Antecedent angina pectoris predicts worse outcome after myocardial infarction in patients receiving thrombolytic therapy: Experience gleaned from the international tissue plasminogen activator/streptokinase mortality trial

The significance of antecedent angina in predicting clinical outcome was assessed in 8,329 patients with acute myocardial infarction receiving thrombolytic therapy with either recombinant tissue type plasminogen activator or streptokinase. There were 2,370 patiets with antecedent angina for >1 month, 1,512 patients with antecedent angina for ≤1 month and 4,447 patients with no antecedent angina. The longer the duration of angina, the worse the baseline characteristics in the three groups: the mean patient age was 65 versus 62 versus 61 years, respectively (p < 0.0001); the rate of previous myocardial infarction was 37% versus 18% versus 10% (p < 0.0001); and the rate of hypertension was 40% versus 31% versus 27% (p < 0.0001). Antecedent angina was associated with a longer hospital stay (11.3 and 11.7 days vs. 10.8 days, p < 0.0001), a higher incidence of bypass surgery (2.2% vs. 1.2% vs. 0.7%, p = 0.0001), a worse Killip class at discharge (10.6% of patients in class >1 vs. 8.7% vs. 6.4%, p = 0.0001), and a higher hospital and 6-month mortality (12.1% and 18% vs. 8.9% and 11.6% vs. 6.6% and 9.2%, respectively, p < 0.0001). A multivariate analysis taking into account all baseline characteristics confirmed the independent association of antecedent angina with mortality, with a relative risk of 1.4 to 1.47 (p < 0.001). Antecedent angina predicts a worse clinical outcome and a more intense use of medical resources in patients with acute myocardial infarction receiving thrombolytic therapy.