The Relationship between Clinical Frailty Score, CT-Derived Body Composition, Systemic Inflammation, and Survival in Patients with Chronic Limb-Threatening Ischemia

Abstract

Frailty is a chronic condition with complex etiology and impaired functional performance that has been associated with altered body composition and chronic inflammation. Chronic limb-threatening ischemia (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. Consecutive patients presenting as unscheduled admissions to a single tertiary center with CLTI were included over a 12-month period. Frailty was diagnosed using the Clinical Frailty Scale (CFS). Body composition was assessed using computerised tomography (CT) at the L3 vertebral level (CT-BC) to generate visceral and subcutaneous fat indices, skeletal muscle index, and skeletal muscle density. Skeletal muscle index and skeletal muscle density 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. There were 190 patients included with a median (interquartile range) follow-up of 22 (6) months (range 15-32months) and 79 deaths during the follow-up period. One hundred patients (53%) had a CFS >4. CFS >4 (hazard ratio [HR] 2.14, 95% confidence interval [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 (odds ratio 1.88, 95% CI 1.09-3.24, P<0.01) was independently associated with CFS >4. Patients with CT-SS 0 and CFS ≤4 had 90% (standard error [SE] 5%) 1-year survival, compared with 35% (SE 9%) in patients with CT-SS 2 and CFS >4 (P<0.001). Patients with mGPS 0 and CFS ≤4 had 94% (SE 4%) 1-year survival compared with 44% (SE 6%) in the mGPS 2 and CFS >4 subgroup (P<0.001). 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.