99th Percentile and Analytical Imprecision of Troponin and Creatine Kinase-MB Mass Assays: An Objective Platform for Comparison of Assay Performance

Cardiac troponins in blood are the most sensitive and specific biochemical markers of myocardial damage and are paramount for classification, risk stratification, and customized therapy in patients with acute coronary syndromes (1)(2). Despite the overt advantages, some important obstacles to troponin analysis and interpretation have remained, such as assay standardization, interference, preanalytical variability, and imprecision (3).Introduction of the 99th percentile reference limit for the diagnosis of myocardial infarction by the European Society of Cardiology/American College of Cardiology (ESC/ACC) Consensus Committee (4)(5) has largely been driven by the demonstration that even the lowest detectable amounts of cardiac troponins in blood are associated with increased cardiac risk (6)(7)(8). Conversely, patients with any detectable troponins benefit from early coronary or pharmacologic intervention (6)(7)(8). Implementation of the new definition of acute myocardial infarction is not trivial because it will almost double the number of patients with a diagnosis of acute myocardial …