Utilization of LDH isoenzymes in the diagnosis of myocardial infarction.

With the arrival of managed care, increased pressure is being placed on the health-care system to reduce the use of laboratory services. When evaluating less expensive methods to measure CK-MB to help reduce costs of triaging patients suspected of having myocardial infarction (MI), we also had an opportunity to evaluate the ordering pattern of LDH isoenzymes for these same patients. We found that LDH isoenzymes were continuously ordered as a routine test at least 14% of the time. We worked with the Division of Cardiology to reduce the use of LDH isoenzymes in two ways: 1) by changing the protocol of triaging suspected MI patients and 2) by reporting the test result only after director approval. This article summarizes our approach to reducing the use of LDH isoenzymes, an expensive test in terms of reagent cost and technician time.