Mechanisms of benefits of sodium-glucose cotransporter 2 inhibitors in heart failure with preserved ejection fraction

Myocardial Inflammation in Heart Failure With Reduced and Preserved Ejection Fraction

Heart failure (HF) is characterized by a progressive decline in cardiac function and represents one of the largest health burdens worldwide. Clinically, 2 major types of HF are distinguished based on the left ventricular ejection fraction (EF): HF with reduced EF and HF with preserved EF. While both types share several risk factors and features of adverse cardiac remodeling, unique hallmarks beyond ejection fraction that distinguish these etiologies also exist. These differences may explain the fact that approved therapies for HF with reduced EF are largely ineffective in patients suffering from HF with preserved EF. Improving our understanding of the distinct cellular and molecular mechanisms is crucial for the development of better treatment strategies. This article reviews the knowledge of the immunologic mechanisms underlying HF with reduced and preserved EF and discusses how the different immune profiles elicited may identify attractive therapeutic targets for these conditions. We review the literature on the reported mechanisms of adverse cardiac remodeling in HF with reduced and preserved EF, as well as the immune mechanisms involved. We discuss how the knowledge gained from preclinical models of the complex syndrome of HF as well as from clinical data obtained from patients may translate to a better understanding of HF and result in specific treatments for these conditions in humans.

Predictors of developing renal dysfunction following diagnosis of transthyretin cardiac amyloidosis

BACKGROUND

In patients with transthyretin cardiac amyloidosis (ATTR-CA), renal dysfunction is a poor prognostic indicator. Limited data are available on variables that portend worsening renal function (wRF) among ATTR-CA patients.

OBJECTIVES

This study assesses which characteristics place patients at higher risk for the development of wRF (defined as a drop of ≥10% in glomerular filtration rate [GFR]) within the first year following diagnosis of ATTR-CA.

METHODS

We included patients with ATTR-CA (n = 134) evaluated between 2/2016 and 12/2022 and followed for up to 1 year at our amyloid clinic. Patients were stratified into two groups: a group with maintained renal function (mRF) and a group with wRF and compared using appropriate testing. Significant variables in the univariate analysis were included in the multivariable logistic regression model to determine characteristics associated with wRF.

RESULTS

Within a follow-up period of 326 ± 118 days, the median GFR% change measured -6% [-18%, +8]. About 41.8% (n = 56) had wRF, while the remainder had mRF. In addition, in patients with no prior history of chronic kidney disease (CKD), 25.5% developed de novo CKD. On multivariable logistic regression, only New York Heart Association (NYHA) class ≥III (odds ratio [OR]: 3.9, 95% confidence interval [CI]: [1.6-9.3]), history of ischemic heart disease (IHD) (OR: 0.3, 95% CI: [0.1-0.7]), and not receiving SGLT-2i (OR: 0.1, 95% CI: [0.02-0.5]) were significant predictors of wRF.

CONCLUSION

Our study demonstrated that the development of de novo renal dysfunction or wRF is common following the diagnosis of ATTR-CA. Additionally, we identified worse NYHA class and no prior history of IHD as significant predictors associated with developing wRF, while receiving SGLT-2i therapy appeared to be protective in this population.

Safety and Efficacy of Anti-Hypertensive Medications in Patients with Heart Failure with Preserved Ejection Fraction: A Systematic Review and Meta-analysis

INTRODUCTION

Hypertension (HTN) is a co-morbidity that is commonly associated with heart failure with preserved ejection fraction (HFpEF). However, it remains unclear whether treatment of hypertension in HFpEF patients is associated with improved cardiovascular outcomes.

AIM

The purpose of this meta-analysis is to evaluate the association of anti-hypertensive medical therapy with cardiovascular outcomes in patients with HFpEF.

METHODS

We performed a database search for studies reporting on the association of anti-hypertensive medications with cardiovascular outcomes and safety endpoints in patients with HFpEF. The databases searched include OVID Medline, Web of Science, and Embase. The primary endpoint was all-cause mortality. Secondary endpoints include cardiovascular (CV) mortality, worsening heart failure (HF), CV hospitalization, composite major adverse cardiovascular events (MACE), hyperkalemia, worsening renal function, and hypotension.

RESULTS

A total of 12 studies with 14062 HFpEF participants (7010 treated with medical therapy versus 7052 treated with placebo) met inclusion criteria. Use of anti-hypertensive medications was not associated with lower all-cause mortality, CV mortality or CV hospitalization compared to treatment with placebo (OR 1.02, 95% CI 0.77-1.35; p = 0.9, OR 0.88, 95% CI 0.73-1.06; p = 0.19, OR 0.99, 95% CI 0.87-1.12; p = 0.83, OR 0.90, 95% CI 0.79-1.03; p = 0.11). Anti-hypertensive medications were not associated with lower risk of subsequent acute myocardial infarction (AMI) (OR 0.53, 95% CI 0.07-3.73; p = 0.5). Use of anti-hypertensive medications was associated with a statistically significant lower risk of MACE (OR 0.90, 95% CI 0.83-0.98; p = 0.02).

CONCLUSIONS

While treatment with anti-hypertensive medications was not associated with lower risk of all-cause mortality, their use may be associated with reduce risk of adverse cardiovascular outcomes in patients with HFpEF regardless of whether they have HTN. Additional high quality studies are required to clarify this association and determine the effect based on specific classes of medications.

Relationship of interleukin-16 with different phenogroups in acute heart failure with preserved ejection fraction

AIMS

Interleukin-16 (IL-16) has been reported to mediate left ventricular myocardial fibrosis and stiffening in patients with heart failure with preserved ejection fraction (HFpEF). We sought to elucidate whether IL-16 has a distinct impact on pathophysiology and prognosis across different subphenotypes of acute HFpEF.

METHODS AND RESULTS

We analysed 211 patients enrolled in a prospective multicentre registry of acute decompensated HFpEF for whom serum IL-16 levels after stabilization were available (53% female, median age 81 [interquartile range 75-85] years). We divided this sub-cohort into four phenogroups using our established clustering algorithm. The study endpoint was all-cause death. Patients were subclassified into phenogroup 1 ('rhythm trouble' [n = 69]), phenogroup 2 ('ventricular-arterial uncoupling' [n = 49]), phenogroup 3 ('low output and systemic congestion' [n = 41]), and phenogroup 4 ('systemic failure' [n = 52]). After a median follow-up of 640 days, 38 patients had died. Among the four phenogroups, phenogroup 2 had the highest IL-16 level. The IL-16 level showed significant associations with indices of cardiac hypertrophy, diastolic dysfunction, and congestion only in phenogroup 2. Furthermore, the IL-16 level had a significant predictive value for all-cause death only in phenogroup 2 (C-statistic 0.750, 95% confidence interval 0.606-0.863, P = 0.017), while there was no association between the IL-16 level and the endpoint in the other phenogroups.

CONCLUSIONS

Our results indicated that the serum IL-16 level had a significant association with indices that reflect the pathophysiology and prognosis of HFpEF in a specific phenogroup in acute HFpEF.

Effects of glucose-lowering drugs on cardiovascular outcomes in patients with type 2 diabetes: an update

INTRODUCTION

Over the last few years, there has been a substantial increase in the data available about the benefits of sodium-glucose cotransporter-2 (SGLT2) inhibitors and glucagon-like peptide-1 receptor agonists (GLP-1 RAs) in improving cardiovascular and renal outcomes in patients with type 2 diabetes (T2D). Very little new information is available for the other groups of glucose-lowering drugs.

AREAS COVERED

This brief report summarizes the recent information about the respective benefits of the two newer groups of glucose-lowering drugs and the effects on cardiovascular risk factors that may be involved in these benefits. The articles reviewed were identified by a Medline search.

EXPERT OPINION

Recent guidelines recommend SGLT2 inhibitors or GLP-1 RAs with proven cardiovascular disease benefits as potential first line treatment for patients with T2D and established atherosclerotic cardiovascular disease (ASCVD) or those with high risk of ASCVD or with chronic kidney disease or heart failure. Both groups of drugs have been shown to reduce major adverse cardiovascular events, but the mechanisms vary between them. SGLT2 inhibitors are preferred for the treatment and prevention of heart failure and chronic kidney disease, whereas GLP-1 RAs are more effective in reducing body weight and improving glycemic control in patients with T2D.

Obesity/cardiometabolic phenotype of heart failure with preserved ejection fraction: mechanisms to recent trials

PURPOSE OF REVIEW

Heart failure with preserved ejection fraction (HFpEF) is a leading and growing cause of morbidity and mortality globally. Of the various phenotypes identified, the obesity (or cardiometabolic) phenotype appears to be most common. The purpose of this review is to provide the clinician with an abridged understanding of recent developments that have elucidated obesity/visceral adiposity as a central mechanism linking inflammation/immune dysregulation to the development of the HFpEF syndrome. Recent clinical trials examining the efficacy of pharmacological treatments that target obesity in HFpEF will also be discussed.

RECENT FINDINGS

Recent data indicate that visceral adiposity and insulin resistance in HFpEF serve as key mechanisms driving inflammation and immune dysregulation, which play a critical role in the development of cardiac stiffness, diastolic dysfunction and fibrosis in HFpEF. In obesity, alterations in macrophage polarization, changes in innate and adaptive immune systems and altered myocardial energetics promote metabolic inflammation in HFpEF. Finally, emerging data suggest that inflammatory biomarkers, specifically, IL-6, may provide useful information about HFpEF severity and symptom burden in obesity.

SUMMARY

The obesity phenotype of HFpEF is seen in upward of 80% with HFpEF. Obesity is not just a bystander, but plays an essential role in the pathobiology and clinical course of HFpEF. Targeting overweight/obesity in HFpEF with GLP-1 receptor agonists holds promise in these patients.

AdipoRon ameliorates the progression of heart failure with preserved ejection fraction via mitigating lipid accumulation and fibrosis

INTRODUCTION

Obesity and imbalance in lipid homeostasis contribute greatly to heart failure with preserved ejection fraction (HFpEF), the dominant form of heart failure. Few effective therapies exist to control metabolic alterations and lipid homeostasis.

OBJECTIVES

We aimed to investigate the cardioprotective roles of AdipoRon, the adiponectin receptor agonist, in regulating lipid accumulation in the two-hit HFpEF model.

METHODS

HFpEF mouse model was induced using 60 % high-fat diet plus L-NAME drinking water. Then, AdipoRon (50 mg/kg) or vehicle were administered by gavage to the two-hit HFpEF mouse model once daily for 4 weeks. Cardiac function was evaluated using echocardiography, and Postmortem analysis included RNA-sequencing, untargeted metabolomics, transmission electron microscopy and molecular biology methods.

RESULTS

Our study presents the pioneering evidence that AdipoR was downregulated and impaired fatty acid oxidation in the myocardia of HFpEF mice, which was associated with lipid metabolism as indicated by untargeted metabolomics. AdipoRon, orally active synthetic adiponectin receptor agonist, could upregulate AdipoR1/2 (independently of adiponectin) and reduce lipid droplet accumulation, and alleviate fibrosis to restore HFpEF phenotypes. Finally, AdipoRon primarily exerted its effects through restoring the balance of myocardial fatty acid intake, transport, and oxidation via the downstream AMPKα or PPARα signaling pathways. The protective effects of AdipoRon in HFpEF mice were reversed by compound C and GW6471, inhibitors of AMPKα and PPARα, respectively.

CONCLUSIONS

AdipoRon ameliorated the HFpEF phenotype by promoting myocardial fatty acid oxidation, decreasing fatty acid transport, and inhibiting fibrosis via the upregulation of AdipoR and the activation of AdipoR1/AMPKα and AdipoR2/PPARα-related downstream pathways. These findings underscore the therapeutic potential of AdipoRon in HFpEF. Importantly, all these parameters get restored in the context of continued mechanical and metabolic stressors associated with HFpEF.