Graft patency at 3 months after off- and on-pump coronary bypass surgery: a randomized trial

Coronary artery bypass grafting (CABG) is performed either with the aid of cardiopulmonary bypass (on-pump) or without cardiopulmonary bypass (off-pump). There is a scarcity of angiographic data to support the non-inferiority of off-pump technique to on-pump technique. The objective of this study is to ascertain the non-inferiority of off-pump CABG when compared to on-pump CABG in terms of angiographically assessed graft patency at 3 months.

A total of 320 patients with multivessel coronary artery disease were enrolled in a multicenter prospective randomized trial either to on-pump CABG (n = 162) or off-pump CABG (n = 158) between March 2016 through March 2017. Graft patency was evaluated by using either multidetector computerized tomographic angiography or conventional coronary angiography at 3 months. The major adverse cardiac and cardiovascular events (MACCE) were also analyzed at 3 months.

The median number of grafts per patient in off-pump was 3.00 (Q1:3.00 and Q3:4.00) vs on-pump 4.00 (Q1:3.00 to Q3:4.00), and the mean number of grafts per patient was lower in the off-pump CABG at 3.45 ± 0.75 vs 3.64 ± 0.70 in the on-pump CABG (p = 0.01). There was no significant difference in mortality at 3 months between the off-pump (0.63%) and on-pump groups (1.85%) with p value of 0.62. The cumulative combined MACCE showed significant difference between off-pump group (0.63%) and on-pump group (5.55%), p = 0.01. Follow-up angiograms were done in 239 (75%) patients with 120 off-pump and 119 in the on-pump group. The analysis was also done regarding graft patency in a graded manner—when analysis of A (excellent) grafts vs B (stenosed) grafts and O (occluded) grafts were made, there was no statistically significant difference in overall graft patency at 3 months between on-pump [376 /429 grafts (87.6%)] and off-pump [366 /420 grafts (87.1%)] groups (p = 0.82). The patency rates were similar among bypass conduits (left internal thoracic artery (ITA) in off-pump (91.4%) vs on-pump (92.9%) p = 0.66, right ITA in off-pump (82.1%) vs on-pump (81.8%) p = 0.97, radial artery in off-pump (84.4%) vs on-pump (82.6%) p = 0.81; saphenous vein in off-pump (85.8%) vs on-pump (86.3%), p = 0.86 and among 3 coronary territories.

Off-pump CABG is non-inferior to on-pump CABG in terms of overall graft patency at 3 months and was associated with a fewer combined cumulative MACCE compared to on-pump CABG.