Assessment of a creatine kinase-MB/myoglobin kit in the prehospital setting in patients presenting with acute nontraumatic chest pain: The 'Shahal' experience

Objectives: To evaluate the usefulness of a novel qualitative, rapid, bedside immunoassay device for the detection of elevated creatine kinase MB(mass) (CK-MB) and myoglobin as a supportive tool for decision-making by the physician who is evaluating patients who present with chest pain. Design: Prospective study. Setting: Prehospital (mobile intensive care units). Patients: Three hundred twenty-eight consecutive patients, age 71 ± 13 yrs (64% males), who were admitted to the hospital via Shahal's mobile intensive care units. Intervention: During a 6-month period, based on clinical presentations and electrocardiograms, the mobile's physicians classified patients into groups of high or low probability of having an acute myocardial infarction and, thereafter, used a rapid bedside STATus kit® (Spectral Diagnostics, Toronto, Ontario, Canada) to determine blood creatine kinase/MB and myoglobin. Measurement and Main Results: Myocardial infarction was confirmed in 59 (18%) patients. If measured >2 hrs after onset, diagnostic sensitivities, specificities, and positive and negative predictive values for physicians were as follows: 71%, 90%, 46%, and 96%, respectively, compared with 100%, 85%, 44%, and 100%, respectively, if assessed by the kit. Conclusions: If used 2 to 12 hrs from the onset of symptoms, this device is a convenient diagnostic aid to prevent a misdiagnosis of acute myocardial infarction or unnecessary hospitalization to exclude infarction. This tool may be a promising cost-cutting factor in these days of escalating expenses and dwindling resources.