Changing the diagnosis of acute myocardial infarction: Implications for practice and clinical investigations

The new definition of MI is a major step forward in our understanding and interpretation of clinical information in the setting of CVD. Before arriving at its final consensus document, the Joint ESC/ACC Committee for the Redefinition of MI weighed a number of issues. In the end it achieved an important balance between addressing societal needs and allowing the new, sensitive troponin markers to become a component of one of the most important diagnoses that we make in cardiovascular medicine. Clearly, issues of standardization and improvements in precision of troponin assays are principal milestones yet to be achieved, but progress toward these goals should be fueled by the ESC/ACC's recommendations for the redefinition of MI and by the review of its implications conducted at the DCRI/AHJ experts meeting. It is difficult to predict what the epidemiological aspects of applying the redefinition of MI will be. It should be recognized, however, that the clinical definition of MI has been in constant flux since the 1950s, when Dr. Paul Dudley White was quoted as saying, "Small heart attacks are so common that they are within the normal range." As our diagnostic capabilities have improved over the last 5 decades, so has our ability to define more precisely the most important diagnosis in heart disease. This discussion and recommendations arising from our experts meeting highlight the possibilities that the new definition of MI creates for the practice of cardiovascular medicine. We have also identified several questions that require further investigation before the full potential of this new definition can be realized in clinical practice and clinical trials.