Cardiac event rate after non-Q-wave acute myocardial infarction and the significance of its anterior location

To correlate cardiac event rate with infarct location on the electrocardiogram in patients recovering from a non-Q-wave acute myocardial infarction (AMI), 135 consecutive patients with enzymatically proven non-Q-wave AMI were followed prospectively for a median of 9.9 months. Of these, 65 patients were classified as having had an anterior non-Q-wave AMI, defined as new ST- or T-wave changes, or both, in leads V₁ through V₄ (group 1). The remaining 70 patients were classified as having had inferior or lateral non-Q-wave AMI, or both, defined as ST- or T-wave changes in 2 consecutive leads (II, II aVF; II and aVL or V₅ and V₆) (group 2). At baseline group I was older and had a higher incidence of previous AMI than group 2. After adjusting for baseline variables, the patients in group I had a 29% reinfarction and 32% mortality rate, which was significantly higher (p < 0.002 for both) when compared to group 2, which had a reinfarction and mortality rate of 8 and 9%, respectively. Patients with anterior non-Q-wave AMI are at very high risk for developing a major cardiac event very soon after the index AMI. This high risk is probably related to a larger area of residual ischemic but viable myocardium in the infarct-related artery when compared to inferolateral non-Q-wave AMI.