An audit of glycaemic control and impact on surgical outcomes among inpatients with critical limb-threatening ischaemia (CLTI)

Background: Diabetes mellitus is a key risk factor for peripheral arterial disease (PAD), with poor glycaemic control in diabetic patients linked to foot ulceration, delayed wound healing and an increased need for surgery and amputations. Most UK vascular centres have specialist multidisciplinary diabetes foot clinics to address this. Despite these efforts, diabetic foot complications, often associated with PAD, remain prevalent. We conducted an audit of inpatients with critical limb-threatening ischaemia (CLTI) to assess their glycaemic control and correlate it with limb-related outcomes. Methods: Data were collected from a single tertiary vascular centre with focus on inpatients with CLTI over a 6-week period from 2 January 2023 to 12 February 2023, including all admitted patients during this time frame. Glycaemic control was audited against national guidelines. A multivariate analysis examined the relationship between HbA1c/blood glucose levels and post-procedural outcomes, adjusting for age, body mass index (BMI) and sepsis status, with glycaemic control categorised according to National Institute of Health Care and Excellence (NICE) guidelines. Results: Of 236 inpatients, 120 with CLTI had blood glucose or HbA1c data available. The cohort was mostly male (70.3%), with a median age of 70 years. Among them, 92 patients (76.6%) had type 2 diabetes, four patients (3.3%) had type 1 diabetes and 24 (20%) were not diabetic. Median HbA1c and glucose levels were 8.7% and 10.7 mmol/L, respectively. Based on NICE guidelines, 54 patients (45%) were well controlled (Group 1) and 66 patients (55%) were poorly controlled (Group 2). Foot outcomes were linked to diabetes control: primary healing was higher in Group 1 (42.5%) than in Group 2 (18.1%) (p=0.002). Group 1 had fewer minor amputations (11% vs 24%, p=0.002) and major adverse events (major amputation and death) (12.9% vs 33.3%, p=0.002). Multivariate analysis when adjusted for age, C-reactive protein and BMI along with the glycaemic status showed poor glycaemic control was significantly associated with poorer wound healing and amputations (p<0.01), but not with unplanned surgeries (p>0.05). Five deaths occurred, all in poorly controlled patients. Conclusion: Many vascular inpatients with CLTI with or without diabetes have inadequate glycaemic control, which is associated with adverse outcomes. This audit highlights that, despite a well-established multidisciplinary diabetic foot service in a tertiary centre and known associations between poor glycaemic control and adverse outcomes, diabetes management remains suboptimal and continues to affect patient outcomes. There is a need for actionable pathways to improve glycaemic control across care settings for this high-risk population.