Off-pump coronary artery bypass may decrease the patency of saphenous veingrafts

Background. There is concern that a hypercoagulable status is caused after coronary artery bypass grafting without cardiopulmonary bypass (off-pump co ronary artery bypass grafting, or OPCAB) and may potentially endanger the p atency of the anastomosis. The aims of this study were: (1) to compare 1-ye ar graft patency after OPCAB with that of conventional coronary artery bypa ss grafting (CABG) and that of on-pump beating CABG; and (2) to demonstrate any differences in patency of various conduits among the three groups. Methods. We analyzed the results of 122 consecutive OPCAB cases (group I) c ompared with those of 65 consecutive conventional CABG cases (group II) and those of 19 consecutive on-pump beating CABG cases (group III). In group I , coronary angiography (CAG) was performed immediately postoperatively and 1 year after surgery. In groups II and III, CAG was performed 1 year after surgery. Graft patency was graded as grade A (excellent), grade B (fair), o r grade O (occluded). Results. The average number of distal anastomoses in groups I, If, and III were 3.1 +/- 1.1, 3.7 +/- 0.9, and 3.6 +/- 0.9, respectively. In group I, p ostoperative CAG was performed in 92% of patients (112/122) before discharg e. The patency rate (grade A + B) was 96.4% (162/168) for arterial grafts, and 85.6% (160/187) for saphenous vein grafts (SVG). One-year follow-up CAG was performed in 74% of patients (90/122). The patency rate was 97.8% (132 /135) for arterial grafts and 67.9% (106/156) for SVG. In group II, 1-year follow-up CAG was performed in 65% of patients (42/65). The patency rate (g rade A + B) was 93.5% (43/46) for arterial grafts and 88.3% (98/111) for SV G. In group III, 1-year follow-up CAG was performed in 89% of patients (17/ 19). The patency rate (grade A + B) was 100% (19/19) for arterial grafts an d 86.8% (33/38) for SVG. Conclusions. Our results demonstrate that the patency rate of SVG after OPC AB was significantly lower than that of arterial grafts in the early postop erative CAG (p < 0.001), and was also significantly lower than those of SVG of group II (p < 0.001) and group III (p < 0.01) in the postoperative 1-ye ar CAG, although there was no significant difference in 1-year patency of a rterial grafts among the three groups. Our data suggest that a specific per ioperative anticoagulant therapy may be advisable in patients undergoing OF CAB with SVG. (C) 2001 by The Society of Thoracic Surgeons.