High-Sensitivity Cardiac Troponin I for Predicting Death in a Female Emergency Department Population

Abstract

To the Editor: The Third Universal Definition of Myocardial Infarction has indicated that “sex-dependent values may be recommended for high-sensitivity troponin assays” (1). This statement is supported by several reference-interval studies that reported that women had lower concentrations and 99th percentile cutoffs with the high-sensitivity assays than men (2, 3). Despite these findings, it is unclear whether this information—gained only from the use of high-sensitivity assays—would be important for diagnostic or prognostic purposes in the female population. Presently, only Roche Diagnostics' high-sensitivity cardiac troponin T (hs-cTnT)1 assay and Abbott Diagnostics' high-sensitivity cardiac troponin I (hs-cTnI) assay have been approved by regulatory bodies. These assays are in clinical use throughout the world (outside the US). Roche has discontinued the fourth-generation cTnT assay in jurisdictions where the hs-cTnT assay has achieved regulatory approval; therefore, prospective comparisons of the readjusted hs-cTnT assay (in 2012) and the fourth-generation assay for assessing sex-specific clinical performance are no longer possible in many regions. Nevertheless, studies that assess both high-sensitivity and sensitive cTnI assays with respect to health outcomes in the female population are essential if sex-specific cutoffs are to be used. To this end, we performed a large prospective observational study of emergency department (ED) patients to assess whether an incremental benefit for predicting hospital death for women at presentation (compared with men) exists when a high-sensitivity cardiac troponin assay is used, vs. a sensitive cardiac troponin assay. After ethics approval was obtained, every adult patient who presented to the ED at the Hamilton General Hospital and Juravinski Hospital and had a cTnI test (ARCHITECT STAT TnI; Abbott Diagnostics) and results over a period of 3 months also had the same sample measured with a …