“Specialist CLTI [chronic limb-threatening ischaemia] clinics are inclusive, safe, effective, efficient, and alleviate pressure on vascular units,” Assad Khan (Leeds Vascular Institute, Leeds, UK) stated at the 2023 Vascular Society of Great Britain and Ireland’s (VSGBI) annual scientific meeting (22–24 November, Dublin, Ireland).
By way of background, Khan noted that the incidence of CLTI is predicted to rise, and that the number of emergency CLTI admissions to hospital are rising year on year, according to the latest Hospital Episode Statistics data from NHS Digital. The VSGBI estimates treatment of CLTI accounts for over 50% of the emergency vascular workload in the UK.
Khan stated that there is single-centre evidence available to indicate that specialist clinics are beneficial for CLTI patients. He referenced some of his own work from a different centre, published in 2020, and another study published in 2021, in which Andrew Nickinson (Leicester, UK) and colleagues outline how the introduction of a vascular limb salvage service at the Leicester Vascular Institute improved one-year amputation outcomes for patients with CLTI.
Khan explained that all CLTI patients admitted to the Leeds Vascular Institute during a one-year period (28 March 2021–28 March 2022), counting those who had been revascularised, were included in a prospective, observational cohort study. Patients with diabetic foot infection and acute limb ischaemia were among those excluded from the research. The presenter shared that a total of 391 patients were enrolled in the study, comprising 205 inpatients and 186 outpatients, however outcomes were focused on the patients undergoing revascularisation (128 amongst the inpatient group and 149 in the outpatients). The average age, frailty (as determined by Rockwood Clinical Frailty Score) and smoking status exhibited no statistically significant difference between groups.
Looking at the revascularisation strategies used, Khan noted that 68% of patients in the inpatient group underwent endovascular intervention compared to 64% in the outpatient group. Sixteen per cent of patients were treated with a hybrid approach in the inpatient group compared to 15% in the outpatient group, and 15% were treated surgically in the inpatient group, compared to 21% in the outpatient group with no statistically significant difference. Time to definitively image was lower in the inpatient group than in the outpatient group, at three days compared to 19. The same was true for time to revascularisation, at six days and 39 days, respectively.
Khan acknowledged some limitations, including the fact that there were more patients with Wound, Ischaemia, foot Infection (WIfI) stage 4 in the inpatient group compared to the outpatient group (38 vs. 21) who are significantly more likely to be amputated. Therefore, a subgroup analysis of patients with WIfI Stage 2 and 3 disease (inpatients n=88, outpatients n=125) was performed.
Reporting 30-day subgroup outcomes for outpatients relative to inpatients when adjusted for age, WIfI Stage, sex and frailty, Khan detailed that the odds ratio (OR) for major amputation was 0.141 (p=0.01), for discharge home was 6.950 (p=0.001), for major adverse limb events (MALE) was 0.407 (p=0.01) and for major adverse cardiovascular events (MACE) was 0.167 (p=0.038).
Khan then reported that at 12 months, rates of amputation-free survival (74% vs. 53%) and major amputation (7% vs. 28%) were better amongst outpatients. After adjusting for age, sex, WIfI stage and frailty, the OR for amputation-free survival was 2.565 (p=0.001) and for major amputation was 0.259 (p=0.001) for outpatients relative to inpatients. There was no statistically significant difference in mortality between the two groups (18% vs. 23%) with an OR for mortality of 1.035 (p=0.913) for outpatients relative to inpatients. He noted that the difference in amputation-free survival was driven by amputation reduction rather than a survival benefit.
Finally, Khan shared that the length of stay was longer in the inpatient group than the outpatient group, at 17 days compared to one, and that the number of bed days were higher in the inpatient compared to the outpatient group (3,798 vs. 716). Bed costs (£1,188,744 vs. £224,108), costs per patient (£22,983 vs. £9,283) and total operational costs (£632,520 vs. £191,775) were also higher in the inpatient group.
These findings led Khan to conclude that specialist CLTI clinics might be a viable alternative to emergency admission.
