cTnI concentrations were measured by use of the following US Food and Drug Administration-cleared assays: the Ortho-Clinical Diagnostics (OCD) Vitros Troponin
I-ES assay on the Vitros ECi /ECiQ System, the Abbott Diagnostics Architect STAT Troponin-I on the i2000SR System, and the Beckman Coulter Access Accu TnI on the Access system.