Additive benefits of sacubitril/valsartan to dapagliflozin in cardiometabolic and age related cardiac dysfunction

Background. Pathophysiology of heart failure with preserved ejection fraction (HFpEF) remains incompletely understood due to the marked heterogeneity of affected patients, who are typically older, frequently female, and burdened by multiple comorbidities. HFpEF disproportionately affects postmenopausal women and is strongly associated with central obesity and metabolic dysfunction. While current guidelines recommend SGLT2i for all HFpEF patients , combination treatments targeting complementary pathways may improve outcomes due to potential synergistic effects. Many HFpEF patients are already receiving treatments for underlying comorbidities or may require additional therapies. In this view, the identification of patient subgroups most likely to benefit from specific therapeutic combinations is crucial. Evidence from PARAGON-HF suggests enhanced responsiveness to angiotensin receptor neprilysin inhibitors (ARNi) in women. Because both aging and obesity amplify renin-angiotensin-aldosterone system RAAS activation, dual ARNi-SGLT2i therapy may provide synergistic benefit in this subgroup. Aim. To evaluate the long-term effects of sacubitril/valsartan (S/V) alone or combined with dapagliflozin (D) in a dysmetabolic aging heart failure model (DAHF) using female Fischer-344 rats that reproduce features of metabolic stress, adiposity, and cardiac aging typical of HFpEF. Methods. 15-month-old Fischer 344 female rats were treated with S/V (60 mg/kg/day) alone DAHF(S/V) or with a combination of S/V and dapagliflozin (0.1mg/Kg/day) DAHF-(S/V+D) for 45 weeks. Echocardiography and hemodynamic analysis were used to assess cardiac function. Heart tissue was used for molecular and histological analysis. All data were analyzed using one-way ANOVA, and Tukey’s post-test. A p-value <0.05 was considered statistically significant. Results. Echocardiographic and hemodynamic analyses showed that both treatments effectively improved diastolic dysfunction. These benefits were accompanied by reduced plasma NT-proBNP and myocardial BNP levels, consistent with alleviated wall stress. Both treatments rebalanced RAAS signaling, downregulating ACE1/AT1R and upregulating the ACE2/Ang-(1-7)/Mas axis, thereby restoring a cardioprotective profile and improving metabolic homeostasis. the reductions in body weight and relative visceral and liver fat observed in DAHF-S/V group, with no further significant reduction, when combined with dapagliflozin, indicating that integrated modulation of RAAS and natriuretic peptide pathways interrupts the “vicious cycle” ectopic fat. Both treatments attenuated fibrosis, with reduced expression of key pro-fibrotic markers (collagen I/III, MMPs, TGF-β/TGF-βR1, SMADs, and pro-fibrotic miRNAs). Notably, S/V and S/V+D reduced inflammation and endothelial dysfunction by decreasing inflammatory markers (NF-κB, MCP-1), cytokines (IL-1β, IL-6), and endothelial indicators (VCAM-1, ET-1, iNOS). Only the combination therapy restored eNOS expression, in line with the marked reduction in oxidative stress observed exclusively in the S/V+D group, which exhibited lower reactive oxygen species and reactivation of the Nrf2/Keap1 antioxidant pathway. In parallel, the combined treatment strengthened the AMPK/NAMPT/Sirtuin axis, promoting mitochondrial biogenesis, enhanced antioxidant capacity, and improved metabolic resilience. It also reduced the pro-senescent miRNAs miR-34a and miR-146a both negative regulators of the NAD⁺-biosynthetic enzyme NAMPT, thereby modulating key senescence-related metabolic pathways. Consistent with these effects, the combination restored NAMPT and SIRT1 expression and decreased acetyl-p53Lys381 and p21CIP, indicating a reversal of senescenceassociated signaling. Moreover, the longevity protein Klotho, typically diminished in aged and dysmetabolic myocardium, was reinstated only by combined therapy, suggesting synergistic reinforcement of AMPK/SIRT1 and Nrf2/Keap1 antioxidant pathways. Conclusions. Long-term treatment with S/V, especially when combined with DAPA, improves cardiac function but also has a beneficial effects on deeper metabolic, oxidative-stress and ageing-related mechanisms, particularly relevant in older female rats who develop the cardiometabolic HFpEF phenotype. In conclusion, the combination of SGLT2i and ARNi provided enhanced cardiac protection in a model representative of postmenopausal HFpEF with central obesity, offering mechanistic evidence that supports sex-specific therapeutic strategies. These findings strengthen the rationale for a precision medicine approach tailored to elderly women with HFpEF.