Efficacy and safety of SGLT2 inhibitors in heart failure: systematic review and meta-analysis

Management of Type 2 Diabetes in Stage C Heart Failure with Reduced Ejection Fraction

Type 2 diabetes is an increasingly common comorbidity of stage C heart failure with reduced ejection fraction (HFrEF). The two diseases are risk factors for each other and can bidirectionally independently worsen outcomes. The regulatory requirement of cardiovascular outcomes trials for antidiabetic agents has led to an emergence of novel therapies with robust benefits in heart failure, and clinicians must now ensure they are familiar with the management of patients with concurrent diabetes and stage C HFrEF. This review summarises the current evidence for the management of type 2 diabetes in stage C HFrEF, recapitulating data from landmark heart failure trials regarding the use of guideline-directed medical therapy for heart failure in patients with diabetes. It also provides a preview of upcoming clinical trials in these populations.

Sodium-glucose cotransporter-2 inhibitors in heart failure: an updated meta-analysis

Aims

We aimed to examine efficacy and safety outcomes of sodium‐glucose cotransporter‐2 inhibitor (SGLT2i) for the treatment of heart failure (HF), especially in patients with heart failure with preserved ejection fraction (HFpEF).

Methods and results

PubMed, Web of Science, and Cochrane Library were searched to identify randomized controlled trials comparing SGLT2i vs. placebo in HF patients. A total of 10 studies with 23 852 HF patients were eventually included. Compared with placebo, SGLT2i is associated with a lower incidence of composite of first hospitalization for heart failure (HHF) or cardiovascular death (CV death) [hazard ratio (HR) = 0.76 95% confidence interval (CI) = 0.71–0.81], which is consistent regardless of the diabetes status, type of gliflozines used, and follow‐up duration. SGLT2i can reduce the risk of total HHF or CV death (HR = 0.74, 95%CI = 0.68–0.81), first HHF (HR = 0.69, 95%CI = 0.64–0.75), CV death (HR = 0.88, 95%CI = 0.80–0.96), any death (HR = 0.90, 95%CI = 0.83–0.97), and any serious events (HR = 0.90, 95%CI = 0.87–0.93) in HF patients, at the cost of increased risk of urinary tract infections (risk ratio = 1.17, 95%CI = 1.03–1.33). In HFpEF patients, SGLT2i is associated with a significant reduction of composite of first HHF or CV death (HR = 0.81, 95%CI = 0.73–0.91), first HHF (HR = 0.71, 95%CI = 0.62–0.82), and total HHF or CV death (HR = 0.61, 95%CI = 0.43–0.86).

Conclusions

Sodium‐glucose cotransporter‐2 inhibitor contributed to better efficacy outcomes in overall HF patients and showed an inspiring breakthrough in the treatment of HFpEF.

Pharmacological treatment options for heart failure with reduced ejection fraction: A 2022 update

INTRODUCTION

Despite considerable advances in the treatment of heart failure with reduced ejection fraction (HFrEF) over the last 60 years, mortality and morbidity remains high. Fortunately, in the last years, further developments expanded the toolbox for HF treatment.

AREAS COVERED

The authors provide an overview of recent developments in HF treatment and bring the recommendations in the HF guidelines of the European Society of Cardiology into perspective.

EXPERT OPINION

Nowadays, basic pharmacological treatment of patients with HFrEF consists of a combination of angiotensin converting enzyme (ACE) inhibitors/angiotensin receptor-neprilysin inhibitor (ARNI), beta-blockers, mineralocorticoid receptor antagonists (MRA), and the SGLT2 inhibitors dapagliflozin or empagliflozin. Treatment initiation of all four drug classes should be fast and simultaneous. In some cases, the ARNI sacubitril/valsartan may be initiated even in ACE inhibitor-naïve patients. Further HF treatment has to be individualized. Another important point is that both SGLT2 inhibitors and vericiguat can be used in patients with severely reduced kidney function. Finally, an important piece in the HF management puzzle is the treatment of its comorbidities. For instance, patients hospitalized for acute HF decompensation should be systematically screened for iron deficiency, since HF patients with proven iron deficiency benefit from intravenous ferric carboxymaltose.

Role of dipeptidyl peptidase 4 inhibitors in the new era of antidiabetic treatment

The last few years important changes have occurred in the field of diabetes treatment. The priority in the therapy of patients with diabetes is not glycemic control per se rather an overall management of risk factors, while individualization of glycemic target is suggested. Furthermore, regulatory authorities now require evidence of cardiovascular (CV) safety in order to approve new antidiabetic agents. The most novel drug classes, i.e., sodium-glucose transporter 2 inhibitors (SGLT2-i) and some glucagon-like peptide-1 receptor agonists (GLP-1 RA), have been demonstrated to reduce major adverse CV events and, thus, have a prominent position in the therapeutic algorithm of hyperglycemia. In this context, the role of previously used hypoglycemic agents, including dipeptidyl peptidase 4 (DPP-4) inhibitors, has been modified. DPP-4 inhibitors have a favorable safety profile, do not cause hypoglycemia or weight gain and do not require dose uptitration. Furthermore, they can be administered in patients with chronic kidney disease after dose modification and elderly patients with diabetes. Still, though, they have been undermined to a third line therapeutic choice as they have not been shown to reduce CV events as is the case with SGLT2-i and GLP-1 RA. Overall, DPP-4 inhibitors appear to have a place in the management of patients with diabetes as a safe class of oral glucose lowering agents with great experience in their use.

Effect of sodium-glucose cotransporter-2 inhibitors on cardiac remodelling: a systematic review and meta-analysis

AIMS

To examine the effects of sodium-glucose cotransporter-2 inhibitors (SGLT2i) on cardiac remodelling in patients with type 2 diabetes mellitus (T2DM) and/or heart failure (HF), and to explore the subsets of patients who may have greater benefit from SGLT2i therapy.

METHODS AND RESULTS

Four electronic databases were searched for randomized controlled trials (RCTs) that evaluated the effects of SGLT2i on parameters reflecting cardiac remodelling in patients with T2DM and/or HF. Standardized mean differences (SMDs) or mean differences (MDs) were pooled. Subgroup analyses were performed according to the baseline HF and T2DM, HF type, SGLT2i agent, follow-up duration, and imaging modality. A total of 13 RCTs involving 1251 patients were analysed. Sodium-glucose cotransporter-2 inhibitors treatment significantly improved left ventricular (LV) ejection fraction [SMD, 0.35; 95% confidence interval (CI) (0.04, 0.65); P = 0.03], LV mass [SMD, -0.48; 95% CI (-0.79, -0.18); P = 0.002], LV mass index [SMD, -0.27; 95% CI (-0.49, -0.05); P = 0.02], LV end-systolic volume [SMD, -0.37; 95% CI (-0.71; -0.04); P = 0.03], LV end-systolic volume index [MD, -0.35 mL/m2; 95% CI (-0.64, -0.05); P = 0.02], and E-wave deceleration time [SMD, -0.37; 95% CI (-0.70, -0.05); P = 0.02] in the overall population. Subgroup analyses showed that the favourable effects of SGLT2i on LV remodelling were only significant in HF patients, especially HF with reduced ejection fraction (HFrEF), regardless of glycaemic status. Among the four included SGLT2i, empagliflozin was associated with a greater improvement of LV mass, LV mass index, LV end-systolic volume, LV end-systolic volume index, LV end-diastolic volume, and LV end-diastolic volume index (all P < 0.05).

CONCLUSIONS

Sodium-glucose cotransporter-2 inhibitors treatment significantly reversed cardiac remodelling, improving LV systolic and diastolic function, LV mass and volume, especially in patients with HFrEF and amongst those taking empagliflozin compared with other SGLT2i. Reversed remodelling may be a mechanism responsible for the favourable clinical effects of SGLT2i on HF.

Robustness of outcomes in trials evaluating sodium-glucose co-transporter 2 inhibitors for heart failure

AIMS

Recent trials have evaluated sodium-glucose co-transporter 2 inhibitors in patients with heart failure (HF). We sought to assess the robustness of findings from these trials using the fragility index (FI).

METHODS AND RESULTS

Fragility index is defined as the minimum number of patients that must be moved from the 'non-event' to the 'event' group to turn a statistically significant result to non-significant. In addition to FI, fragility quotient [(FQ); FI divided by the sample size] was calculated to assess the proportion of events that must be moved to change the significance. For statistically non-significant outcomes, reverse fragility index (RFI) and reverse fragility quotient (RFQ) were calculated. Robustness of findings after pooling data from all three trials was also assessed. A robust reduction in first HF hospitalization or cardiovascular mortality was seen with dapagliflozin (FI = 62 and FQ = 0.013), empagliflozin (FI = 50 and FQ = 0.013), and sotagliflozin (FI = 60 and FQ = 0.049). Dapagliflozin nominally improved all-cause and cardiovascular mortality, with modest FI (n = 8 and 5) and FQ (0.002 and 0.001). Empagliflozin and sotagliflozin did not demonstrate statistically significant reductions in all-cause mortality, with modest RFI (empagliflozin: RFI = 26 and RFQ = 0.007; sotagliflozin: RFI = 6 and RFQ = 0.005). A similar trend was seen with cardiovascular mortality (empagliflozin: RFI = 24 and RFQ = 0.006; sotagliflozin: RFI = 7 and RFQ = 0.006). Upon meta-analysis, the result for first HF hospitalization or cardiovascular mortality was robust (FI = 95 and FQ = 0.010). The reductions in all-cause (FI = 12 and FQ = 0.001) and cardiovascular mortality (FI = 9 and FQ = 0.001), while statistically significant, were fragile.

CONCLUSION

Improvement in the composite outcome of first HF hospitalization or cardiovascular death was highly concordant and robust across sodium-glucose co-transporter 2 inhibitor trials. In contrast, secondary endpoints of all-cause and cardiovascular mortality were statistically fragile, underscoring the need to power trials for mortality to fully understand the benefit of therapies on fatal events.

Association of Sodium-Glucose Cotransporter 2 Inhibitors With Cardiovascular Outcomes in Patients With Type 2 Diabetes and Other Risk Factors for Cardiovascular Disease: A Meta-analysis

IMPORTANCE

The cardiovascular outcome in selected populations when sodium-glucose cotransporter 2 inhibitors (SGLT2-Is) are emerging as standard therapy is not clearly understood. It is important to learn the magnitude of cardiovascular benefit using SGLT2-Is across the select subgroups that include both sexes and multiple age and racial and ethnic groups.

OBJECTIVES

To evaluate the association between use of SGLT2-Is and cardiovascular benefits in a prespecified group in a larger sample size using data obtained from randomized clinical trials.

DATA SOURCES

Search of electronic databases PubMed, Google Scholar, Web of Science, and Cochrane from inception to January 10, 2021, with additional studies identified through conference papers and meeting presentations, ClinicalTrials.gov, and reference lists of published studies.

STUDY SELECTION

Placebo-controlled randomized clinical trials in which participants had atherosclerotic cardiovascular disease (ASCVD) or risk factors for ASCVD, diabetes, or heart failure and which reported the primary outcome were included in this study. Multicenter observational and nonobservational studies and those with different outcomes of interest were excluded.

DATA EXTRACTION AND SYNTHESIS

Medical Subject Heading search terms included SGLT2-I and multiple cardiovascular outcomes in different combinations. The study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline. The analysis of all outcomes was performed using a Mantel-Haenszel equation and the random-effects model.

MAIN OUTCOMES AND MEASURES

Six efficacy outcomes of SGLT2-I use (cardiovascular death and hospitalization for heart failure [HHF] as the primary outcome and major adverse cardiovascular event, HHF, cardiovascular death, acute myocardial infarction, and all-cause mortality as secondary outcomes), were evaluated. Subgroup analysis was performed for the primary outcome of cardiovascular death or HHF. Odds ratios (ORs) and 95% CIs were used to compare 2 interventions.

RESULTS

Ten studies with 71 553 participants were included, among whom 39 053 received SGLT2-Is; among studies that reported these data, 28 809 were men and 15 655 were women (mean age, 65.2 [range, 61.9-70.0] years). Race and ethnicity were defined in the original trials and were categorized as Asian, Black, or other (6900 participants) and White (26 646 participants) for the purposes of this analysis (the category "other" was not specified consistently). In terms of age, 16 793 were younger than 65 years and 17 087 were 65 years or older. At a mean follow-up 2.3 (range, 0.8-4.2) years, the SGLT2-I group favored reduction in primary outcome (3165 of 39 053 [8.10%] vs 3756 of 32 500 [11.56%]; OR, 0.67 [95% CI, 0.55-0.80]; P < .001). No difference was noted in the rate of acute myocardial infarction compared with the placebo group (1256 of 26 931 [4.66%] vs 958 of 20 373 [4.70%]; OR, 0.95 [95% CI, 0.87-1.03]; P = .22). Subgroup analysis favored SGLT2-I use for the primary outcome in both sexes, age groups, and racial and ethnic groups.

CONCLUSIONS AND RELEVANCE

This meta-analysis supports that SGLT2-Is have emerged as an effective class of drugs for improving cardiovascular morbidity and mortality in selected patients. Sodium-glucose cotransporter 2 inhibitors were not associated with reduced risk of acute myocardial infarction. Future long-term prospective studies are warranted to understand the long-term cardiovascular benefits.

Empagliflozin Ameliorates Ouabain-Induced Na+ and Ca2+ Dysregulations in Ventricular Myocytes in an Na+-Dependent Manner

PURPOSE

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a novel class of glucose-lowering agents that have improved clinical outcomes in patients with heart failure; however, their therapeutic mechanisms remain elusive. Although contradictory results have been reported, it has been proposed that improving Na⁺ homeostasis may be the underlying mechanism of action of SGLT2 inhibitors in heart failure treatment. This study explored whether empagliflozin ameliorates Na⁺ and Ca²⁺ handling disorders induced by ouabain in an Na⁺-dependent manner.

METHODS

Isolated ventricular myocytes of mice were incubated with ouabain to establish a cellular model of Na⁺ overload. Effects of empagliflozin on Na⁺ and Ca²⁺ handling were evaluated using an ionOptix system and a confocal microscope. Distinct cytosolic Na⁺ levels were established by incubating different ouabain concentrations (10, 50, and 100 μmol/L).

RESULTS

In the absence of ouabain, 1 μmol/L empagliflozin had a negligible impact on Na⁺ and Ca²⁺ handling in ventricular myocytes. Ouabain (50 μmol/L) significantly enhanced cytosolic Na⁺ levels and dysregulated Ca²⁺ handling, including an increased Ca²⁺ transient amplitude, elevated Ca²⁺ content in the sarcoplasmic reticulum, and enhanced spontaneous Ca²⁺ release normalized by treatment with 1 μmol/L empagliflozin within 10 min. All Na⁺ and Ca²⁺ handling abnormalities induced by ouabain were reversed by 1 μmol/L empagliflozin. The efficacy of empagliflozin was more potent at higher cytosolic Na⁺ levels. Pretreatment with the Na⁺/H⁺ exchanger (NHE) inhibitor (1 μmol/L cariporide) abolished the effects of empagliflozin.

CONCLUSION

Empagliflozin ameliorates ouabain-induced Na⁺ and Ca²⁺ handling disorders in a cytosolic Na⁺-dependent manner, potentially by inhibiting the NHE.

Impact of preexisting diabetes mellitus on cardiovascular and all-cause mortality in patients with atrial fibrillation: A meta-analysis

OBJECTIVE

To determine the impact of preexisting diabetes mellitus on cardiovascular and all-cause mortality in patients with atrial fibrillation (AF) by conducting a meta-analysis.

METHODS

PubMed and Embase databases were comprehensively searched for relevant studies publishing until May 19, 2022. Cohort studies or post-hoc analyses of clinical trials that investigated the association of diabetes mellitus with cardiovascular or all-cause mortality in AF patients were included.

RESULTS

A total of 21 studies with 526,136 AF patients were identified. The pooled prevalence of diabetes mellitus in patients with AF was 26%. The summary multivariable-adjusted risk ratio (RR) of all-cause mortality was 1.37 (95% confidence intervals [CIs] 1.23-1.53) for patients with diabetes versus those without diabetes. Moreover, diabetes mellitus was also associated with an increased risk of cardiovascular mortality (RR 1.46; 95% CI 1.34-1.58). Stratified analyses suggested that the impact of diabetes on all-cause and cardiovascular mortality was consistently observed in each named subgroup.

CONCLUSION

The presence of diabetes mellitus in patients with AF is associated with an increased risk of cardiovascular and all-cause mortality, even after adjustment for important confounding factors.

Effects of sodium-glucose cotransporter-2 inhibitors on cardiac structural and electrical remodeling: from myocardial cytology to cardiodiabetology

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) have changed the clinical landscape of diabetes mellitus (DM) therapy through their favourable effects on cardiovascular outcomes. Notably, the use of SGLT2i has been linked to cardiovascular benefits regardless of DM status, while their pleiotropic actions remain to be fully elucidated. What we do know is that SGLT2i exert beneficial effects even at the level of the myocardial cell, and that these are linked to an improvement in the energy substrate, resulting in less inflammation and fibrosis. SGLT2i ameliorate myocardial extracellular matrix remodeling, cardiomyocyte stiffness and concentric hypertrophy, achieving beneficial remodeling of the left ventricle with significant implications for the pathogenesis and outcome of heart failure. Most studies show a significant improvement in markers of diastolic dysfunction along with a reduction in left ventricular hypertrophy. In addition to these effects there is electrophysiological remodeling, which explains initial data suggesting that SGLT2i have an antiarrhythmic action against both atrial and ventricular arrhythmias. However, future studies need to clarify not only the exact mechanisms of this beneficial functional, structural, and electrophysiological cardiac remodeling, but also its magnitude, and to determine whether this is a class or a drug effect.

Pharmacological treatment of type 2 diabetes in elderly patients with heart failure: randomized trials and beyond

Heart failure (HF) and type 2 diabetes mellitus (T2DM) represent two important public health problems, and despite improvements in the management of both diseases, they are responsible for high rates of hospitalizations and mortality. T2DM accelerates physiological cardiac aging through hyperglycemia and hyperinsulinemia. Thus, HF and T2DM are chronic diseases widely represented in elderly people who often are affected by numerous comorbidities with important functional limitations making it difficult to apply the current guidelines. Several antidiabetic drugs should be used with caution in elderly individuals with T2DM. For instance, sulfonylureas should be avoided due to the risk of hypoglycemia associated with its use. Insulin should be used with caution because it is associated with higher risk of hypoglycemia, and may determine fluid retention which can lead to worsening of HF. Thiazolindinediones should be avoided due to the increased risk of fluid retention and HF. Biguanides may lead to a slightly increased risk of lactic acidosis in particular in elderly individuals with impaired renal function. Dipeptidyl peptidase 4 (DPP-4) inhibitors are safe having few side effects, minimal risk of hypoglycemia, and a neutral effect on cardiovascular (CV) outcome, even if it has been reported that saxagliptin treatment is associated with increased risk of hospitalizations for HF (hHF). Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have shown a CV protection without a significant reduction in hHF. On the other hand, sodium-glucose cotransporter 2 (SGLT2) inhibitors have shown a significant improvement in CV outcome, with a strong reduction of hHF and a positive impact on renal damage progression. However, it is necessary to consider the possible some side effects related to their use in elderly individuals including hypotension, bone fractures, and ketoacidosis.It is important to remark that elderly patients, in particular the very elderly, are not sufficiently represented in the trials; thus, the management and treatment of elderly diabetic patients with HF should be mainly based on the integration of scientific evidence with clinical judgment and patients' condition, with respect to the dignity and quality of life.

SGLT2 Inhibition for Cardiovascular Diseases, Chronic Kidney Disease, and NAFLD

Sodium glucose cotransporter 2 (SGLT-2) inhibitors are the latest class of antidiabetic medications. They prevent glucose reabsorption in the proximal convoluted tubule to decrease blood sugar. Several animal studies revealed that SGLT-2 is profoundly involved in the inflammatory response, fibrogenesis, and regulation of numerous intracellular signaling pathways. Likewise, SGLT-2 inhibitors markedly attenuated inflammation and fibrogenesis and improved the function of damaged organ in animal studies, observational studies, and clinical trials. SGLT-2 inhibitors can decrease blood pressure and ameliorate hypertriglyceridemia and obesity. Likewise, they improve the outcome of cardiovascular diseases such as heart failure, arrhythmias, and ischemic heart disease. SGLT-2 inhibitors are associated with lower cardiovascular and all-cause mortality as well. Meanwhile, they protect against nonalcoholic fatty liver disease (NAFLD), chronic kidney disease, acute kidney injury, and improve micro- and macroalbuminuria. SGLT-2 inhibitors can reprogram numerous signaling pathways to improve NAFLD, cardiovascular diseases, and renal diseases. For instance, they enhance lipolysis, ketogenesis, mitochondrial biogenesis, and autophagy while they attenuate the renin-angiotensin-aldosterone system, lipogenesis, endoplasmic reticulum stress, oxidative stress, apoptosis, and fibrogenesis. This review explains the beneficial effects of SGLT-2 inhibitors on NAFLD and cardiovascular and renal diseases and dissects the underlying molecular mechanisms in detail. This narrative review explains the beneficial effects of SGLT-2 inhibitors on NAFLD and cardiovascular and renal diseases using the results of latest observational studies, clinical trials, and meta-analyses. Thereafter, it dissects the underlying molecular mechanisms involved in the clinical effects of SGLT-2 inhibitors on these diseases.

Potential Mechanisms of SGLT2 Inhibitors for the Treatment of Heart Failure With Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is an unsolved and growing concern in cardiovascular medicine. While no treatment options that improve prognosis in HFpEF patients has been established so far, SGLT2 inhibitors (SGLT2i) are currently being investigated for the treatment of HFpEF patients. SGLT2i have already been shown to mitigate comorbidities associated with HFpEF such as type 2 diabetes and chronic renal disease, however, more recently there has been evidence that they may also directly improve diastolic function. In this article, we discuss some potential beneficial mechanisms of SGLT2i in the pathophysiology of HFpEF with focus on contractile function.

Sodium-glucose co-transporter-2 inhibitors in the non-diabetic heart failure patient

Heart failure (HF) with reduced ejection fraction (HFrEF) is a global cause of morbidity and mortality with over 60 million estimated cases worldwide. The burden of HF care is expected to increase with an ageing population as evidenced by the fact that 80% of HF-related hospitalizations occur in those aged above 65. Given the significant morbidity and mortality associated with HFrEF, there is a need for new prognostic therapies that have an impact on morbidity and mortality. In February of 2021, the National institute for Health and Care Excellence (NICE) released new guidance on the utility of Dapagliflozin for the management of heart failure with reduced ejection fraction (HFrEF). NICE advocated that dapagliflozin is a viable treatment option in symptomatic HFrEF patients on optimal medical management. The current list price of dapagliflozin is around £36.59 per 28-tablet pack with an estimated annual cost of £476.98 equating to £6939 per quality-adjusted life year. The guidance was mainly based on evidence produced from the 2019 DAPA-HF trial. This demonstrated that in HFrEF population, the use of dapagliflozin led to a significant reduction in worsening HF events, cardiovascular, and all-cause death. In this article, we summarize the evidence base for sodium-glucose co-transporter-2 inhibitors in the non-diabetic heart failure patient.

The diuretic effects of SGLT2 inhibitors: A comprehensive review of their specificities and their role in renal protection

Sodium-glucose cotransporter type 2 inhibitors (SGLT2is) are new oral glucose-lowering agents that provide cardiovascular and renal protection in both patients with and without type 2 diabetes. Because of their unique mechanism of action, increased glucosuria is associated with osmotic diuresis and some natriuresis, yet the latter seems mostly transient. The potential role of the diuretic effect in overall cardiovascular and renal protection by SGLT2is remains a matter of debate. Precise evaluation of the diuretic effect is not so easy and most studies relied upon indirect estimations that led to divergent results, presumably also explained by different study designs and population characteristics. Everybody agrees upon the fact that SGLT2is are different from other classical diuretics (thiazides and loop diuretics) as they present some favourable properties, i.e. reduced sympathetic activity, preserved potassium balance, lower risk of acute renal injury, decrease of serum uric acid level. The potential role of the diuretic effect of SGLT2is on renal outcomes is still unclear, yet their ability to reduce albuminuria and dampen the risk of heart failure may contribute to improve renal prognosis besides other complex underlying mechanisms. In this comprehensive review we first critically analyse the results obtained with indirect methods that assess a diuretic effect of SGLT2is, second we describe the specificities of the diuretic activity of SGLT2is compared with other classical diuretics, and third we discuss the potential mechanisms by which the diuretic effect of SGLT2is could contribute to the improvement of renal outcomes consistently reported with this innovative amazing pharmacological class.

Effects of SGLT2 Inhibitors on Ion Homeostasis and Oxidative Stress associated Mechanisms in Heart Failure

Sodium-glucose cotransporter 2 (SGLT2) inhibitors present a class of antidiabetic drugs, which inhibit renal glucose reabsorption resulting in the elevation of urinary glucose levels. Within the past years, SGLT2 inhibitors have become increasingly relevant due to their effects beyond glycemic control in patients with type 2 diabetes (T2DM). Although dedicated large trials demonstrated cardioprotective effects of SGLT2 inhibitors, the exact mechanisms responsible for those benefits have not been fully identified. Alterations in Ca²⁺ signaling and oxidative stress accompanied by excessive reactive oxygen species (ROS) production, fibrosis and inflammatory processes form cornerstones of potential molecular targets for SGLT2 inhibitors. This review focused on three hypotheses for SGLT2 inhibitor-mediated cardioprotection: ion homeostasis, oxidative stress and endothelial dysfunction.

Overview of Sodium-Glucose Co-transporter 2 (SGLT2) Inhibitors for the Treatment of Non-diabetic Heart Failure Patients

Heart failure (HF) is a clinical syndrome that results from any structural or functional impairment of ventricular filling or ejection of blood, and results in low life quality and expectancy, creating a significant burden on the healthcare system. The pharmacological HF management has remained unchanged for a decade, however, several randomized clinical trials have demonstrated the potential clinical benefits of sodium-glucose cotransporter-2 inhibitors, an antidiabetic agent, by reducing the rate of hospitalizations for HF, cardiovascular death, and all-cause death. The cardioprotective effects are characterized by reduction of inflammatory, metabolic and ionic dyshomeostasis despite the diabetic status. Since the United States Food and Drug Administration (FDA) approval in May 2020, SGLT2 inhibitors have been used mostly in heart failure with reduced ejection fraction (HFrEF). In this review article, we provide a comprehensive overview of the potential benefits, effectiveness, and safety profile of SGLT2 inhibitors used in HF patients with no history of diabetes mellitus.

SGLT2 Inhibitors and Their Mode of Action in Heart Failure-Has the Mystery Been Unravelled?

PURPOSE OF REVIEW

SGLT2 inhibitors (SGLT2i) are new drugs for patients with heart failure (HF) irrespective of diabetes. However, the mechanisms of SGLT2i in HF remain elusive. This article discusses the current clinical evidence for using SGLT2i in different types of heart failure and provides an overview about the possible underlying mechanisms.

RECENT FINDINGS

Clinical and basic data strongly support and extend the use of SGLT2i in HF. Improvement of conventional secondary risk factors is unlikely to explain the prognostic benefits of these drugs in HF. However, different multidirectional mechanisms of SGLT2i could improve HF status including volume regulation, cardiorenal mechanisms, metabolic effects, improved cardiac remodelling, direct effects on cardiac contractility and ion-homeostasis, reduction of inflammation and oxidative stress as well as an impact on autophagy and adipokines. Further translational studies are needed to determine the mechanisms of SGLT2i in HF. However, basic and clinical evidence encourage the use of SGLT2i in HFrEF and possibly HFpEF.

Influence of receptor selectivity on benefits from SGLT2 inhibitors in patients with heart failure: a systematic review and head-to-head comparative efficacy network meta-analysis

Background

Receptor selectivity of sodium-glucose cotransporter-2 inhibitors (SGLT2i) varies greatly between agents. The overall improvement of cardiovascular (CV) outcomes in heart failure (HF) patients varies between trials. We, therefore, evaluated the comparative efficacy of individual SGLT2i and the influence of their respective receptor selectivity thereon.

Methods

We identified randomized controlled trials investigating the use of SGLT2i in patients with HF—either as the target cohort or as a subgroup of it. Comparators included placebo or any other active treatment. The primary endpoint was the composite of hospitalization for HF or CV death. Secondary outcomes included all-cause mortality, CV mortality, hospitalization for HF, worsening renal function (RF), and the composite of worsening RF or CV death. Evidence was synthesized using network meta-analysis. In addition, the impact of receptor selectivity on outcomes was analysed using meta-regression.

Results

We identified 18,265 patients included in 22 trials. Compared to placebo, selective and non-selective SGLT2i improved fatal and non-fatal HF events. Head-to-head comparisons suggest superior efficacy with sotagliflozin as compared to dapagliflozin, empagliflozin or ertugliflozin. No significant difference was found between canagliflozin and sotagliflozin. Meta-regression analyses show a decreasing benefit on HF events with increasing receptor selectivity of SGLT2i. In contrast, receptor selectivity did not affect mortality and renal endpoints and no significant difference between individual SGLT2i was noted.

Conclusion

Our data point towards a class-effect of SGLT2i on mortality and renal outcomes. However, non-selective SGLT2i such as sotagliflozin may be superior to highly selective SGLT2i in terms of HF outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00392-021-01913-z.

Imeglimin prevents heart failure with preserved ejection fraction by recovering the impaired unfolded protein response in mice subjected to cardiometabolic stress

The pathogenesis of heart failure with preserved ejection fraction (HFpEF) in obese diabetic patients has been implicated in metainflammation. Increased expression of inducible nitric oxide synthase (iNOS) and dysfunction of the unfolded protein response (UPR), especially inositol-requiring enzyme 1α-X-box binding protein 1 (IRE1α-Xbp1s) signaling in the heart, have been associated with HFpEF. We investigated the effect of imeglimin, a potential new treatment for type 2 diabetes, on the pathogenesis of HFpEF. We induced obesity, impaired glucose tolerance, and cardiac hypertrophy with fibrosis, fat accumulation, and diastolic dysfunction in wild-type mice with a high-fat diet (HFD) and the nitric oxide synthase (NOS) inhibitor l-NAME for 16 weeks. Treatment with imeglimin starting at 10 weeks not only improved their abnormal systemic glucose metabolism and visceral obesity but also their cardiac abnormalities. We found that imeglimin suppressed the upregulation of iNOS, and restored the expression of Xbp1s and the expression of the E3 ubiquitin ligase STIP1 homology and U-box-containing protein 1 (STUB1), which is responsible for the degradation of Forkhead box protein O1 (FoxO1), a direct transcriptional target of Xbp1s. It also suppressed the excessive transcriptional activity of FoxO1, which is located downstream of Xbp1s and is involved in the form development of HFpEF and cardiac adipogenesis. Imeglimin also restored the expression of Glutathione peroxidase 4 (GPX4), which protects cells against excess lipid peroxidation and governs a novel form of programmed cell death, called ferroptosis.

Meta-analyzing the factors affecting the efficacy of gliflozins in patients with heart failure based on heart failure trials

BACKGROUND

The factors affecting the efficacy of gliflozins in patients with heart failure (HF) are not clear. We aimed to evaluate the effects of 11 important factors on the efficacy of gliflozins in HF patients.

METHODS

Randomized trials assessing gliflozins in HF patients were included. The outcome of interest was composite HF outcome, a composite of cardiovascular death, or hospitalization for HF. Meta-analysis was done according to 11 factors: status of type 2 diabetes, sex, use of angiotensin receptor-neprilysin inhibitor, age, history of hospitalization for HF, estimated glomerular filtration rate, body mass index, New York Heart Association (NYHA) class, race, region, and left ventricular ejection fraction.

RESULTS

Compared with placebo, gliflozins reduced the risk of composite HF outcome by 14% in the subgroup of patients with NYHA class III or IV (hazard ratios [HR] 0.86, 95% confidence intervals [CI] 0.75-0.99), by 34% in the subgroup of patients with NYHA class II (HR 0.66, 95% CI 0.59-0.74), and by 85% in the subgroup of patients with NYHA class I (HR 0.15, 95% CI 0.03-0.73). This between-group difference was approximate to statistical significance (Psubgroup = .06). The benefit of gliflozins in HF patients was not affected by the other 10 factors (Psubgroup ≥ .123).

CONCLUSIONS

Gliflozins are applicable for a broad population of HF patients as for preventing HF events, while gliflozins may lead to greater benefits in patients with mild HF than in those with moderate to severe HF.

Meta-Analysis on the Safety and Cardiorenal Efficacy of SGLT2 Inhibitors in Patients Without T2DM

The cardiorenal benefits of sodium-glucose cotransporter 2 (SGLT2) inhibitors in patients with type 2 diabetes mellitus (T2DM) are established, whereas those in patients without T2DM are not established. We sought to assess the cardiorenal efficacy and safety of SGLT2 inhibitors in non-T2DM patients by performing a meta-analysis based on the subgroup data of non-T2DM patients from relevant secondary analysis articles in which subgroup analyses were done according to the status of diabetes. Compared to placebo, SGLT2 inhibitors significantly reduced heart failure hospitalization [risk ratio (RR) 0.70, 95% confidence interval (CI) 0.59–0.83] and kidney-specific composite outcome (RR 0.55, 95% CI 0.40–0.75) and increased Kansas City Cardiomyopathy Questionnaire total score by 1.15 (95% CI 1.05–1.25) in patients without T2DM with heart failure (HF) or chronic kidney disease (CKD), whereas gliflozins did not significantly affect cardiovascular death, all-cause mortality, volume depletion, fracture, and amputation in this vulnerable population. There was no event of major hypoglycemia or diabetic ketoacidosis observed in the non-T2DM subgroup in included trials. These findings will further prompt gliflozins to be used for the prevention of HF and renal failure events and for the improvement of life quality in patients without T2DM with HF or CKD.

Heart failure drug titration, discontinuation, mortality and heart failure hospitalization risk: a multinational observational study (US, UK and Sweden)

AIMS

Use and dosing of guideline-directed medical therapy (GDMT) in patients with heart failure (HF) have been shown to be suboptimal. Among new users of GDMT in HF, we followed the real-life patterns of dose titration and discontinuation of angiotensin-converting enzyme inhibitors (ACEi), angiotensin receptor blockers (ARB), beta-blockers, mineralocorticoid receptor antagonists (MRA) and angiotensin receptor-neprilysin inhibitors (ARNI).

METHODS AND RESULTS

New users were identified in health care databases in Sweden, UK and US between 2016-2019. Inclusion criterion was a recent HF hospitalization (HHF) triggering the initiation of GDMT. Patients were grouped by GDMT, i.e. ACEi, ARB, beta-blocker, MRA and ARNI, and stratified by initial dose. Follow-up was 12 months, until death or study end. Outcomes were dose titration within each drug class, discontinuation and first HHF or death. Dose/discontinuation follow-up was assessed daily based on the coverage length of a filled prescription and reported on day 365. New users of ACEi (n = 8426), ARB (n = 2303), beta-blockers (n = 10 476), MRA (n = 17 421), and ARNI (n = 29 546) were identified. Over 12 months, target dose achievement was 15%, 10%, 12%, 30%, and discontinuation was 55%, 33%, 24% and 27% for ACEi, ARB, beta-blockers and ARNI, respectively. MRA was rarely titrated and discontinuation rates were high (40%). Event rates for HHF or death ranged from 40.0-86.9 per 100 patient-years across the treatment groups.

CONCLUSION

Despite high risk of clinical events following HHF, new initiation of GDMT was followed by consistent patterns of low up-titration and early GDMT discontinuation in three countries with different health care and economies. Our data highlight the urgent need for moving away from long sequential approach when initiating HF treatment and for improving just-in-time decision support for patients and health care providers.

Sodium-glucose transporter inhibition in heart failure: from an unexpected side effect to a novel treatment possibility

Sodium-glucose transporter-2 inhibitors (SGLT2i), originally launched as glucose-lowering drugs, have been studied in large cardiovascular outcome trials to ascertain safety. Surprisingly, these compounds reduced the risk of cardiovascular events (cardiovascular death, non-fatal myocardial and non-fatal stroke) and total mortality. The mechanisms behind this benefit are only partly understood, but a major contributor is the reduction of heart failure hospitalisations, evident already within weeks after the initiation of the SGLT2i. SGLT2 inhibition increases urinary glucose excretion, thereby improving glycaemic control in an insulin-independent manner. Moreover, SGLT2i potentially impact the cardiovascular system both indirectly via weight loss and blood pressure lowering and directly through osmotic diuresis and increased sodium excretion and presumably by improving myocardial energetics. The aim of this review is to summarise evidence from all major outcome trials investigating SGLT2i in patients with diabetes, as well as recent evidence from trials in heart failure patients without glucose perturbations, which pave the way for novel treatment of large groups of patients. The results of these studies have been taken into account in recently issued guidelines for the management of diabetes and cardiovascular disease. An important task for diabetologists, cardiologists and general practitioners is to incorporate them into clinical practice to the benefit of many patients.