Objective. - To design a strategy for cardiac injury marker testing in the diagnosis of acute myocardial infarction. Design. - Prospective study. Group I (n = 54 patients): evaluation of clinical performance. Specimens collected at 0, 3, 6, and 12 (± 1.5) hours after presentation. World Health Organization criteria were used for diagnosis of acute myocardial infarction. Group II (n = 57 patients): evaluation of temporal evolution. Time intervals 0 to 1.5, 1.5 to 4.5, 4.5 to 7.5, and 7.5 to 13.5 hours. Patients identified by positive creatine kinase-MB (CK-MB) mass or myoglobin. Fourteen patients in Group I qualified for Group II. Hence, the total number of patients was 97. Setting. - A team of laboratorians and clinicians at the University of California, Davis, hospital assessed the clinical performance and temporal evolution of serial CK-MB isoform, troponin I, and troponin T results in comparison to parallel CK-MB mass and myoglobin results. Main Outcome Measures. - Group I: sensitivity, specificity, and positive and negative predictive values. Group II: the time interval of the first positive result for each cardiac injury marker. Strategy and conclusions were based on study results and a literature review. Participants. - Emergency department patients with acute onset of chest pain and other complaints, possibly indicative of myocardial ischemia, who were under evaluation for admission. Results. - Twenty-seven cases of acute myocardial infarction were documented. Group I: troponin I had the highest specificity (100%) and the highest positive predictive value (100%); troponin I, troponin T, and CK-MB mass had the highest sensitivity (90.0%); and the negative predictive values of troponin I, troponin T, and CK-MB mass were comparable (97.8%, 97.6%, and 97.6%, respectively). Group II: early diagnosis (within 1.5 hours) was provided by both CK-MB isoforms and CK-MB mass, and then by myoglobin and troponins, in order of decreasing frequency. Conclusions. - Creatinine kinase-MB mass, myoglobin and troponin I were selected as the cardiac injury markers of choice at our institution of myoglobin and CK-MB mass initially - and serially if warranted by heightened clinical suspicion - with troponin I added if indicated for (1) specific confirmation, (2) late presentation, or (3) risk stratification.
|Original language||English (US)|
|Number of pages||7|
|Journal||Archives of Pathology and Laboratory Medicine|
|State||Published - Mar 1998|
ASJC Scopus subject areas
- Pathology and Forensic Medicine
- Medical Laboratory Technology