Early diagnosis of myocardial infarction with MB CK isoforms

Over 5 million patients with chest pain present annually to the ER in the US but only 10% will have infarction with < 50% identified by ECG. Early diagnosis of infarction in the ER to triage provides more appropriate and early therapy, less unnecessary use of CCU, and is more cost effective. A rapid automated MB CK isoform assay (25 min) was evaluated in a prospective study of 1110 patients presenting to the ER with chest pain. This assay was shown to have a sensitivity of 96% and specificity of 93% to diagnose infarction within 6 h of onset of chest pain. In 92% the diagnosis was confirmed within 1 h of arrival at the ER. Similar sensitivity and specificity for total MB CK, troponin T, and troponin I required 16 h from onset of pain. Thus, MB CK isoforms provide a rapid diagnosis early after onset of infarction and have the requisite sensitivity and specificity for triaging patients in the ER.