Importance of early recurrent ischemia on one-year survival after non-Q-wave acute myocardial infarction

Several studies have emphasized the prognostic importance of early postinfarction myocardial ischemia-defined as angina with transient ST-T wave changes ≥24 hours after an acute myocardial infarction (AMI)-on short-term outcome in patients with non-Q-wave AMI.^1-5 Risk stratification after AMI is generally based on the early clinical features associated with infarction and on the delineation of high-risk predischarge variables.^5,6 Thus, the importance of clarifying the prognostic significance of early postinfarction angina on late outcome after non-Q-wave AMI is apparent. Previously, we reported that spontaneous postinfarction angina associated with ischemic ST-T wave changes was an especially severe form of early recurrent ischemia that frequently presaged infarct extension and death within 14 days of non-Q-wave AMI.⁷ Overall, patients with early recurrent ischemia exhibited a 4-fold increased incidence of MB-creatine kinase-confirmed reinfarction, and a 10-fold increased incidence of death within 2 weeks, compared to patients without it.⁷ In the present study, we used the extensive database created for the Diltiazem Reinfarction Study for 2 purposes. The first was to determine if post-AMI angina complicating non-Q-wave AMI before hospital discharge was associated with a worse late prognosis (i.e., higher reinfarction and mortality at 1 year) in those patients surviving until hospital discharge. The second was to assess whether spontaneous angina associated with transient ischemic electrocardiographic changes during the early recovery phase of non-Q-wave AMI was as predictive of adverse long-term outcome as it was of poor short-term outcome during hospitalization.