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 who received thrombolytic therapy with either recombinant tissue-type plasminogen activator or streptokinase. There were 2,370 patients with antecedent angina for greater than 1 month, 1,512 patients with antecedent angina for less than or equal to 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 less than 0.0001); the rate of previous myocardial infarction was 37% versus 18% versus 10% (p less than 0.0001); and the rate of hypertension was 40% versus 31% versus 27% (p less than 0.0001). Antecedent angina was associated with a longer hospital stay (11.3 and 11.7 days vs. 10.8 days, p less than 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 greater than 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 less than 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 less than 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.