RESUMEN
We compared a rapid, point-of-care multimarker protocol with a single and serial troponin I (TnI)-only protocol in 5,244 patients admitted to the emergency department with chest pain. The diagnosis of acute myocardial infarction (AMI) was based on a doubling myoglobin level accompanied by at least a 50% increase in the creatine kinase (CK)-MB level with no detectable TnI; a doubling of myoglobin level together with any detectable TnI; or a TnI level of 0.4 ng/mL (0.4 microg/L) or more, irrespective of myoglobin or CK-MB results. By using these new criteria, 145 of 148 cases were positive for AMI (positive predictive value [PPV], 92.4%) and 3 were negative, which were also negative by the core laboratory TnI assay. Twelve confirmed non-AMI cases were positive by the new protocol, with 10 of 12 confirmed by the core laboratory as positive for TnI. The negative predictive value (NPV) was 99.9% the overall diagnostic accuracy was 99.7%. The TnI-only protocol had a sensitivity of 68.2% with an NPV of 99.1%. With lower TnI-only cutoffs, 4 patients had false-negative results, and a PPV of 36.4% was observed. Our rapid multimarker protocol seems superior to a TnI-only approach for rapidly triaging patients with chest pain or AMI.
Asunto(s)
Biomarcadores/sangre , Dolor en el Pecho/diagnóstico , Servicios Médicos de Urgencia/métodos , Infarto del Miocardio/sangre , Infarto del Miocardio/diagnóstico , Sistemas de Atención de Punto , Algoritmos , Dolor en el Pecho/etiología , Creatina Quinasa/sangre , Femenino , Humanos , Tiempo de Internación , Masculino , Persona de Mediana Edad , Infarto del Miocardio/complicaciones , Mioglobina/sangre , Sensibilidad y Especificidad , Resultado del Tratamiento , Troponina I/sangreRESUMEN
BACKGROUND: The diagnosis and management of acute ischemic stroke are limited by the lack of rapid diagnostic assays for use in an emergency setting. Computed tomography (CT) scanning is used to diagnose hemorrhagic stroke but is relatively ineffective (<33% sensitive) in detecting ischemic stroke. The ability to correlate blood-borne protein biomarkers with stroke phenotypes would aid in the development of such rapid tests. METHODS: ELISAs for >50 protein biomarkers were developed for use on a high-throughput robotic workstation. These assays were used to screen plasma samples from 214 healthy donors and 223 patients diagnosed with stroke, including 82 patients diagnosed with acute ischemic stroke. Marker assay values were first compared by univariate analysis, and then the top markers were subjected to multivariate analysis to derive a marker panel algorithm for the prediction of stroke. RESULTS: The top markers from this analysis were S-100b (a marker of astrocytic activation), B-type neurotrophic growth factor, von Willebrand factor, matrix metalloproteinase-9, and monocyte chemotactic protein-1. In a panel algorithm in which three or more marker values above their respective cutoffs were scored as positive, these five markers provided a sensitivity of 92% at 93% specificity for ischemic stroke samples taken within 6 h from symptom onset. CONCLUSION: A marker panel approach to the diagnosis of stroke may provide a useful adjunct to CT scanning in the emergency setting.