A double-blind, multicentered study comparing the accuracy of diagnostic markers to predict short- and long-term clinical events and their utility in patients presenting with chest pain.
BACKGROUND
Millions of patients present annually with chest pain, but only 10% have myocardial infarction (MI). We recently reported comparative sensitivity and specificity of available markers in the diagnosis of MI; however, optimum interpretation of marker results requires prognostic follow-up data.


OBJECTIVE
The study was undertaken to study the accuracy of CK-MB subforms, troponin I and T, myoglobin, and CK-MB in predicting clinical events at 30 days and 6 months.


METHODS
In all, 955 consecutive patients with chest pain were enrolled in a prospective, multicenter, double-blind study to test the prognostic accuracy of these markers.


RESULTS
Myocardial infarction was diagnosed in 119 by CK-MB mass criteria and unstable angina (UA) in 203 patients by clinical criteria. Follow-up at 30 days and 6 months was available in 824 and 724 patients, respectively, with mortalities of 2.8 and 4.14%, respectively. Cumulative 6-month mortality was 5.6% in MI, 4.4% in UA, and 3.0% in others. Revascularization was reported in 9.3% of patients by 6 months. A positive test on each of the markers except myoglobin was predictive of revascularization. The composite endpoint of death or revascularization occurred in 107 patients by 6 months and a positive result on each of the markers was predictive of this composite endpoint (p < 0.05). The relative risk of death or revascularization for patients who did not have MI but tested positive on each of the markers was > 1.0 but did not reach statistical significance.


CONCLUSIONS
With the possible exception of myoglobin, each of the diagnostic markers displayed similar prognostic performance in patients with chest pain presenting to emergency departments. The most appropriate markers to triage patients with chest pain, which has both adequate early diagnostic sensitivity and prognostic accuracy, are the CK-MB subforms.
Fromm
R
R
Section of Cardiology, Baylor College of Medicine, Houston, Texas 77030, USA.
Meyer
D
D
Zimmerman
J
J
Boudreaux
A
A
Wun
C C
CC
Smalling
R
R
Davis
B
B
Habib
G
G
Roberts
R
R
D000328:Adult; D015415:Biomarkers / Q000097:blood; D002637:Chest Pain / Q000175:diagnosis*; D003402:Creatine Kinase / Q000097:blood; D052279:Creatine Kinase, MB Form; D004311:Double-Blind Method; D005500:Follow-Up Studies; D006801:Humans; D007527:Isoenzymes / Q000097:blood; D009203:Myocardial Infarction / Q000175:diagnosis*; D009211:Myoglobin / Q000032:analysis; D011379:Prognosis; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013997:Time Factors; D019210:Troponin I / Q000097:blood; D020107:Troponin T / Q000097:blood
D015415:Biomarkers; D007527:Isoenzymes; D009211:Myoglobin; D019210:Troponin I; D020107:Troponin T; D003402:Creatine Kinase; D052279:Creatine Kinase, MB Form