Decoding the effects of SGLT2 inhibitors on cardiac arrhythmias in heart failure

Association of Continued Use of SGLT2 Inhibitors From the Ambulatory to Inpatient Setting With Hospital Outcomes in Patients With Diabetes: A Nationwide Cohort Study

OBJECTIVE

Limited data are available on the continuation of outpatient sodium glucose cotransporter 2 inhibitors (SGLT2is) during hospitalization. The objective was to evaluate associations of SGLT2i continuation in the inpatient setting with hospital outcomes.

RESEARCH DESIGN AND METHODS

This nationwide cohort study used Veterans Affairs health care system data of acute care hospitalizations between 1 April 2013 and 31 August 2021. A total of 36,505 admissions of patients with diabetes with an outpatient prescription for an SGLT2i prior to hospitalization were included. The exposure was defined as SGLT2i continuation during hospitalization. Admissions where SGLT2i was continued were compared with admissions where it was discontinued. The primary outcome was in-hospital mortality. Secondary outcomes were acute kidney injury (AKI) and length of stay (LOS). Negative binomial propensity score-weighted and zero-truncated analyses were used to compare outcomes and adjusted for multiple covariates, including demographics and comorbidities.

RESULTS

Mean (SE) age was 67.2 (0.1) and 67.5 (0.1) years (P = 0.03), 97.0% and 96.6% were male (P = 0.1), 71.3% and 72.1% were White, and 20.8% and 20.5% were Black (P = 0.52) for the SGLT2i continued and discontinued groups, respectively. After adjustment for covariates (age, sex, race, BMI, Elixhauser comorbidity index, procedures/surgeries, and insulin use), the SGLT2i continued group had a 45% lower mortality rate (incidence rate ratio [IRR] 0.55, 95% CI 0.42-0.73, P < 0.01), no difference in AKI (IRR 0.96, 95% CI 0.90-1.02, P = 0.17), and decreased LOS (4.7 vs. 4.9 days) (IRR 0.95, 95% CI 0.93-0.98, P < 0.01) versus the SGLT2i discontinued group. Similar associations were observed across multiple sensitivity analyses.

CONCLUSIONS

Continued SGLT2i during hospitalization among patients with diabetes was associated with lower mortality, no increased AKI, and shorter LOS.

The therapeutic potential of ketones in cardiometabolic disease: impact on heart and skeletal muscle

β-Hydroxybutyrate (βOHB) is the major ketone in the body, and it is recognized as a metabolic energy source and an important signaling molecule. While ketone oxidation is essential in the brain during prolonged fasting/starvation, other organs such as skeletal muscle and the heart also use ketones as metabolic substrates. Additionally, βOHB-mediated molecular signaling events occur in heart and skeletal muscle cells, and via metabolism and/or signaling, ketones may contribute to optimal skeletal muscle health and cardiac function. Of importance, when the use of ketones for ATP production and/or as signaling molecules becomes disturbed in the presence of underlying obesity, type 2 diabetes, and/or cardiovascular diseases, these changes may contribute to cardiometabolic disease. As a result of these disturbances in cardiometabolic disease, multiple approaches have been used to elevate circulating ketones with the goal of optimizing either ketone metabolism or ketone-mediated signaling. These approaches have produced significant improvements in heart and skeletal muscle during cardiometabolic disease with a wide range of benefits that include improved metabolism, weight loss, better glycemic control, improved cardiac and vascular function, as well as reduced inflammation and oxidative stress. Herein, we present the evidence that indicates that ketone therapy could be used as an approach to help treat cardiometabolic diseases by targeting cardiac and skeletal muscles.

Sodium-glucose cotransporter type 2 inhibitors and cardiac arrhythmias

The introduction of sodium-glucose cotransporter 2 (SGLT2) inhibitors as a new and effective class of therapeutic agents for type 2 diabetes (T2D) preventing the reabsorption of glucose in the kidneys and thus facilitating glucose excretion in the urine, but also as agents with cardiovascular benefits, particularly in patients with heart failure (HF), regardless of the diabetic status, has ushered in a new era in treating patients with T2D and/or HF. In addition, data have recently emerged indicating an antiarrhythmic effect of the SGLT2 inhibitors in patients with and without diabetes. Prospective studies, randomized controlled trials and meta-analyses have provided robust evidence for a protective and beneficial effect of these agents against atrial fibrillation, ventricular arrhythmias and sudden cardiac death. The antiarrhythmic mechanisms involved include reverse atrial and ventricular remodeling, amelioration of mitochondrial function, reduction of hypoglycemic episodes with their attendant arrhythmogenic effects, attenuated sympathetic nervous system activity, regulation of sodium and calcium homeostasis, and suppression of prolonged ventricular repolarization. These new data on antiarrhythmic actions of SGLT2 inhibitors are herein reviewed, potential mechanisms involved are discussed and pictorially illustrated, and treatment results on specific arrhythmias are described and tabulated.

Contemporary management of ventricular arrhythmias in heart failure

Enhanced ventricular arrhythmogenesis is commonly experienced by patients in the end-stage of heart failure spectrum. A high burden of ventricular arrhythmias can affect the ventricular systolic function, lead to unexpected hospitalizations and further deteriorate the prognosis. Management of ventricular arrhythmias in this population is challenging. Implantable cardioverter-defibrillators are protective for the immediate termination of life-threatening arrhythmias but they have no impact in reducing the arrhythmic burden. Combination treatment with invasive (catheter ablation, mechanical hemodynamic support, sympathetic denervation) and noninvasive (antiarrhythmic drugs, medical therapy for heart failure, programming of implantable devices) therapies is commonly required. The aim of this review is to present the available therapeutic options, with main focus on recently published data for catheter ablation and provide a stepwise treatment approach.

Effect of sodium glucose cotransporter 2 inhibitors on atrial tachy-arrhythmia burden in patients with cardiac implantable electronic devices

INTRODUCTION

Use of sodium glucose cotransporter 2 inhibitors (SGLT2i) was associated with a reduction in atrial fibrillation hospitalizations. Therefore, we aim to evaluate the effects of SGLT2i on atrial tachy-arrhythmias (ATA) in patients with cardiac implantable electronic devices (CIEDs).

METHODS

All 13 888 consecutive patients implanted with a CIED in two tertiary medical centers were enrolled. Treatment with SGLT2i was assessed as a time dependent variable. The primary endpoint was the total number of ATA. Secondary endpoints included total number of ventricular tachy-arrhythmias (VTA), ATA and VTA, and death. All events were independently adjudicated blinded to the treatment. Multivariable propensity score modeling was performed.

RESULTS

During a total follow-up of 24 442 patient years there were 62 725 ATA and 10 324 VTA events. Use of SGLT2i (N = 696) was independently associated with a significant 22% reduction in the risk of ATA (hazard ratio [HR] = 0.78 [95% confidence interval {CI} = 0.70-0.87]; p < .001); 22% reduction in the risk of ATA/VTA (HR = 0.78 [95% CI = 0.71-0.85]; p < .001); and with a 35% reduction in the risk of all-cause mortality (HR = 0.65 [95% CI = 0.45-0.92]; p = .015), but was not significantly associated with VTA risk (HR = 0.92 [95% CI = 0.80-1.06]; p = .26). SGLT2i were associated with a lower ATA burden in heart failure (HF) patients but not among diabetes patients (HF: HR = 0.68, 95% CI = 0.58-0.80, p < .001 vs. Diabetes: HR = 0.95, 95% CI = 0.86-1.05, p = .29; p < .001 for interaction between SGLT2i indication and ATA burden).

CONCLUSION

Our real world findings suggest that in CIED HF patients, those with SGLT2i had a pronounced reduction in ATA burden and all-cause mortality when compared with those not on SGLT2i.

A Model-Informed Approach to Accelerate the Clinical Development of Janagliflozin, an Innovative SGLT2 Inhibitor

AIM

To apply model-informed drug development (MIDD) approach to support the decision making in drug development and accelerate the clinical development of janagliflozin, an orally selective SGLT2 inhibitor.

METHOD

We previously developed a mechanistic pharmacokinetic/pharmacodynamic (PK/PD) model of janagliflozin based on preclinical data to optimize dose design in the first-in-human (FIH) study. In the current study, we used clinical PK/PD data of the FIH study to validate the model and then simulate the PK/PD profiles of multiple ascending dosing (MAD) study in healthy subjects. Besides, we developed a population PK/PD model of janagliflozin to predict steady-state urinary glucose excretion (UGE [UGE,ss]) in healthy subjects in the Phase 1 stage. This model was subsequently used to simulate the UGE, ss in patients with type 2 diabetes mellitus (T2DM) based on a unified PD target (ΔUGEc) across healthy subjects and patients with T2DM. This unified PD target was estimated from our previous work of model-based meta-analysis (MBMA) for the same class of drugs. The model-simulated UGE,ss in patients with T2DM was validated by data from the clinical Phase 1e study. Finally, at the end of the Phase 1 study, we simulated the 24-week hemoglobin A1c (HbA1c) level in patients with T2DM of janagliflozin based on the quantitative UGE/FPG/HbA1c relationship informed by our previous MBMA study for the same class of drugs.

RESULTS

The pharmacologically active dose (PAD) levels of multiple ascending dosing (MAD) study were estimated to be 25, 50,100 mg once daily (QD) for 14 days based on the effective PD target of approximately 50 g daily UGE in healthy subjects. Besides, our previous MBMA analysis for the same class of drugs has provided a unified effective PD target of ΔUGEc approximately 0.5-0.6 g/(mg/dL) in both healthy subjects and patients with T2DM. In this study, the model-simulated steady-state ΔUGEc (ΔUGEc,ss) of janagliflozin in patients with T2DM were 0.52, 0.61 and 0.66 g/(mg/dL) for 25, 50, 100 mg QD dose levels. Finally, we estimated that HbA1c at 24 weeks would decrease 0.78 and 0.93 from baseline for the 25 and 50 mg QD dose groups.

CONCLUSIONS

The application of MIDD strategy adequately supported the decision making at each stage of janagliflozin development process. A waiver of Phase 2 study was successfully approved for janagliflozin based on these model-informed results and suggestions. This MIDD strategy of janagliflozin could be further utilized to support the clinical development of other SGLT2 inhibitors.

Antiarrhythmic effects and mechanisms of sodium-glucose cotransporter 2 inhibitors: A mini review

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are a new type of oral hypoglycaemic agent with good cardiovascular protective effects. There are several lines of clinical evidence suggest that SGLT2i can significantly reduce the risks of heart failure, cardiovascular death, and delay the progression of chronic kidney disease. In addition, recent basic and clinical studies have also reported that SGLT2i also has good anti-arrhythmic effects. However, the exact mechanism is poorly understood. The aim of this review is to summarize recent clinical findings, studies of laboratory animals, and related study about this aspect of the antiarrhythmic effects of SGLT2i, to further explore its underlying mechanisms, safety, and prospects for clinical applications of it.

Cardiac mechanisms of the beneficial effects of SGLT2 inhibitors in heart failure: Evidence for potential off-target effects

Sodium glucose cotransporter 2 inhibitors (SGLT2i) constitute a promising drug treatment for heart failure patients with either preserved or reduced ejection fraction. Whereas SGLT2i were originally developed to target SGLT2 in the kidney to facilitate glucosuria in diabetic patients, it is becoming increasingly clear that these drugs also have important effects outside of the kidney. In this review we summarize the literature on cardiac effects of SGLT2i, focussing on pro-inflammatory and oxidative stress processes, ion transport mechanisms controlling sodium and calcium homeostasis and metabolic/mitochondrial pathways. These mechanisms are particularly important as disturbances in these pathways result in endothelial dysfunction, diastolic dysfunction, cardiac stiffness, and cardiac arrhythmias that together contribute to heart failure. We review the findings that support the concept that SGLT2i directly and beneficially interfere with inflammation, oxidative stress, ionic homeostasis, and metabolism within the cardiac cell. However, given the very low levels of SGLT2 in cardiac cells, the evidence suggests that SGLT2-independent effects of this class of drugs likely occurs via off-target effects in the myocardium. Thus, while there is still much to be understood about the various factors which determine how SGLT2i affect cardiac cells, much of the research clearly demonstrates that direct cardiac effects of these SGLT2i exist, albeit mediated via SGLT2-independent pathways, and these pathways may play a role in explaining the beneficial effects of SGLT2 inhibitors in heart failure.

Mechanisms Underlying Antiarrhythmic Properties of Cardioprotective Agents Impacting Inflammation and Oxidative Stress

The prevention of cardiac life-threatening ventricular fibrillation and stroke-provoking atrial fibrillation remains a serious global clinical issue, with ongoing need for novel approaches. Numerous experimental and clinical studies suggest that oxidative stress and inflammation are deleterious to cardiovascular health, and can increase heart susceptibility to arrhythmias. It is quite interesting, however, that various cardio-protective compounds with antiarrhythmic properties are potent anti-oxidative and anti-inflammatory agents. These most likely target the pro-arrhythmia primary mechanisms. This review and literature-based analysis presents a realistic view of antiarrhythmic efficacy and the molecular mechanisms of current pharmaceuticals in clinical use. These include the sodium-glucose cotransporter-2 inhibitors used in diabetes treatment, statins in dyslipidemia and naturally protective omega-3 fatty acids. This approach supports the hypothesis that prevention or attenuation of oxidative and inflammatory stress can abolish pro-arrhythmic factors and the development of an arrhythmia substrate. This could prove a powerful tool of reducing cardiac arrhythmia burden.