Background Composite (Y/T) coronary artery bypass graft surgery (CABG) confers full arterial revascularisation, and “hands off” aorta compared to conventional bypass graft surgery. However, the composite surgical configuration could lead to preferential blood flow down one arm than the other (left internal mammary artery LIMA or radial artery RA) with its potential impact on graft patency.

Aim To investigate the impact of bypass graft configuration on short-term grafts patency and cardiac related quality of life.

Methods and Results This is a single centre randomised, controlled trial Between March 2006 and July 2007, 322 patients undergoing isolated bypass graft surgery at our institution were screened and 89 (27%) met the inclusion criteria and were randomised. Patients were allocated to conventional (conv n=46) or composite (comp n=43). The two primary end points were graft patency defined as (Thrombolysis In Myocardial Infarction) TIMI III flow in distal anastomosis at angiography 12–24 months after surgery, and cardiac-related health status assesses by Seattle angina questionnaire (SAQ). Baseline characteristics were similar between the two groups apart from diabetes where there were more diabetic patients in the composite arm than the conventional one (15(35%) vs 5(11%) p<0.01 respectively). Trial was stopped prematurely following 18 months interim analysis which showed significant graft failure in the composite arm (40%). Final Analysis was performed on intention to treat basis. Sixty-five (73%) had follow-up angiography (34 conv, 31 comp), with total of 116 graft in conventional arm and 100 grafts in composite arm. All patients in both groups had LIMA graft to left anterior descending artery (LAD). Graft patency rate was significantly higher in the conventional compared to composite arm (95(82%) vs 59(59%) p<0.001 respectively). Three main domains of the SAQs there was significant improvement between before and 6 months after surgery in both groups. There were no significant differences between the two groups in the percentage of improvement in these four domains (Physical limitation, Angina stability, Angina frequency, Quality of life).

Conclusions In our randomised trial, composite bypass graft surgery was associated with higher graft failure rate at 12–24 months after surgery compared to conventional type. This difference may be due to the composite conduit configuration. Further blood flow characteristics study in this configuration can help understand such an important finding and its implication on our clinical practice. Despite the difference in graft patency there were no differences in physical limitation, angina stability, angina frequency, or quality of life between the two groups.