Myoglobin and troponin I elevation predict 5-year mortality in patients with undifferentiated chest pain in the emergency department.
BACKGROUND
The long-term prognostic significance of elevated cardiac markers in an undifferentiated patient population with chest pain is unknown.


METHODS
Serum troponin I (cTnI), creatine kinase-MB (CK-MB), and myoglobin were measured at presentation in 951 consecutive patients evaluated in the emergency department for possible acute coronary syndrome, and all-cause mortality was measured over 5 years.


RESULTS
Final diagnoses included myocardial infarction in 70 (7.4%), unstable angina in 78 (8.2%), stable angina in 26 (2.7%), heart failure in 135 (14.2%), syncope in 61 (6.4%), arrhythmia in 62 (6.5%), and noncardiac diagnoses in 519 (54.6%). Our study population had a mean (+/-SD) age of 63 (+/-16), 434 (46%) were male, 774 (81%) were African American, 408 (43%) had known coronary artery disease, 647 (68%) had hypertension, 244 (26%) had diabetes mellitus, and 237 (25%) had a serum creatinine>or=1.5 mg/dL. At 5 years, there were 349 (36.7%) deaths. In a multivariate model with adjustment for baseline covariates, an elevated cTnI>or=1.0 ng/mL (hazard ratio [HR] 1.7, 95% CI 1.3-2.3) and myoglobin>or=200 ng/mL (HR 1.6, 95% CI 1.2-2.1), but not CK-MB>or=9.0 ng/mL (HR 0.9, 95% CI 0.6-1.3), remained independent predictors of all-cause mortality. Patients with both elevated cTnI and myoglobin had a particularly high mortality rate.


CONCLUSIONS
Among patients evaluated in the emergency department for possible acute coronary syndromes, myoglobin and cTnI at presentation are powerful, independent predictors of long-term (5-year) prognosis.
Jaffery
Zehra
Z
Department of Internal Medicine, Henry Ford Hospital, Detroit, MI 48202, USA. zjyaali@yahoo.com
Nowak
Richard
R
Khoury
Nabil
N
Tokarski
Glen
G
Lanfear
David E
DE
Jacobsen
Gordon
G
McCord
James
J
D054058:Acute Coronary Syndrome / Q000097:blood / Q000150:complications / Q000401:mortality; D000368:Aged; D002637:Chest Pain / Q000097:blood* / Q000209:etiology / Q000401:mortality*; D052279:Creatine Kinase, MB Form / Q000097:blood*; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009211:Myoglobin / Q000097:blood*; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate; D013997:Time Factors; D019210:Troponin I / Q000097:blood*
D009211:Myoglobin; D019210:Troponin I; D052279:Creatine Kinase, MB Form