A method is presented for routine estimation of ultimate
infarct size in patients with acute
myocardial infarction (AMI). This method implies the calculation of the total quantity of
alpha-hydroxybutyrate dehydrogenase (HBDH) released by the heart per liter of plasma, with the use of five to seven plasma samples per patient during the first 4 days after onset of
infarction. The choice of HBDH for this purpose was motivated by a relatively small error in estimated
enzyme release for slowly eliminated
enzymes. The practicality of this method was studied in the coronary care unit at Leiden University Hospital where, in 1979, 146 patients with AMI were included in the study. In 100 patients (68%) HBDH-
infarct size could be calculated precisely, and in 12 other patients (8%) the assessment of HBDH-
infarct size was less accurate. In 34 patients (23%), HBDH-
infarct size was unobtainable because of early death (eight cases),
infarctions too small in size to assess or nonexistent (six cases), too much time elapsed since
infarction (six cases), and incomplete plasma sampling (14 cases). Analysis of data shows that the larger HBDH-
infarct sizes were found to be associated significantly with signs of
heart failure, low
stroke index and low ejection fraction, presence of
tachycardias and interventricular conduction disturbances, high score of left ventricular wall motion abnormalities, large myocardial perfusion defect measured with
thallium-201, in-hospital death, and death in the first year after
infarction. A low but significant correlation was observed between HBDH-
infarct size and the severity of coronary arterial lesions.