Improved early risk stratification and diagnosis of myocardial infarction, using a novel troponin I assay concept.
BACKGROUND
We evaluated the clinical performance of a novel cardiac troponin I (cTnI) assay specifically designed to improve the very early risk stratification in acute coronary syndromes.


METHODS
Serum and plasma samples (taken 0, 6-12 h and 24 h after admission) from 531 patients with suspected acute coronary syndrome were studied using a novel investigational cTnI assay, reference cTnI assay and myoglobin. The lowest cTnI concentration giving a total assay imprecision of 10% was used as the positive myocardial infarction (MI) cut-off value.


RESULTS
At the time of admission, the investigational assay was positive in 27.9% of the patients, the reference cTnI assay was positive in only 17.5% (P < 0.001) and myoglobin in 24.1% (P = 0.067). Receiver operating characteristic (ROC) curve analysis for the detection of myocardial injury on admission gave area-under-curve (AUC) values of 0.937, 0.775 and 0.762, respectively (P < 0.001). Of those MI patients who presented within 3 h of symptom onset, 50.0% were identified by the investigational assay at the time of presentation, compared with 44.2% by myoglobin (P = 0.791) but only 11.5% by the reference assay (P < 0.001).


CONCLUSIONS
The novel cTnI assay considerably improves the performance of cTnI as an early rule-in biomarker for MI.
Ilva
T
T
Department of Medicine, University of Turku, FIN-20520 Turku, Finland. tuomo.ilva@pp.inet.fi
Eriksson
S
S
Lund
J
J
Porela
P
P
Mustonen
H
H
Pettersson
K
K
Pulkki
K
K
Voipio-Pulkki
L-M
LM
D000368:Aged; D019540:Area Under Curve; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000379:methods / Q000592:standards; D008297:Male; D009203:Myocardial Infarction / Q000175:diagnosis*; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D019210:Troponin I / Q000097:blood*
D019210:Troponin I