Sarcopenia is an Independent Predictor of All-Cause Death and Major Adverse Cardiovascular Events in Patients with...

Peripheral arterial disease (PAD) is a chronic vascular disease with high morbidity, often accompanied by sarcopenia. However, the prognostic value and mechanistic relevance of computed tomography (CT)-defined sarcopenia in PAD remain unclear. This study aims to assess the independent impact of sarcopenia on all-cause mortality and major adverse cardiovascular events in PAD patients, and to determine optimal third lumbar vertebra skeletal muscle index (L3-SMI) cutoffs for risk stratification.

In this retrospective cohort study, 208 PAD patients were grouped by L3-SMI into sarcopenia (n = 110) and nonsarcopenia (n = 98). Multivariate Cox regression evaluated associations with mortality and major adverse cardiovascular events (MACE), while restricted cubic spline (RCS) models explored dose-response patterns. Kaplan-Meier and log-rank tests compared survival, and Spearman correlation analyzed functional and metabolic associations.

The sarcopenia group exhibited significantly higher age (71.5 ± 9.38 vs. 65.81 ± 10.25 years, P < 0.001), while lower L3-SMI (36.48 ± 5.67 vs. 47.31 ± 7.88 cm²/m², P < 0.001), lower body mass index (22.31 ± 2.96 vs. 25.77 ± 2.72 kg/m², P < 0.001), lower albumin (37 vs. 39 g/L, P = 0.005), and lower serum phosphate (1.14 vs. 1.23 mmol/L, P = 0.009). Over a 36-month median follow-up, sarcopenia was associated with increased all-cause death (27% vs. 14%, P = 0.034) and MACE incidence (28% vs. 14%, P = 0.024). Multivariate Cox regression revealed that each 1-unit decrease in L3-SMI elevated death risk by 7% (adjusted hazard ratio [HR] = 0.93, 95% confidence interval [CI]: 0.88-0.98, P = 0.009) and MACE risk by 9% (adjusted HR = 0.92, 95% CI: 0.86-0.96, P = 0.008). RCS analysis identified nonlinear dose-response relationships: L3-SMI <40.97 cm²/m² sharply increased death risk (HR = 3.3), while L3-SMI <48.78 cm²/m² significantly amplified MACE risk (HR = 7.89). Correlations between L3-SMI and Barthel index (r = 0.56, P < 0.001), serum phosphate (r = 0.53, P = 0.002), and Fontaine stage (r = -0.39, P = 0.007) suggested sarcopenia might exacerbate disease progression via metabolic dysregulation, immune suppression, and functional decline.

CT-defined sarcopenia independently predicts poor outcomes in PAD. L3-SMI thresholds enable early risk stratification and support targeted interventions to improve prognosis. These findings underscore the importance of incorporating body composition assessment into routine risk evaluation for PAD patients.