Noninvasive assessment of patients following aortocoronary bypass surgery.

A simple, accurate, noninvasive method is required for the objective evaluation of aortocoronary bypass surgery. Stress myocardial imaging with intravenous injection of potassium-43 or thallium-201 was used an average of 4.4 months after direct myocardial revascularization in 77 patients to assess the accuracy of stress myocardial imaging in predicting completeness of revascularization. The results were correlated with maximal treadmill exercise tests, extent of revascularization and status of bypass grafts (occlusion, stenosis and distal disease). We found stress myocardial imaging to be a more sensitive method than the stress electrocardiogram for the detection of incomplete revascularization. The method appears to be a sensitive noninvasive means of evaluating the results of aortocoronary bypass surgery.