Author Affiliations: Department of Medicine, University of Arizona, Tucson.
We were pleased to note that the authors understand the confounding elements that occur in the analysis of post–percutaneous coronary intervention (PCI) biomarker elevations when one is not sensitive to the need for a normal baseline troponin value. We would presume also that the authors of the letter are cognizant of the fact that both troponin and creatine kinase–MB (CKMB) assays manifest marked variation in normal values and dynamic ranges. It is for this reason that we were disappointed that their articulation did not point out that in the data sets that they combined it was not possible to ascertain the specific assays performed nor whether the baseline values used were normal. These concerns are not obviated by the fact that their results seem to support what some have previously reported.
Jaffe A, Alpert J. Misconstrued Intentions: Setting the Record Straight—Reply. Arch Intern Med. 2012;172(18):1425-1427. doi:10.1001/archinternmed.2012.4125