title: The sensitivity of cardiac markers stratified by symptom duration.
abstract: We compared the sensitivity of three commonly used cardiac markers between two subpopulations, those who came to the Emergency Department (ED) late (6-24 h) after their symptoms began, and those who arrived earlier (<6 h), in a prospective comparative trial. Among all adult patients who presented to our ED with symptoms suggestive of acute myocardial infarction (MI), we drew serum for myoglobin, CK-MB, and troponin I upon arrival (time 0) and 2 h later. Outcomes, including acute MI, were determined. Sensitivities for all three markers between the subpopulations who arrived fewer than 6 h from symptom onset were compared to those who arrived later (6-24 h). We enrolled 346 eligible subjects, 36% of whom described cardiac symptoms as beginning 6 or more hours earlier; 14% suffered acute MIs. For time 0, the sensitivity of all three markers for acute MI was significantly higher among those subjects with symptoms of 6 or more hours' duration as compared to those with less. For troponin I, the increase in sensitivity between these two subpopulations approached 300%. At the time of the 2-h sample, the differences in sensitivities were much less and were not statistically significant. We conclude that cardiac marker values obtained at time 0 among Emergency Department patients who arrive 6 or more hours after cardiac symptom onset provide significantly higher sensitivities as compared to those obtained in patients who arrive earlier. For troponin I, the increase in sensitivity approaches threefold.
authors.affiliation: Massachusetts General Hospital, Boston, Massachusetts 02114, USA.
authors.forename: John T
authors.initials: JT
authors.lastname: Nagurney
authors.forename: David F M
authors.initials: DF
authors.lastname: Brown
authors.forename: Claudia
authors.initials: C
authors.lastname: Chae
authors.forename: Yuchiao
authors.initials: Y
authors.lastname: Chang
authors.forename: Won G
authors.initials: WG
authors.lastname: Chung
authors.forename: Hilarie
authors.initials: H
authors.lastname: Cranmer
authors.forename: Li
authors.initials: L
authors.lastname: Dan
authors.forename: Jonathan
authors.initials: J
authors.lastname: Fisher
authors.forename: Shamai
authors.initials: S
authors.lastname: Grossman
authors.forename: Usha
authors.initials: U
authors.lastname: Tedrow
authors.forename: Kent
authors.initials: K
authors.lastname: Lewandrowski
authors.forename: Ik-Kyung
authors.initials: IK
authors.lastname: Jang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000787:Angina Pectoris / Q000175:diagnosis* / Q000503:physiopathology; D000789:Angina, Unstable / Q000175:diagnosis* / Q000503:physiopathology; D015415:Biomarkers; D001900:Boston; D052279:Creatine Kinase, MB Form / Q000097:blood*; D004636:Emergency Service, Hospital; D005260:Female; D006785:Hospitals, University; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000503:physiopathology; D009211:Myoglobin / Q000097:blood*; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires; D013997:Time Factors; D019210:Troponin I / Q000097:blood*
chemical_list: D015415:Biomarkers; D009211:Myoglobin; D019210:Troponin I; D052279:Creatine Kinase, MB Form