Preliminary evaluation of astragaloside IV on renal artery stenosis-associated left ventricular remodeling in rabbits

This exploratory study assessed the potential influence of astragaloside IV (AsIV) on renal artery stenosis–associated left ventricular remodeling and preliminarily explored the feasibility of two-dimensional speckle tracking echocardiography (2D-STE) in evaluating relevant alterations.

Left ventricular myocardial fibrosis (LVMF) was induced by constricting the left renal artery with U-shaped silver clips (0.7 mm inner diameter for mild fibrosis; 0.2 mm for severe fibrosis). Two-month-old male New Zealand white rabbits were randomly assigned to five groups (n = 5 per group): the sham operation (Control), mild LVMF model (Group A), severe LVMF model (Group B), mild LVMF + AsIV (Group C), and severe LVMF + AsIV (Group D). Serial echocardiographic evaluations were performed at 1 week and 4 weeks after treatment, including conventional and 2D-STE parameters. Histological examinations were conducted at 4 weeks after treatment, encompassing HE and Masson staining, cardiac index calculation.

Compared with the Control group, model groups A and B showed increased ventricular wall thickness (IVSd and LVPWd), decreased global longitudinal strain (GLS-A2C and GLS-AVG), and exacerbated LVMF with elevated CVF. AsIV treatment (Groups C and D) relatively mitigated these changes after 4 weeks, with diminished ventricular wall thickening and a trend toward reduced fibrosis. Moreover, 2D-STE could detect early subtle cardiac function changes before conventional echocardiography.

AsIV may attenuate renal artery stenosis–associated left ventricular remodeling, 2D-STE emerges as a highly sensitive and feasible tool for early detection of myocardial functional improvement. This study provides preliminary observational evidence for further investigation.