Prognostic value of simple frailty and malnutrition screening tools for determining surgical risk in patients with chronic limb threatening ischaemia undergoing major vascular surgery: a retrospective cross-sectional study

Abstract

Abstract Background: This study aims to explore the prognostic value of simple frailty and malnutrition tools for determining postoperative outcomes at 30 days and one year in patients with chronic limb threatening ischaemia (CLTI) undergoing major surgery. Methods: This was a single-centre retrospective observational cross-sectional study in a tertiary UK Vascular Centre. We applied the Derby Frailty Index (DFI), the Acute Frailty Network Criteria (AFNC), the Prognostic Nutritional Index (PNI) and the Geriatric Nutritional Risk Index (GNRI) to routinely collect clinical audit data recorded from a combination of medical and nursing notes, blood test results and discharge letters. Results: We included 73 patients who had undergone amputation (mean age 69 (range 57–77) years; 71% male; mean body mass index (BMI) 27 (range 23–31) kg/m2) and 66 patients who had undergone bypass surgery (mean age 73 (range 64–81) years; 70% male; BMI 26 (22–30) kg/m2). The 30-day mortality rate of a frail patient (DFI and AFNC, respectively) was 21% (n=8/39) and 23% (n=6/26) compared with 7% (n=7/100) for non-frail patients. Frailty was associated with 30-day (DFI: odds ratio (OR) 3.4 (95% CI 1.2 to 10.2), p=0.027; AFNC: OR 3.4 (95% CI 1.1 to 10.7), p=0.034) and one-year (DFI: OR 7.95 (95% CI 3.4 to 18.6), p<0.001; AFNC: OR 5.9 (95% CI 2.4 to 14.7), p<0.001) mortality. Frailty, according to the AFNC, was also associated with an increased risk of re-admission. Neither of the malnutrition screening tools was associated with 30-day or one-year mortality (p>0.05). Conclusions: Our analysis confirms that both the DFI and AFNC tools identify patients with CLTI who are at the greatest risk of poor outcomes following major surgery. Frailty warrants further investigation and should be part of the consent and joint decision-making process in this patient population, to personalise care and minimise the risk of poorer outcomes.