Background: Myocardial fibrosis is a multistep process, which results in collagen deposition in the injured muscle. Empagliflozin, a sodium-glucose cotransporter 2 inhibitor (SGLT2i), decreases cardiovascular events risk. Little is known on the effects of empagliflozin in non-diabetic patients early post myocardial infarction.
Methods: Fourteen non-diabetic rats underwent myocardial infarction induction, and treated or not (control)immediately after myocardial infarction by daily empagliflozin (30 mg/kg/day). We evaluated cardiac function at baseline, 2 and 4 weeks after myocardial infarction by echocardiography, and prior to sacrifice by Millar pressure-volume system. We performed histological and biochemical evaluation of fibrosis and humoral factors promoting fibrosis.
Results: Baseline ejection fractions were 69.9 ± 5.3% and 76.4 ± 5.4%, and dropped to final values of 40.1 ± 5.8% and 39.4 ± 5.4% in the control and empagliflozin groups, respectively (P < 0.001 vs. baseline, P > 0.05 between groups). Collagen deposition, measured as collagen volume fraction, was higher in both the scar and the remote cardiac areas of the control group 79.1 ± 6.2% and 4.6 ± 2.5% for control, and 53.8 ± 5.4% and 2.5 ± 1.3% for empagliflozin group, respectively (P < 0.05 for each). Remote cardiac muscle collagen, measured by hydroxyproline, was 4.1 ± 0.4 μg/μl and 3.6 ± 0.2 μg/μl (P = 0.07). TGF-β1 and Smad3 expression decreased by empagliflozin-18.73 ± 16.32%, 9.16 ± 5.69% and 16.32 ± 5.4%, 7.00 ± 5.28% in the control and empagliflozin groups, respectively (P < 0.05).
Conclusion/interpretation: Empagliflozin administered early after myocardial infarction reduce myocardial fibrosis and inhibit the TGF-β1/Smad3 fibrotic pathway, probably prior to exerting any hemodynamic or physiological effect.
Keywords: Collagen deposition; Empagliflozin; Fibrosis; Myocardial infarction; TGF-β1/Smad3 pathway.