One-hour rule-out and rule-in of acute myocardial infarction using high-sensitivity cardiac troponin T.
BACKGROUND
High-sensitivity cardiac troponin (hs-cTn) assays seem to improve the early diagnosis of acute myocardial infarction (AMI), but it is unknown how to best use them in clinical practice. Our objective was to develop and validate an algorithm for rapid rule-out and rule-in of AMI.


METHODS
A prospective multicenter study enrolling 872 unselected patients with acute chest pain presenting to the emergency department. High-sensitivity cardiac troponin T (hs-cTnT) was measured in a blinded fashion at presentation and after 1 hour. The final diagnosis was adjudicated by 2 independent cardiologists. An hs-cTnT algorithm incorporating baseline values as well as absolute changes within the first hour was derived from 436 randomly selected patients and validated in the remaining 436 patients. The primary prognostic end point was death during 30 days of follow-up.


RESULTS
Acute myocardial infarction was the final diagnosis in 17% of patients. After applying the hs-cTnT algorithm developed in the derivation cohort to the validation cohort, 259 patients (60%) could be classified as "rule-out," 76 patients (17%) as "rule-in," and 101 patients (23%) as in the "observational zone" within 1 hour. Overall, this resulted in a sensitivity and negative predictive value of 100% for rule-out, a specificity and positive predictive value of 97% and 84%, respectively, for rule-in, and a prevalence of AMI of 8% in the observational zone group. Cumulative 30-day survival was 99.8%, 98.6%, and 95.3% (P < .001) in patients classified as rule-out, observational zone, and rule-in, respectively.


CONCLUSIONS
Using a simple algorithm incorporating hs-cTnT baseline values and absolute changes within the first hour allowed a safe rule-out as well as an accurate rule-in of AMI within 1 hour in 77% of unselected patients with acute chest pain. This novel strategy may obviate the need for prolonged monitoring and serial blood sampling in 3 of 4 patients.
Department of Cardiology, University Hospital Basel, Switzerland.
Tobias
T
Reichlin
Christian
C
Schindler
Beatrice
B
Drexler
Raphael
R
Twerenbold
Miriam
M
Reiter
Christa
C
Zellweger
Berit
B
Moehring
Ronny
R
Ziller
Rebeca
R
Hoeller
Maria
M
Rubini Gimenez
Philip
P
Haaf
Mihael
M
Potocki
Karin
K
Wildi
Cathrin
C
Balmelli
Michael
M
Freese
Claudia
C
Stelzig
Heike
H
Freidank
Stefan
S
Osswald
Christian
C
Mueller
D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D002637:Chest Pain / Q000097:blood / Q000175:diagnosis*; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000175:diagnosis*; D011379:Prognosis; D011446:Prospective Studies; D020107:Troponin T / Q000097:blood*
D020107:Troponin T