Abstract 1640: Comparison of Early Patency of off-Pump and on-Pump Multivessel Coronary Artery Bypass Surgery Assessed by MDCT
Objectives: Off-pump coronary artery bypass surgery (CABG) has been shown to be at least as safe as on-pump CABG but graft patency rate with this technique remains controversial. The aim of this study was to compare early graft patency following off-pump vs. on-pump CABG using 64-multidetector computed tomography (64-MDCT).
Methods: Since December 2006 all patients (Pts) undergoing CABG in our institution were prospectively included in the study. Early postoperative graft patency was assessed by 64-MDCT performed before discharge. Graft patency was assessed independently by 2 operators and patency rate compared between off-pump and on-pump. Choice of the technique was left to operator decision. Exclusion criteria were atrial fibrillation and creatinine >140 μmol/l. Scan protocol was standardized using 64×0.625mm slice collimation (pitch 0.2), 400 ms rotation time and simultaneous electrocardiogram gating. Pts with heart rates ≥65 bpm received intravenous beta-blockade.
Results: From December 2006 to May 2007, 134 Pts, 66±11 years old, were included. Eleven were excluded due to arrhythmias or tachycardia despite beta-blockade and 15 due to unavailability of MDCT before discharge. MDCT was performed in 108 Pts (69 in the on-pump group and 39 in the off-pump group), 8±6 and 8±2 days (p=0.39) after surgery. Age, sex, and risk factors were similar in the 2 groups. The number of grafts in the on-pump group was 188 vs. 125 in the off-pump group (2.7±0.9 vs 4.1±1.2 grafts/pt, respectively; P<0.03). There was a greater proportion of radial grafts used in the on-pump group (11.2 vs 0%, P< 0,01). MDCT was able to assess gaft patency in 98% of cases: 183/188 grafts on-pump (97%) and 123/125 off-pump (98%), P=0.92. In the on-pump group, 3 grafts were occluded (4.3%): all involving a right mammary artery graft, 1 on LAD, 1 on the right coronary artery and 1 on a marginal branch and in the Off-pump group, 1 left mammary graft on LAD was occluded (2.5%, p=0.39)
Conclusions: Graft patency can be assessed before discharge with 64-MDCI in 80.8% of cases. When MDCI is performed the ability to visualise grafts and assess patency is 98%. The graft patency rate in patients undergoing on pump and off pump CABG is similar in the postoperative period.