INCIDENCE AND FOLLOW-UP OF BRAUNWALD SUBGROUPS IN UNSTABLE ANGINA-PECTORIS

Objectives. This study was performed to establish the prognosis of pat ients with unstable angina within the subgroups of the Braunwald class ification. Background. Among many classifications of unstable angina, the Braunwald classification is frequently used. However, the incidenc e and risk for each subgroup in clinical practice have not been establ ished. Methods. Prospective data for 417 consecutive patients admitted for suspected unstable angina were analyzed. Patients were classified according to Braunwald criteria and followed up for 6 months. Surviva l, infarct-free survival and infarct-free survival without interventio n are reported for each class. Results. After in-hospital observation the final diagnosis was acute myocardial infarction in 26 patients (6% ), noncoronary chest pain in 109 (26%) and definite unstable angina in 282 (68%). Recurrence of chest pain was significantly different for t he different severity classes (28%, 45% and 64% for classes I [acceler ated angina], II [subacute angina at rest] and III [acute angina at re st], respectively) but not for clinical circumstances (49% and 53% for classes B [primary unstable angina] and C [postinfarction unstable an gina], respectively). Six-month and infarct-free survival (96% and 88% , respectively) were not significantly different between severity clas ses but were significantly different (p = 0.01) between classes B (97% and 89%) and C (89% and 80%). Infarct-free survival without intervent ion was best for class II (72%), intermediate for class I (53%) and wo rst for class III (35%). In multivariate analysis, elderly age, male g ender, hypertension, class C and maximal (intravenous) therapy were in dependent predictors for death; elderly age and class C for infarct-fr ee survival; and male gender, class III, class C, electrocardiographic changes and maximal therapy were associated with infarct free surviva l without intervention. Conclusions. Braunwald classification is an ap propriate instrument to predict outcome. Risk stratification by these criteria provides a tool for patient selection in clinical trials and for evaluation of treatment strategies.