Do SGLT-2 inhibitors exhibit similar cardiovascular benefit in patients with heart failure with reduced or preserved ejection fraction?

Efficacy and safety of sodium-glucose cotransporter-2 inhibitors in heart failure with mildly reduced or preserved ejection fraction: an overview of 36 systematic reviews

The recently published randomized trials (RCTs) evaluating the effect of Sodium-glucose cotransporter-2 inhibitors (SGLT2i) in heart failure with mildly reduced (HFmrEF) or preserved ejection fraction (HFpEF) led researchers to perform a plethora of systematic reviews (SRs), often providing contradictory conclusions. This overview of reviews was aimed at summarizing the evidence of these SRs, quantifying the overlap, re-analyzing the evidence in case new studies that were identified, and mapping knowledge gaps. Literature search was conducted through Medline, Scopus, and Cochrane until March 22, 2023. Overall, 36 SRs synthesizing results from 18 RCTs were identified. A substantial overlap was identified among the SRs synthesizing large heart failure or cardiovascular outcome trials (CVOTs). Regarding the composite outcome of cardiovascular (CV) mortality or hospitalization for heart failure (HHF), all authors reported a significant favorable effect. A beneficial effect was also noted for CV and all-cause mortality, albeit not significant. Our meta-analysis demonstrated a significant improvement in health-related quality-of-life (HRQoL) as assessed by the Kansas City Cardiomyopathy Questionnaire Overall Summary Score (KCCQ-OSS, MD = 1.97, p < 0.001), Total Symptom Score (KCCQ-TSS, MD = 2.29, p < 0.001), Clinical Summary Score (KCCQ-CSS, MD = 1.59, p < 0.001), and the 6-min walking distance (MD = 10.78 m, p = 0.032). Regarding safety, SGLT2i were associated with a significantly lower risk of serious adverse events compared to placebo (RR = 0.94, p = 0.002). The use of SGLT2i in HFpEF is both efficient and safe. Further research is required to clarify the impact of SGTL2i on different subphenotypes of HFpEF and the cardiorespiratory capacity of these patients.

Scientific evidence of sodium-glucose cotransporter-2 inhibitors for heart failure with preserved ejection fraction: an umbrella review of systematic reviews and meta-analyses

Background

It remains controversial whether sodium-glucose cotransporter-2 inhibitors (SGLT-2is) are effective in treating heart failure with preserved ejection fraction (HFpEF).

Purpose

The objective of this umbrella review is to provide a summary of the available evidence regarding the efficacy and safety of SGLT-2is for the treatment of HFpEF.

Methods

We extracted pertinent systematic reviews and meta-analyses (SRs/MAs) from PubMed, EMBASE, and the Cochrane Library that were published between the inception of the database and December 31, 2022. Two independent investigators assessed the methodological quality, risk of bias, report quality, and evidence quality of the included SRs/MAs in randomized controlled trials (RCTs). We further evaluated the overlap of the included RCTs by calculating the corrected covered area (CCA) and assessed the reliability of the effect size by performing excess significance tests. Additionally, the effect sizes of the outcomes were repooled to obtain objective and updated conclusions. Egger's test and sensitivity analysis were used to clarify the stability and reliability of the updated conclusion.

Results

This umbrella review included 15 SRs/MAs, and their methodological quality, risk of bias, report quality, and evidence quality were unsatisfactory. The total CCA for 15 SRs/MAs was 23.53%, indicating a very high level of overlap. The excess significance tests did not reveal any significant results. Our updated MA demonstrated that the incidence of the composite of hospitalization for heart failure (HHF) or cardiovascular death (CVD), first HHF, total HHF, and adverse events as well as the Kansas City Cardiomyopathy Questionnaire Total Symptom Score (KCCQ-TSS) and 6 min-walk distance (6MWD) were all substantially improved in the SGLT-2i intervention group compared to the control group. However, there was limited evidence that SGLT-2is could improve CVD, all-cause death, plasma B-type natriuretic peptide (BNP) level, or plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) level. Egger's test and sensitivity analysis proved that the conclusion was stable and reliable.

Conclusions

SGLT-2 is a potential treatment for HFpEF with favourable safety. Given the dubious methodological quality, reporting quality, evidence quality, and high risk of bias for certain included SRs/MAs, this conclusion must be drawn with caution.

Systematic Review Registration

https://inplasy.com/, doi: 10.37766/inplasy2022.12.0083, identifier INPLASY2022120083.

SGLT-2 inhibitors as cardio-renal protective agents

Despite remarkable advances in diabetes care, patients with type 2 diabetes are still burdened by higher morbidity and mortality than non-diabetic individuals. Atherosclerotic cardiovascular disease, heart failure, and chronic kidney disease represent the most relevant causes of morbidity and mortality and sustain each other in a vicious circle. Cardiovascular diseases are the main cause of death in patients with chronic kidney disease, and, in turn, chronic kidney disease is a significant contributor to the risk of major cardiovascular events and hospitalization for heart failure. Cardiovascular outcome trials with SGLT-2 inhibitors in type 2 diabetes yielded unprecedented results on prevention of worsening heart failure and renal disease progression and mortality, further confirmed by randomized controlled trials in patients with baseline heart failure and chronic kidney disease, with or without diabetes, and observations from the real-world setting. However, the evidence regarding SGLT-2 inhibitors benefit on atherosclerotic cardiovascular events is conflicting. Hence, SGLT-2 inhibitors represent a remarkably valuable weapon in diabetes management, to be used in the context of a multi-targeted treatment strategy to address the many issues of this multifaceted disease.

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.

Diabetes and SGLT2-iss inhibitors in patients with heart failure with preserved or mid-range left ventricular ejection fractions

Diabetic patients frequently develop heart failure with preserved (HFpEF) or mid-range (HFmEF) cardiac ejection fractions. This condition may be secondary to diabetic cardiomyopathy or one of several relevant comorbidities, mainly hypertension. Several mechanisms link diabetes to HFpEF or HFmEF. Among these, non-enzymatic glycation of interstitial proteins, lipotoxicity, and endothelial dysfunction may promote structural damage and ultimate lead to heart failure. Findings from several large-scale trials indicated that treatment with sodium/glucose cotransporter 2 inhibitors (SGLT2-iss) resulted in significant improvements in cardiovascular outcomes in diabetic patients with high cardiovascular risk. However, there is currently some evidence that suggests a clinical advantage of using SGLT2-iss specifically in cases of HFpEF or HFmEF. Preclinical and clinical studies revealed that SGLT2-iss treatment results in a reduction in left ventricular mass and improved diastolic function. While some of the beneficial effects of SGLT2-iss have already been characterized (e.g., increased natriuresis and diuresis as well as reduced blood pressure, plasma volume, and arterial stiffness, and nephron-protective activities), there is increasing evidence suggesting that SGLT2-iss may have direct actions on the heart. These findings include SGLT2-iss-mediated reductions in the expression of hypertrophic foetal genes and diastolic myofilaments stiffness, increases in global phosphorylation of myofilament regulatory proteins (in HFpEF), inhibition of cardiac late sodium channel current and Na⁺/H⁺ exchanger activity, metabolic shifts, and effects on calcium cycling. Preliminary data from previously published studies suggest that SGLT2-iss could be useful for the treatment of HFpEF and HFmEF. Several large ongoing trials, including DELIVER AND EMPEROR -preserved have been designed to evalute the efficacy of SGLT2-iss in improving clinical outcomes in patients diagnosed with HFpEF. The goal of this manuscript is to review the use of SGLT2-iss inhibitors for HFpEF or HFmEF associated with diabetes.