Bilateral internal thoracic artery grafting: propensity analysis of the left internal thoracic artery versus the right internal thoracic artery as a bypass graft to the left anterior descending artery

OBJECTIVES To compare different configurations of the bilateral internal thoracic arteries for the left coronary system and examine early and late outcomes, including mid-term graft patency. METHODS We reviewed 877 patients who underwent primary isolated coronary artery bypass grafting using in situ bilateral internal thoracic arteries [in situ right internal thoracic artery (RITA)-to-left anterior descending artery (LAD) grafting, n = 683; in situ left internal thoracic artery (LITA)-to-LAD grafting, n = 194]. We compared mid-term patency between the grafts. Propensity score matching was performed to investigate early and long-term outcomes. RESULTS The 2-year patency rate for RITA-to-LAD and LITA-to-LAD grafts were similar. Multivariate analysis revealed that RITA-to-non-LAD anastomosis (P = 0.029), postoperative length of stay (P = 0.003) and chronic obstructive pulmonary disease (P = 0.005) were associated with graft failure. After statistical adjustment, 176 propensity-matched pairs were available for comparison. RITA-to-LAD grafting enabled a more distal anastomosis. Kaplan–Meier analysis revealed that the incidences of death, repeat revascularization and myocardial infarction were significantly higher in the LITA-to-LAD group among both the unmatched and matched samples (P = 0.045 and 0.029, respectively). CONCLUSIONS The mid-term patency and outcomes of RITA-to-LAD grafting are good and reduces future cardiac event, in contrast to LITA-to-LAD grafting.