Minimal myocardial injury after uncomplicated coronary bypass surgery. Various sources of overestimation.
Myocardial injury after aorto-coronary bypass surgery was estimated in 72 patients from total release into plasma of cardiac creatine kinase (CK-MB) and alpha-hydroxybutyrate dehydrogenase (HBD). Activities of CK-MB were determined both by immuno-inhibition of CK-M units and by ion-exchange chromatography. After correction for per-operative hemolysis, the estimates based on HBD were in agreement with the estimates based on CK-MB as determined by the ion-exchange method. Both enzymes indicated a mean loss of only about 2 gram-equivalents of myocardium. Such minimal injury was also found in metabolic and ultrastructural studies of myocardial biopsies in the same patients, as reported earlier. However, approximately two-fold larger estimates of injury were obtained from plasma CK-MB activities determined by immuno-inhibition. This apparent extra release of CK-MB runs parallel with massive release of CK-activity from skeletal muscle damaged by surgery. Taking also into account the various calculation methods used by different authors, overestimates as large as 10-20 gram-equivalents of lost myocardium after uncomplicated bypass surgery, as published in the literature, can be explained.
Hermens
W T
WT
Department of Biophysics, University of Limburg, Maastricht, The Netherlands.
Willems
G M
GM
van der Vusse
G J
GJ
D002852:Chromatography, Ion Exchange; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D003402:Creatine Kinase / Q000097:blood; D006801:Humans; D006884:Hydroxybutyrate Dehydrogenase / Q000097:blood; D009206:Myocardium / Q000473:pathology*
C035749:2-hydroxybutyrate dehydrogenase; D006884:Hydroxybutyrate Dehydrogenase; D003402:Creatine Kinase