Does grafting of the left anterior descending artery with the in situ right internal thoracic artery have an impact on late outcomes in the context of bilateral internal thoracic artery usage?

Background: Despite their well-established advantages, bilateral internal thoracic arteries (BITA) are still largely underused. This is partly because of the technical complexities associated with the use of the right internal thoracic artery (RITA) to guarantee the universally accepted gold standard left internal thoracic artery (LITA) to left anterior descending artery (LAD) graft. The use of the in situ RITA for LAD grafting is a less technically demanding strategy. The impact of this strategy on early and late outcomes is investigated in the context of BITA usage.Methods: Among 1667 patients undergoing first-time isolated coronary artery bypass grafting using BITA, in situ RITA for LAD grafting was used in 546 patients compared with in situ LITA to LAD in 1121 patients. Propensity score matching was carried out to investigate the impact of in situ RITA to LAD on early and late outcomes including mortality and need for repeat revascularization.Results: A total of 546 propensity matched pairs were available for comparison. In the propensity matched cohort, the mean follow-up time was 7.8 +/- 3.8 years. RITA to LAD did not increase the risk for late death (hazard ratio [HR], 0.78; 95% confidence interval [CI], 0.48-1.26), the need for repeat revascularization (HR, 0.83; 95% CI, 0.70-2.42), and the composite of death or repeat revascularization (HR, 0.81; 95% CI, 0.64-1.14).Conclusions: Using in situ BITA with retrosternal in situ RITA for LAD grafting is a technically less demanding, safe, and effective strategy that can increase usage of BITA by avoiding a composite graft configuration or technically challenging retrocaval routing of in situ RITA through the transverse sinus.