The global need to define normality: the 99th percentile value of cardiac troponin.

BACKGROUND: How to select a presumably normal population for the establishment of 99th percentile cutoffs for cardiac troponin assays has not been adequately addressed. Lack of attention to this question can result in misleading medical decision cutoffs. CONTENT: From our review of the peer-reviewed literature, including international recommendations, no uniform procedure is followed and no uniform guideline has been published by experts or regulatory agencies to guide researchers or manufacturers of cardiac troponin assays in their quest to define the health or "normality" of a reference population that is used to establish an accurate 99th percentile value. As we progress globally into the era of high-sensitivity cardiac troponin assays, we propose several suggested approaches to define presumably normal individuals by use of clinical and biomarker surrogates.
SUMMARY: Our uniform approach to defining who is normal and who may not be normal will help to define diagnostic and risk outcomes assessments in the management of patients with suspected myocardial injury, both for use in current clinical practice and clinical research, as well as for the potential future use of cardiac troponin in primary prevention.