Sacubitrilat reduces pro-arrhythmogenic sarcoplasmic reticulum Ca2+ leak in human ventricular cardiomyocytes of patients with end-stage heart failure

Anti-Arrhythmic Effects of Heart Failure Guideline-Directed Medical Therapy and Their Role in the Prevention of Sudden Cardiac Death: From Beta-Blockers to Sodium-Glucose Cotransporter 2 Inhibitors and Beyond

Sudden cardiac death (SCD) accounts for a substantial proportion of mortality in heart failure with reduced ejection fraction (HFrEF), frequently triggered by ventricular arrhythmias (VA). This review aims to analyze the pathophysiological mechanisms underlying VA and SCD in HFrEF and evaluate the effectiveness of guideline-directed medical therapy (GDMT) in reducing SCD. Beta-blockers, angiotensin receptor-neprilysin inhibitors, and mineralocorticoid receptor antagonists have shown significant efficacy in reducing SCD risk. While angiotensin-converting enzyme inhibitors and angiotensin receptor blockers exert beneficial impacts on the renin-angiotensin-aldosterone system, their direct role in SCD prevention remains less clear. Emerging treatments like sodium-glucose cotransporter 2 inhibitors show promise but necessitate further research for conclusive evidence. The favorable outcomes of those molecules on VA are notably attributable to sympathetic nervous system modulation, structural remodeling attenuation, and ion channel stabilization. A multidimensional pharmacological approach targeting those pathophysiological mechanisms offers a complete and synergy approach to reducing SCD risk, thereby highlighting the importance of optimizing GDMT for HFrEF. The current landscape of HFrEF pharmacotherapy is evolving, with ongoing research needed to clarify the full extent of the anti-arrhythmic benefits offered by both existing and new treatments.

Ion channel trafficking implications in heart failure

Heart failure (HF) is recognized as an epidemic in the contemporary world, impacting around 1%-2% of the adult population and affecting around 6 million Americans. HF remains a major cause of mortality, morbidity, and poor quality of life. Several therapies are used to treat HF and improve the survival of patients; however, despite these substantial improvements in treating HF, the incidence of HF is increasing rapidly, posing a significant burden to human health. The total cost of care for HF is USD 69.8 billion in 2023, warranting a better understanding of the mechanisms involved in HF. Among the most serious manifestations associated with HF is arrhythmia due to the electrophysiological changes within the cardiomyocyte. Among these electrophysiological changes, disruptions in sodium and potassium currents' function and trafficking, as well as calcium handling, all of which impact arrhythmia in HF. The mechanisms responsible for the trafficking, anchoring, organization, and recycling of ion channels at the plasma membrane seem to be significant contributors to ion channels dysfunction in HF. Variants, microtubule alterations, or disturbances of anchoring proteins lead to ion channel trafficking defects and the alteration of the cardiomyocyte's electrophysiology. Understanding the mechanisms of ion channels trafficking could provide new therapeutic approaches for the treatment of HF. This review provides an overview of the recent advances in ion channel trafficking in HF.

Sacubitril/valsartan effects on arrhythmias and left ventricular remodelling in heart failure: An observational study

AIMS

Conflicting results have been reported in the literature on the potential antiarrhythmic effect of sacubitril/valsartan in heart failure patients with reduced ejection fraction (HFrEF). The objectives of this study were: 1- to evaluate the long term effects of sacubitril/valsartan on arrhythmic burden in HFrEF patients; 2- to evaluate the correlation between the reduction of premature ventricular complexes during f-up and reverse remodelling.

METHODS

We identified 255 consecutive HFrEF patients treated with sacubitril/valsartan between March 2017 and May 2020 and followed by the Heart Failure and Cardiac Transplant Unit of IRCCS San Matteo Hospital in Pavia (Italy). Within this subgroup, 153 patients underwent 24 h-Holter-ECG or implantable cardioverter defibrillators (ICD) interrogation at baseline, at 12 months (t1) and at 24 months (t2) and transthoracic echocardiography at baseline and after 12 months after the beginning of sacubitril/valsartan. Cardiac-related hospitalizations were analyzed in the 12 months preceding and during 24 months following the drug starting date.

RESULTS

Global burden of 24-h premature ventricular complexes (PVC) was significantly reduced at 12 months (t1) and at 24 months (t2) as compared to the same period before treatment (1043 [304-3360] vs 768 [82-2784] at t1 vs 114 [9-333] at t2, P = 0.000). In the subgroup of patients implanted with biventricular ICD (n = 30), the percentage of biventricular pacing increased significantly (96% [94-99] vs 98% [96-99] at t1 vs 98%[97-100] at t2; P = 0.027). The burden of non-sustained ventricular tachycardia and sustained ventricular tachycardia did not change from baseline to t1 and t2, but a reduction of patients with at least one ICD appropriate shock was reported. The correlations between reduction in 24 h PVC and reduction in LV-ESVi or improvement in LVEF were not statistically significant (respectively R = 0.144, P = 0.197 and R = -0.190, P = 0.074). Heart failure related hospitalizations decreased during follow up (11.1% in the year before treatment vs 4.6% at t1 and 4.6% at t2; P = 0.040).

CONCLUSION

Sacubitril/valsartan reduced the number of premature ventricular complexes and increased the percentage of biventricular pacing in a cohort of HFrEF patients already on optimal medical therapy. PVC reduction did not correlate with reverse left ventricular remodelling. Whether sacubitril/valsartan has any direct antiarrhythmic effects is an issue to be better explored in future studies.

The Rare Condition of Left Ventricular Non-Compaction and Reverse Remodeling

Left ventricular non-compaction (LVNC) is a rare disease defined by morphological criteria, consisting of a two-layered ventricular wall, a thin compacted epicardial layer, and a thick hyper-trabeculated myocardium layer with deep recesses. Controversies still exist regarding whether it is a distinct cardiomyopathy (CM) or a morphological trait of different conditions. This review analyzes data from the literature regarding diagnosis, treatment, and prognosis in LVNC and the current knowledge regarding reverse remodeling in this form of CM. Furthermore, for clear exemplification, we report a case of a 41-year-old male who presented symptoms of heart failure (HF). LVNC CM was suspected at the time of transthoracic echocardiography and was subsequently confirmed upon cardiac magnetic resonance imaging. A favorable remodeling and clinical outcome were registered after including an angiotensin receptor neprilysin inhibitor in the HF treatment. LVNC remains a heterogenous CM, and although a favorable outcome is not commonly encountered, some patients respond well to therapy.

The Impact of Angiotensin Receptor-Neprilysin Inhibitors on Arrhythmias in Patients with Heart Failure: A Systematic Review and Meta-analysis

Angiotensin receptor-neprilysin inhibitor (ARNI) use has become increasingly popular. Current guidelines recommend using ARNI therapy for heart failure with reduced (HFrEF) and preserved ejection fraction (HFpEF). As therapies become more widely available, heart failure-associated burdens such as ventricular arrhythmias and sudden cardiac death (SCD) will become increasingly prevalent. We conducted a systematic review and meta-analysis to assess the impact of ARNI therapy on HFrEF and HFpEF pertaining to arrhythmogenesis and SCD. We performed a search of MEDLINE (PubMed), the Cochrane Library, and ClinicalTrials.gov for relevant studies. The odds ratios (ORs) of SCD, ventricular tachycardia (VT), ventricular fibrillation (VF), atrial fibrillation/flutter (AF), supraventricular tachycardia (SVT), and implantable cardioverter-defibrillator (ICD) shocks were calculated. A total of 10 studies, including 6 randomized controlled trials and 4 observational studies, were included in the analysis. A total of 18,548 patients from all studies were included, with 9,328 patients in the ARNI arm and 9,220 patients in the angiotensin-converting enzyme inhibitor (ACEI)/angiotensin II receptor blocker (ARB) arm, with a median follow-up time of 15 months. There was a significant reduction in the composite outcomes of SCD and ventricular arrhythmias in patients treated with ARNIs compared to those treated with ACEIs/ARBs (OR, 0.71; 95% confidence interval, 0.54-0.93; P = .01; I² = 17%; P = .29). ARNI therapy was also associated with a significant reduction in ICD shocks. There was no significant reduction in the VT, VF, AF, or SVT incidence rate in the ARNI group compared to the ACEI/ARB group. In conclusion, the use of ARNIs confers a reduction in composite outcomes of SCD and ventricular arrhythmias among patients with heart failure. These outcomes were mainly driven by SCD reduction in patients treated with ARNIs.

Molecular mechanisms of sacubitril/valsartan in cardiac remodeling

Cardiovascular diseases have become a major clinical burden globally. Heart failure is one of the diseases that commonly emanates from progressive uncontrolled hypertension. This gives rise to the need for a new treatment for the disease. Sacubitril/valsartan is a new drug combination that has been approved for patients with heart failure. This review aims to detail the mechanism of action for sacubitril/valsartan in cardiac remodeling, a cellular and molecular process that occurs during the development of heart failure. Accumulating evidence has unveiled the cardioprotective effects of sacubitril/valsartan on cellular and molecular modulation in cardiac remodeling, with recent large-scale randomized clinical trials confirming its supremacy over other traditional heart failure treatments. However, its molecular mechanism of action in cardiac remodeling remains obscure. Therefore, comprehending the molecular mechanism of action of sacubitril/valsartan could help future research to study the drug's potential therapy to reduce the severity of heart failure.

A narrative review on sacubitril/valsartan and ventricular arrhythmias

Sacubitril/valsartan, the first angiotensin receptor neprilysin inhibitor approved by the Food and Drug Administration for marketing, has been shown to reduce the risk of cardiovascular death or heart failure hospitalization and improve symptoms in patients with chronic heart failure with a reduced ejection fraction. However, some researchers have also found that sacubitril/valsartan has an antiarrhythmic effect. The mechanism by which sacubitril/valsartan reduces the mortality associated with malignant ventricular arrhythmias is not precise. Many studies have concluded that ventricular arrhythmia is associated with a reduction in myocardial fibrosis. This article reviews the current understanding of the effects of sacubitril/valsartan on the reduction of ventricular arrhythmia and explains its possible mechanisms. The results of this study suggest that sacubitril/valsartan reduces the occurrence of appropriate implantable cardioverter-defibrillator shocks. Meanwhile, sacubitril/valsartan may reduce the occurrence of ventricular arrhythmias by affecting 3 pathways of B-type natriuretic peptide, Angiotensin II, and Bradykinin. The conclusion of this study is that sacubitril/valsartan reduces the number of implantable cardioverter-defibrillator shocks and ventricular arrhythmias in heart failure with reduced ejection fraction patients.

Effects of BNP and Sacubitrilat/Valsartan on Atrial Functional Reserve and Arrhythmogenesis in Human Myocardium

Background

Although the angiotensin receptor-neprilysin inhibitor (ARNI) sacubitril/valsartan started a new era in heart failure (HF) treatment, less is known about the tissue-level effects of the drug on the atrial myocardial functional reserve and arrhythmogenesis.

Methods and Results

Right atrial (RA) biopsies were retrieved from patients (n = 42) undergoing open-heart surgery, and functional experiments were conducted in muscle strips (n = 101). B-type natriuretic peptide (BNP) did not modulate systolic developed force in human myocardium during β-adrenergic stimulation, but it significantly reduced diastolic tension (p < 0.01) and the probability of arrhythmias (p < 0.01). In addition, patient's plasma NTproBNP positively correlated with isoproterenol-induced contractile reserve in atrial tissue in vitro (r = 0.65; p < 0.01). Sacubitrilat+valsartan (Sac/Val) did not show positive inotropic effects on atrial trabeculae function but reduced arrhythmogeneity. Atrial and ventricular biopsies from patients with end-stage HF (n = 10) confirmed that neprilysin (NEP) is equally expressed in human atrial and ventricular myocardium. RA NEP expression correlates positively with RA ejection fraction (EF) (r = 0.806; p < 0.05) and left ventricle (LV) NEP correlates inversely with left atrial (LA) volume (r = −0.691; p < 0.05).

Conclusion

BNP ameliorates diastolic tension during adrenergic stress in human atrial myocardium and may have positive long-term effects on the inotropic reserve. BNP and Sac/Val reduce atrial arrhythmogeneity during adrenergic stress in vitro. Myocardial NEP expression is downregulated with declining myocardial function, suggesting a compensatory mechanism in HF.

The Application of Angiotensin Receptor Neprilysin Inhibitor in Cardiovascular Diseases: A Bibliometric Review From 2000 to 2022

Cardiovascular disease (CVD) has become a huge challenge for the global public health system due to its high morbidity, mortality and severe economic burden. In recent years, angiotensin receptor neprilysin inhibitor (ARNI), a new class of drugs, has shown good therapeutic effects on CVD patients in several clinical studies, reducing the morbidity and mortality of CVD patients. In this study, we retrieved publications on ARNI research in the cardiovascular field from the Web of Science core collection and analyzed the annual output, spatial and temporal distribution, institutions and authors, core journals, keywords and co-cited literature based on CiteSpace. As a result, 604 publications were retrieved, and the number of annual publications generally increased year by year, with the largest number of articles. The analysis of the co-occurrence of output countries and authors showed that a few developed countries such as the United States, Canada, and United Kingdom are the most active in this field, forming academic groups represented by John Joseph Valentine McMurray and Scott D. Solomon, and New England Journal of Medicine, Cirulation, and Journal of the American College of Cardiology are the most popular journals in the field, with research hotspots focused on ARNI in the treatment of total ejection fraction heart failure, hypertension and its target organ damage, with the potential for future benefit throughout the cardiovascular event chain as research progresses. This study reveals the prospective application of ARNI in the cardiovascular field and the research hotspots, providing broader and deeper guidance for its use in the clinic, which is beneficial to improve the treatment and prognosis of CVD patients.

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.

Sacubitril/valsartan versus angiotensin inhibitors and arrhythmia endpoints in heart failure with reduced ejection fraction

Background

Angiotensin receptor–neprilysin inhibitor (ARNI) therapy has been associated with improved survival for patients with symptomatic heart failure and reduced ejection fraction (HFrEF).

Objectives

We performed a meta-analysis of arrhythmia endpoints from studies comparing ARNI with angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) for patients with HFrEF to assess for incremental benefit.

Methods

We searched PubMed, Embase, and ClinicalTrials.gov. Baseline study characteristics were collected and outcomes were sustained ventricular arrhythmias, atrial arrhythmias, appropriate implantable cardioverter-defibrillator (ICD) therapy, sudden cardiac death (SCD), and biventricular (BiV) pacing rate.

Results

We included 9 studies, 4 randomized trials, and 5 observational studies (5589 patients on ARNI vs 5615 on ACEIs/ARBs). Follow-up ranged from 2 to 51 months. The mean age was 65.4 ± 9.8 years, with 77.3% male patients and a mean ejection fraction of 29.0% ± 7.6%. Ischemic cardiomyopathy was present in 62% of patients. In the ARNI group, there were less SCD (odds ratio [OR] 0.78, 95% confidence interval [CI] 0.63–0.96; P = .02), ventricular arrhythmias (OR 0.45, 95% CI 0.25–0.79; P = .005), and appropriate ICD therapy (OR 0.39, 95% CI 0.21–0.74; P = .004). Higher rates of BiV pacing were seen (mean difference 3.13, 95% CI 2.58–3.68; P < .00001) when compared with ACEIs/ARBs. No difference in atrial arrhythmias was seen.

Conclusion

ARNI therapy provides incremental benefit with respect to ventricular tachyarrhythmias/SCD, which may, in part, explain improved outcomes in patients with HFrEF compared to ACEIs/ARBs. There was increased BiV pacing and decreased ICD therapy in the ARNI group.

Angiotensin Receptor-Neprilysin Inhibitor (ARNI) and Cardiac Arrhythmias

The renin-angiotensin-aldosterone system (RAAS) plays a major role in cardiovascular health and disease. Short-term RAAS activation controls water and salt retention and causes vasoconstriction, which are beneficial for maintaining cardiac output in low blood pressure and early stage heart failure. However, prolonged RAAS activation is detrimental, leading to structural remodeling and cardiac dysfunction. Natriuretic peptides (NPs) are activated to counterbalance the effect of RAAS and sympathetic nervous system by facilitating water and salt excretion and causing vasodilation. Neprilysin is a major NP-degrading enzyme that degrades multiple vaso-modulatory substances. Although the inhibition of neprilysin alone is not sufficient to counterbalance RAAS activation in cardiovascular diseases (e.g., hypertension and heart failure), a combination of angiotensin receptor blocker and neprilysin inhibitor (ARNI) was highly effective in several clinical trials and may modulate the risk of atrial and ventricular arrhythmias. This review summarizes the possible link between ARNI and cardiac arrhythmias and discusses potential underlying mechanisms, providing novel insights about the therapeutic role and safety profile of ARNI in the cardiovascular system.

Sacubitrilat reduces pro-arrhythmogenic sarcoplasmic reticulum Ca2+ leak in human ventricular cardiomyocytes of patients with end-stage heart failure

Aims

Inhibition of neprilysin and angiotensin II receptor by sacubitril/valsartan (Val) (LCZ696) reduces mortality in heart failure (HF) patients compared with sole inhibition of renin–angiotensin system. Beneficial effects of increased natriuretic peptide levels upon neprilysin inhibition have been proposed, whereas direct effects of sacubitrilat (Sac) (LBQ657) on myocardial Ca²⁺ cycling remain elusive.

Methods and results

Confocal microscopy (Fluo‐4 AM) was used to investigate pro‐arrhythmogenic sarcoplasmic reticulum (SR) Ca²⁺ leak in freshly isolated murine and human ventricular cardiomyocytes (CMs) upon Sac (40 μmol/L)/Val (13 μmol/L) treatment. The concentrations of Sac and Val equalled plasma concentrations of LCZ696 treatment used in PARADIGM‐HF trial. Epifluorescence microscopy measurements (Fura‐2 AM) were performed to investigate effects on systolic Ca²⁺ release, SR Ca²⁺ load, and Ca²⁺‐transient kinetics in freshly isolated murine ventricular CMs. The impact of Sac on myocardial contractility was evaluated using in toto‐isolated, isometrically twitching ventricular trabeculae from human hearts with end‐stage HF. Under basal conditions, the combination of Sac/Val did not influence diastolic Ca²⁺‐spark frequency (CaSpF) nor pro‐arrhythmogenic SR Ca² leak in isolated murine ventricular CMs (n CMs/hearts = 80/7 vs. 100/7, P = 0.91/0.99). In contrast, Sac/Val treatment reduced CaSpF by 35 ± 9% and SR Ca²⁺ leak by 45 ± 9% in CMs put under catecholaminergic stress (isoproterenol 30 nmol/L, n = 81/7 vs. 62/7, P < 0.001 each). This could be attributed to Sac, as sole Sac treatment also reduced both parameters by similar degrees (reduction of CaSpF by 57 ± 7% and SR Ca²⁺ leak by 76 ± 5%; n = 101/4 vs. 108/4, P < 0.01 each), whereas sole Val treatment did not. Systolic Ca²⁺ release, SR Ca²⁺ load, and Ca²⁺‐transient kinetics including SERCA activity (k_SERCA) were not compromised by Sac in isolated murine CMs (n = 41/6 vs. 39/6). Importantly, the combination of Sac/Val and Sac alone also reduced diastolic CaSpF and SR Ca²⁺ leak (reduction by 74 ± 7%) in human left ventricular CMs from patients with end‐stage HF (n = 71/8 vs. 78/8, P < 0.05 each). Myocardial contractility of human ventricular trabeculae was not acutely affected by Sac treatment as the developed force remained unchanged over a time course of 30 min (n trabeculae/hearts = 3/3 vs. 4/3).

Conclusion

This study demonstrates that neprilysin inhibitor Sac directly improves Ca²⁺ homeostasis in human end‐stage HF by reducing pro‐arrhythmogenic SR Ca²⁺ leak without acutely affecting systolic Ca²⁺ release and inotropy. These effects might contribute to the mortality benefits observed in the PARADIGM‐HF trial.