Estimation of acute myocardial infarct size in man by serum CK-MB measurements.

Abstract

SUMMARY This study was performed to determine the relationship between myocardial infarct size estimated by serum CK-MB methods and the extent of irreversible injury in acute myocardial infarction. In 321 consecutive patients, infarct size was estimated by different mathematical models, and in 22 patients who died in hospital, the extent of myocardial necrosis was determined by autopsy. We also investigated the depletion of CK-MB in infarcted tissue, the recovery of CK-MB in the plasma volume, and the elimination of CK-MB from plasma.Myocardial CK-MB depletion was relatively greater in the larger infarcts, whereas the recovery of enzyme in plasma was independent of the infarct size. Correction of serum CK-MB for changes in plasma volume improved the estimate significantly (p < 0.05). The correlation between the measured infarct size (g) and the estimated infarct size (units per liter and gram-equivalents) was highly significant (r = 0.85-0.89, SEE = 23-27%, p < 0.001). Thus, a semiquantitative expression of the extent of myocardial necrosis can be determined in vivo. AMI. Of these, 72 were excluded: 48 because the symptoms of AMI had lasted more than 15 hours before admission or because the second blood sample did not show higher CK-MB activity than the first and 24 because not enough blood samples had been obtained because patients died or were transferred to another department. The remaining 321 patients form the study group. Forty-three of these patients died within 18 days and were divided into group A, which included 22 patients in whom a detailed heart autopsy was performed, and group B, which included 21 patients in whom no detailed heart autopsy was performed. All patients autopsied had survived for at least 48 hours from the appearance of CK-MB activity in serum and there were no signs of reinfarction before death. Furthermore, all plasma curves showed a pure elimination phase (first-order kinetics).The 22 patients in group A included 12 women and 10 men who died at a mean age of 69.7 years (range 49-88 years). The median time from onset of symptoms until death was 6.4 days (range 2-14 days). Cardiogenic shock was the main cause of death in 12 patients and recurrent ventricular fibrillation in six patients. Two died from asystole and two from noncardiac causes.Heart biopsies were taken postmortem every 6 hours for 30 hours in eight patients from group B. The total enzyme depletion in whole heart homogenates was measured in 10 other patients.In 10 patients who died without signs of heart disease, myocardial biopsies were made to estimate CK and CK-MB activity. Tissue extracts were made from about 0.3 g tissue (wet weight) in a mixture of 10 ml 0.25 mol/ 1 sucrose, 3 ml 0.01 mol/l TRIS buffer (pH 7.4), 3 ml 1 mmol/l EGTA (pH 7.4) and 3 ml 1 mmol/ I mercaptoethanol, and homogenized on ice in an Ultra Turax blender for 1 minute. The homogenate was centrifuged (3500 g) and the supernatant was used to determine isoenzyme activity. The samples were diluted with heat-inactivated serum or TRIS buffer to the line...

Comparison of Two Immunoinhibitory Methods with Agarose Gel-Electrophoresis for Measuring the MB Isoenzyme of Creatine Kinase in Serum from Cases of Suspected Myocardial Infarction

“…We have earlier shown that the electrophoretic method may be used to estimate infarct size (13). Our data clearly demonstrate that similar results would be obtained with the dry chemistry method.…”

“…Finally the electrophoretic method and dry chemistry method were used to estimate infarct size (13) in eight patients with acute myocardial infarction. Creatine kinase-MB was measured by both methods in 9 -11 serum samples taken from each patient over two days (about every four hours).…”

The Correlation between Infarct Size and the QRS Axis Change after Thrombolytic Therapy in ST Elevation Acute Myocardial Infarction

“…Until now, the studies on jeopardized myocardium and infarct sizing have primarily used ST deviations and QRS scores [6][7][8]. In fact, biochemical markers, primarily CK-MB and troponin (Tn) T, have long been used for infarct sizing [9][10][11][12][13][14]. In this context, for infarct sizing, markers like CK-MB and myoglobin are more appropriate than Tn T because of the higher rate of rising and falling serum levels.…”

Complete recovery in plasma of enzymes lost from the heart after permanent coronary artery occlusion in the dog.

“…Several clinical studies also have produced convincing correlations between enzymatic and histologic estimates of infarct size. [4][5][6][7] After permanent coronary occlusion in the dog, however, only about 15% of the total creatine kinase (CK) activity depleted from the heart was recovered in plasma,8 and it was shown that even a limited variability in this recovery would cause large errors in the estimates.9 Such variability was indeed demonstrated. '0411 Moreover, it was reported that this figure of 15% was changed significantly after interventions such as reperfusion12 and lymphatic obstruction.…”