The cardiac profile and proposed practice guideline for acute ischemic heart disease.

Presented with an ever-increasing array of potential tests of myocardial injury, the clinical pathologist in conjunction with physicians in primary care, cardiology, and other clinical disciplines must evolve a practical approach for each individual institution. This involves identifying the tests available for immediate (stat) or timed performance, the appropriate patients for whom testing is desired, the schedule of frequency and duration of testing, and the manner in which the test results are to be interpreted. A guideline is presented to address these issues with the purpose of stimulating local adoption of an appropriately modified version to accommodate the current state of the art. Selective choice of an early marker, creatine kinase MB by mass immunoassay, in conjunction with cardiac troponin I (cTnI), is proposed as the appropriate combination of laboratory tests that emphasizes the cardiospecificity of cTnI for the variety of applications in which the "cardiac profile" formerly has been used, including the spectrum of clinical settings in which suspected myocardial infarction must be considered. A rationale is provided with emphasis on the relative merit of the various biochemical markers in contrast with other modalities for evaluating suspected myocardial injury.