Objectives: To estimate myocardial perfusion in patients with severe coronary artery disease performing before and early after single-photon emission computed tomography coronary artery bypass grafting; to predict results of complete myocardial revascularisation by preoperative perfusion data.
Material and methods: Ten patients with stable coronary artery disease and resting left ventricular wall motion abnormalities (mean ejection fraction 31.8+/-6.4%, mean wall motion index 2.09+/-0.25) underwent (99m)Tc-MIBI single-photon emission computed tomography at rest and after nitrate administration before coronary artery bypass grafting and stress-rest single-photon emission computed tomography early (3 and 6 months) after surgery. We estimated myocardial perfusion, postoperative recovery and calculated scintigraphic indices.
Results: The mean number of distal anastomoses was 3.0+/-0.7 and all of the patients had complete myocardial revascularisation. Out of 84 revascularized segments with different degree of myocardial perfusion disorders, 49 (58.3%) segments improved after 3 months and 53 (63.1%) improved after 6 months postoperatively. Amount of segments with fixed perfusion defects increased from 60 preoperatively to 72 after 3 months and 67 after 6 months. Postoperative myocardial perfusion recovery was incomplete following 3 months, but after 6 months it nearly reached ultimate level. Postoperative index of myocardial perfusion recovery was found better than predicted preoperatively.
Conclusions: Estimation of myocardial perfusion changes with single-photon emission computed tomography during early postoperative period, particularly after 6 months, confirms excellent and final results of complete surgical myocardial revascularization. Preoperative single-photon emission computed tomography after nitrate administration provides more information in prediction of postoperative results of complete myocardial revascularization. Estimation of function of fixed perfusion defects can help to predict correct results and to identify hibernating myocardium.