Long-term impact of a left upper limb arteriovenous fistula on coronary artery bypass surgery with left internal thoracic artery to left anterior descending artery anastomosis

BACKGROUND: The left internal thoracic artery (LITA) to left anterior descending artery (LAD) anastomosis is standard in coronary artery bypass grafting (CABG) owing to its long-term patency. However, in hemodialysis patients with an ipsilateral upper-limb arteriovenous fistula (AVF), in-situ LITA grafting may raise concern for coronary steal syndrome (CSS). We assessed whether AVF laterality influences outcomes after CABG with LITA-LAD in hemodialysis patients. METHODS: We retrospectively reviewed hemodialysis patients who underwent isolated primary CABG with in-situ LITA-LAD between 2002 and 2020. Patients were classified by AVF side (ipsilateral vs. contralateral). The primary endpoint was all-cause mortality; secondary endpoints were cardiac death, major adverse cardiac events (MACEs), and in-hospital mortality. Propensity score matching (2 : 1), time-to-event analyses, and competing-risk analyses were performed. RESULTS: Of 206 patients (169 ipsilateral and 37 contralateral), 99 (66 ipsilateral and 33 contralateral) were matched, achieving covariate balance. All-cause mortality was similar in the overall and matched cohorts (log-rank P = 0.89 and P = 0.34), and AVF laterality was not associated with mortality (hazard ratio: 0.98, 95% confidence interval: 0.57-1.69, P = 0.94). Cardiac death, MACEs, and in-hospital mortality did not differ significantly; all four in-hospital deaths occurred in the ipsilateral group (three due to cardiac causes). CONCLUSION: In hemodialysis patients undergoing CABG with in-situ LITA-LAD, an ipsilateral AVF was not associated with worse survival or cardiovascular outcomes, supporting the safety of in-situ LITA grafting even when ipsilateral to an AVF. Future studies should identify CSS high-risk subgroups (e.g. subclavian artery stenosis, forearm vs. upper-arm AVF).