It has been well known that the Braunwald classification is an appropriate clinical parameter in the prediction of the outcome in patients with unstable angina. However, the ability of the classification to predict prognosis of unstable angina according to treatment strategy is not established. We evaluated the relation between severity of angina on admission and outcome of primary unstable angina with early invasive strategy.

148 patients (M 85, F 63, age 61±10) with suspected unstable angina were divided into three subgroups on the basis of the Braunwald classification on admission. The patients were followed up to 6 months prospectively if the final diagnosis was primary unstable angina. Early invasive strategy was used for the treatment of unstable angina. Major cardiac events were assessed during hospitalization and 6 months follow-up period according to the Braunwald classification.

Unstable angina was diagnosed in 95 patients (64%). Among these patients, 89 patients with primary unstable angina were followed up to 6 months. Clinical characteristics including number of patients, mean age, sex ratio, risk factors, coronary angiographic findings and revascularization rate during hospitalization were not different in three subgroups of these patients. Among these patients, early coronary revascularizations was performed in 67 patients (75%) and 2 (2%) deaths/myocardial infarctions occurred during hospitalization. During the follow-up period, 1 (1%) myocardial infarction/death and 12 (13%) revascularizations occurred. Cardiac event rate (death, myocardial infarction or revascularization) was not different during hospitalization and 6 months follow-up period among subgroups of severity class.

Clinical outcome should be reevaluated after early coronary intervention to predict cardiac event in patients with unstable angina.