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

Abstract

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.

Keywords: 99mTc-sestamibi SPECT; CABG; Composite Y-grafts; Multi-slice computed tomography.