Usefulness of a novel nutritional index associated with frailty and poor outcomes in patients with lower extremity arterial disease

Abstract Background Evidence has indicated the close association between malnutrition or frailty and adverse outcomes in patients with lower extremity arterial disease (LEAD) following endovascular treatment (EVT). We have previously proposed a novel and simply calculable nutritional index by using serum levels of triglyceride, total cholesterol and body weight (TCBI) which was a useful prognostic indicator for patients with several cardiovascular disorders such as coronary artery disease, cardiogenic shock and heart failure. However, the application of the TCBI in patients with LEAD has been rarely evaluated. Moreover, no study has simultaneously addressed the prognostic implication of nutritional and frailty indices. Purpose The aim of present study was to investigate the association between TCBI and an index of frailty and sarcopenia, computed tomography (CT)-based psoas muscle index (PMI), in patients with LEAD following EVT. Moreover, we assessed the prognostic implication of TCBI in this population. Methods This single-center retrospective analysis involved consecutive patients with LEAD who underwent EVT for the first time since 2009 to 2020 (n=591). We divided patients into three groups according to tertiles of TCBI: lowest tertile (T1, <731.1); middle tertile (T2, 731.1–1243.6); and highest tertile (T3, ≥1243.6). We measured cross-sectional areas of psoas muscle at the level of forth lumber vertebra by CT-scan and obtained PMI (psoas muscle area normalized by height) in study participants. Primary and secondary endpoints were all-cause death and major adverse cardiovascular and limb events (MACLE), the composite of cardiovascular death (CV death), non-fatal myocardial infarction, stroke, clinically driven target vessel revascularization (CD-TVR), major amputation and development to limb ischemia. Median and the range of follow up period was 2.3 and 0–10 years, respectively. Results There was a positive significant correlation between log-transformed TCBI and PMI (Spearman’s correlation coefficient (r) between TCBI and PMI: 0.31, p<0.0001) (Figure 1). Kaplan-Meier analyses revealed the lowest cumulative incidences of both all-cause death and MACLE in patients with the highest tertile of TCBI (Figure 2). Constantly, multivariate Cox hazard analyses adjusted by age, sex, prior myocardial infarction, diabetes, chronic kidney disease (≥ stage3), left ventricular ejection fraction, use of statins, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers, and serum albumin level indicated the decreased risk of all-cause death (hazard ratio (HR): 0.66, 95% confidence interval (CI): 0.44–0.91, p=0.02) and MACLE (HR: 0.73, 95% CI: 0.59–0.89, p=0.003) by increase of TCBI, respectively. Conclusion This study showed a potential pathological link between poor nutritional status and advanced frailty/sarcopenia, which was associated with increased risk of poor prognosis in patients with LEAD following EVT.