Background: Empagliflozin showed efficacy in controlling glycaemia, leading to reductions in HbA1c levels, weight loss and blood pressure, compared to standard treatment. Moreover, the EMPA-REG OUTCOME trial demonstrated a 14% reduction of major adverse cardiovascular events (MACE), a 38% reduction in cardiovascular (CV) death and a 35% reduction in the hospitalization rate for heart failure (HF). These beneficial effect on HF were apparently independent from glucose control. However, no mechanistic in vivo studies are available to explain these results, yet. We aimed to determine the effect of empagliflozin on left ventricular (LV) function in a mouse model of doxorubicin-induced cardiomyopathy (DOX-HF).Methods: Male C57Bl/6 mice were randomly assigned to the following groups: controls (CTRL, n = 7), doxorubicin (DOX, n = 14), DOX plus empagliflozin (DOX + EMPA, n = 14), or DOX plus furosemide (DOX + FURO group, n = 7). DOX was injected intraperitoneally. LV function was evaluated at baseline and after 6 weeks of treatment using high-resolution echocardiography with 2D speckle tracking (Vevo 2100). Histological assessment was obtained using Haematoxylin and Eosin and Masson’s Goldner staining.Results: A significant decrease in both systolic and diastolic LV function was observed after 6 weeks of treatment with doxorubicin. EF dropped by 32% (p = 0.002), while the LS was reduced by 42% (p < 0.001) and the CS by 50% (p < 0.001). However, LV function was significantly better in the DOX + EMPA group, both in terms of EF (61.30 ± 11% vs. 49.24 ± 8%, p = 0.007), LS (− 17.52 ± 3% vs. − 13.93 ± 5%, p = 0.04) and CS (− 25.75 ± 6% vs. − 15.91 ± 6%, p < 0.001). Those results were not duplicated in the DOX + FURO group. Hearts from the DOX + EMPA group showed a 50% lower degree of myocardial fibrosis, compared to DOX mice (p = 0.03). No significant differences were found between the DOX + FURO and the DOX group (p = 0.103).Conclusion: Empagliflozin attenuates the cardiotoxic effects exerted by doxorubicin on LV function and remodelling in nondiabetic mice, independently of glycaemic control. These findings support the design of clinical studies to assess their relevance in a clinical setting.

An electrocardiogram (ECG) is not always immediately available in individuals with suspected acute coronary syndromes. Smartwatches are widespread and increasingly being used for digital health information. Apple Watch Series 4 (Apple Inc) introduced an integrated ECG tool that allows recording a single-lead ECG.^1-3 This smartwatch can reliably detect atrial fibrillation and has received US Food and Drug Administration approval.^4,5

Phenotypic switch of vascular smooth muscle cells (VSMCs) plays a key role in the pathogenesis of different vascular diseases, such as atherosclerosis and restenosis after coronary intervention. MicroRNAs have been identified as key regulators of VSMC biology. The miR-23b is highly expressed in VSMCs and it is involved in differentation, proliferation, and migration of several non-vascular cell types. However, the role of miR-23b in vascular disease is currently unknown. Thus, the aim of the present study was to evaluate the role of miR-23b on VSMC phenotypic switch in vitro and after vascular injury in vivo. To determine the changes of miR-23b expression in the injured arterial wall, we used the standard rat carotid artery balloon injury model. In vivo studies demonstrated that miR-23b is down-regulated after vascular injury. Gain-of-function studies showed that overexpression of miR-23b inhibited VSMC proliferation and migration, whereas the opposite effect was obtained with the in vitro inhibition of miR-23b. We further demonstrated that miR-23b can significantly promote the expression of VSMC marker genes such as smooth muscle α-actin (ACTA2) and smooth muscle myosin heavy chain (MYH11). Overexpression of miR-23b in balloon-injured arteries by Ad-miR-23b markedly decreased neointimal hyperplasia. Finally, miR-23b specifically suppresses urokinase-type plasminogen activator, SMAD family member 3, and transcription factor forkhead box O4 (FoxO4) expression in phenotypically modulated VSMCs. By luciferase reporter assay, we validated the transcription factor FoxO4 as a direct target of miR-23b in VSMCs. We identify miR-23b as a novel regulator of VSMC phenotypic switch in vitro and following vascular injury in vivo.