Abstract Background Heart Failure (HF) is a complex clinical syndrome with poor prognosis. Pulmonary hypertension (PH) often complicates HF but can hardly be addressed therapeutically. Sodium-glucose co-transporter 2 inhibitors (SGLT2i) improve cardiovascular outcomes in patients with HF. Whether SGLT2i positively impact on HF-associated PH is poorly understood. Omics offer great promise in the discovery of novel biomarkers and therapeutic targets for HF and PH. Aims We investigated novel markers associated with HF and PH, as well as how these biomarkers vary in response to HF-modyfing therapies, including SGLT2i. We also explored the impact of SGLT2i, compared with conventional anti-HF therapy, on HF-associated PH and right ventricular function. Methods Seventy-four patients with HF and reduced ejection fraction (HFrEF) with/without diabetes were divided into a gliflozin (G)-group receiving 10 mg/day empagliflozin or dapagliflozin, and a control (C)-group receiving conventional anti-HF therapy. Resting echocardiography, analyses on senescence markers [leucocyte telomere length (LTL), mitochondrial DNA copy number (mtDNAcn)], as well as measurement of two microRNAs (miRNA-21 and miRNA-92, recently implicated in response to treatment in HFpEF patients), were performed. Shotgun proteomic analyses were conducted on peripheral blood mononuclear cells. Results Compared to group C, group G had a significantly higher ejection fraction (EF, 42±13 vs 33±8, p=0.001), reduced left ventricular filling pressures (11±3 vs 15±5, p=0.001), reduced pulmonary artery systolic pressure (PAPs, 31±11 vs 46±15, p=0.001), better right ventricular-pulmonary artery coupling index (0.64±0.31 vs 0.44±0.22, p=0.002), increased LTL (Figure 1 A), higher mtDNAcn (Figure 1 B), reduced miRNA-21 levels (Figure 1 C) and no significant changes of miRNA-92 (Figure 1 D). Functional proteomic analysis showed that, compared with the C-group, the protein cargo from the G-group was able to trigger several biological pathways, showing a significant activation of T lymphocytes immune response (p-value=9.67x10-06, z-score=2.21) chemotaxis of monocytes (p-value=9.39x10-07, z-score=2.0), leukocytes (p-value=9.67x10-10, z-score=2.0)and phagocytes (p-value)=3.10x10-10, z-score=2.03) (Figure 2). Compared with the C-group, the G-group showed a downregulation of activin signaling pathway (z-score=-2.12), which is a novel therapeutic target in pulmonary arterial hypertension (PAH). Conclusions In HF patients, SGLT2i therapy is associated with improved left ventricular function and improved pulmonary hemodynamics. Activin is overactive in HF patients and its serum levels may be reduced by SGLT2i. SGLT2i may preserve LTL and mtDNA-cn as well as modulate the expression of specific miRNA implied in the regulation of endothelial function. SGLT2i may represent an additional therapeutic tool in patients with HF-associated PH, an area with no approved treatment options beyond traditional HF therapy.Figure 1:genomic analysesFigure 2:proteomic analyses