Changes of creatine phosphokinase MB levels in the context of myocardial reperfusion injury

Abstract

In patients with initially elevated levels of creatine phosphokinase MB (CPK-MB), its increase after percutaneous coronary intervention (PCI) may be due not only to additional injury, but also to natural release during myocardial infarction. Therefore, CPK-MB should be evaluated relative to the initial values.Aim. To compare the CPK-MB dynamics after myocardial reperfusion relative to baseline values and the upper limit of normal (ULN) for the optimal approach to determining myocardial reperfusion injury in patients with acute coronary syndrome.Material and methods. A single center observational study was conducted with the participation of 90 patients hospitalized with a diagnosis of acute coronary syndrome. Patients underwent a biochemical blood test for CPK-MB twice and its dynamics was determined relative to the initial value and ULN.Results. Between the ischemia time and CPK-MB dynamics relative to the initial values, there is a moderate negative correlation. At the same time, the ratio of CPKMB after surgery to ULN is not associated with ischemia time. Analysis of covariance showed that the CPK-MB dynamics, determined relative to the initial values, is 20% dependent on the ischemia time. Individual features of coronary system anatomy, localization of the infarct-associated artery and the subsequent reperfusion procedure together explain the CPK-MB dynamics after surgery by 27%. When the ratio of CPK-MB to ULN is included in the analysis of covariance, all the above factors lose statistical significance.Conclusion. Thus, for a more accurate assessment of myocardial reperfusion injury after PCI, not the upper limit of normal should be analyzed, but the initial values of CPK-MB. In patients with the left heart dominant, as well as in the infarction localization in the system of right or left anterior descending artery, there is a slight change in the marker. On the contrary, more pronounced dynamics is observed in patients with tortuous coronary arteries and with implantation of 2 or more stents. At the same time, the assessment of CPK-MB in relation to ULN is not associated with the ischemia time and does not depend on the clinical and angiographic characteristics and tactics of the operation.