Empagliflozin inhibits aortic valve calcification and fibrosis in a murine wire injury model
T Ohmori, K Miki, L Fujimura, T Kato, S MiyagawaAbstract
Background
Aortic stenosis is a progressive disease characterised by advancing aortic valve fibrosis and calcification. However, no pharmacological therapy has been established to slow valve disease progression. While the SGLT2 inhibitor empagliflozin has demonstrated significant cardiovascular benefits, its effects on aortic valve fibrosis, calcification, and function preservation remains unclear.
Purpose
This study aimed to determine whether empagliflozin suppresses the progression of aortic valve fibrosis and calcification and preserves valve function in a murine aortic valve wire injury (AVWI) model.
Methods
Male C57BL/6 mice aged 8–12 weeks were assigned to three groups (n=10 per group): sham, AVWI+vehicle, and AVWI+empagliflozin. AVWI was induced by inserting a 0.014-inch guidewire via the right carotid artery to injure the aortic valve, and sham mice underwent the same surgical procedure without wire-induced valve injury. At week 2, AVWI mice with a peak aortic jet velocity (PeakV) >2.0 m/s were randomized to receive empagliflozin (3 mg/kg/day via osmotic pump) or vehicle. Echocardiography was performed at baseline and at weeks 2, 4, 8, and 12. At week 12, the aortic valves were harvested for histological and immunohistochemical analyses (H&E, Masson’s trichrome, Sirius Red, von Kossa, RUNX2, and αSMA). Data are presented as mean±SD.
Results
Following AVWI, PeakV increased by week 2, reaching 2.39±0.24 m/s in the empagliflozin group and 2.37±0.29 m/s in the vehicle group at week 2 (P = 0.91) (sham 1.17±0.12 m/s). After week 4 onward, PeakV remained stable in the empagliflozin group, but continued to rise in the vehicle group (P<0.001 for group-by-time interaction). At week 12, PeakV was significantly lower in the empagliflozin group than in the vehicle group (2.00±0.41 m/s vs. 3.33±0.60 m/s, P < 0.001; sham 1.27±0.20 m/s). Empagliflozin also attenuated the increases in relative wall thickness (0.50±0.06 vs. 0.58±0.08, P = 0.021; sham 0.44±0.03) and heart weight-to-body weight ratio (3.12±0.25 mg/g vs. 3.95±0.99 mg/g, P = 0.028; sham 2.52±0.24 mg/g). Histological analysis demonstrated that empagliflozin reduced AVWI-induced increases in valve area and leaflet thickness. Furthermore, empagliflozin was found to attenuated fibrosis remodelling (Masson’s trichrome and Sirius Red) and calcification (von Kossa) while reducing the expression of RUNX2 and αSMA, as determined by immunohistochemical analysis, compared with the vehicle group.
Conclusions
Empagliflozin suppresses aortic valve fibrosis and calcification, preventing the deterioration of valve function in a murine AVWI model. These findings suggest that empagliflozin may be a promising pharmacological strategy for attenuating the progression of fibrotic and calcific aortic valve disease.