginning of the ascending CK curve (To); the time from To to the peak CK (Tp). The Dp/Ki ratio was employed for the estimate of myocardial infarct size. From the available data, acceptable CK curves could be derived in 7,632 cases (3,568 treated with SK, 4,064 control pts.). Compared with control group (Fig. 1--Tab. I) the SK treated pts presented increased Ki and Kd values and reduced To, (p greater than 0.001), Dp/Ki (p greater than 0.05). The earlier SK treatment was started, the higher difference (Fig. 2) was observed between the two groups (SK and C). No significant difference was found between the two groups (SK and C) with regard to sex (Fig. 3), age, history of previous myocardial infarct, re-infarction, early post-infarction angina. Statistically significant similar differences of the above parameters between SK and C groups, were also found when various infarct locations were considered, with the only exception of not-Q infarct (Fig. 4). In the cases complicated by pericarditis (Tab. II, Fig. 5), independently of treatment, reduced reperfusion related indexes and increased Dp/Ki ratio were observed. Severe left ventricular impairment (Killip class 4) tends to reduce (Tab. III) the differences in enzyme parameters between the two groups (SK and C). The patients who died (18 hours after the onset of symptoms) exhibited as the only significant difference compared to survivors the infarct-size related CK parameters (Dp/Ki), independently from the treatment. The mathematical model used in this study proved to be easily feasible and useful for the evaluation of the effect of the treatment in acute myocardial infarct.(ABSTRACT TRUNCATED AT 400 WORDS)