Original researchY grafts with the left internal mammary artery and radial artery. Mid-term functional and angiographic results. Cohort study

- What is already known on this topic?
- Arterial conduits are the best choice for coronary artery revascularization. Mid-term results of left mammary and radial artery in Y shape is lacking.
- What this study adds?
- This study firstly provides functional and angiographic evaluation of Y-graft. Results support the use of Y grafts for coronary artery revascularization.

Background. This retrospective cohort study investigated the functional and haemodynamic mid-term results over 3-years follow up of the left internal mammary artery (LIMA) conduit in composite Y-graft configuration with radial artery (RA) in a population of patients who underwent off-pump coronary artery bypass grafting (CABG). Methods. 148 patients who underwent off-pump CABG with composite Y-graft, were evaluated over 3-year follow up. Two-day dipyridamole induced maximal hyperaemia/rest 99mTc-sestamibi was scheduled preoperatively and 36 months after surgery for functional evaluation. Morphological evaluation was performed by 64 slice multidetector computed tomography (CT) 36 months after surgery. Results. Clinical adverse events were rare within 3 years follow up. Minimal to severe scintigraphic evidence of stress induced ischaemia occurred in 24 patients. Left ventricular (LV) hypertrophy (HR 3.1; 95% CI, 1.5-9.3; p = 0.01) and poor coronary run off (HR 4.1; 95% CI, 2.1-10.8; p = 0.005) were significant multivariate predictors of reversible stress induced ischaemia. 64 slice multidetector CT showed that the main stem of Y composite grafts was patent in all patients, while distal LIMA or RA was stenosed or occluded in 9 patients. Conclusion. Composite Y-graft was adequate to meet the flow requirements of target coronary artery either at rest or during maximal hyperaemia. The use of Y-graft should be carefully evaluated in patients with LV hypertrophy and/or poor coronary run-off.