A Sustained Effect of Coronary Bypass Surgery in Stable Angina Pectoris

One hundred patients with angina pectoris were randomly allocated for medical therapy and bypass surgery in groups of 50 patients each. The effect of the respective therapies was assessed by annual exercise testing for up to five years. The surgical group was also studied by postoperative coronary angiograms at three weeks, one year and five years after the operation. The medical group was subjected to repeated coronary angiography five years after randomization. All of the variables depicting exercise tolerance were significantly improved in the surgical group but remained largely at the initial level in the medical group. A subgroup analysis of the surgical series revealed that the sustained improvement was largely confined to the completely revascularized subset of patients. The slowly increasing use of beta blocking compounds in the surgical group also contributed to the favourable results for bypass surgery.