Incidence of Undetectable, Measurable, and Increased Cardiac Troponin I Concentrations Above the 99th Percentile Using a High-Sensitivity vs a Contemporary Assay in Patients Presenting to the Emergency Department.
We compared the incidence of undetectable [below the limit of detection (LoD)], measurable (LoD to 99th percentile), and increased cardiac troponin I (cTnI) concentrations above the 99th percentile between Abbott high-sensitivity cTnI (hs-cTnI) and contemporary cTnI assays in a US emergency department population.



Patients (n = 2100) presenting to the emergency department who had serial cTnI (0, 3, 6, 9 h) measurements ordered on clinical indication were enrolled. Contemporary cTnI [Abbott Architect used clinically; 99th percentile: 0.030 μg/L (30 ng/L)] and hs-cTnI [Abbott investigational; sex-specific 99th percentiles: female (F) 16 ng/L, male (M) 34 ng/L] assays simultaneously measured fresh EDTA plasma.



The hs-cTnI assay measured fewer undetectable cTnI concentrations compared to the contemporary cTnI assay across baseline (F: 31% vs 47%, M: 22% vs 40%) and serial (F: 21% vs 46%; M: 19% vs 54%) measurements. Conversely, the proportion of measurable cTnI concentrations was higher using hs-cTnI compared to contemporary cTnI assay across both baseline (F: 46% vs 31%; M: 60% vs 33%) and serial (F: 48% vs 28%; M: 83% vs 40%) measurements. The overall proportion of patients with increased cTnI concentrations above the 99th percentile was not significantly different between the contemporary (31%) and hs-cTnI (26%) assays (P = 0.09).



In patients presenting to the emergency department, the use of the Abbott hs-cTnI assay provides clinicians with more numeric cTnI concentrations. This occurs via a shift from results below the LoD to those between the LoD and the 99th percentile and does not increase in the number of cTnI concentrations above the 99th percentile.
Department of Laboratory Medicine and Pathology, Hennepin County Medical Center, and University of Minnesota, Minneapolis, MN; sara.love@hcmed.org.
Sara A
SA
Love
Division of Cardiology, Department of Medicine, Hennepin County Medical Center and Minneapolis Heart Institute, Abbott-Northwestern Hospital, Minneapolis, MN;
Yader
Y
Sandoval
Department of Emergency Medicine, Hennepin County Medical Center and University of Minnesota, Minneapolis, MN;
Stephen W
SW
Smith
Department of Laboratory Medicine and Pathology, Hennepin County Medical Center, Minneapolis, MN;
Jennifer
J
Nicholson
Cardiac Biomarkers Trials Laboratory (CBTL), Minneapolis Medical Research Foundation, Minneapolis, MN.
Jing
J
Cao
Cardiac Biomarkers Trials Laboratory (CBTL), Minneapolis Medical Research Foundation, Minneapolis, MN.
Ranka
R
Ler
Cardiac Biomarkers Trials Laboratory (CBTL), Minneapolis Medical Research Foundation, Minneapolis, MN.
Karen
K
Schulz
Department of Laboratory Medicine and Pathology, Hennepin County Medical Center, and University of Minnesota, Minneapolis, MN; Cardiac Biomarkers Trials Laboratory (CBTL), Minneapolis Medical Research Foundation, Minneapolis, MN.
Fred S
FS
Apple
D000368:Aged; D001774:Blood Chemical Analysis / Q000592:standards; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012680:Sensitivity and Specificity; D019210:Troponin I / Q000097:blood*
D019210:Troponin I