Effect of dapagliflozin on ventricular arrhythmias, resuscitated cardiac arrest, or sudden death in DAPA-HF

SGLT2 Inhibitors and Their Antiarrhythmic Properties

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are gaining ground as standard therapy for heart failure with a class-I recommendation in the recently updated heart failure guidelines from the European Society of Cardiology. Different gliflozins have shown impressive beneficial effects in patients with and without diabetes mellitus type 2, especially in reducing the rates for hospitalization for heart failure, yet little is known on their antiarrhythmic properties. Atrial and ventricular arrhythmias were reported by clinical outcome trials with SGLT2 inhibitors as adverse events, and SGLT2 inhibitors seemed to reduce the rate of arrhythmias compared to placebo treatment in those trials. Mechanistical links are mainly unrevealed, since hardly any experiments investigated their impact on arrhythmias. Prospective trials are currently ongoing, but no results have been published so far. Arrhythmias are common in the heart failure population, therefore the understanding of possible interactions with SGLT2 inhibitors is crucial. This review summarizes evidence from clinical data as well as the sparse experimental data of SGLT2 inhibitors and their effects on arrhythmias.

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.

Protective effects of Dapagliflozin on the vulnerability of ventricular arrhythmia in rats with pulmonary artery hypertension induced by monocrotaline

Monocrotaline (MCT)-induced pulmonary artery hypertension (PAH) has been reported to cause right heart failure (RHF). Moreover, Right heart diseases have been determined to cause ventricular arrhythmia (VA). So we can conclude that MCT-induced PAH increases the incidence of VA. In addition, Previous studies have determined the benefits of Dapagliflozin (DA) on the cardiac system, but the responses of MCT-induced RHF to DA are not fully reported. So the present study sought to evaluate the effects of DA on the MCT-induced PAH. A dose intraperitoneal injection of MCT (60 mg/kg) was carried out to induce a rat model with PAH. DA (60 mg/l) was administered for 4 weeks following MCT injection. Echocardiography, body weight, blood pressure, blood glucose, electrophysiological study, and Western blot were performed. Four weeks after the MCT injection, MCT-treated rats decreased body weight, blood glucose and blood pressure. In addition, MCT caused the formation of PAH and RHF. Moreover, MCT-induced PAH rats increased the incidence of VA, prolonged action potential duration (APD), and shortened effective refractory period (ERP). Additionally, PAH rats significantly prevented the activated expressions of Ion channel proteins such as potassium channel (Kv1.5, Kv2.1, Kv4.2, Kv4.3) and L-type Ca channel (Cav1.2). As we expected, these changes above in PAH rats were reversed when DA was administered. Mechanistically, DA significantly reduced the levels of toll-like receptor (TLR4), the nuclear factor kappa B (NF-κB) in MCT-treated rats. In conclusion, these findings determine that DA reduces the vulnerability of VA in PAH rats through the TLR4/NF-κB signaling pathway.

Sodium-Glucose Cotransporter 2 Inhibitors and Heart Failure: A Bedside-to-Bench Journey

Type 2 diabetes mellitus (T2DM) and heart failure (HF) are multifactorial diseases sharing common risk factors, such as obesity, hyperinsulinemia, and inflammation, with underlying mechanisms including endothelial dysfunction, inflammation, oxidative stress, and metabolic alterations. Cardiovascular benefits of sodium-glucose cotransporter 2 (SGLT2) inhibitors observed in diabetic and non-diabetic patients are also related to their cardiac-specific, SGLT-independent mechanisms, in addition to the metabolic and hemodynamic effects. In search of the possible underlying mechanisms, a research campaign has been launched proposing varied mechanisms of action that include intracellular ion homeostasis, autophagy, cell death, and inflammatory processes. Moreover, the research focus was widened toward cellular targets other than cardiomyocytes. At the moment, intracellular sodium level reduction is the most explored mechanism of direct cardiac effects of SGLT2 inhibitors that mediate the benefits in heart failure in addition to glucose excretion and diuresis. The restoration of cardiac Na⁺ levels with consequent positive effects on Ca²⁺ handling can directly translate into improved contractility and relaxation of cardiomyocytes and have antiarrhythmic effects. In this review, we summarize clinical trials, studies on human cells, and animal models, that provide a vast array of data in support of repurposing this class of antidiabetic drugs.

The Future of Antiarrhythmic Drug Therapy: Will Drugs Be Entirely Replaced by Procedures?

Antiarrhythmic drug therapy has traditionally been centered in modulating the generation or propagation of the cardiac action potential by drugs acting on membrane ion channels. The history of this approach has been disappointing, marked by catastrophic failures such as those of sodium channel blockers or sotalol to treat ventricular arrhythmias in the setting of structural cardiomyopathies, which led to increased mortality, and by modest clinical efficacy in paroxysmal atrial fibrillation. As catheter ablation has become an established effective therapy for most tachyarrhythmias, membrane-acting drugs have been relegated to symptomatic control of benign arrhythmias in normal hearts or to adjunctive treatments of ventricular tachycardia (combined with catheter ablation and cardiac defibrillators) in the setting of cardiomyopathies. Novel targets of biological modulation of arrhythmia substrates beyond the membrane potential appear promising and could represent future opportunities for arrhythmia pharmacotherapy.

Management of ventricular tachycardia in patients with ischaemic cardiomyopathy: contemporary armamentarium

Worldwide, ∼4 million people die from sudden cardiac death every year caused in more than half of the cases by ischaemic cardiomyopathy (ICM). Prevention of sudden cardiac death after myocardial infarction by implantation of a cardioverter-defibrillator (ICD) is the most common, even though not curative, therapy to date. Optimized ICD programming should be strived for in order to decrease the incidence of ICD interventions. Catheter ablation reduces the recurrence of ventricular tachycardias (VTs) and is an important adjunct to sole ICD-based treatment or pharmacological antiarrhythmic therapy in patients with ICM, as conclusively demonstrated by seven randomized controlled trials (RCTs) in the last two decades. However, none of the conducted trials was powered to reveal a survival benefit for ablated patients as compared to controls. Whereas thorough consideration of an early approach is necessary following two recent RCTs (PAUSE-SCD, BERLIN VT), catheter ablation is particularly recommended in patients with recurrent VT after ICD therapy. In this context, novel, pathophysiologically driven ablation strategies referring to deep morphological and functional substrate phenotyping based on high-resolution mapping and three-dimensional visualization of scars appear promising. Emerging concepts like sympathetic cardiac denervation as well as radioablation might expand the therapeutical armamentarium especially in patients with therapy-refractory VT. Randomized controlled trials are warranted and on the way to investigate how these translate into improved patient outcome. This review summarizes therapeutic strategies currently available for the prevention of VT recurrences, the optimal timing of applicability, and highlights future perspectives after a PAUSE in BERLIN.

Effect of sacubitril/valsartan on investigator-reported ventricular arrhythmias in PARADIGM-HF

Aims

Sudden death is a leading cause of mortality in heart failure with reduced ejection fraction (HFrEF). In PARADIGM‐HF, sacubitril/valsartan reduced the incidence of sudden death. The purpose of this post hoc study was to analyse the effect of sacubitril/valsartan, compared to enalapril, on the incidence of ventricular arrhythmias.

Methods and results

Adverse event reports related to ventricular arrhythmias were examined in PARADIGM‐HF. The effect of randomized treatment on two arrhythmia outcomes was analysed: ventricular arrhythmias and the composite of a ventricular arrhythmia, implantable cardioverter defibrillator (ICD) shock or resuscitated cardiac arrest. The risk of death related to a ventricular arrhythmia was examined in time‐updated models. The interaction between heart failure aetiology, or baseline ICD/cardiac resynchronization therapy‐defibrillator (CRT‐D) use, and the effect of sacubitril/valsartan was analysed. Of the 8399 participants, 333 (4.0%) reported a ventricular arrhythmia and 372 (4.4%) the composite arrhythmia outcome. Ventricular arrhythmias were associated with higher mortality. Compared with enalapril, sacubitril/valsartan reduced the risk of a ventricular arrhythmia (hazard ratio [HR] 0.76, 95% confidence interval [CI] 0.62–0.95; p = 0.015) and the composite arrhythmia outcome (HR 0.79, 95% CI 0.65–0.97; p = 0.025). The treatment effect was maintained after adjustment and accounting for the competing risk of death. Baseline ICD/CRT‐D use did not modify the effect of sacubitril/valsartan, but aetiology did: HR in patients with an ischaemic aetiology 0.93 (95% CI 0.71–1.21) versus 0.53 (95% CI 0.37–0.78) in those without an ischaemic aetiology (p for interaction = 0.020).

Conclusions

Sacubitril/valsartan reduced the incidence of investigator‐reported ventricular arrhythmias in patients with HFrEF. This effect may have been greater in patients with a non‐ischaemic aetiology.

The effect of dapagliflozin on ventricular arrhythmias, cardiac arrest, or sudden death in people with heart failure: a tick in another box for sodium-glucose cotransporter 2 inhibitors

INTRODUCTION

Despite the progress made in the treatment of heart failure with reduced ejection fraction (HFrEF) in recent years, the prognosis of the disease remains poor, with ventricular arrhythmias (VA) contributing significantly to increased mortality.

AREAS COVERED

A recently published post hoc analysis of the DAPA-HF trial evaluated the effect of the sodium-glucose cotransporter 2 inhibitor (SGLT2i) dapagliflozin versus placebo on the incidence of VA, resuscitated cardiac arrest, or sudden death among people with HFrEF. During a median follow-up of 18.2 months, the composite primary outcome occurred in 140 (5.9%) people who received dapagliflozin compared to 175 (7.4%) participants in the placebo arm (hazard ratio 0.79; 95 confidence interval 0.63-0.99, P = 0.037). Animal studies suggest that SGLT2i could ameliorate the deleterious effects of myocardial injury, through various mechanisms, including reduced sympathetic activity, improved oxidative stress, tissue oxygenation, autophagy, heart energy metabolism, and promotion of cardiac remodeling.

EXPERT OPINION

Taken together, the above findings indicate a place for SGLT2i in future trials investigating novel treatments to improve survival in patients with acute cardiovascular episodes. This is primarily applicable for acute decompensated HF; however, their use could also be evaluated in other conditions that induce VA, such as acute coronary syndromes.

Use of disease-modifying drugs in diabetic patients with heart failure with reduced ejection fraction

Type 2 diabetes mellitus and heart failure are closely related, patients with type 2 diabetes mellitus have a higher risk of developing heart failure, and those with heart failure are at increased risk of developing type 2 diabetes. Although no specific randomized clinical trials have been conducted to test the effect of cardiovascular therapies (drugs and/or devices) in diabetic patients with heart failure, a lot of evidence shows that all interventions effective in improving prognosis in patients with heart failure reduced ejection fraction are equally beneficial in patients with and without diabetes. However, the use of disease-modifying drugs in patients with diabetes and heart failure reduced ejection fraction is a clinical challenge due to the increased risk of adverse effects. For example, β-blockers are underutilized in diabetic patients due to the theoretical unfavorable effects on glucose metabolism as well as the use of drugs that interact with the renin-angiotensin system can be challenged in patients with diabetic nephropathy because of the risk of hyperkalemia. This review outlines the current use of disease-modifying drugs in diabetic patients with heart failure reduced ejection fraction. In addition, the role of novel pharmacologic agents as type 2 sodium-glucose co-transporter inhibitors (SGLT2ii) is discussed.

Dapagliflozin: A Review in Symptomatic Heart Failure with Reduced Ejection Fraction

Dapagliflozin [Farxiga^® (USA); Forxiga^® (EU)], a sodium–glucose cotransporter 2 (SGLT2) inhibitor, was recently approved in the USA and the EU for the treatment of adults with symptomatic heart failure with reduced ejection fraction (HFrEF). The cardiovascular (CV) benefits of dapagliflozin were first observed in the DECLARE-TIMI 58 trial, in which dapagliflozin 10 mg/day significantly reduced the risk of CV death or hospitalization for HF in patients with type 2 diabetes mellitus (T2DM) who had or were at risk for atherosclerotic CV disease. In the subsequent DAPA-HF trial, dapagliflozin 10 mg/day in addition to standard of care was associated with a significantly lower risk of worsening HF or CV death than placebo in patients with HFrEF, regardless of the presence or absence of T2DM. The benefits of dapagliflozin also remained consistent regardless of background HF therapies. Dapagliflozin was generally well tolerated, with an overall safety profile consistent with its known safety profile in other indications. In conclusion, dapagliflozin is an effective and generally well-tolerated treatment that represents a valuable new addition to the options available for symptomatic HFrEF.

Heart failure (HF) is a major cause of death and disability. HFrEF occurs when the left ventricular ejection fraction is ≤ 40%. Conventional treatments for HFrEF include angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, angiotensin receptor-neprilysin inhibitors, β-blockers, mineralocorticoid receptor antagonists, hydralazine/isosorbide dinitrate, and ivabradine. Dapagliflozin [Farxiga^® (USA); Forxiga^® (EU)] is an SGLT2 inhibitor originally developed for the treatment of T2DM. It was the first SGLT2 inhibitor to be approved for the treatment of adults with symptomatic HFrEF. When added to standard therapy, dapagliflozin significantly reduced the risk of worsening HF or CV death in patients with HFrEF, regardless of whether or not they had T2DM. Moreover, the beneficial effects of dapagliflozin were seen regardless of patients’ usual HF medications. Dapagliflozin was generally well tolerated and is a valuable option for the treatment of symptomatic HFrEF.

Electrical Ventricular Remodeling in Dilated Cardiomyopathy

Ventricular arrhythmias contribute significantly to morbidity and mortality in patients with heart failure (HF). Pathomechanisms underlying arrhythmogenicity in patients with structural heart disease and impaired cardiac function include myocardial fibrosis and the remodeling of ion channels, affecting electrophysiologic properties of ventricular cardiomyocytes. The dysregulation of ion channel expression has been associated with cardiomyopathy and with the development of arrhythmias. However, the underlying molecular signaling pathways are increasingly recognized. This review summarizes clinical and cellular electrophysiologic characteristics observed in dilated cardiomyopathy (DCM) with ionic and structural alterations at the ventricular level. Furthermore, potential translational strategies and therapeutic options are highlighted.

Highlights of Cardiovascular Disease Studies Presented at the 2021 European Society of Cardiology Congress

PURPOSE OF REVIEW

This review highlights select studies presented at the virtual 2021 European Society of Cardiology (ESC) Congress.

RECENT FINDINGS

Reviewed studies assess single photon emission computed tomography, positron emission tomography, magnetic resonance imaging in coronary artery disease (PACIFIC-II); empagliflozin in heart failure with preserved ejection fraction (EMPEROR-Preserved); dapagliflozin in chronic heart failure (DAPA-HF); proprotein convertase subtilisin/kexin type 9 inhibitor and its lipid lowering effects (NATURE-PCSK9); fixed-dose combination therapies with or without aspirin in primary prevention; overview of contrasting results between REDUCE-IT versus STRENGTH trials; Quadruple UltrA-low-dose tReaTment for hypertension (QUARTET); evolocumab and changes in plaque composition on optical coherence tomography (HUYGENS); and low-dose rivaroxaban during the acute phase of acute coronary syndrome (H-REPLACE). Research presented at the 2021 ESC Congress shows promise in reducing burden of cardiovascular disease and reinforces the value of cardiovascular disease prevention.