Abstract
OBJECTIVES: This study was conducted to compare improvements in myocardial perfusion between Y-composite and aortocoronary configurations during 1 year after coronary artery bypass grafting (CABG). METHODS: Of 311 off-pump CABG patients using the saphenous vein as Y-composite (composite group) or aortocoronary (aorta group) graft, 204 patients who underwent myocardial single-photon emission computed tomography during the preoperative period, at 3 months after surgery, and at 1 year after surgery were enrolled. After 2:1 propensity score matching, 43 matched sets with 86 composite and 43 aortocoronary patients were compared. Based on a 17-segment model, the degree of perfusion impairment for each segment was evaluated semiquantitatively via a reversibility score, which was defined as rest minus stress perfusion values. The improvement in perfusion was evaluated based on the temporal changes in reversibility scores and was compared using a linear mixed model. RESULTS: Of 2193 segments, 795 segments (518 and 277 segments in composite and aorta groups, respectively) demonstrated a significant decrease in perfusion on preoperative myocardial single-photon emission computed tomography and were successfully revascularized by CABG. Median (quartile 1, quartile 3) preoperative reversibility scores in the ischemic segments were 7 (4, 13) and 7 (4, 12) in composite and aorta groups, respectively (P = .575). Median (quartile 1, quartile 3) reversibility scores at 3 months and 1 year postsurgery were 0 (0, 4) and 0 (0, 5) in the composite group and 0 (0, 4) and 0 (0, 5) in the aorta group, and there was no significant difference in the pattern of improvement in myocardial perfusion between the groups (P = .592). CONCLUSIONS: Myocardial perfusion improvement during the first year after CABG was not significantly different between Y-composite and aortocoronary configurations.