The SGLT2 inhibitor empagliflozin reduces mortality and prevents progression in experimental pulmonary hypertension

SGLT2 inhibitors as a potential therapeutic option for pulmonary hypertension: mechanisms and clinical perspectives

Pulmonary arterial hypertension (PAH), one subtype of pulmonary hypertension (PH), is a life-threatening condition characterized by pulmonary arterial remodeling, elevated pulmonary vascular resistance, and blood pressure in the pulmonary arteries, leading to right heart failure and increased mortality. The disease is marked by endothelial dysfunction, vasoconstriction, and vascular remodeling. The role of Sodium-Glucose Co-Transporter-2 (SGLT2) inhibitors, a class of medications originally developed for diabetes management, is increasingly being explored in the context of cardiovascular diseases, including PAH, due to their potential to modulate these pathophysiological processes. In this review, we systematically examine the burgeoning evidence from both basic and clinical studies that describe the effects of SGLT2 inhibitors on cardiovascular health, with a special emphasis on PAH. By delving into the complex interactions between these drugs and the potential pathobiology that underpins PH, this study seeks to uncover the mechanistic underpinnings that could justify the use of SGLT2 inhibitors as a novel therapeutic approach for PAH. We collate findings that illustrate how SGLT2 inhibitors may influence the normal function of pulmonary arteries, possibly alleviating the pathological hallmarks of PAH such as inflammation, oxidative stress, aberrant cellular proliferation, and so on. Our review thereby outlines a potential paradigm shift in PAH management, suggesting that these inhibitors could play a crucial role in modulating the disease's progression by targeting the potential dysfunctions that drive it. This comprehensive synthesis of existing research underscores the imperative need for further clinical trials to validate the efficacy of SGLT2 inhibitors in PAH and to integrate them into the therapeutic agents used against this challenging disease.

Glycolysis modulation: New therapeutic strategies to improve pulmonary hypertension (Review)

Pulmonary hypertension (PH) is a progressive life‑threatening cardiopulmonary vascular disease involving various pathological mechanisms, including hypoxia, cellular metabolism, inflammation, abnormal proliferation and apoptosis. Specifically, metabolism has attracted the most attention. Glucose metabolism is essential to maintain the cardiopulmonary vascular function. However, once exposed to a noxious stimulus, intracellular glucose metabolism changes or switches to an alternative pathway more suitable for adaptation, which is known as metabolic reprogramming. By promoting the switch from oxidative phosphorylation to glycolysis, cellular metabolic reprogramming plays an important role in PH development. Suppression of glucose oxidation and secondary upregulation of glycolysis are responsible for various features of PH, including the proliferation and apoptosis resistance of pulmonary artery endothelial and smooth muscle cells. In the present review, the roles and importance of the glucose metabolism shift were discussed to aid in the development of new treatment approaches for PH.

Complement Immune System in Pulmonary Hypertension-Cooperating Roles of Circadian Rhythmicity in Complement-Mediated Vascular Pathology

Originally discovered in the 1890s, the complement system has traditionally been viewed as a "compliment" to the body's innate and adaptive immune response. However, emerging data have shown that the complement system is a much more complex mechanism within the body involved in regulating inflammation, gene transcription, attraction of macrophages, and many more processes. Sustained complement activation contributes to autoimmunity and chronic inflammation. Pulmonary hypertension is a disease with a poor prognosis and an average life expectancy of 2-3 years that leads to vascular remodeling of the pulmonary arteries; the pulmonary arteries are essential to host homeostasis, as they divert deoxygenated blood from the right ventricle of the heart to the lungs for gas exchange. This review focuses on direct links between the complement system's involvement in pulmonary hypertension, along with autoimmune conditions, and the reliance on the complement system for vascular remodeling processes of the pulmonary artery. Furthermore, circadian rhythmicity is highlighted as the disrupted homeostatic mechanism in the inflammatory consequences in the vascular remodeling within the pulmonary arteries, which could potentially open new therapeutic cues. The current treatment options for pulmonary hypertension are discussed with clinical trials using complement inhibitors and potential therapeutic targets that impact immune cell functions and complement activation, which could alleviate symptoms and block the progression of the disease. Further research on complement's involvement in interstitial lung diseases and pulmonary hypertension could prove beneficial for our understanding of these various diseases and potential treatment options to prevent vascular remodeling of the pulmonary arteries.

Pharmacologic Treatment of Pulmonary Hypertension Due to Heart Failure with Preserved Ejection Fraction: Are There More Arrows on Our Bow?

Pulmonary hypertension (PH) associated with heart failure with preserved ejection fraction (PH-HFpEF) represents a frequent form of PH related to left ventricular dysfunction. The pathophysiology of PH-HFpEF is intricate, and varied and includes vascular, cardiac, and pulmonary factors that contribute synergistically to developing this clinical syndrome. Improved knowledge of the pathophysiology of PH-HFpEF has paved the way for the use of new drugs such as angiotensin receptor neprilysin inhibitors (ARNIs), non-steroidal mineral corticoid receptor antagonist (nsMRA), sodium-glucose cotransporter inhibitors (SGLT2is), levosimendan, and glucagon-like peptide 1 (GLP-1) agonists. ARNIs are a widely used drug for the treatment of PH associated with heart failure with reduced ejection fraction. They have also recently been used in PH-HFpEF patients with hemodynamic benefits that need to be confirmed in future research. Finerenone is an innovative non-steroidal mineralocorticoid receptor antagonist that exhibits notable cardioprotective and renoprotective properties in individuals suffering from chronic diabetic kidney disease. It also enhances outcomes for patients with heart failure, whether they have mildly reduced or preserved ejection fraction. Moreover, in experimental studies, finerenone has been found to lower pulmonary artery pressure, reduce muscularization, and decrease the wall thickness of pulmonary arteries. SGLT2i have revolutionized the treatment of patients with heart failure irrespective of left ventricular ejection fraction, and their treatment is also associated with an improvement in the hemodynamics profile in patients with PH-HFpEF. Levosimendan is a widely used inodilator in the treatment of acute and advanced heart failure. In addition, its use in patients with PH-HFpEF (supported by the positive effects on pulmonary hemodynamics that levosimendan exerts) has recently demonstrated hemodynamic benefit in a small phase 2 study that paved the way for phase 3 studies and the creation of an oral formulation of levosimendan. Finally, GLP1 agonists are a class of drugs that, in preliminary evidence, have shown a positive effect on cardiac hemodynamics, mainly by facilitating left ventricular unloading. These effects, along with the reduction in insulin resistance and weight loss, likely lead to beneficial outcomes for PH-HFpEF patients, especially those with obesity as a comorbidity.

Cardioprotection of Canagliflozin, Dapagliflozin, and Empagliflozin: Lessons from preclinical studies

Clinical and preclinical studies have elucidated the favorable effects of Inhibitors of Sodium-Glucose Cotransporter-2 (iSGLT2) in patients and animal models with type 2 diabetes. Notably, these inhibitors have shown significant benefits in reducing hospitalizations and mortality among patients with heart failure. However, despite their incorporation into clinical practice for indications beyond diabetes, the decision-making process regarding their use often lacks a systematic approach. The selection of iSGLT2 remains arbitrary, with only a limited number of studies simultaneously exploring the different classes of them. Currently, no unique guideline establishes their application in both clinical and basic research. This review delves into the prevalent use of iSGLT2 in animal models previously subjected to induced cardiac stress. We have compiled key findings related to cardioprotection across various animal models, encompassing diverse dosages and routes of administration. Beyond their established role in diabetes management, iSGLT2 has demonstrated utility as agents for safeguarding heart health and cardioprotection can be class-dependent among the iSGLT2. These findings may serve as valuable references for other researchers. Preclinical studies play a pivotal role in ensuring the safety of novel compounds or treatments for potential human use. By assessing side effects, toxicity, and optimal dosages, these studies offer a robust foundation for informed decisions, identifying interventions with the highest likelihood of success and minimal risk to patients. The insights gleaned from preclinical studies, which play a crucial role in highlighting areas of knowledge deficiency, can guide the exploration of novel mechanisms and strategies involving iSGLT2.

Dapagliflozin alleviates right heart failure by promoting collagen degradation by reducing ROS levels

BACKGROUND

Right ventricular (RV) fibrosis is an important pathological change that occurs during the development of right heart failure (RHF) induced by pulmonary hypertension (PH). Dapagliflozin (DAPA), a sodium-glucose cotransporter 2 (SGLT2) inhibitor, has been shown to play a major role in left heart failure, but it is unclear whether it has a positive effect on RHF. This study aimed to clarify the effect of DAPA on PH-induced RHF and investigate the underlying mechanisms.

METHODS

We conducted experiments on two rat models with PH-induced RHF and cardiac fibroblasts (CFs) exposed to pathological mechanical stretch or transforming growth factor-beta (TGF-β) to investigate the effect of DAPA.

RESULTS

In vivo, DAPA could improve pulmonary hemodynamics and RV function. It also attenuated right heart hypertrophy and RV fibrosis. In vitro, DAPA reduced collagen expression by increasing the production of matrix metalloproteinase 2 (MMP2) and matrix metalloproteinase 9 (MMP9). Additionally, DAPA was found to reduce reactive oxygen species (ROS) levels in CFs and the right heart in rats. Similar to DAPA, the ROS scavenger N-acetylcysteine (NAC) exerted antifibrotic effects on CFs. Therefore, we further investigated the mechanism by which DAPA promoted collagen degradation by reducing ROS levels.

CONCLUSIONS

In summary, we concluded that DAPA ameliorated PH-induced structural and functional changes in the right heart by increasing collagen degradation. Our study provides new ideas for the possibility of using DAPA to treat RHF.

The effects of sodium-glucose cotransporter 2 inhibitors on the 'forgotten' right ventricle

With the progress in diagnosis, treatment and imaging techniques, there is a growing recognition that impaired right ventricular (RV) function profoundly affects the prognosis of patients with heart failure (HF), irrespective of their left ventricular ejection fraction (LVEF). In addition, right HF (RHF) is a common complication associated with various diseases, including congenital heart disease, myocardial infarction (MI), pulmonary arterial hypertension (PAH) and dilated cardiomyopathy (DCM), and it can manifest at any time after left ventricular assist devices (LVADs). The sodium-glucose cotransporter 2 (SGLT2) inhibition by gliflozins has emerged as a cornerstone medicine for managing type 2 diabetes mellitus (T2DM) and HF, with an increasing focus on its potential to enhance RV function. In this review, we aim to present an updated perspective on the pleiotropic effects of gliflozins on the right ventricle and offer insights into the underlying mechanisms. We can ascertain their advantageous impact on the right ventricle by discussing the evidence obtained in animal models and monumental clinical trials. In light of the pathophysiological changes in RHF, we attempt to elucidate crucial mechanisms regarding their beneficial effects, including alleviation of RV overload, reduction of hyperinsulinaemia and inflammatory responses, regulation of nutrient signalling pathways and cellular energy metabolism, inhibition of oxidative stress and myocardial fibrosis, and maintenance of ion balance. Finally, this drug class's potential application and benefits in various clinical settings are described, along with a prospective outlook on future clinical practice and research directions.

Effect of dapagliflozin on pulmonary vascular remodeling in rats with chronic hypoxic pulmonary arterial hypertension

OBJECTIVE

To investigate the effects of sodium-glucose co-transporter 2 inhibitor dapagliflozin on pulmonary vascular remodeling in a rat model of chronic hypoxic pulmonary arterial hypertension.

METHODS

Eighteen female Sprague-Dawley rats were divided into three groups: control (CON), chronic hypoxia (HYP), and chronic hypoxia + dapagliflozin. The HYP and dapagliflozin groups were subjected to hypoxia and received saline or dapagliflozin. The CON group was normoxic and received saline. Body weight and fasting blood glucose were measured, and after 21 days, lung and heart tissues were analyzed for pulmonary artery reconstruction and right ventricular hypertrophy. Western blotting assessed Bax and Bcl-2 protein levels.

RESULTS

Chronic hypoxia increased pulmonary artery wall thickness and lung fibrosis and caused right ventricular hypertrophy. Dapagliflozin reduced these changes, decreasing artery wall thickness, fibrosis, and hypertrophy while increasing the Bax/Bcl-2 ratio.

CONCLUSION

Dapagliflozin alleviates chronic hypoxia-induced pulmonary artery wall thickening and lung tissue fibrosis in rats, potentially through proapoptotic effects.

The possible effect of anti-diabetic agents GLP-1RA and SGLT-2i on the respiratory system function

Type 2 Diabetes (T2D) is a chronic disease with increasing incidence and prevalence and serious chronic complications, especially from cardiovascular system. However, other organs can be affected too. Several studies have associated T2D, especially when poorly controlled, with multiple pulmonary diseases. T2D is a common comorbidity among patients with asthma, Chronic Obstructive Pulmonary Disease (COPD), and Obstructive Sleep Apnea Syndrome (OSAS), and it is related to higher respiratory infection incidence, prevalence and severity. Glucagon-like peptide-1 receptor agonists (GLP-1RA) and Sodium-glucose co-transporter-2 inhibitors (SGLT-2i) are novel antihyperglycaemic agents with established cardiovascular benefits. There are also limited studies indicating their potential benefit in respiratory function. The aim of this article is to review data on the impact of GLP-1RA and SGLT-2i on respiratory function and describe the possible clinical benefits. Key findings indicate that GLP-1RA significantly improve lung function in patients with COPD, evidenced by improvements in spirometry measurements. Additionally, both GLP-1RA and SGLT-2i are associated with a decreased risk of severe and moderate exacerbations in COPD patients and have shown potential in reducing the incidence of respiratory disorders, including asthma and pneumonia. The mechanisms underlying these benefits are not yet fully understood and include multiple effects, such as anti-inflammatory action and oxidative stress reduction.

Empagliflozin Attenuates Pulmonary Arterial Remodeling Through Peroxisome Proliferator-Activated Receptor Gamma Activation

The loss of peroxisome proliferator-activated receptor gamma (PPARγ) exacerbates pulmonary arterial hypertension (PAH), while its upregulation reduces cell proliferation and vascular remodeling, thereby decreasing PAH severity. SGLT2 inhibitors, developed for type 2 diabetes, might also affect signal transduction in addition to modulating sodium-glucose cotransporters. Pulmonary arterial smooth muscle cells (PASMCs) isolated from patients with idiopathic pulmonary arterial hypertension (IPAH) were treated with three SGLT2 inhibitors, canagliflozin (Cana), dapagliflozin (Dapa), and empagliflozin (Empa), to investigate their antiproliferative effects. To assess the impact of Empa on PPARγ, luciferase reporter assays and siRNA-mediated PPARγ knockdown were employed to examine regulation of the γ-secretase complex and its downstream target Notch3. Therapy involving daily administration of Empa was initiated 21 days after inducing hypoxia-induced PAH in mice. Empa exhibited significant antiproliferative effects on fast-growing IPAH PASMCs. Empa activated PPARγ to prevent formation of the γ-secretase complex, with specific impacts on presenilin enhancer 2 (PEN2), which plays a crucial role in maintaining γ-secretase complex stability, thereby inhibiting Notch3. Similar results were obtained in lung tissue of chronically hypoxic mice. Empa attenuated pulmonary arterial remodeling and right ventricle hypertrophy in a hypoxic PAH mouse model. Moreover, PPARγ expression was significantly decreased and PEN2, and Notch3 levels were increased in lung tissue from PAH patients compared with non-PAH lung tissue. Empa reverses vascular remodeling by activating PPARγ to suppress the γ-secretase-Notch3 axis. We propose Empa as a PPARγ activator and potential therapeutic for PAH.

Canagliflozin alleviates pulmonary hypertension by activating PPARγ and inhibiting its S225 phosphorylation

Pulmonary hypertension (PH) is a progressive fatal disease with no cure. Canagliflozin (CANA), a novel medication for diabetes, has been found to have remarkable cardiovascular benefits. However, few studies have addressed the effect and pharmacological mechanism of CANA in the treatment of PH. Therefore, our study aimed to investigate the effect and pharmacological mechanism of CANA in treating PH. First, CANA suppressed increased pulmonary artery pressure, right ventricular hypertrophy, and vascular remodeling in both mouse and rat PH models. Network pharmacology, transcriptomics, and biological results suggested that CANA could ameliorate PH by suppressing excessive oxidative stress and pulmonary artery smooth muscle cell proliferation partially through the activation of PPARγ. Further studies demonstrated that CANA inhibited phosphorylation of PPARγ at Ser225 (a novel serine phosphorylation site in PPARγ), thereby promoting the nuclear translocation of PPARγ and increasing its ability to resist oxidative stress and proliferation. Taken together, our study not only highlighted the potential pharmacological effect of CANA on PH but also revealed that CANA-induced inhibition of PPARγ Ser225 phosphorylation increases its capacity to counteract oxidative stress and inhibits proliferation. These findings may stimulate further research and encourage future clinical trials exploring the therapeutic potential of CANA in PH treatment.

Unlocking the Potential: Angiotensin Receptor Neprilysin and Sodium Glucose Co-Transporter 2 Inhibitors for Right Ventricle Dysfunction in Heart Failure

This review article examines the mechanism of action of Angiotensin Receptor-Neprilysin Inhibitors (ARNIs) and Sodium-Glucose Co-Transporter 2 Inhibitors (SGLT2is) in managing chronic right ventricular (RV) dysfunction. Despite advancements in heart failure (HF) treatment, RV dysfunction remains a significant contributor to morbidity and mortality. This article explores the The article explores the impact of ARNIs and SGLT2is on RV function based on clinical and preclinical evidence, and the potential benefits of combined therapy. It highlights the need for further research to optimize patient outcomes and suggests that RV function should be considered in future clinical trials as part of risk stratification for HF therapies. This review underscores the importance of the early initiation of ARNIs and SGLT2is as per guideline-directed medical therapy for eligible HFrEF and HFpEF patients to improve co-existing RV dysfunction.

Improvements of myocardial strain and work in diabetes patients with normal ejection fraction after empagliflozin treatment

AIMS/INTRODUCTION

To assess the effect of empagliflozin treatment on left ventricular (LV), right ventricular (RV) and left atrial (LA) functions in diabetes patients with normal ejection fraction.

MATERIALS AND METHODS

The study included a total of 128 diabetes patients with multiple cardiovascular risk factors who were subjected to a 6-month follow up from the initiation of empagliflozin treatment. Before and after treatment with empagliflozin, LV, RV and LA strain, and noninvasive myocardial work parameters were evaluated by speckle tracking echocardiography.

RESULTS

In 128 diabetes patients (mean age 56 ± 8 years, 85 men) with multiple cardiovascular risk factors, myocardial strain and work parameters were impaired, despite the absence of significant clinical symptoms of heart failure. After 6-month treatment with empagliflozin, the absolute value of LV strain in all directions increased, represented by LV global longitudinal strain (-18.0 ± 1.7% to -19.2 ± 1.7% [mean ± SD]). The same trend in LV global work efficiency (93 [91-94] % to 94 [93-95] % [median (IQR)]), RV free-wall longitudinal strain (-24.0 ± 2.7% to -25.0 ± 2.8%), LA reservoir (31 ± 5% to 34 ± 5%) and conduit strain (-14 ± 4% to -16 ± 4%) was also observed. LV mass index (106.9 ± 16.8-103.6 ± 16.4 g/m2) and LV global wasted work (143 [111-185] mmHg% to 108 [88-141] mmHg%) decreased after treatment (P < 0.05 for all). LV volume and LA volume index remained unchanged after treatment. In the multivariable analysis, the change in LA reservoir strain (β = 0.050, P = 0.035) and baseline global longitudinal strain (β = -0.488, P < 0.001) were independent predictors of improvement in LV global longitudinal strain.

CONCLUSIONS

This study suggests that 6-month treatment with empagliflozin improved LV, RV and LA functions in diabetes patients with normal ejection fraction.

Emerging therapies: Potential roles of SGLT2 inhibitors in the management of pulmonary hypertension

Pulmonary hypertension (PH) is a pathophysiological disorder that may involve multiple clinical conditions and may be associated with a variety of cardiovascular and respiratory diseases. Pulmonary hypertension due to left heart disease (PH-LHD) currently lacks targeted therapies, while Pulmonary arterial hypertension (PAH), despite approved treatments, carries considerable residual risk. Metabolic dysfunction has been linked to the pathogenesis and prognosis of PH through various studies, with emerging metabolic agents offering a potential avenue for improving patient outcomes. Sodium-glucose cotransporter 2 inhibitor (SGLT-2i), a novel hypoglycemic agent, could ameliorate metabolic dysfunction and exert cardioprotective effects. Recent small-scale studies suggest SGLT-2i treatment may improve pulmonary artery pressure in patients with PH-LHD, and the PAH animal model shows that SGLT-2i can reduce pulmonary vascular remodeling and prevent progression in PAH, suggesting potential benefits for patients with PH-LHD and perhaps PAH. This review aims to succinctly review PH's pathophysiology, and the connection between metabolic dysfunction and PH, and investigate the prospective mechanisms of action of SGLT-2i in PH-LHD and PAH management.

Canagliflozin inhibits PASMCs proliferation via regulating SGLT1/AMPK signaling and attenuates artery remodeling in MCT-induced pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) was a devastating disease characterized by artery remodeling, ultimately resulting in right heart failure. The aim of this study was to investigate the effects of canagliflozin (CANA), a sodium-glucose cotransporter 2 inhibitor (SGLT2i) with mild SGLT1 inhibitory effects, on rats with PAH, as well as its direct impact on pulmonary arterial smooth muscle cells (PASMCs). PAH rats were induced by injection of monocrotaline (MCT) (40 mg/kg), followed by four weeks of treatment with CANA (30 mg/kg/day) or saline alone. Pulmonary artery and right ventricular (RV) remodeling and dysfunction in PAH were alleviated with CANA, as assessed by echocardiography. Hemodynamic parameters and structural of pulmonary arteriole, including vascular wall thickness and wall area, were reduced by CANA. RV hypertrophy index, cardiomyocyte hypertrophy, and fibrosis were decreased with CANA treatment. PASMCs proliferation was inhibited by CANA under stimulation by platelet-derived growth factor (PDGF)-BB or hypoxia. Activation of AMP kinase (AMPK) was induced by CANA treatment in cultured PASMCs in a time- and concentration-dependent manner. These effects of CANA were attenuated when treatment with compound C, an AMPK inhibitor. Abundant expression of SGLT1 was observed in PASMCs and pulmonary arteries, while SGLT2 expression was undetectable. SGLT1 increased in response to PDGF-BB or hypoxia stimulation, while PASMCs proliferation was inhibited and beneficial effects of CANA were counteracted by knockdown of SGLT1. Our research demonstrated for the first time that CANA inhibited the proliferation of PASMCs by regulating SGLT1/AMPK signaling and thus exerted an anti-proliferative effect on MCT-induced PAH.

Diabetes mellitus, glycemic traits, SGLT2 inhibition, and risk of pulmonary arterial hypertension: A Mendelian randomization study

This study aimed to investigate the causal role of diabetes mellitus (DM), glycemic traits, and sodium-glucose cotransporter 2 (SGLT2) inhibition in pulmonary arterial hypertension (PAH). Utilizing a two-sample two-step Mendelian randomization (MR) approach, we determined the causal influence of DM and glycemic traits (including insulin resistance, glycated hemoglobin, and fasting insulin and glucose) on the risk of PAH. Moreover, we examined the causal effects of SGLT2 inhibition on the risk of PAH. Genetic proxies for SGLT2 inhibition were identified as variants in the SLC5A2 gene that were associated with both levels of gene expression and hemoglobin A1c. Results showed that genetically inferred DM demonstrated a causal correlation with an increased risk of PAH, exhibiting an odds ratio (OR) of 1.432, with a 95% confidence interval (CI) of 1.040-1.973, and a p-value of 0.028. The multivariate MR analysis revealed comparable outcomes after potential confounders (OR = 1.469, 95%CI = 1.021-2.115, p = 0.038). Moreover, genetically predicted SGLT2 inhibition was causally linked to a reduced risk of PAH (OR = 1.681*10-7, 95%CI = 7.059*10-12-0.004, p = 0.002). Therefore, our study identified the suggestively causal effect of DM on the risk of PAH, and SGLT2 inhibition may be a potential therapeutic target in patients with PAH.

Effect of Semaglutide and Empagliflozin on Pulmonary Structure and Proteomics in Obese Mice

Objective

This study utilized proteomics to investigate changes in protein expression associated with lung health in obese mice exposed to semaglutide and empagliflozin through a high-fat diet.

Methods

Twenty-eight male C57BL/6JC mice were randomly assigned to two groups: a control diet group (n = 7) and a high-fat diet group (n = 21). The HFD group was further divided into three groups: HFD group (n = 7), Sema group (n = 7), and Empa group (n = 7). Post-treatment, mice underwent assessments including glucose tolerance, lipids, oxidative stress markers, body weight, lung weight, and structure. Proteomics identified differentially expressed proteins (DEPs) in lung tissue, and bioinformatics analyzed the biological processes and functions of these proteins.

Results

Semaglutide and empagliflozin significantly attenuated obesity-induced hyperglycemia, abnormal lipid metabolism, oxidative stress response, and can decrease alveolar wall thickness, enlarge alveolar lumen, and reduce collagen content in lung tissue. Both medications also attenuated lung elastic fibre cracking and disintegration. In the HFD/NCD group, there were 66 DEPs, comprising 30 proteins that were increased and 36 that were decreased. Twenty-three DEPs overlapped between Sema/HFD and Empa/HFD, with 11 up-regulated and 12 down-regulated simultaneously. After analysing DEPs in different groups, four proteins - LYVE1, BRAF, RGCC, and CHMP5 - were all downregulated in the HFD group and upregulated by semaglutide and empagliflozin treatment.

Conclusion

This study demonstrates that obesity induced by a high-fat diet causes a reduction in the expression of LYVE1, BRAF, RGCC, and CHMP5 proteins, potentially affecting lung function and structure in mice. Significantly, the administration of semaglutide and empagliflozin elevates the levels of these proteins, potentially offering therapeutic benefits against lung injury caused by obesity. Merging semaglutide with empagliflozin may exert a more pronounced impact.

Drug Safety Evaluation of Sodium-Glucose Cotransporter 2 Inhibitors in Diabetic Comorbid Patients by Review of Systemic Extraglycemic Effects

Purpose

The aim of this study is to evaluate the safety of this drug in diabetic patients with comorbidities of all systems.

Method

In this review, the beneficial effects of this drug and its mechanism on the disorders of every system of humans in relation to diabetes have been studied, and finally, its adverse effects have also been discussed. The search for relevant information is carried out in the PubMed and Google Scholar databases by using the following terms: diabetes mellitus type 2, SGLT, SGLT2 inhibitors, (SGLT2 inhibitors) AND (Pleiotropic effects). All English-published articles from 2016 to 2023 have been used in this study. It should be noted that a small number of articles published before 2016 have been used in the introduction and general informations.

Results

Its beneficial effects on improving cardiovascular disease risk factors and reducing adverse events caused by cardiovascular and renal diseases have proven in most large clinical studies that these effects are almost certain. It also has beneficial effects on other human systems such as the respiratory system, the gastrointestinal system, the circulatory system, and the nervous system; more of them are at the level of clinical and pre-clinical trials but have not been proven in large clinical trials or meta-analyses.

Conclusion

With the exception of a few adverse effects, this drug is considered a good choice and safe for all diabetic patients with comorbidities of all systems.

Chapter 2: Clinical and Mechanistic Potential of Sodium-Glucose Co-Transporter 2 (SGLT2) Inhibitors in Heart Failure with Preserved Ejection Fraction

Sodium-glucose co-transporter 2 inhibitors (SGLT2i) have emerged as an important approach for the treatment of heart failure in patients with or without diabetes. Although the precise mechanisms underpinning their clinical impact remain incompletely resolved, mechanistic studies and insights from major clinical trials have demonstrated the impact of SGLT2 inhibitors on numerous cardio-renal-metabolic pathways of relevance to heart failure with preserved ejection fraction (HFpEF), which, in the contemporary era, constitutes approximately half of all patients with heart failure. Despite rates of morbidity and mortality that are commensurate with those of heart failure with reduced ejection fraction, disease-modifying therapies have comparatively been severely lacking. As such, HFpEF remains among the greatest unmet needs in cardiovascular medicine. Within the past decade, HFpEF has been established as a highly integrated disorder, involving not only the cardiovascular system, but also the lungs, kidneys, skeletal muscle, and adipose tissue. Given their multisystem impact, SGLT2i offer unique promise in addressing the complex pathophysiology of HFpEF, and in recent randomized controlled trials, were shown to significantly reduce heart failure events and cardiovascular death in patients with HFpEF. Herein, we discuss several proposed mechanisms of clinical benefit of SGLT2i in HFpEF.

The SGLT2i Dapagliflozin Reduces RV Mass Independent of Changes in RV Pressure Induced by Pulmonary Artery Banding

BACKGROUND

Sodium glucose linked transporter 2 (SGLT2) inhibition not only reduces morbidity and mortality in patients with diagnosed heart failure but also prevents the development of heart failure hospitalization in those at risk. While studies to date have focused on the role of SGLT2 inhibition in left ventricular failure, whether this drug class is efficacious in the treatment and prevention of right heart failure has not been explored.

HYPOTHESIS

We hypothesized that SGLT2 inhibition would reduce the structural, functional, and molecular responses to pressure overload of the right ventricle.

METHODS

Thirteen-week-old Fischer F344 rats underwent pulmonary artery banding (PAB) or sham surgery prior to being randomized to receive either the SGLT2 inhibitor: dapagliflozin (0.5 mg/kg/day) or vehicle by oral gavage. After 6 weeks of treatment, animals underwent transthoracic echocardiography and invasive hemodynamic studies. Animals were then terminated, and their hearts harvested for structural and molecular analyses.

RESULTS

PAB induced features consistent with a compensatory response to increased right ventricular (RV) afterload with elevated mass, end systolic pressure, collagen content, and alteration in calcium handling protein expression (all p < 0.05 when compared to sham + vehicle). Dapagliflozin reduced RV mass, including both wet and dry weight as well as normalizing the protein expression of SERCA 2A, phospho-AMPK and LC3I/II ratio expression (all p < 0.05).

SIGNIFICANCE

Dapagliflozin reduces the structural, functional, and molecular manifestations of right ventricular pressure overload. Whether amelioration of these early changes in the RV may ultimately lead to a reduction in RV failure remains to be determined.

Left Ventricular Mass Index Predicts Renal Function Decline in Patients with Chronic Kidney Disease

Background and Objectives: Several studies revealed a relation between abnormal cardiac remodeling and glomerular filtration rate (GFR) decline, but there are limited data regarding echocardiographic changes in chronic kidney disease (CKD). This study evaluated the abnormal cardiac structures characterizing patients with CKD, assessing the independent association between echocardiographic parameters and the risk of decline in renal function. Materials and Methods: In total, 160 patients with CKD were studied. All patients underwent an echocardiographic exam and 99mTc-DTPA renal scintigraphy to measure the GFR. After the baseline assessments, patients were followed prospectively for 12 months, or until the endpoint achievement, defined as a worsening in renal function (doubling of baseline serum creatinine, GFR decline ≥25%, the start of dialysis). Results: Patients with GFR values of 34.8 ± 15 mL/min, identifying stages III-IV of CKD, were associated with high levels of left ventricular mass index (LVMi) (101.9 ± 12.2 g/m2), which was related to proteinuria, systolic blood pressure, and pulmonary artery systolic pressure in a multiple regression model. During the observational period, 26% of patients reached the endpoint. Regression analysis revealed LVMi as a predictor of change in renal function after adjusting for kidney and cardiac risk factors. Multiple Cox regression indicated that an increase in LVMi was associated with a 12% increased risk of kidney disease progression (HR: 1.12; 95% CI: 1.04-1.16; p = 0.001). Conclusions: In patients with CKD, high LVMi represents an independent predictor of the progressive decline of the renal function, until the start of renal replacement therapy. Echocardiography can help identify patients at high risk for renal disease worsening in patients with CKD independently of clinical cardiac involvement.

Canagliflozin ameliorates hypobaric hypoxia-induced pulmonary arterial hypertension by inhibiting pulmonary arterial smooth muscle cell proliferation

Pulmonary arterial hypertension (PAH) is a disease with a high mortality and few treatment options to prevent the development of pulmonary vessel remodeling, pulmonary vascular resistance, and right ventricular failure. Canagliflozin, a sodium-glucose cotransporter 2 (SGLT2) inhibitor, is originally used in diabetes patients which could assist the glucose excretion and decrease blood glucose. Recently, a few studies have reported the protective effect of SGLT2 inhibitor on monocrotaline-induced PAH. However, the effects of canagliflozin on hypobaric hypoxia-induced PAH as well as its mechanism still unclear. In this study, we used hypobaric hypoxia-induced PAH mice model to demonstrate if canagliflozin could alleviate PAH and prevent pulmonary vessel remodeling. We found that daily canagliflozin administration significantly improved survival in mice with hypobaric hypoxia-induced PAH compared to vehicle control. Canagliflozin treatment significantly reduced right ventricular systolic pressure and increased pulmonary acceleration time determined by hemodynamic assessments. Canagliflozin significantly reduced medial wall thickening and decreased muscularization of pulmonary arterioles compared to vehicle treated mice. In addition, canagliflozin inhibited the proliferation and migration of pulmonary arterial smooth muscle cells through suppressing glycolysis and reactivating AMP-activated protein kinase signaling pathway under hypoxia condition. In summary, our findings suggest that canagliflozin is sufficient to inhibit pulmonary arterial remodeling which is a potential therapeutic strategy for PAH treatment.

Effects of empagliflozin on right ventricular adaptation to pressure overload

Background

Right ventricular (RV) failure is the prime cause of death in patients with pulmonary arterial hypertension. Novel treatment strategies that protect the RV are needed. Empagliflozin, a sodium-glucose co-transporter-2 inhibitor, shows cardioprotective effects on the left ventricle in clinical and preclinical studies, but its direct effects on RV remain elusive. We investigated the effects of empagliflozin on RV dysfunction induced by pulmonary trunk banding (PTB).

Methods

Male Wistar rats (116 ± 10 g) were randomized to PTB or sham surgery. One week after surgery, PTB animals received empagliflozin mixed into the chow (300 mg empagliflozin/kg chow; PTB-empa, n = 10) or standard chow (PTB-control, n = 10). Sham rats (Sham, n = 6) received standard chow. After five weeks, RV function was evaluated by echocardiography, cardiac MRI, and invasive pressure-volume measurements.

Results

PTB caused RV failure evident by decreased cardiac output compared with sham. PTB-empa rats had a 49% increase in water intake compared with PTB-control yet no differences in hematocrit or blood glucose. Treatment with empagliflozin decreased RV end-systolic pressures without any changes in RV cardiac output or ventricular-arterial coupling (Ees/Ea). The decrease in RV end-systolic pressure was complemented by a slight reduction in RV cross sectional area as a sign of reduced hypertrophy. Load-independent measures of RV systolic and diastolic function were not affected in PTB-empa rats compared with PTB-control.

Conclusion

Empagliflozin treatment reduced RV end-systolic pressure in RV failure induced by pressure overload. Further studies are needed to elucidate whether this simply relates to a diuretic effect and/or additional independent beneficial RV effects.

The Relationship between Pulmonary Artery Pressure and Mortality in Type 2 Diabetes: A Fremantle Diabetes Study Phase II and National Echocardiographic Database of Australia Data Linkage Study

An elevated estimated right ventricular systolic pressure (eRVSP) identified on echocardiography is present in one-third of individuals with type 2 diabetes, but its prognostic significance is unknown. To assess the relationship between eRVSP and mortality, prospective data from 1732 participants in the Fremantle Diabetes Study Phase II were linked with the National Echocardiographic Database of Australia. Of this cohort, 416 (mean age 70.6 years, 47.4% males) had an eRVSP measured and 381 (91.4%) had previously confirmed type 2 diabetes. Receiver- operating characteristic analysis of the relationship between eRVSP and all-cause mortality was conducted. Survival analyses were performed for participants with type 2 diabetes diagnosed before first measured eRVSP (n = 349). Cox regression identified clinical and echocardiographic associates of all-cause mortality. There were 141 deaths (40.4%) during 2348 person-years (mean ± SD 6.7 ± 4.0 years) of follow-up. In unadjusted Kaplan-Meier analysis, mortality rose with higher eRVSP (log-rank test, p < 0.001). In unadjusted pairwise comparisons, eRVSP >30 to 35, >35 to 40, and >40 mmHg had significantly increased mortality compared with eRVSP ≤ 30 mmHg (p = 0.025, p = 0.001, p < 0.001, respectively). There were 50 deaths in 173 individuals (29.1%) with eRVSP ≤ 30 mmHg, and 91 in 177 (51.4%) with eRVSP > 30 mmHg (log-rank test, p < 0.001). In adjusted models including age, Aboriginal descent, Charlson Comorbidity Index ≥ 3 and left heart disease, eRVSP > 30 mmHg predicted a two-fold higher all-cause mortality versus ≤ 30 mmHg. An eRVSP > 30 mmHg predicts increased all-cause mortality in type 2 diabetes. Where available, eRVSP could inform type 2 diabetes outcome models.

Sodium-Glucose Cotransporter-2 Inhibitor, Empagliflozin, Suppresses the Inflammatory Immune Response to Influenza Infection

Influenza is a highly contagious, acute respiratory disease that causes significant public health and economic threats. Influenza infection induces various inflammatory mediators, IFNs, and recruitment of inflammatory cells in the host. This inflammatory "cytokine storm" is thought to play a role in influenza-induced lung pathogenesis. Empagliflozin is a drug primarily used to lower blood glucose in type II diabetes patients by inhibiting the sodium-glucose cotransporter-2 (SGLT-2) found in the proximal tubules in the kidneys. In this study, we have investigated the effects of empagliflozin on the pulmonary immune response to influenza infection. C57BL/6 mice (wild type) were infected with influenza A/PR/8/34 and treated with empagliflozin, and the disease outcomes were analyzed. Empagliflozin treatment decreased the expression of the inflammatory cytokines IL-1β, IL-6, and CCL2; the percentage of inflammatory monocytes and inducible NO synthase-positive macrophages; and IFN response genes Stat1 and CXCL9 during influenza infection. Further, empagliflozin treatment decreases the expression of IL-6, CCL2, and CCL5 in RAW264.7 macrophages and bone marrow-derived macrophages. However, empagliflozin treatment increased influenza viral titer during infection. Despite fostering an increased viral burden, treatment with empagliflozin decreases the mortality in wild type and high fat diet-induced atherosclerotic LDLR-/- mice. Based on our findings, empagliflozin may have therapeutic implications for use in patients to prevent lung damage and acute respiratory illness.

Acquired cardiovascular disease in adults with congenital heart disease

Rates of successful surgical repair and life expectancy for patients with congenital heart disease have increased dramatically in recent decades. Thanks to advances in diagnosis, treatment, and follow-up care, an ever-increasing number of individuals with congenital heart disease are reaching advanced age. The exposure to cardiovascular risk factors during their lifetime is modifying the outlook and late clinical trajectory of adult congenital heart disease (ACHD). Their disease burden is shifting from congenital to acquired, primarily atherosclerotic cardiovascular disease (ASCVD) with worrisome consequences. In addition, the complex background of ACHD often curbs appropriate preventive strategies by general practitioners or adult cardiologists. Comprehensive guidance for the prevention and management of acquired heart disease in ACHD patients is currently not available, as this topic has not been covered by the European Society of Cardiology (ESC) guidelines on cardiovascular disease prevention or the ESC guidelines for the management of ACHD. In this document, a state-of-the-art overview of acquired heart disease in ACHD patients and guidance on ASCVD prevention for both ACHD specialists and non-ACHD cardiologists are provided. The aim is to provide a clinical consensus statement to foster the development of a sustainable strategy for the prevention of ASCVD in a practical and simple-to-follow way in this ever-growing cardiovascular cohort, thus reducing their cardiovascular burden.

Comparative Metabolomics in Single Ventricle Patients after Fontan Palliation: A Strong Case for a Targeted Metabolic Therapy

Most studies on single ventricle (SV) circulation take a physiological or anatomical approach. Although there is a tight coupling between cardiac contractility and metabolism, the metabolic perspective on this patient population is very recent. Early findings point to major metabolic disturbances, with both impaired glucose and fatty acid oxidation in the cardiomyocytes. Additionally, Fontan patients have systemic metabolic derangements such as abnormal glucose metabolism and hypocholesterolemia. Our literature review compares the metabolism of patients with a SV circulation after Fontan palliation with that of patients with a healthy biventricular (BV) heart, or different subtypes of a failing BV heart, by Pubmed review of the literature on cardiac metabolism, Fontan failure, heart failure (HF), ketosis, metabolism published in English from 1939 to 2023. Early evidence demonstrates that SV circulation is not only a hemodynamic burden requiring staged palliation, but also a metabolic issue with alterations similar to what is known for HF in a BV circulation. Alterations of fatty acid and glucose oxidation were found, resulting in metabolic instability and impaired energy production. As reported for patients with BV HF, stimulating ketone oxidation may be an effective treatment strategy for HF in these patients. Few but promising clinical trials have been conducted thus far to evaluate therapeutic ketosis with HF using a variety of instruments, including ketogenic diet, ketone esters, and sodium-glucose co-transporter-2 (SGLT2) inhibitors. An initial trial on a small cohort demonstrated favorable outcomes for Fontan patients treated with SGLT2 inhibitors. Therapeutic ketosis is worth considering in the treatment of Fontan patients, as ketones positively affect not only the myocardial energy metabolism, but also the global Fontan physiopathology. Induced ketosis seems promising as a concerted therapeutic strategy.

Emerging pharmacotherapies for the treatment of pulmonary arterial hypertension

INTRODUCTION

Pulmonary arterial hypertension (PAH) is a progressive and life-threatening disease. Approved treatment options currently primarily target abnormal cell signaling pathways involved in vasoconstriction and proliferation, such as those mediated by prostacyclin, cyclic guanosine monophosphate, and endothelin.

AREAS COVERED

Recent advancements have led to new applications and modes of delivery of currently approved PAH medications. At the same time, novel drugs targeting specific molecular pathways involved in PAH pathogenesis have been developed and are being investigated in clinical trials. This review summarizes investigational drug trials for PAH gathered from a comprehensive search using PubMed and ClinicalTrials.gov between 2003 and 2023. It includes both currently approved medications studied at different doses or new administration forms and experimental drugs that have not yet been approved.

EXPERT OPINION

Approved treatments for PAH target imbalances in pulmonary vasoactive pathways that work primarily on enhancing pulmonary vasodilation with less salient effects on pulmonary vascular remodeling. The advent of more locally acting inhaled medications offers additional therapeutic options that may improve the ease of drug delivery and reduce adverse systemic effects. The more recent emphasis on developing and applying therapeutics that directly impact the aberrant signaling pathways implicated in PAH appears more likely to advance the treatment of this devastating disease.

Empagliflozin Ameliorates Bleomycin-Induced Pulmonary Fibrosis in Rats by Modulating Sesn2/AMPK/Nrf2 Signaling and Targeting Ferroptosis and Autophagy

Pulmonary fibrosis (PF) is a life-threatening disorder that severely disrupts normal lung architecture and function, resulting in severe respiratory failure and death. It has no definite treatment. Empagliflozin (EMPA), a sodium-glucose cotransporter 2 (SGLT2) inhibitor, has protective potential in PF. However, the mechanisms underlying these effects require further elucidation. Therefore, this study aimed to evaluate the ameliorative effect of EMPA against bleomycin (BLM)-induced PF and the potential mechanisms. Twenty-four male Wister rats were randomly divided into four groups: control, BLM treated, EMPA treated, and EMPA+BLM treated. EMPA significantly improved the histopathological injuries illustrated by both hematoxylin and eosin and Masson's trichrome-stained lung tissue sections, as confirmed by electron microscopic examination. It significantly reduced the lung index, hydroxyproline content, and transforming growth factor β1 levels in the BLM rat model. It had an anti-inflammatory effect, as evidenced by a decrease in the inflammatory cytokines' tumor necrosis factor alpha and high mobility group box 1, inflammatory cell infiltration into the bronchoalveolar lavage fluid, and the CD68 immunoreaction. Furthermore, EMPA mitigated oxidative stress, DNA fragmentation, ferroptosis, and endoplasmic reticulum stress, as evidenced by the up-regulation of nuclear factor erythroid 2-related factor expression, heme oxygenase-1 activity, glutathione peroxidase 4 levels, and a decrease in C/EBP homologous protein levels. This protective potential could be explained on the basis of autophagy induction via up-regulating lung sestrin2 expression and the LC3 II immunoreaction observed in this study. Our findings indicated that EMPA protected against BLM-induced PF-associated cellular stress by enhancing autophagy and modulating sestrin2/adenosine monophosphate-activated protein kinase/nuclear factor erythroid 2-related factor 2/heme oxygenase 1 signaling.

Empagliflozin inhibits autophagy and mitigates airway inflammation and remodelling in mice with ovalbumin-induced allergic asthma

Empagliflozin, a selective inhibitor of Na⁺-glucose cotransporter-2, has been reported to exert anti-inflammatory and anti-fibrotic effects in addition to autophagy modulation. Addressing the role of autophagy in allergic asthma revealed controversial results. The potential effect of empagliflozin treatment on airway inflammation and remodelling as well as autophagy modulation in a murine model of allergic asthma was investigated. Over a 7-week period, male BALB/c mice were sensitized and challenged by intraperitoneal injection and inhalation of ovalbumin, respectively. Animals were treated with empagliflozin (10 mg/kg; orally) and/or rapamycin (an autophagy inducer; 4 mg/kg; intraperitoneally) before every challenge. Methacholine-induced airway hyperresponsiveness was evaluated one day after the last challenge. After euthanasia, serum, bronchoalveolar lavage fluid, and lung tissues were collected for biochemical, histopathological, and immunohistochemical assessment. Results revealed that empagliflozin decreased airway hyperresponsiveness, serum ovalbumin-specific immunoglobulin E, and bronchoalveolar lavage total and differential leukocytic counts. Levels of inflammatory and profibrotic cytokines (IL-4, IL-5, IL-13, IL-17, and transforming growth factor-β1) were all inhibited. Moreover, empagliflozin preserved pulmonary microscopic architecture and alleviated bronchiolar epithelial thickening, goblet cell hyperplasia, fibrosis and smooth muscle hypertrophy. These effects were associated with inhibition of ovalbumin-activated autophagic flux, as demonstrated by decreased LC3B expression and LC3BII/I ratio, as well as increased P62 expression. However, the therapeutic potential of empagliflozin was inhibited when rapamycin was co-administered. In conclusion, this study demonstrates that empagliflozin has immunomodulatory, anti-inflammatory, and anti-remodelling properties in ovalbumin-induced allergic asthma and suggests that autophagic flux inhibition may play a role in empagliflozin's anti-asthmatic effects.

Tofogliflozin, a sodium-glucose cotransporter 2 inhibitor, improves pulmonary vascular remodeling due to left heart disease in mice

BACKGROUND

Group 2 pulmonary hypertension (PH) represents PH caused by left heart disease (PH-LHD). LHD induces left-sided filling and PH, finally leading to pulmonary vascular remodeling. Tofogliflozin (TOFO) is a sodium-glucose cotransporter 2 (SGLT2) inhibitor used in the treatment of diabetes. Recent studies have shown that SGLT2 inhibitors have beneficial effects on heart failure, but the effects of SGLT2 inhibitors on PH-LHD remain unclear. We hypothesized that TOFO has protective effects against pulmonary vascular remodeling in PH-LHD mice.

METHODS

We generated two murine models of PH-LHD: a transverse aortic constriction (TAC) model; and a high-fat diet (HFD) model. C57BL/6J mice were subjected to TAC and treated with TOFO (3 mg/kg/day) for 3 weeks. AKR/J mice were fed HFD and treated with TOFO (3 mg/kg/day) for 20 weeks. We then measured physical data and right ventricular systolic pressure (RVSP) and performed cardiography. Human pulmonary artery smooth muscle cells (PASMCs) were cultured and treated with TOFO.

RESULTS

Mice treated with TOFO demonstrated increased urine glucose levels. TAC induced left ventricular hypertrophy and increased RVSP. TOFO treatment improved RVSP. HFD increased body weight (BW) and RVSP compared with the normal chow group. TOFO treatment ameliorated increases in BW and RVSP induced by HFD. Moreover, PASMCs treated with TOFO showed suppressed migration.

CONCLUSIONS

TOFO treatment ameliorated right heart overload and pulmonary vascular remodeling for PH-LHD models, suggesting that SGLT2 inhibitors are effective for treating PH-LHD.

Molecular mechanisms and targets of right ventricular fibrosis in pulmonary hypertension

Right ventricular fibrosis is a stress response, predominantly mediated by cardiac fibroblasts. This cell population is sensitive to increased levels of pro-inflammatory cytokines, pro-fibrotic growth factors and mechanical stimulation. Activation of fibroblasts results in the induction of various molecular signaling pathways, most notably the mitogen-activated protein kinase cassettes, leading to increased synthesis and remodeling of the extracellular matrix. While fibrosis confers structural protection in response to damage induced by ischemia or (pressure and volume) overload, it simultaneously contributes to increased myocardial stiffness and right ventricular dysfunction. Here, we review state-of-the-art knowledge of the development of right ventricular fibrosis in response to pressure overload and provide an overview of all published preclinical and clinical studies in which right ventricular fibrosis was targeted to improve cardiac function.

The right ventricle in tetralogy of Fallot: adaptation to sequential loading

Right ventricular dysfunction is a major determinant of outcome in patients with complex congenital heart disease, as in tetralogy of Fallot. In these patients, right ventricular dysfunction emerges after initial pressure overload and hypoxemia, which is followed by chronic volume overload due to pulmonary regurgitation after corrective surgery. Myocardial adaptation and the transition to right ventricular failure remain poorly understood. Combining insights from clinical and experimental physiology and myocardial (tissue) data has identified a disease phenotype with important distinctions from other types of heart failure. This phenotype of the right ventricle in tetralogy of Fallot can be described as a syndrome of dysfunctional characteristics affecting both contraction and filling. These characteristics are the end result of several adaptation pathways of the cardiomyocytes, myocardial vasculature and extracellular matrix. As long as the long-term outcome of surgical correction of tetralogy of Fallot remains suboptimal, other treatment strategies need to be explored. Novel insights in failure of adaptation and the role of cardiomyocyte proliferation might provide targets for treatment of the (dysfunctional) right ventricle under stress.

Effect of Dapagliflozin on Cardiac Function and Metabolic and Hormonal Responses to Exercise

OBJECTIVE

This work aimed to investigate the effect of the SGLT2 inhibitor, dapagliflozin (DAPA), on cardiac function and the metabolic and hormonal response to moderate exercise in people with type 2 diabetes.

METHODS

This was a double-blind, placebo-controlled crossover study with a 4-week washout period. Nine participants were randomly assigned to receive either 4 weeks of DAPA or 4 weeks of placebo. After each treatment, they underwent an exercise protocol with 2 consecutive 10-minute stages at a constant load corresponding to 40% and 70% maximal oxygen consumption (VO2max), coupled with hormonal and metabolic analysis. A blinded transthoracic echocardiogram was performed 3 days later.

RESULTS

During the exercise protocol, glucose and lactate were lower (P < .0001 and P < .05, respectively) and β-hydroxybutyrate (BOBH) and growth hormone (GH) were higher (P < .0005 and P = .01) following DAPA treatment compared to placebo. There was a trend for lower insulin with DAPA. Adrenalin, noradrenalin, and glucagon were not different. Following DAPA participants demonstrated an increased mean peak diastolic mitral annular velocity (e') in comparison to placebo (P = .03). The indexed left atrial volume and right ventricular e" were reduced following DAPA compared with placebo (P = .045 and P = .042, respectively). Arterial stiffness was not different between treatments (DAPA 9.35 ± 0.60 m/s; placebo 9.07 ± 0.72 m/s).

CONCLUSION

During exercise, GH may be more important than catecholamines in driving the shift from glucose to fatty acid metabolism by SGLT2 inhibitors. The 4-week crossover design showed changes in cardiac function were rapid in onset and reversible.

Identification of diagnostic biomarkers for idiopathic pulmonary hypertension with metabolic syndrome by bioinformatics and machine learning

Idiopathic pulmonary hypertension (IPAH) is a condition that affects various tissues and organs and the metabolic and inflammatory systems. The most prevalent metabolic condition is metabolic syndrome (MS), which involves insulin resistance, dyslipidemia, and obesity. There may be a connection between IPAH and MS, based on a plethora of studies, although the underlying pathogenesis remains unclear. Through various bioinformatics analyses and machine learning algorithms, we identified 11 immune- and metabolism-related potential diagnostic genes (EVI5L, RNASE2, PARP10, TMEM131, TNFRSF1B, BSDC1, ACOT2, SAC3D1, SLA2, P4HB, and PHF1) for the diagnosis of IPAH and MS, and we herein supply a nomogram for the diagnosis of IPAH in MS patients. Additionally, we discovered IPAH's aberrant immune cells and discuss them here.

Heart failure in systemic right ventricle: Mechanisms and therapeutic options

d-loop transposition of the great arteries (d-TGA) and congenitally corrected transposition of the great arteries (cc-TGA) feature a right ventricle attempting to sustain the systemic circulation. A systemic right ventricle (sRV) cannot support cardiac output in the long run, eventually decompensating and causing heart failure. The burden of d-TGA patients with previous atrial switch repair and cc-TGA patients with heart failure will only increase in the coming years due to the aging adult congenital heart disease population and improvements in the management of advanced heart failure. Clinical data still lags behind in developing evidence-based guidelines for risk stratification and management of sRV patients, and clinical trials for heart failure in these patients are underrepresented. Recent studies have provided foundational data for the commencement of robust clinical trials in d-TGA and cc-TGA patients. Further insights into the multifactorial nature of sRV failure can only be provided by the results of such studies. This review discusses the mechanisms of heart failure in sRV patients with biventricular circulation and how these mediators may be targeted clinically to alleviate sRV failure.

The Emerging Role of Sodium-glucose Cotransporter 2 Inhibitors in Heart Failure

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are a relatively novel drug class that most cardiologists are becoming familiar with. By contrasting glucose reabsorption in the proximal convoluted tubule of the nephron, SGLT2 inhibition results in glycosuria with improved glycemic control. Although originally introduced as anti-diabetic medications, the cardiovascular effects of SGLT2i have progressively emerged, leading them to become one of the four pillars for the treatment of heart failure with reduced ejection fraction (HFrEF) according to the 2021 guidelines from the European Society of Cardiology. Also, two recent randomized trials have demonstrated SGLT2i as the first compounds with proven prognostic impact in heart failure with preserved ejection fraction (HFpEF), setting a milestone in the treatment for this condition. While the exact pathogenic mechanisms mediating the substantial reduction in cardiovascular death and heart failure (HF) hospitalizations are still controversial, there is growing clinical evidence on the efficacy and safety of SGLT2i in various subsets of patients with HF. As known, heart failure is a complex and heterogeneous clinical syndrome with a magnitude of phenotypes and a variety of underlying hemodynamic and physiological aspects which cannot be fully incorporated into the traditional left ventricular ejection fraction based classification adopted in clinical trials. The aim of this review is to provide an overview of the cardiovascular benefits and indications of SGLT2i across different HF patterns and to highlight current gaps in knowledge that should be addressed by future research.

Impact of SGLT2 Inhibitor Therapy on Right Ventricular Function in Patients with Heart Failure and Reduced Ejection Fraction

Background: The impact of sodium-glucose cotransporter-2 inhibitors (SGLT2is) in addition to optimal medical therapy (OMT) on the right ventricular (RV) systolic function using advanced echocardiographic analysis among outpatients with heart failure and a reduced ejection fraction (HFrEF) has thus far been poorly investigated. Methods: This was a single-center, prospective, single-blinded study in which an echocardiographic expert was blinded to the allocation of the treatment. A total of 36 outpatients with HFrEF were randomized to either OMT or OMT+SGLT2i. Both groups underwent an echocardiographic examination of the RV systolic function at the baseline and at the 3-month follow-up (3mFU). Results: The patients in both groups did not significantly differ with respect to the relevant baseline comorbidities, therapy, and clinical characteristics. The patients receiving OMT+SGLT2i showed a significant improvement from the baseline to the 3mFU in all the measured RV echocardiographic parameters, while for the OMT group, a significant improvement after the 3mFU was observed for TAPSE and s'. The mean percent change from the baseline to the 3mFU was significant when comparing OMT+SGLT2i to the OMT group concerning RV FWS (+91% vs. +28%, p = 0.039), TR maxPG (-27% vs. +19%, p = 0.005), and TR Vmax (-17% vs. +13%, p = 0.008), respectively. Conclusions: Adding SGLT2i to OMT in patients with HFrEF resulted in a greater improvement in the RV systolic function from the baseline to the 3mFU compared to the OMT alone.

Association of Glucose-Lowering Drugs With Outcomes in Patients With Diabetes Before Hospitalization for COVID-19: A Systematic Review and Network Meta-analysis

IMPORTANCE

Patients with COVID-19 have a high prevalence of diabetes, and diabetes and blood glucose control are determinants of intensive care unit admission and mortality.

OBJECTIVE

To evaluate the association between COVID-19-related adverse outcomes and 8 antihyperglycemic drugs in patients with diabetes who were subsequently diagnosed and hospitalized with COVID-19.

DATA SOURCES

Data were retrieved and collected in PubMed, Embase, Cochrane Central Register, Web of Science, and ClinicalTrials.gov from database inception to September 5, 2022.

STUDY SELECTION

For this systematic review and network meta-analysis, randomized clinical trials and observational studies conducted among patients with diabetes while receiving glucose-lowering therapies for at least 14 days before the confirmation of COVID-19 infection were included after blinded review by 2 independent reviewers and consultations of disagreement by a third independent reviewer. Of 1802 studies initially identified, 31 observational studies met the criteria for further analysis.

DATA EXTRACTION AND SYNTHESIS

This study follows the Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guideline. Bayesian network meta-analyses were performed with random effects.

MAIN OUTCOMES AND MEASURES

A composite adverse outcome, including the need for intensive care unit admission, invasive and noninvasive mechanical ventilation, or in-hospital death.

RESULTS

Thirty-one distinct observational studies (3 689 010 patients with diabetes hospitalized for COVID-19) were included. The sodium-glucose cotransporter-2 inhibitors (SGLT-2is) were associated with relatively lower risks of adverse outcomes compared with insulin (log of odds ratio [logOR], 0.91; 95% credible interval [CrI], 0.57-1.26), dipeptidyl peptidase-4 inhibitors (logOR, 0.61; 95% CrI, 0.28-0.93), secretagogues (logOR, 0.37; 95% CrI, 0.02-0.72), and glucosidase inhibitors (logOR, 0.50; 95% CrI, 0.00-1.01). Based on the surface under the cumulative ranking curves value, SGLT-2is were associated with the lowest probability for adverse outcomes (6%), followed by glucagon-like peptide-1 receptor agonists (25%) and metformin (28%). A sensitivity analysis revealed that the study was reliable.

CONCLUSIONS AND RELEVANCE

These findings suggest that the use of an SGLT-2i before COVID-19 infection is associated with lower COVID-19-related adverse outcomes. In addition to SGLT-2is, glucagon-like peptide-1 receptor agonists and metformin were also associated with relatively low risk of adverse outcomes.

Dapagliflozin reduces the vulnerability of rats with pulmonary arterial hypertension-induced right heart failure to ventricular arrhythmia by restoring calcium handling

Background

Malignant ventricular arrhythmia (VA) is a major contributor to sudden cardiac death (SCD) in patients with pulmonary arterial hypertension (PAH)-induced right heart failure (RHF). Recently, dapagliflozin (DAPA), a sodium/glucose cotransporter-2 inhibitor (SGLT2i), has been found to exhibit cardioprotective effects in patients with left ventricular systolic dysfunction. In this study, we examined the effects of DAPA on VA vulnerability in a rat model of PAH-induced RHF.

Methods

Rats randomly received monocrotaline (MCT, 60 mg/kg) or vehicle via a single intraperitoneal injection. A day later, MCT-injected rats were randomly treated with placebo, low-dose DAPA (1 mg/kg/day), or high-dose (3 mg/kg/day) DAPA orally for 35 days. Echocardiographic analysis, haemodynamic experiments, and histological assessments were subsequently performed to confirm the presence of PAH-induced RHF. Right ventricle (RV) expression of calcium (Ca²⁺) handling proteins were detected via Western blotting. RV expression of connexin 43 (Cx43) was determined via immunohistochemical staining. An optical mapping study was performed to assess the electrophysiological characteristics in isolated hearts. Cellular Ca²⁺ imaging from RV cardiomyocytes (RVCMs) was recorded using Fura-2 AM or Fluo-4 AM.

Results

High-dose DAPA treatment attenuated RV structural remodelling, improved RV function, alleviated Cx43 remodelling, increased the conduction velocity, restored the expression of key Ca²⁺ handling proteins, increased the threshold for Ca²⁺ and action potential duration (APD) alternans, decreased susceptibility to spatially discordant APD alternans and spontaneous Ca²⁺ events, promoted cellular Ca²⁺ handling, and reduced VA vulnerability in PAH-induced RHF rats. Low-dose DAPA treatment also showed antiarrhythmic effects in hearts with PAH-induced RHF, although with a lower level of efficacy.

Conclusion

DAPA administration reduced VA vulnerability in rats with PAH-induced RHF by improving RVCM Ca²⁺ handling.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01614-5.

Anti-Arrhythmic Effects of Sodium-Glucose Co-Transporter 2 Inhibitors

Arrhythmias are clinically prevalent with a high mortality rate. They impose a huge economic burden, thereby substantially affecting the quality of life. Sodium-glucose co-transporter 2 inhibitor (SGLT2i) is a new type of hypoglycemic drug, which can regulate blood glucose level safely and effectively. Additionally, it reduces the occurrence and progression of heart failure and cardiovascular events significantly. Recently, studies have found that SGLT2i can alleviate the occurrence and progression of cardiac arrhythmias; however, the exact mechanism remains unclear. In this review, we aimed to discuss and summarize new literature on different modes in which SGLT2i ameliorates the occurrence and development of cardiac arrhythmias.

Effects of SGLT2 inhibitors on cardiac structure and function

SGLT2 inhibitors reduce cardiovascular death or hospitalization for heart failure, regardless of the presence or absence of diabetes in patients at high cardiovascular risk and in those with heart failure and reduced ejection fraction (HFrEF). In patients with HF and preserved EF, empagliflozin also showed favorable effects mainly related to the reduction of hospitalization for heart failure. These favorable effects are beyond the reduction of glycemic levels and mainly related to beneficial hemodynamic and anti-inflammatory effects of these drugs and improved cardiac energy metabolism. In this review, we aimed to evaluate the effects of SGLT2 inhibitor on cardiac remodeling and function, which is still incompletely clear.

Notopterol Attenuates Monocrotaline-Induced Pulmonary Arterial Hypertension in Rat

Introduction

Current targeted pulmonary arterial hypertension (PAH) therapies have improved lung hemodynamics, cardiac function, and quality of life; however, none of these have reversed the ongoing remodeling of blood vessels. Considering notopterol, a linear furocoumarin extracted from the root of traditional Chinese medicine Qiang-Huo (Notopterygium incisum), had shown the antiproliferative and anti-inflammatory properties in previous studies, we hypothesized that it could play a role in ameliorating PAH.

Methods

In vivo, we conducted monocrotaline (MCT) induced PAH rats and treated them with notopterol for 3 weeks. Then, the rats were examined by echocardiography and RV catheterization. The heart and lung specimens were harvested for the detection of gross examination, histological examination and expression of inflammatory molecules. In vitro, human pulmonary arterial smooth muscle cells (HPASMCs) were treated with notopterol after hypoxia; then, cell proliferation was assessed by cell counting kit-8 and Edu assay, and cell migration was detected by wound healing assays.

Results

We found that notopterol improved mortality rate and RV function while reducing right ventricular systolic pressure in MCT-induced PAH rats. Furthermore, notopterol reduced right ventricular hypertrophy and fibrosis, and it also eased pulmonary vascular remodeling and MCT-induced muscularization. In addition, notopterol attenuated the pro-inflammatory factor (IL-1β, IL-6) and PCNA in the lungs of PAH rats. For the cultured HPASMCs subjected to hypoxia, we found that notopterol can inhibit the proliferation and migration of HPASMCs.

Conclusion

Our studies show that notopterol exerts anti-inflammatory and anti-proliferative effects in the pulmonary arteries, which may contribute to prevention of PAH.

The first experience with sodium-glucose cotransporter 2 inhibitor for the treatment of systemic right ventricular failure

In congenitally corrected transposition of the great arteries, the morphological right ventricle supports the systemic circulation. This chronic exposure to pressure overload ultimately leads to systemic right ventricular (sRV) dysfunction and heart failure. Pharmacological options for the treatment of sRV failure are poorly defined and no solid recommendations are made in the most recent guidelines. Sodium-glucose cotransporter 2 (SGLT-2) inhibitors are a new class of antihyperglycaemic drugs that have been demonstrated to significantly reduce the risk of worsening heart failure and death from cardiovascular causes in patients with chronic heart failure with reduced left ventricular ejection fraction, yet no data are available in sRV patients. We report on the treatment and clinical follow-up of a patient with advanced heart failure and poor sRV function in the context of congenitally corrected transposition of the great arteries, who did not tolerate sacubitril/valsartan and had a high burden of heart-failure-related hospitalizations. Treatment with dapagliflozin was well tolerated and resulted in (small) subjective and objective functional and echocardiographic improvement and a reduction in heart-failure-related hospitalizations.

Prognostic Implications of Right Ventricular Free Wall Strain in Recipients of Cardiac Resynchronization Therapy

Right ventricular (RV) function is an important prognostic marker in cardiac resynchronization therapy (CRT) recipients. Measuring RV systolic function with echocardiography, however, remains challenging due to the complexity of right heart morphology. Evaluation of RV function with RV free wall strain (FWS) may improve risk stratification in recipients of CRT compared with conventional RV function parameters. In 871 recipients of CRT (mean age 65 ± 11 years, 75% were men), RV function was assessed by RV fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE), and RV FWS measured by speckle tracking echocardiography. RV dysfunction was defined as RV FWS <23%, RV FAC <35%, and TAPSE <17 mm according to present guidelines. Patients were followed up for the primary end point of all-cause mortality. RV FWS identified a higher percentage of patients with RV systolic dysfunction (80.6%) in comparison with RV FAC (44.1%) and TAPSE (60.6%). During a median follow-up of 97 (53 to 145) months, 521 patients (59.8%) died. Recipients of CRT with RV FWS <23% had higher event rates than those with RV FWS ≥23% (p <0.001). On multivariable analysis, RV FWS <23% was independently associated with all-cause mortality (hazard ratio 1.618; 95% confidence interval 1.252 to 2.092; p <0.001) and demonstrated incremental prognostic value over baseline clinical parameters as well as conventional RV function parameters. In conclusion, RV FWS is more sensitive than conventional echocardiographic markers of RV function in detecting impaired RV function. RV FWS is independently associated with all-cause mortality and demonstrates incremental prognostic value over conventional RV function parameters in recipients of CRT.

VPO1/HOCl/ERK pathway mediates the right ventricular remodeling in rats with hypoxic pulmonary hypertension

Right ventricular (RV) remodeling is a major feature of pulmonary arterial hypertension (PAH). Vascular peroxidase 1 (VPO1) is reported to participate in the process of PAH. This study aims to explore whether VPO1 contributes to hypoxia-induced cardiac hypertrophy and the underlying mechanisms. SD rats were exposure to continuous hypoxia (10% O₂) for 3 weeks, which showed RV hypertrophy (increases in the ratio of RV weight to tibia length, cardiac cell size and hypertrophic markers), concomitant with upregulation of VPO1, elevation in hypochlorous acid (HOCl) production and ERK phosphorylation. In hypoxia (3% O₂)-induced hypertrophic H9c2 cells, similar characteristics of cardiac hypertrophy to that of hypoxia-treated rats were observed. Administration of VPO1 siRNA or NaHS (the HOCl inhibitor) suppressed HOCl production, ERK phosphorylation, and cardiac hypertrophy. Replacement of hypoxia with NaClO (exogenous HOCl) could also induce cardiac cell hypertrophy and activate ERK signaling pathway. In addition, hypoxia-induced cardiac hypertrophy could be blocked by PD98059 (the ERK-specific inhibitor). Based on these observations, we conclude that VPO1 promotes RV remodeling in PAH rats through catalyzing HOCl production, leading to the activation of ERK signaling. Thus, VPO1 may have the potential as a therapeutic target for PAH.

Dapagliflozin, sildenafil and their combination in monocrotaline-induced pulmonary arterial hypertension

Background

Dapagliflozin, a selective inhibitor of sodium-glucose cotransporter 2 (SGLT2), can reduce cardiovascular events and mortality in patients with heart failure. A number of mechanisms have been proposed to explain the beneficial effects of SGLT2 inhibitors. The purpose of this study was to determine whether dapagliflozin can improve pulmonary vascular remodelling and the efficacy of dapagliflozin as an add-on therapy to sildenafil in rats with pulmonary arterial hypertension (PAH).

Methods

A monocrotaline (MCT)-induced PAH rat model was used in our study. MCT-injected rats were randomly divided into four groups and treated for 3 weeks with daily per os treatment with vehicle, dapagliflozin (1 mg/kg/day), sildenafil (25 mg/kg/day), or a combination of dapagliflozin (1 mg/kg/day) and sildenafil (25 mg/kg/day). Haemodynamic measurements, histological analysis, enzyme-linked immunosorbent assay and western blotting analysis were employed to detect the changes in PAH rats after treatments.

Results

Dapagliflozin significantly attenuated MCT-induced increases in right ventricular systolic pressure (RVSP) and right ventricular hypertrophy (RVH) in PAH rats. Dapagliflozin effectively decreased the thickening of pulmonary artery media and decreased the muscularization of pulmonary arterioles in PAH rats. Moreover, dapagliflozin attenuated nucleotide-binding domain-like receptor protein 3 (NLRP3) inflammasome activation in lung tissues and the levels of interleukin-1β (IL-1β) and interleukin-18 (IL-18) in plasma. However, dapagliflozin as an add-on therapy to sildenafil in rats with PAH did not show a more pronounced beneficial effect on right ventricular systolic pressure and pulmonary vascular remodelling in MCT rats than sildenafil alone.

Conclusions

Dapagliflozin reduces right ventricular systolic pressure and pulmonary vascular remodelling in a rat model of PAH. However, combination therapy with dapagliflozin and sildenafil was not more effective than monotherapy with sildenafil in PAH rats.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-01939-7.

Effects of SGLT2 inhibitors on cardiovascular outcomes in patients with stage 3/4 CKD: A meta-analysis

INTRODUCTION

After stage 3 CKD, the risk of adverse cardiovascular events increased significantly. Therefore, we performed a meta-analysis to investigate the cardiovascular protective effect of SGLT2 inhibitors in patients with stage 3/4 CKD with different baseline kidney function or underlying diseases.

METHOD

To identify eligible trials, we systematically searched the Embase, PubMed, Web of Science, and Cochrane library databases from inception to April 15, 2021. The primary cardiovascular outcome was defined as a combination of cardiovascular mortality and hospitalization due to heart failure. Baseline kidney functions (stage 3a CKD: eGFR45-59mL/min per 1.73m2, stage 3b CKD: eGFR30-44mL/min per 1.73m2, stage 4 CKD: eGFR<30mL/min per 1.73m2) and underlying diseases (Type 2 diabetes, heart failure (Preserved ejection fraction or reduced ejection fraction), atherosclerotic cardiovascular disease) were used to stratify efficacy and safety outcomes. The results were subjected to a sensitivity analysis to ensure that they were reliable.

RESULTS

In the present study, a total of eleven trials were included that involved a total of 27,823 patients with stage 3/4 CKD. The treatment and control groups contained 14,451 and 13,372 patients, respectively. In individuals with stage 3/4 CKD, SGLT2 inhibitors reduced the risk of primary cardiovascular outcomes by 26% (HR 0.74, [95% CI 0.69-0.80], I2 = 0.00%), by 30% in patients with stage 3a CKD (HR 0.70, [95% CI 0.59-0.84], I2 = 18.70%), by 23% in patients with stage 3b CKD (HR 0.77, [95% CI 0.66-0.90], I2 = 2.12%), and by 29% in patients with stage 4 CKD (HR 0.71, [95% CI 0.53-0.96], I2 = 0.00%). The risk of primary outcomes was reduced by 29% (HR 0.71, [95% CI 0.63-0.80], I2 = 0.00%) in patients with type 2 diabetes, by 28% (HR 0.72, [95% CI 0.56-0.93], I2 = 37.23%) in patients with heart failure with preserved ejection fraction, by 21% (HR 0.79, [95% CI 0.70-0.89], I2 = 0.00%) in patients with heart failure with reduced ejection fraction, and by 25% (HR 0.75, [95% CI 0.64-0.88], I2 = 0.00%) in patients with atherosclerotic cardiovascular disease.

CONCLUSIONS

For stage 3/4 CKD, SGLT2 inhibitors significantly decreased the risk of primary cardiovascular outcomes, and these benefits were consistent throughout the spectrum of different kidney functions, even in stage 4 CKD. There was no evidence of increased adverse outcomes across different baseline clinical complications, such as type 2 diabetes, heart failure, or atherosclerotic cardiovascular disease.