Differential Classification of Acute Myocardial Infarction into ST- and Non-ST Segment Elevation Is Not Valid or Rational

Abstract

The distinction between ST elevation and nonST elevation infarcts is widely accepted and is employed as a guide to management. This is review of the world literature to assess the basis for this distinction, since the two studies on which it is based are seriously flawed in method and conclusions. Pathologic and clinical studies were reviewed from the world literature. The pathology of the two subsets is identical as are the morbidity, mortality and clinical course. Non-ST elevation infarcts are likely to be subsequent, to occur in older patients and to involve the circumflex artery: this subset therefore includes a high-risk group. ST deviation in any part of the electric field of the heart will predictably be accompanied by reciprocal deviation if the entire field of the heart is mapped. Further, ST deviation of infarction is often transient, resolving in minutes so that infarcts will be predictably misclassified. ST deviation per se is therefore not a rational basis for classification of infarcts. In fact, invasive therapy is indicated in both subsets with identical results. The distinction between ST elevation and non-ST elevation infarcts is baseless. The high risk subgroup included in the non-ST elevation infarct set should not be denied the benefit of early invasive therapy.