LAUSR

Many factors influence graft patency following infra-inguinal bypass (IIB). Glycaemic variability (GV) is associated with increased risk of multiple adverse outcomes. However, the impact of GV on outcomes following IIB is unknown. A 3-year single centre retrospective case notes analysis of all people undergoing IIB between 2017–2019. Rutherford stage, graft conduit, bypass level, procedure details, baseline demographics, co-morbidities, mean HbA1c and GV (HbA1c SD) were assessed. Time to re-intervention, ipsilateral amputation or death were recorded to determine primary (PP). Were reported as hazard ratios (HR) following multivariate adjustment.193 IIB outcomes were analysed: mean (±SD) age 68.9(9.2) years; 135(69.9%) male. 156 (80.8%) had pre-operative HbA1c for analysis and 88(45.6%) had DM; 87(45.1%) were current smokers; 107(55.4%) underwent emergency procedures. Those without diabetes were more likely to smoke (P=0.011), but those with DM were more likely to have IHD (0.007), had higher Rutherford stage (p=0.0006), underwent more distal bypasses (p=0.004) and more emergency procedures (p=0.04). GV>9.1% was associated with significantly lower PP than GV<9.1%, 198 [105–377] vs. 713 [313-1287] days (p=0.02). Univariate predictors of PP included Rutherford stage 4 vs 3 (p=0.01), level of bypass, (p=0.0003), DM (p=0.04) and GV>9.1% (p=0.02). On multivariate adjustment, GV >9.1% and level of bypass remained independent predictors of primary patency, HR 1.96 (95% CI:1.12-3.42, p=0.018) and HR 2.54 (95%CI:1.24-5.22, p=0.038) respectively. We have demonstrated GV and level of bypass as independent predictors of graft failure on multivariate analysis. Therefore, optimising GV should be a therapeutic target to improve outcomes.