VA STUDY OF UNSTABLE ANGINA - 10-YEAR RESULTS SHOW DURATION OF SURGICAL ADVANTAGE FOR PATIENTS WITH IMPAIRED EJECTION FRACTION

Background In a randomized study of unstable angina, medically treated patients with impaired left ventricular (LV) ejection fractions (EF=0 .3 to 0.58) were at significantly higher risk of mortality than patien ts treated by coronary artery bypass graft surgery (CABG). Because the duration of this surgical advantage is unknown, 10-year cumulative mo rtality rates of patients with impaired LVEF were determined and compa red with the previously observed rates at 2, 5, and 8 years. Methods a nd Results Of 468 patients with unstable angina, 237 were randomized t o receive medical treatment alone and 231 patients to have CABG. Basel ine characteristics, which were equally distributed between the two tr eatment groups, included age, LVEF, number of diseased coronary arteri es, diabetes, clinical presentation (type I or type II), prior myocard ial infarction, and smoking. Mortality was determined by life-table an alysis and risk factors by logistic regression analysis. Patients were divided into terciles according to LVEF, and the mortality rates of m edical and surgical patients in the lowest tercile were compared. The 10-year mortality rate for all medical patients was 38% and for all su rgical patients, 39%. When LVEF was treated as a continuous variable, there was a significant relation between mortality and LVEF for medica lly treated patients but not for surgical patients. The cumulative mor tality rate for the lowest-tercile (EF 0.3 to 0.58) medical patients w as 49%; for the lowest-tercile surgical patients, 41% (P=.15). Conclus ions The surgical advantage for patients with impaired LVEF that was s ignificant at 5 years (P=.03) and 8 years (P=.05) appears to have dimi nished at 10 years (P=.15).