Additive benefits of dapagliflozin to sacubitril/valsartan in cardiometabolic age-related cardiac dysfunction involve endothelial oxidative defense and senescence

Background Population aging with increased life expectancy and a rise in risk factors such as obesity, diabetes and cardiometabolic disease, result in growing prevalence of HF with preserved ejection fraction (HFpEF). Before the introduction of sodium-glucose cotransporter 2 inhibitors (SGLT2i) into HFpEF guidelines, the PARAGON-HF trial showed a trend to lower the primary endpoint in patients treated with angiotensin receptor-neprilysin inhibitors (ARNI). ARNI could be relevant in diabetes and the excess of adipose tissue because of the activation of leptin-aldosterone-neprilysin axis, particularly active during aging and in women. Clinical trials suggested that the benefits of SGLT2i may be complementary to those of an ARNI but a direct study of SGLT2i addition was not done. Methods We tested the combination of ARNI and SGLT2i in the model where two drivers of HFpEF combine: metabolic stress and chronologic ageing. Cardiometabolic phenotype of female, obese-prone Fisher 344 rats consist of lipid excess, leptin and insulin resistance and cardiac dysfunction that develops late in age. Long-term (45 weeks) treatment with ARNI alone or the combination of ARNI and SGLT2i (dapagliflozin) was initiated at age were structural and functional abnormalities were absent. Results Time-dependent body weight gain was reduced both by ARNI and ARNI+SGLT2i. Cardiac hypertrophy was decreased. However, echocardiography and hemodynamic analysis showed further improvement of function with the drug association. In the search of the mechanism of this benefit, we studied several aspects of adverse cardiac remodelling. ARNI alone and ARNI+SGLT2i similarly downregulated TGF-b1/Smad2-3 pathway, reduced myocardial fibrosis and toned-down inflammation (IL-6, IL-b1, NFKB, TNF-a, MCP-1). The increased level of iNOS, typical of chronic inflammation was present and was parallel to the reduction in eNOS expression. Interestingly, the expression of eNOS was recovered in dysmetabolic old female hearts only when SGLT2i was added. Moreover, the addition of SGLT2i resulted in the decreased myocardial oxidative damage in terms of the protein (3-nitrotyrosine), nucleic acid (8-OHdG) and lipid (HNE) oxidation. Mitochondrial fraction showed the increased expression and activity of mitochondrial superoxide dismutase following the addition of SGLT2i to ARNI. These in vivo results were corroborated with the unique approach to isolate cardiac endothelial cells from the old dysmetabolic rats after long-term treatments showing the involvement of AMPK/NAMPT/SIRT1 and SIRT3. In addition, the in vitro exposure of primary cardiac ECs obtained from old dysmetabolic untreated animals evidenced that the addition of SGLT2i drives the acquisition of the antioxidant phenotype by coronary ECs. Effective antioxidant defence translated to lower extent of cell senescence both in vivo and in vitro. Conclusions The addition of SGLT2i to ARNI is beneficial for aging dysmetabolic female heart.