The sensitivity of cardiac markers stratified by symptom duration.
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.
Nagurney
John T
JT
Massachusetts General Hospital, Boston, Massachusetts 02114, USA.
Brown
David F M
DF
Chae
Claudia
C
Chang
Yuchiao
Y
Chung
Won G
WG
Cranmer
Hilarie
H
Dan
Li
L
Fisher
Jonathan
J
Grossman
Shamai
S
Tedrow
Usha
U
Lewandrowski
Kent
K
Jang
Ik-Kyung
IK
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*
D015415:Biomarkers; D009211:Myoglobin; D019210:Troponin I; D052279:Creatine Kinase, MB Form