Asymptomatic cardiac ischemi pilot (ACIP) study: Outcome at 1 year for patients with asymptomatic cardiac ischemi randomized to medical therapy or revascularization

Objectives This report discusses the outcome at 1 year in patients in the Asymptomatic Cardiac Ischemi Pilot (ACIP) study. Background Comparative efficacy of medical therapy versus revascularization in treatment of asymptomatic ischemi is unknown. The ACIP study assessed the ability of three treatment strategies to suppress ambulatory electrocardiographic (ECG) ischemi to determine whether large-scale trial studying the impact of these strategies on clinical outcomes was feasible. Methods Five hundred fifty-eight patients with coronary anatomy amenable to revascularization, at least one episode of asymptomatic ischemi on the 48-h ambulatory ECG and ischemi on treadmill exercise testing were randomized to one of three treatment strategies: 1) medication to suppress angin (angina-guided strategy, n = 183); 2) medication to suppress both angin and ambulatory ECG ischemi (ischemia-guided strategy, n = 183); or 3) revascularization strategy (angioplasty or bypass surgery, n = 192). Medication was titrated atenolol-nifedipine or diltiazemisosorbide dinitrate. Results The revascularization group received less medication and had less ischemi on serial ambulatory ECG recordings and exercise testing than those assigned to the medical strategies. The ischemia-guided group received more medication but had suppression of ischemi similar to the angina-guided group. At 1 year, the mortality rate was 4.4% in the angina-guided group (8 of 183), 1.6% in the ischemia-guided group (3 of 183) and 0% in the revascularization group (overall, p = 0.004; angina-guided vs. revascularization, p = 0.003; other pairwise comparisons, p = NS). Frequency of myocardial infarction, unstable angina, stroke and congestive heart failure was not significantly different among the three strategies. The revascularization group had significantly fewer hospital admissions and nonprotocol revascularizations at 1 year. The incidence of death, myocardial infarction, nonprotocol revascularization or hospital admissions at 1 year was 32% with the angina-guided medical strategy, 31% with the ischemia-guided medical strategy and 18% with the revascularization strategy (p = 0.003). Conclusions After 1 year, revascularization was superior to both angina-guided and ischemia-guided medical strategies in suppressing asymptomatic ischemi and was associated with better outcome. These findings require confirmation by larger scale trial.