Patients with acute coronary syndrome and normal high-sensitivity troponin.
BACKGROUND
Failure to identify patients with acute coronary syndrome (ACS) is a serious clinical problem. The incidence, characteristics, and outcome of ACS patients with normal high-sensitivity cardiac troponin T (hs-cTnT) levels at presentation are unknown.


METHODS
In a prospective multicenter study, hs-cTnT was determined in a blinded fashion in 1181 consecutive patients presenting with acute chest pain to the emergency department. The final diagnosis of ACS was adjudicated by 2 independent cardiologists. Patients were followed for 12 months.


RESULTS
ACS was the adjudicated diagnosis in 351 patients (30%), including 187 patients with acute myocardial infarction (AMI) and 164 patients with unstable angina (UA). At presentation, hs-cTnT was normal (<.014 ug/L) in 112 ACS patients (32%), including 11 patients (6%) with AMI and 101 patients (62%) with UA (P <.001). Multivariable analysis revealed previous statin treatment, younger age, preserved renal function, and the absence of ST deviation on the electrocardiogram as independently associated with normal hs-cTnT levels. Mortality rates in ACS patients with normal hs-cTnT level were 0.0% at 30 days, 0.0% at 90 days, and 2.0% (95% confidence interval, 0.5-7.9) at 360 days, which was significantly lower than in ACS patients with elevated hs-cTnT level at presentation (17.5% at 360 days, P <.001). Conversely, AMI rates at 360 days was higher in ACS patients with normal versus elevated hs-cTnT levels (P=.004).


CONCLUSIONS
Almost one third of ACS patients have normal hs-cTnT levels at presentation, mostly patients with UA. ACS patients with normal hs-cTnT have a very low mortality, but an increased rate of AMI during the subsequent 360 days.
Department of Internal Medicine, Division of Cardiology, University Hospital, Basel, Switzerland.
Christophe
C
Meune
Cathrin
C
Balmelli
Raphael
R
Twerenbold
Tobias
T
Reichlin
Miriam
M
Reiter
Philip
P
Haaf
Stephan
S
Steuer
Stefano
S
Bassetti
Konstantin
K
Sakarikos
Isabel
I
Campodarve
Christa
C
Zellweger
Affan
A
Irfan
Beatrice
B
Drexler
Christian
C
Mueller
D054058:Acute Coronary Syndrome / Q000097:blood* / Q000175:diagnosis* / Q000401:mortality; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D016009:Chi-Square Distribution; D003937:Diagnosis, Differential; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D018709:Statistics, Nonparametric; D014336:Troponin / Q000097:blood*
D015415:Biomarkers; D014336:Troponin