A total of 1,959 patients were screened by AECG monitoring; 49 percent had asymptomatic ischemia, and 65 percent were enrolled in the study. The 618 patients were randomized to one of the three treatment strategies: 202 to angina-guided medical strategy with titration of anti-ischemic medication to relieve angina; 202 to angina-guided plus AECG ischemia-guided medical strategy with titration of anti-ischemic medication to eliminate both angina and AECG ischemia; and 212 to revascularization by angioplasty or bypass surgery. Patients able to take either beta-adrenergic blocking agents or calcium antagonists were also randomized to receive one of two medical combination regimens: atenolol plus nifedipine or diltiazem plus isosorbide dinitrate. Those who could be treated with only one regimen, such as asthmatic patients, were assigned to the appropriate regimen. The primary outcome was the absence of ischemia at twelve weeks. Recruitment ended in January 1993. Clinical based follow-up was completed for 18 months and survival status free of MI was completed for 24 months