Improved sensitivity of point of care troponin I values using reporting to below 99th percentile of normals. Schneider HG et al.

摘要

It was with interest that we read the article by Schneider et al. about the improved sensitivity of a point of care cardiac troponin I (cTnl) assay by reporting values below the 99th percentile [1]. We have received numerous clinical queries regarding the discordant results observed between cardiac troponins measured on the Beckman Coulter AccuTnl? (Beckman Coulter Diagnostics, Brea, CA, USA) and Abbott iSTAT cTnl (Abbott Diagnostics, Lane Cove, NSW, Australia) predominantly with the Beckman being "positive" and the iSTAT "negative". The stated 99th percentile cut-offs for the Beckman and iSTAT are 40 ng/L and 80 ng/L respectively [2,3]. The iSTAT cTnl package insert states that the 99th percentile cut-off was established on 162 apparently healthy donors, but cautions that each facility should establish its own reference range [3]. Apple et al. evaluated 19 cTn assays' 99th percentiles for a healthy population, and published an iSTAT 99th percentile cTnl of 39 ng/L (90% CI 27-53 ng/L) [4].