SGLT2 Inhibitors: From Antihyperglycemic Agents to All-Around Heart Failure Therapy

Uptake of Sodium-Glucose Cotransporter-2 Inhibitors in Hospitalized Patients With Heart Failure: Insights From the Veterans Affairs Healthcare System

BACKGROUND

The use of sodium-glucose cotransporter-2 inhibitors (SGLT2is) in Veterans Affairs (VA) patients hospitalized with heart failure (HF) has not been reported previously.

METHODS

VA electronic health record data were used to identify patients hospitalized for HF (primary or secondary diagnosis) from 01/2019-11/2022. Patients with SGLT2i allergy, advanced/end-stage chronic kidney disease (CKD) or advanced HF therapies were excluded. We identified factors associated with discharge SGLT2i prescriptions for patients hospitalized due to HF in 2022. We also compared SGLT2i and angiotensin receptor-neprilysin inhibitor (ARNI) prescription rates. Hospital-level variations in SGLT2i prescriptions were assessed via the median odds ratio.

RESULTS

A total of 69,680 patients were hospitalized due to HF; 10.3% were prescribed SGLT2i at discharge (4.4% newly prescribed, 5.9% continued preadmission therapy). SGLT2i prescription increased over time and was higher in patients with HFrEF and primary HF. Among 15,762 patients hospitalized in 2022, SGLT2i prescription was more likely in patients with diabetes (adjusted odds ratio [aOR] 2.27; 95% confidence interval [CI]: 2.09-2.47) and ischemic heart disease (aOR 1.14; 95% CI: 1.03-1.26). Patients with increased age (aOR 0.77 per 10 years; 95% CI: 0.73-0.80) and lower systolic blood pressure (aOR 0.94 per 10 mmHg; 95% CI: 0.92-0.96) were less likely to be prescribed SGLT2i, and SGLT2i prescription was not more likely in patients with CKD (aOR 1.07; 95% CI 0.98-1.16). The adjusted median odds ratio suggested a 1.8-fold variation in the likelihood that similar patients at 2 random VA sites were prescribed SGLT2i (range 0-21.0%). In patients with EF ≤ 40%, 30.9% were prescribed SGLT2i while 26.9% were prescribed ARNI (P < 0.01).

CONCLUSION

One-tenth of VA patients hospitalized for HF were prescribed SGLT2i at discharge. Opportunities exist to reduce variation in SGLT2i prescription rates across hospitals and to promote its use in patients with CKD and older age.

Empagliflozin and liraglutide ameliorate HFpEF in mice via augmenting the Erbb4 signaling pathway

Heart failure with preserved ejection fraction (HFpEF) is closely associated with metabolic derangement. Sodium glucose cotransporter-2 inhibitors (SGLT2i) and glucagon-like peptide-1 receptor agonists (GLP-1RA) exert anti-HFpEF effects, but the underlying mechanisms remain unclear. In this study, we explored the anti-HFpEF effects of empagliflozin and liraglutide and the underlying molecular mechanisms in a mouse model of HFpEF. This model was established by high-fat diet (HFD) feeding plus Nω-nitro-L-arginine methyl ester (L-NAME) treatment. The mice were treated with empagliflozin (20 mg·kg-1·d-1, i.g.) or liraglutide (0.3 mg·kg-1·d-1, i.p.) or their combination for 4 weeks. At the end of the experimental protocol, cardiac function was measured using ultrasound, then mice were euthanized and heart, liver, and kidney tissues were collected. Nuclei were isolated from frozen mouse ventricular tissue for single-nucleus RNA-sequencing (snRNA-seq). We showed that administration of empagliflozin or liraglutide alone or in combination significantly improved diastolic function, ameliorated cardiomyocyte hypertrophy and cardiac fibrosis, as well as exercise tolerance but no synergism was observed in the combination group. Furthermore, empagliflozin and/or liraglutide lowered body weight, improved glucose metabolism, lowered blood pressure, and improved liver and kidney function. After the withdrawal of empagliflozin or liraglutide for 1 week, these beneficial effects tended to diminish. The snRNA-seq analysis revealed a subcluster of myocytes, in which Erbb4 expression was down-regulated under HFpEF conditions, and restored by empagliflozin or liraglutide. Pseudo-time trajectory analysis and cell-to-cell communication studies confirmed that the Erbb4 pathway was a prominent pathway essential for both drug actions. In the HFpEF mouse model, both empagliflozin and liraglutide reversed Erbb4 down-regulation. In rat h9c2 cells, we showed that palmitic acid- or high glucose-induced changes in PKCα and/or ERK1/2 phosphorylation at least in part through Erbb4. Collectively, the single-cell atlas reveals the anti-HFpEF mechanism of empagliflozin and liraglutide, suggesting that Erbb4 pathway represents a new therapeutic target for HFpEF. Effects and mechanisms of action of empagliflozin and liraglutide in HFpEF mice. HFpEF was induced with a high-fat diet and L-NAME for 15 weeks, and treatment with empagliflozin and liraglutide improved the HFpEF phenotype. Single nucleus RNA sequencing (snRNA-seq) was used to reveal the underlying mechanism of action of empagliflozin and liraglutide.

Associations and attributable burden between risk factors and all-cause and cause-specific mortality at different ages in patients with hypertension

It remains unclear the age-specific associations of risk factors with deaths and mortality burden attributable across age. In a territory-wide retrospective cohort, 1,012,228 adults with hypertension were identified. Comorbidities including diabetes, chronic kidney disease (CKD), cardiovascular disease (CVD), heart failure, and cancer, and risk factors including current smoking and suboptimal control of blood pressure (BP), glucose and low-density lipoprotein cholesterol were defined. Associations of comorbidities/risk factors with all-cause and cause-specific mortality across age groups (18-54, 55-64, 65-74, and ≥75 years) were assessed. Population attributable fractions were also quantified. During a median follow-up of 10.7 years, 244,268 (24.1%) patients died, with pneumonia (7.2%), cancer (5.1%), and CVD (4.2%) being the leading causes. Despite increasing deaths with age, relative risk of mortality related to comorbidities/risk factors decreased with age; similar patterns were found for cause-specific mortality. The assessed risk factors accounted for 24.0% (95% CI 22.5%, 25.4%) deaths, with highest proportion in the youngest group (33.5% [28.1%, 38.5%] in 18-54 years vs 19.4% [17.0%, 21.6%] in ≥75 years). For mortality burden, CKD was the overall leading risk factor (12.7% [12.4%, 12.9%]) with higher proportions in older patients (11.1-13.1% in ≥65 years), while diabetes was the leading risk factor in younger patients (15.9-13.5% in 18-54 years). The association of comorbidities or risk factors with mortality is stronger in younger patients with hypertension, despite lower absolute mortality in young patients than in the elderly. Leading risk factors differed across age, highlighting the importance of targeted and precise risk management.

Effect of SGLT2 inhibitors on heart failure outcomes and cardiovascular death across the cardiometabolic disease spectrum: a systematic review and meta-analysis

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors have been studied in patients with heart failure, type 2 diabetes, chronic kidney disease, atherosclerotic cardiovascular disease, and acute myocardial infarction. Individual trials were powered to study composite outcomes in one disease state. We aimed to evaluate the treatment effect of SGLT2 inhibitors on specific clinical endpoints across multiple demographic and disease subgroups.

METHODS

In this systematic review and meta-analysis, we queried online databases (PubMed, Cochrane CENTRAL, and SCOPUS) up to Feb 10, 2024, for primary and secondary analyses of large trials (n>1000) of SGLT2 inhibitors in patients with heart failure, type 2 diabetes, chronic kidney disease, and atherosclerotic cardiovascular disease (including acute myocardial infarction). Outcomes studied included composite of first hospitalisation for heart failure or cardiovascular death, first hospitalisation for heart failure, cardiovascular death, total (first and recurrent) hospitalisation for heart failure, and all-cause mortality. Effect sizes were pooled using random-effects models. This study is registered with PROSPERO, CRD42024513836.

FINDINGS

We included 15 trials (N=100 952). Compared with placebo, SGLT2 inhibitors reduced the risk of first hospitalisation for heart failure by 29% in patients with heart failure (hazard ratio [HR] 0·71 [95% CI 0·67-0·77]), 28% in patients with type 2 diabetes (0·72 [0·67-0·77]), 32% in patients with chronic kidney disease (0·68 [0·61-0·77]), and 28% in patients with atherosclerotic cardiovascular disease (0·72 [0·66-0·79]). SGLT2 inhibitors reduced cardiovascular death by 14% in patients with heart failure (HR 0·86 [95% CI 0·79-0·93]), 15% in patients with type 2 diabetes (0·85 [0·79-0·91]), 11% in patients with chronic kidney disease (0·89 [0·82-0·96]), and 13% in patients with atherosclerotic cardiovascular disease (0·87 [0·78-0·97]). The benefit of SGLT2 inhibitors on both first hospitalisation for heart failure and cardiovascular death was consistent across the majority of the 51 subgroups studied. Notable exceptions included acute myocardial infarction (22% reduction in first hospitalisation for heart failure; no effect on cardiovascular death) and heart failure with preserved ejection fraction (26% reduction in first hospitalisation for heart failure; no effect on cardiovascular death).

INTERPRETATION

SGLT2 inhibitors reduced heart failure events and cardiovascular death in patients with heart failure, type 2 diabetes, chronic kidney disease, and atherosclerotic cardiovascular disease. These effects were consistent across a wide range of subgroups within these populations. This supports the eligibility of a large population with cardiorenal-metabolic diseases for treatment with SGLT2 inhibitors.

FUNDING

None.

Impact of Pre-Transplant Left Ventricular Diastolic Pressure on Primary Graft Dysfunction after Lung Transplantation: A Narrative Review

Lung transplantation (LT) constitutes the last therapeutic option for selected patients with end-stage respiratory disease. Primary graft dysfunction (PGD) is a form of severe lung injury, occurring in the first 72 h following LT and constitutes the most common cause of early death after LT. The presence of pulmonary hypertension (PH) has been reported to favor PGD development, with a negative impact on patients' outcomes while complicating medical management. Although several studies have suggested a potential association between pre-LT left ventricular diastolic dysfunction (LVDD) and PGD occurrence, the underlying mechanisms of such an association remain elusive. Importantly, the heterogeneity of the study protocols and the various inclusion criteria used to define the diastolic dysfunction in those patients prevents solid conclusions from being drawn. In this review, we aim at summarizing PGD mechanisms, risk factors, and diagnostic criteria, with a further focus on the interplay between LVDD and PGD development. Finally, we explore the predictive value of several diastolic dysfunction diagnostic parameters to predict PGD occurrence and severity.

Two-hit mouse model of heart failure with preserved ejection fraction combining diet-induced obesity and renin-mediated hypertension

Heart failure with preserved ejection fraction (HFpEF) is increasingly common but its pathogenesis is poorly understood. The ability to assess genetic and pharmacologic interventions is hampered by the lack of robust preclinical mouse models of HFpEF. We have developed a novel "2-hit" model, which combines obesity and insulin resistance with chronic pressure overload to recapitulate clinical features of HFpEF. C57BL6/NJ mice fed a high fat diet for >10 weeks were administered an AAV8-driven vector resulting in constitutive overexpression of mouse Renin1d . Control mice, HFD only, Renin only and HFD-Renin (aka "HFpEF") littermates underwent a battery of cardiac and extracardiac phenotyping. HFD-Renin mice demonstrated obesity and insulin resistance, a 2-3-fold increase in circulating renin levels that resulted in 30-40% increase in left ventricular hypertrophy, preserved systolic function, and diastolic dysfunction indicated by altered E/e', IVRT, and strain measurements; increased left atrial mass; elevated natriuretic peptides; and exercise intolerance. Transcriptomic and metabolomic profiling of HFD-Renin myocardium demonstrated upregulation of pro-fibrotic pathways and downregulation of metabolic pathways, in particular branched chain amino acid catabolism, similar to findings in human HFpEF. Treatment of these mice with the sodium-glucose cotransporter 2 inhibitor empagliflozin, an effective but incompletely understood HFpEF therapy, improved exercise tolerance, left heart enlargement, and insulin homeostasis. The HFD-Renin mouse model recapitulates key features of human HFpEF and will enable studies dissecting the contribution of individual pathogenic drivers to this complex syndrome. Addition of HFD-Renin mice to the preclinical HFpEF model platform allows for orthogonal studies to increase validity in assessment of interventions.

NEW & NOTEWORTHY

Heart failure with preserved ejection fraction (HFpEF) is a complex disease to study due to limited preclinical models. We rigorously characterize a new two-hit HFpEF mouse model, which allows for dissecting individual contributions and synergy of major pathogenic drivers, hypertension and diet-induced obesity. The results are consistent and reproducible in two independent laboratories. This high-fidelity pre-clinical model increases the available, orthogonal models needed to improve our understanding of the causes and assessment treatments for HFpEF.

Sodium-glucose co-transporter 2 Inhibitors Act Independently of SGLT2 to Confer Benefit for Heart Failure with Reduced Ejection Fraction in Mice

Sodium-glucose co-transporter 2 inhibitors (SGLT2i) are novel, potent heart failure medications with an unknown mechanism of action. We sought to determine if the beneficial actions of SGLT2i in heart failure were on- or off-target, and related to metabolic reprogramming, including increased lipolysis and ketogenesis. The phenotype of mice treated with empagliflozin and genetically engineered mice constitutively lacking SGLT2 mirrored metabolic changes seen in human clinical trials (including reduced blood glucose, increased ketogenesis, and profound glucosuria). In a mouse heart failure model, SGLT2i treatment, but not generalized SGLT2 knockout, resulted in improved systolic function and reduced pathologic cardiac remodeling. SGLT2i treatment of the SGLT2 knockout mice sustained the cardiac benefits, demonstrating an off-target role for these drugs. This benefit is independent of metabolic changes, including ketosis. The mechanism of action and target of SGLT2i in HF remain elusive.

Metabolic mechanisms in physiological and pathological cardiac hypertrophy: new paradigms and challenges

Cardiac metabolism is vital for heart function. Given that cardiac contraction requires a continuous supply of ATP in large quantities, the role of fuel metabolism in the heart has been mostly considered from the perspective of energy production. However, the consequence of metabolic remodelling in the failing heart is not limited to a compromised energy supply. The rewired metabolic network generates metabolites that can directly regulate signalling cascades, protein function, gene transcription and epigenetic modifications, thereby affecting the overall stress response of the heart. In addition, metabolic changes in both cardiomyocytes and non-cardiomyocytes contribute to the development of cardiac pathologies. In this Review, we first summarize how energy metabolism is altered in cardiac hypertrophy and heart failure of different aetiologies, followed by a discussion of emerging concepts in cardiac metabolic remodelling, that is, the non-energy-generating function of metabolism. We highlight challenges and open questions in these areas and finish with a brief perspective on how mechanistic research can be translated into therapies for heart failure.

Retatrutide: a triple incretin receptor agonist for obesity management

INTRODUCTION

Obesity treatment is evolving rapidly with the emergence of agents targeting incretin receptors. Retatrutide, a triple agonist of these receptors, shows promise in obesity management.

AREAS COVERED

Retatrutide, in phase-2 trials, exhibited significant reductions in glycated hemoglobin (HbA1c) and dose-dependent weight loss in individuals with type 2 diabetes mellitus (T2DM). In non-T2DM individuals, it produced substantial weight loss and improved glucose levels, albeit with gastrointestinal side effects. The role of glucagon receptor agonism in the management of heart failure and its potential impact on eating patterns have also been covered in this article.

EXPERT OPINION

Although the reductions in HbA1c and dose-dependent weight loss among individuals with T2DM were significantly more for higher doses of retatrutide, it needs to be observed that the active comparator was dulaglutide, which is not approved for the treatment of obesity, at a dose of 1.5 mg, which is much lower than the highest approved dose of 4.5 mg. Dose-dependent increase in heart rate and incidents of mild to moderate cardiac arrythmias raise cardiovascular safety concerns and signify that carrying out long-term cardiovascular outcome trials (CVOTs) will be critical. In addition, retatrutide's potential in heart failure management is intriguing given the series of positive findings of semaglutide on cardiovascular outcomes.

Anti-Diabetic Therapy and Heart Failure: Recent Advances in Clinical Evidence and Molecular Mechanism

Diabetic patients have a two- to four-fold increase in the risk of heart failure (HF), and the co-existence of diabetes and HF is associated with poor prognosis. In randomized clinical trials (RCTs), compelling evidence has demonstrated the beneficial effects of sodium-glucose co-transporter-2 inhibitors on HF. The mechanism includes increased glucosuria, restored tubular glomerular feedback with attenuated renin-angiotensin II-aldosterone activation, improved energy utilization, decreased sympathetic tone, improved mitochondria calcium homeostasis, enhanced autophagy, and reduced cardiac inflammation, oxidative stress, and fibrosis. The RCTs demonstrated a neutral effect of the glucagon-like peptide receptor agonist on HF despite its weight-reducing effect, probably due to it possibly increasing the heart rate via increasing cyclic adenosine monophosphate (cAMP). Observational studies supported the markedly beneficial effects of bariatric and metabolic surgery on HF despite no current supporting evidence from RCTs. Bromocriptine can be used to treat peripartum cardiomyopathy by reducing the harmful cleaved prolactin fragments during late pregnancy. Preclinical studies suggest the possible beneficial effect of imeglimin on HF through improving mitochondrial function, but further clinical evidence is needed. Although abundant preclinical and observational studies support the beneficial effects of metformin on HF, there is limited evidence from RCTs. Thiazolidinediones increase the risk of hospitalized HF through increasing renal tubular sodium reabsorption mediated via both the genomic and non-genomic action of PPARγ. RCTs suggest that dipeptidyl peptidase-4 inhibitors, including saxagliptin and possibly alogliptin, may increase the risk of hospitalized HF, probably owing to increased circulating vasoactive peptides, which impair endothelial function, activate sympathetic tones, and cause cardiac remodeling. Observational studies and RCTs have demonstrated the neutral effects of insulin, sulfonylureas, an alpha-glucosidase inhibitor, and lifestyle interventions on HF in diabetic patients.

Diuretics and Ultrafiltration in Heart Failure

Fluid overload is a risk factor for increased morbidity and mortality, especially in patients with heart disease. The treatment options are limited to diuretics and mechanical fluid removal using ultrafiltration or renal replacement therapy. This paper provides an overview of the challenges of managing fluid overload, outlines the risks and benefits of different pharmacological options and extracorporeal techniques, and provides guidance for clinical practice.

Can sodium-glucose cotransporter 2 inhibitors 'spin the thread of life'?

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) were first used as antidiabetic agents that lower the blood glucose levels by promoting glycosuria. In recent years, randomised clinical trials have demonstrated that SGLT2i reduce cardiovascular-renal events and all-cause mortality in people with and without diabetes. The cardio-renal benefits observed are independent of glucose lowering effect and multiple mechanisms have been proposed for these results. SGLT2i can exert anti-ageing effects on the vasculature and other body organs through several signalling pathways including the activation of the nuclear factor erythroid-2-related factor 2 and the induction of antioxidant enzymes. We speculate that the pro-longevity effects of the SGLT2i are mediated by soluble Klotho, an anti-ageing kidney-derived hormone and an emerging therapeutic target for cardio-renal diseases.