ASYMPTOMATIC CARDIAC ISCHEMIA PILOT (ACIP) STUDY - IMPROVEMENT OF CARDIAC ISCHEMIA AT 1 YEAR AFTER PTCA AND CABG

Background Cardiac ischemia on the ambulatory ECG (AECG) and/or on the exercise treadmill test (ETT) is associated with an increased risk of adverse outcome. Myocardial revascularization more often suppresses c ardiac ischemia than does medical management alone. However, few studi es have compared the effects of percutaneous transluminal coronary ang ioplasty (PTCA) with those of coronary artery bypass grafting (CABG) o n cardiac ischemia and clinical outcome. Methods and Results A total o f 558 patients were randomly assigned to one of three treatment strate gies in the Asymptomatic Cardiac Ischemia Pilot (ACIP) study: angina-g uided medical strategy (n=184), ischemia-guided medical strategy (n=18 2), or revascularization (n=192). In patients assigned to revasculariz ation, the choice of the procedure, PTCA or CABG, was made by the clin ical unit staff and patient based on a coronary angiogram usually perf ormed within 2 months of enrollment. CABG was selected in 78 patients and PTCA in 92 patients. At 12 weeks, ischemia on the AECG was suppres sed in 70% of CABG patients versus 46% of PTCA patients (P=.902). Isch emia on the ETT was no longer present in 46% versus 23% of the patient s, respectively (P=.005). Angina, within 4 weeks of the follow-up visi t, was absent in 90% versus 68%, respectively (P=.001). These clinical variables remained improved in both groups at 1 year. Clinical events (myocardial infarction or repeat revascularization) occurred in 1 CAB G patient versus 7 PTCA patients at 12 weeks, and in 1 versus 16 patie nts, respectively, at 12 months (P<.001). Conclusions Ischemia on the AECG and ETT and angina were relieved in many patients after both proc edures; however, CABG was superior to PTCA, and it was associated with a lower incidence of clinical events at 1 year. These results suggest that more complete revascularization relates to better clinical outco me. However, a large trial is needed to confirm these results.