Background: International guidelines authored and endorsed by professional societies of cardiology, emergency medicine, and laboratory medicine are unanimous that the cutoff concentration for establishing a diagnosis of acute myocardial infarction be set at the 99th percentile of a healthy population. The establishment of the actual 99th percentile value is assay- and sample-dependent and is influenced by the population of individuals selected for testing. We created a sample bank that will enable manufacturers of troponin assays a consistent comparison of the 99th percentile.
Methods: Participants were recruited from those attending the 2015 Annual Meeting of the AACC for the creation of a universal sample bank of apparently healthy individuals (free from uncontrolled diabetes, renal insufficiency, and heart disease). For those who met eligibility criteria and signed a written consent to participate, 60 mL blood was collected into 6 10-mL tubes each (2 serum, 3 heparin plasma, and 1 EDTA). Whole blood was tested for hemoglobin (Hb) A1c, and serum was tested for N-terminal pro–B-type natriuretic peptide (NT-proBNP) and creatinine.
Results: There were a total of 764 individuals who consented during the AACC Annual Meeting. After this initial enrollment, it was determined that there was an insufficient number of male participants recruited. Under the same protocol and consent, blood from 131 additional males was collected at the University of Maryland. Samples were centrifuged, and 240 μL aliquots of the 2 serum, 3 heparin plasma, and 1 EDTA tubes were frozen at 70 °C within 2 h of collection. The labeled samples were divided into boxes containing 1 aliquot from each individual. Sets of these samples were made available for purchase to manufacturers of cardiac troponin assays. Eighty-eight samples were excluded from the database for having a high NT-proBNP (>300 ng/L), low estimated glomerular filtration rate (eGFR) (<60 mL/min/1.73 m2), high Hb A1c (≥6.5%), or preanalytical sample issues and consenting/data issues. The final total was 808 individuals (402 females and 406 males; 60% Caucasian, 26% African or African American, 11% Asian or Pacific Islander, and 3% other).
Conclusions: The creation of a bank of samples from healthy individuals enables a consistent comparison of the 99th percentile results from manufacturers of cardiac troponin assays.
see editorial on page 605
Authors' Disclosures or Potential Conflicts of Interest: Upon manuscript submission, all authors completed the author disclosure form.
Employment or Leadership: F. Apple, S.A. Love, G.L. Myers, R.H. Christenson, AACC.
Consultant or Advisory Role: F. Apple, HyTest, Metanomics Healthcare, and Philips Healthcare; R.H. Christenson, Roche Diagnostics, Siemens Healthcare Diagnostics, and Becton Dickinson.
Stock Ownership: None declared.
Honoraria: F. Apple, Abbott POC; R.H. Christenson, Roche Diagnostics and Siemens Healthcare Diagnostics.
Research Funding: A.H.B. Wu, AACC; R.H. Christenson, Roche Diagnostics, Siemens Healthcare Diagnostics, Alere Diagnsotics, Mitsubushi Chemical; materials and equipment for this study were provided by Thermo Fisher Scientific, Kewaunee Scientific, Tecan, Eppendorf, Becton Dickinson, and Centurion MP.
Expert Testimony: None declared.
Patents: None declared.
Role of Sponsor: The funding organization, AACC, provided technical and administrative support to the study. AACC played no role in the choice of enrolled participants.
- Received January 12, 2017.
- Accepted February 8, 2017.
- © 2017 American Association for Clinical Chemistry