Traditionally, treatment of patients with coronary heart disease has been given for and guided by patients' symptoms. There was a growing trend toward recognizing asymptomatic cardiac ischemia and according it importance equal to that of symptomatic ischemia. Many physicians believed that suppression of asymptomatic ischemia in patients with coronary heart disease would reduce morbidity and mortality. This was leading to rapidly increasing and widespread applications of both medical and revascularization therapies.