Letter by Coscia et al Regarding Article, “High-Sensitivity Cardiac Troponin and the Universal Definition of Myocardial Infarction”

We congratulate Chapman and colleagues 1 for their highly relevant study showing important information on the effect of implementing a high-sensitivity cardiac troponin I assay and the recommendations of the Fourth Universal Definition of Myocardial Infarction (MI) 2 on the investigation, treatment, and outcomes of patients.We would like to ask the authors to provide additional information that will help to better put their findings into perspective.First, please report the median time and interquartile range between the first and second measurement of high-sensitivity cardiac troponin I with information on which absolute or relative concentration change was chosen to qualify for MI.Second, please clarify how the number of patients with type 1 or 2 MI could decrease after the implementation of the Fourth Universal Definition of MI instead of the third definition used during the study enrollment (Figure I in the Data Supplement).Third, please clarify the low rate of coronary angiography (59%) and percutaneous coronary intervention (41%) in the type 1 MI group. 2 Fourth, for many readers, it would be very interesting to know the percentage of type 2 MI with a previously known or new diagnosis of coronary artery disease because this has been found to substantially affect the outcome of type 2 MI. 3,4Fifth, please report the percentage of patients with dual antiplatelet therapy at hospital discharge.Finally, it would be interesting to know the percentage of patients with non-ST-segment-elevation MI or ST-segment-elevation MI in the different groups.