Introduction:
Frailty is a chronic condition with complex aetiology and impaired functional performance, which has been associated altered body composition and chronic inflammation. Chronic Limb Threatening Ischaemia (CLTI) carries significant morbidity and mortality and is associated with poor quality of life. The present study aims to examine these relationships and their prognostic value in patients with CLTI.

Methods:
Consecutive patients presenting as unscheduled admissions to a single tertiary centre with CLTI were included over a 12-month period. Frailty was diagnosed using the clinical frailty scale (CFS). Body composition was assessed using CT at the L3 vertebral level (CT-BC) to generate visceral and subcutaneous fat indices (VFI, SFI), skeletal muscle index (SMI), and skeletal muscle density (SMD). SMI and SMD were combined to form the CT-sarcopenia score (CT-SS). Systemic inflammation was assessed by the modified Glasgow Prognostic Score (mGPS). The primary outcome was overall mortality.

Results:
There were 190 patients included with a median (IQR) follow-up of 22 (6) months (range 15-32 months), and 79 deaths during the follow-up period. 100 patients (53%) had a CFS > 4. CFS > 4 (HR 2.14, 95% CI 1.25 – 3.66, p <0.01), CT-SS (HR 1.47, 95% CI 1.03 – 2.09, p <0.05), and mGPS (HR 1.54, 95% CI 1.11 – 2.13, p <0.01) were independently associated with increased mortality. CT-SS (OR 1.88, 95% CI 1.09 – 3.24, p < 0.01) was independently associated with CFS > 4. Patients with CT-SS 0 & CFS ≤4 had 90% (SE 5%) 1-year survival, compared with 35% (SE 9%) in patients with CT-SS 2 & CFS >4 (p <0.001). Patients with mGPS 0 & CFS ≤ 4 had 94% (SE 4%) 1-year survival compared with 44% (SE 6%) in the mGPS 2 & CFS > 4 subgroup (p <0.001).

Conclusions:
Frailty assessed by CFS was associated with CT-BC. CFS, CT-SS and mGPS were associated with poorer survival in patients presenting as unscheduled admissions with CLTI. CT-SS and mGPS may contribute to part of frailty and prognostic assessment in this patient cohort.