The Association Between Sarcopenia Index and Aortic Valve Sclerosis in Coronary Artery Disease Patients: Insights from a Retrospective Cross-Sectional Analysis and Animal Models.

BACKGROUND: The Sarcopenia Index (SI) is a recognized predictor of cardiovascular risk in patients with coronary artery disease (CAD), yet its association with aortic valve sclerosis (AVSc) remains insufficiently studied. This study aimed to examine the relationship between SI and AVSc in CAD patients. METHODS: In this retrospective study, 1056 CAD patients at Shanghai Ruijin Hospital underwent SI assessment and Doppler echocardiography. SI was calculated as [serum creatinine (mg/dL)/cystatin C (mg/L)] × 100. Logistic regression, subgroup analyses, and restricted cubic splines evaluated the SI-AVSc association. ROC curves determined SI's diagnostic value and its addition to traditional AVSc factors. In parallel with clinical observations, aortic valve changes were analyzed in mice via hematoxylin and eosin, AlizarinRed S, and Masson's trichrome to assess valve thickness, fibrosis and calcification. RESULTS: Patients with the lowest SI levels showed a higher prevalence of AVSc. Multivariate logistic regression revealed that SI was independently associated with AVSc (P<0.001). The C-statistic for SI in identifying AVSc was 0.708 (95% CI: 0.671, 0.744), and it improved risk stratification when SI was added to traditional clinical models (C-statistic increased from 0.840 to 0.866). In the subgroup analysis, the discriminatory power of SI was enhanced among elderly patients. Findings from animal models supported these results, and Spearman correlation analyses revealed negative correlation between SI and peak systolic aortic valve flow velocity (Spearman's rho=-0.578, P=0.006). Histological analysis demonstrated that aortic valve leaflets in the low SI group were thicker and more fibrotic than those in the high SI group, and this complementary approach provided mechanistic insights into how sarcopenia may promote valve degeneration in elder mice. CONCLUSION: Lower Sarcopenia Index is associated with the presence of AVSc in CAD patients. SI improves risk stratification and acts as a valuable associated marker for AVSc, emphasizing its potential clinical utility in enhancing patient management.