Clinical Profile and Ventricular Arrhythmias after Sacubitril/Valsartan Initiation

Do Elderly Patients with Heart Failure and Reduced Ejection Fraction Benefit from Pharmacological Strategies for Prevention of Arrhythmic Events?

BACKGROUND

Heart failure is associated with aging. It is one of the leading causes of morbidity and mortality in Western countries and constitutes the main cause of hospitalization among elderly patients. The pharmacological therapy of patients with heart failure with reduced ejection fraction (HFrEF) has greatly improved during the last years. However, elderly patients less frequently receive recommended medical treatment.

SUMMARY

The quadruple therapy (sacubitril/valsartan, beta-blockers, mineralocorticoid receptor antagonists, and sodium-glucose cotransporter 2 inhibitors) is nowadays the cornerstone of medical treatment since it associates lower risk of heart failure hospitalizations and mortality (also of arrhythmic origin). Cardiac arrhythmias, including sudden cardiac death, are common in patients with HFrEF, entailing worse prognosis. Previous studies addressing the role of blocking the renin-angiotensin-aldosterone system and beta-adrenergic receptors in HFrEF have suggested different beneficial effects on arrhythmia mechanisms. Therefore, the lower mortality associated with the use of the four pillars of HFrEF therapy depends, in part, on lower sudden (mostly arrhythmic) cardiac death.

KEY MESSAGES

In this review, we highlight and assess the role of the four pharmacological groups that constitute the central axis of the medical treatment of patients with HFrEF in clinical prognosis and prevention of arrhythmic events, with special focus on the elderly patient, since evidence supports that most benefits provided are irrespective of age, but elderly patients receive less often guideline-recommended medical treatment.

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.

Exploration of Mechanisms of Sacubitril/Valsartan in the Treatment of Cardiac Arrhythmias Using a Network Pharmacology Approach

Significant reductions in the incidence of cardiac arrhythmia (CA) and sudden cardiac death (SCD), along with amelioration of heart failure, have been reported for treatment with Sacubitril/valsartan (SV). However, its anti-arrhythmic mechanism remains unclear. The current study aims to explore the anti-arrhythmic molecular mechanism of SV. The direct protein targets (DPT) of SV were extracted from DrugBank. The protein-protein interaction (PPI) network of SV DPTs was constructed using STRING, and the indirect protein targets (IPTs) were also identified. A search for arrhythmia-related genes was conducted using GeneCards and the Comparative Toxicogenomics Database (CTD). The DTPs, ITPs, and arrhythmia-related genes from the two datasets were combined in a Venn diagram, and the overlapping genes were identified as core target genes. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses identified the top 20 biological processes and signaling pathways related to disease and the therapeutic effects of SV. The renin-angiotensin system, adrenergic signaling in cardiomyocytes, and gap junction pathways are strongly implicated in the effects of SV on CA. In conclusion, our bioinformatics analyses provided evidence pertaining to the possible antiarrhythmic mechanisms of SV and may contribute to the development of novel drugs for CA.

Sacubitril/Valsartan in the Management of Heart Failure Patients with Cardiac Implantable Electronic Devices

For heart failure patients with cardiac implantable electronic devices (CIEDs), especially those who remain symptomatic after implantation, the best management strategy is still unclear. Although there are several concerns regarding the clinical utilization of sacubitril/valsartan, it has improved the prognosis of patients with heart failure compared with the use of renin-angiotensin system inhibitors in recent years. Recent real-world observational studies and post hoc analyses demonstrated that sacubitril/valsartan might have effects in patients with CIEDs. Given its potential underlying mechanisms, sacubitril/valsartan could improve outcomes of mortality and sudden cardiac death incidence, as well as clinical and echocardiographic evaluations. The possible antiarrhythmic effect of sacubitril/valsartan is still debated. Moreover, given that hypotension is the critical limitation of uptitration, the rise in systolic blood pressure attributed to cardiac resynchronization therapy might support the use of sacubitril/valsartan, with improved tolerance. The clinical utility of sacubitril/valsartan in heart failure patients with CIEDs requires further investigation to determine the actual effects, optimal target populations, and underlying mechanisms.

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.