Introduction: Glycemic variability (GV) is associated with increased risk of several adverse outcomes in people with diabetes (DM). However, on the impact of GV on graft patency following infra-inguinal bypass (IIB) for peripheral arterial disease (PAD) is unknown.

Methods: A 3-year single centre retrospective case notes analysis of those undergoing IIB 2017-2019. HbA1c values for 5 years pre-procedure (minimum of 3) were used to calculate a mean (±SD) HbA1c (MH) and GV. Time to re-intervention, ipsilateral amputation or death were recorded to determine primary (PP) and secondary patency (SP).

Results: 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 had higher Rutherford stage (p<0.01), underwent more distal bypasses (p<0.01) and more emergency procedures (p=0.04). Those with DM had longer mean [IQR] hospital stays 9 [5-21] vs 7 [4-15] days (p=0.017), lower PP 335 [184-542] vs 883 [436-1437] days (p=0.04) and lower SP 751 [387-1108] vs 1079 [895-1593] days (p=0.037). Both MH and GV were associated with amputation free survival time (r=-0.232, p=0.004 and r=-0.243, p=0.011 respectively). A GV>9.1% was associated with significantly lower PP than GV<9.1%, 198[105-377] vs 713 [313-1287] days (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.

Conclusions: We have shown a significant relationship between MH and GV and risk of adverse outcomes in people undergoing IIB. Lowering glycemic variability should be an additional therapeutic target together with lowering mean HbA1c.


K.Dhatariya: Other Relationship; Novo Nordisk, AstraZeneca, Boehringer-Ingelheim, Eli Lilly and Company. P.C.Bennett: None. D.J.Farndon: None.

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