Bedside Multimarker Testing for Risk Stratification in Chest Pain Units: The Chest Pain Evaluation by Creatine Kinase-MB, Myoglobin, and Troponin I (CHECKMATE) Study

We wish to raise several questions about the article by Newby et al. 1 It purports to demonstrate that a quantitative multimarker strategy is better for chest pain patients than a single marker strategy because it identifies patients who are at risk for death earlier.(1) How would the results differ if the recent criteria advocated by the European Society of Cardiology (ESC) and the American College of Cardiology (ACC) 2,3 were used [ie, the 99th percentile of the normal range or at a point with Յ10% imprecision 2-4 ]? (2) Because local values were used for the single marker strategy, were the cut points similar to those used by the Dade-Behring Stratus CS analyzer?It appears to us that had that been the case, more patients would have been detected earlier than reported, especially with the single marker troponin strategy.(3) How would a myoglobin, troponin standard fare?Both Cardiology and Laboratory Medicine groups 2-5 have recommended this standard.( 4) Are there any statistical differences between the markers in Table 1? (5) Since myoglobin and creatine kinase MB (CKMB) both can be released from skeletal muscle, if patients with false-positive CKMB values were included as having myocardial infarctions, they would have been detected with these assays but not troponin.How are the data affected if troponin is utilized as the gold standard?The issues we pose are critical ones to this entire literature.The criteria any investigators chose (even if prospective) can markedly effect the results of studies as well as clinical results and lead to redundant and costly care.That may be the case with the present trial since the issue of cost was not addressed.3][4] Even worse, if these issues are not understood, such studies can confuse us and reduce our ability to diagnose and treat patients in an optimal fashion.