Effect of therapeutic interventions on CK and CK MB serum activity kinetics during acute myocardial infarct

Determination of serum creatine kinase (CK) activity, especially the CK MB, isoenzyme is becoming the main diagnostic criterion for acute myocardial infarct (AMI). The aim of this study was to assess the kinetics of the release CK and CK MB in AMI patients on various therapeutic regimens. The study included 75 AMI patients (within 6 hours from the pain onset). They were divided into three groups according to therapy: 1.NTG i.v. (glyceryl trinitrate, N=29), 2.SK + NTG i.v. (streptokinases + glyceryl trinitrate, N = 29); and 3. SK i.v. (N = 17). Samples for CK and CK MB determination were taken every 4 hours in the course of 72 hours, until serum enzyme values returned to normal. The time interval between the introduction of therapy and CK and CK MB peak values expressed in rankes was the shortest in group 3 and longest in group 1. The difference in maximal CK release in to peripheral blood (chi 2 = 9.5270, p = 0.0180) was statistically significant, while difference in CK MB was not (chi 2 = 2.2733, p = 0.2875--NS) (Kruskal Wallis one way test). Comparing CK release time the CK MB within each group by means of rankes, statistical significance in favour of CK MB (1. NTG i.v. p = 0.0000, 2. SK + NTG p = 0.0001, 3. SK p = 0.0180) was obtained. The rate of CK and CK MB elimination from the circulation, expressed as fractional level of losing kd, did not statistically differ in the three groups. Authors' results showed the therapeutic procedures used in the treatment of AMI patients to differently influence the CK and CK MB kinetics. Thrombolytic therapy changed the CK and CK MB kinetics, due to reperfusion and explained by the washout phenomenon from the infarcted zone of the myocardium.