Are arterial grafts superior to vein grafts for revascularisation of the right coronary system? A systematic review

Background: The optimal conduit choice in revascularisation of the right coronary system (RCA) remains uncertain. This study aims to identify if arterial grafts are superior to saphenous vein (SV) grafts and whether graft failure rates vary between proximal and distal RCA anastomoses. Methods: 29 studies identified by systematic review were analysed for study quality and length of follow-up using Bayesian hierarchical random effects modelling. Heterogeneity was assessed and sensitivity analysis performed. Primary endpoints were graft patency at early, mid and late-term follow-up when compared with SV grafts. Results: There was no difference in early failure of radial artery (RA) or right gastroepiploic artery grafts when compared with SV (OR 0.82, 95% CI (0.14 to 2.68) and OR 1.19 (0.08 to 4.66), respectively). However, mid-term ORs based on observational study data demonstrated increased graft failure with right gastroepiploic artery and right internal thoracic artery compared with SV (OR 2.76 (1.26 to 5.48) and OR 2.07 (0.96 to 3.98), respectively), although right internal thoracic artery did not achieve statistical significance. No significant difference was observed in late graft failure for RA compared with SV (OR 0.47 (0.09 to 1.41)) without study-type disparity. However, simplified statistical pooling revealed significantly lower graft failure was observed with RA grafts to the proximal RCA when compared with SV (χ² 6.15, p=0.01). Conclusions: Arterial grafts do not demonstrate a beneficial reduction of angiographic graft failure when compared with SV grafts on the RCA with the exception of RA to the proximal RCA. Future research should focus on clinical and patient-reported endpoints to identify any benefits of RCA arterial revascularisation.