Smoking Gun Theory

D ow nloaded from DOI: 10.1161/CIRCULATIONAHA.112.150425 2 There are very few things in medicine which are simple. Birth and mortality are relatively straightforward to define. but after that the trouble begins. To the casual observer the etiology of myocardial infarction (MI) is relatively obvious: prolonged myocardial ischemia. However, as Aldrovandi et al1 have taught us in this edition of Circulation, we still have a lot to learn about this disease. Indeed, earlier this year the updated Third Universal Definitions of Myocardial Infarction were published.2 Of course, the tacit fact underlying this publication is that even the definition of an MI remains a major “work in progress.” Nevertheless, it cannot be argued that we have come a very long way in our knowledge of plaque biology and MI. In particular, the last 2-3 decades has seen a revolution in our understanding of this disease. Thanks to a series of pivotal observations, we now appreciate tha