Serum glutamic-oxaloacetic transaminase activity: diagnostic accuracy of the revised spectrophotometric and the dinitrophenylhydrazine methods.

The diagnostic accuracy of two methods for measuring serum glutamic-oxaloacetic transaminase activity was examined in 50 cases of acute myocardial infarction proven by autopsy and in 12 nonfatal cases documented by rigid clinical criteria. All activities measured with the revised spectrophotometric method were elevated during the second day after infarction, and all patients had an elevated activity. The spectrophotometric method therefore had a diagnostic accuracy of 100%. Activities measured with the dinitrophenylhydrazine method of Reitman and Frankel were elevated in only 68% of cases during the second day after infarction, and the activity was elevated in only 76% of all the patients during the first 4 days. Dinitrophenyihydrazine-measured activities were therefore 20-30% inaccurate. The diagnostic inaccuracy of the dinitrophenyihydrazine method could result in 300,000 falsenegative diagnoses of acute myocardial infarction each year in the United States alone.