Antiarrhythmic and Anti-Inflammatory Effects of Sacubitril/Valsartan on Post-Myocardial Infarction Scar

BACKGROUND

Sacubitril/valsartan (Sac/Val) is superior to angiotensin-converting enzyme inhibitors in reducing the risk of heart failure hospitalization and cardiovascular death, but its mechanistic data on myocardial scar after myocardial infarction (MI) are lacking. The objective of this work was to assess the effects of Sac/Val on inflammation, fibrosis, electrophysiological properties, and ventricular tachycardia inducibility in post-MI scar remodeling in swine.

METHODS

After MI, 22 pigs were randomized to receive β-blocker (BB; control, n=8) or BB+Sac/Val (Sac/Val, n=9). The systemic immune response was monitored. Cardiac magnetic resonance data were acquired at 2-day and 29-day post MI to assess ventricular remodeling. Programmed electrical stimulation and high-density mapping were performed at 30-day post MI to assess ventricular tachycardia inducibility. Myocardial samples were collected for histological analysis.

RESULTS

Compared with BB, BB+Sac/Val reduced acute circulating leukocytes (P=0.009) and interleukin-12 levels (P=0.024) at 2-day post MI, decreased C-C chemokine receptor type 2 expression in monocytes (P=0.047) at 15-day post MI, and reduced scar mass (P=0.046) and border zone mass (P=0.043). It also lowered the number and mass of border zone corridors (P=0.009 and P=0.026, respectively), scar collagen I content (P=0.049), and collagen I/III ratio (P=0.040). Sac/Val reduced ventricular tachycardia inducibility (P=0.034) and the number of deceleration zones (P=0.016).

CONCLUSIONS

After MI, compared with BB, BB+Sac/Val was associated with reduced acute systemic inflammatory markers, reduced total scar and border zone mass on late gadolinium-enhanced magnetic resonance imaging, and lower ventricular tachycardia inducibility.

Arrhythmias in Adult Congenital Heart Disease Heart Failure

Heart failure and arrhythmias represent 2 major causes of mortality and morbidity in adults with congenital heart disease. Arrhythmias and heart failure are interdependent, and one may exacerbate the other. Treatment of one also has a positive impact on the other. Management approaches need to be multifaceted, including pharmacotherapy, optimization of hemodynamic status with catheter-based or surgical interventions, and specific management of arrhythmia with device or catheter ablation therapy.

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.

Haemodynamic forces predicting remodelling and outcome in patients with heart failure treated with sacubitril/valsartan

AIMS

A novel tool for the evaluation of left ventricular (LV) systo-diastolic function through echo-derived haemodynamic forces (HDFs) has been recently proposed. The present study aimed to assess the predictive value of HDFs on (i) 6 month treatment response to sacubitril/valsartan in heart failure with reduced ejection fraction (HFrEF) patients and (ii) cardiovascular events.

METHODS AND RESULTS

Eighty-nine consecutive HFrEF patients [70% males, 65 ± 9 years, LV ejection fraction (LVEF) 27 ± 7%] initiating sacubitril/valsartan underwent clinical, laboratory, ultrasound and cardiopulmonary exercise testing evaluations. Patients experiencing no adverse events and showing ≥50% reduction in plasma N-terminal pro-B-type natriuretic peptide and/or ≥10% LVEF increase over 6 months were considered responders. Patients were followed up for the composite endpoint of HF-related hospitalisation, atrial fibrillation and cardiovascular death. Forty-five (51%) patients were responders. Among baseline variables, only HDF-derived whole cardiac cycle LV strength (wLVS) was higher in responders (4.4 ± 1.3 vs. 3.6 ± 1.2; p = 0.01). wLVS was also the only independent predictor of sacubitril/valsartan response at multivariable logistic regression analysis [odds ratio 1.36; 95% confidence interval (CI) 1.10-1.67], with good accuracy at receiver operating characteristic (ROC) analysis [optimal cutpoint: ≥3.7%; area under the curve (AUC) = 0.736]. During a 33 month (23-41) median follow-up, a wLVS increase after 6 months (ΔwLVS) showed a high discrimination ability at time-dependent ROC analysis (optimal cut-off: ≥0.5%; AUC = 0.811), stratified prognosis (log-rank p < 0.0001) and remained an independent predictor for the composite endpoint (hazard ratio 0.76; 95% CI 0.61-0.95; p < 0.01), after adjusting for clinical and instrumental variables.

CONCLUSIONS

HDF analysis predicts sacubitril/valsartan response and might optimise decision-making in HFrEF patients.

Heart failure with reduced ejection fraction and atrial fibrillation: a Sub-Saharan African perspective

Cardiovascular diseases are a well-established cause of death in high-income countries. In the last 20 years, Sub-Saharan Africa (SSA) has seen one of the sharpest increases in cardiovascular disease-related mortality, superseding that of infectious diseases, including HIV/AIDS, in South Africa. This increase is evidenced by a growing burden of heart failure and atrial fibrillation (AF) risk factors. AF is a common comorbidity of heart failure with reduced ejection fraction (HFrEF), which predisposes to an increased risk of stroke, rehospitalizations, and mortality compared with patients in sinus rhythm. AF had the largest relative increase in cardiovascular disease burden between 1990 and 2010 in SSA and the second highest (106.4%) increase in disability-adjusted life-years (DALY) between 1990 and 2017. Over the last decade, significant advancements in the management of both HFrEF and AF have emerged. However, managing HFrEF/AF remains a clinical challenge for physicians, compounded by the suboptimal efficacy of guideline-mandated pharmacotherapy in this group of patients. There may be an essential role for racial differences and genetic influence on therapeutic outcomes of HFrEF/AF patients, further complicating our overall understanding of the disease and its pathophysiology. In SSA, the lack of accurate and up-to-date epidemiological data on this subgroup of patients presents a challenge in our quest to prevent and reduce adverse outcomes. This narrative review provides a contemporary overview of the epidemiology of HFrEF/AF in SSA. We highlight important differences in the demographic and aetiological profile and the management of this subpopulation, emphasizing what is currently known and, more importantly, what is still unknown about HFrEF/AF in SSA.

Effect of sacubitril/valsartan on the occurrence of cardiac arrhythmias and the risk of sudden cardiac death in heart failure: A meta-analysis of randomized controlled trials

Background

Sacubitril/valsartan therapy reduced the risks of death and of hospitalization for heart failure (HF). HF and cardiac arrhythmias have shared physiological mechanisems. Therefore, sacubitril/valsartan may exhibit anti-arrhythmic properties in HF. The purpose of this study was to evaluate the effect of sacubitril/valsartan on the occurrence of cardiac arrhythmias and the risk of sudden cardiac death (SCD) in HF.

Methods

This meta-analysis was performed according to PRISMA guidelines. We searched PubMed and Embase (from inception up to 6 February 2022) to identify randomized control trials (RCTs) on the effect of sacubitril/valsartan on the occurrence of cardiac arrhythmias and the risk of SCD in HF. Primary outcomes were the occurrence of atrial arrhythmias, ventricular arrhythmias, and SCD. Risk ratios (RRs) with 95% confidence intervals (CIs) were pooled using a random-effects model for meta-analysis.

Results

We included 9 RCTs (published between 2012 and 2021) with 18,500 patients (9,244 sacubitril/valsartan vs. 9,256 active control). Enalapril and valsartan were used as active control in six and two studies, respectively. Follow-up ranged from 2 to 35 months. The cumulative occurrence of events was 76, 13, and 48 per 1,000 patient-years for atrial arrhythmias, ventricular arrhythmias and SCD, respectively. There was no significant association between sacubitril/valsartan therapy and the occurrence of atrial arrhythmias (RR 1.06; 95% CI: 0.97–1.17; P = 0.19) and ventricular arrhythmias (RR 0.86; 95% CI 0.68–1.10; P = 0.24). However, sacubitril/valsartan therapy significantly reduced the risk of SCD (RR 0.79; 95% CI 0.70–0.90; P = 0.03) compared with control.

Conclusion

No association between sacubitril/valsartan therapy and the occurrence of atrial and ventricular arrhythmias was found, but sacubitril/valsartan therapy significantly reduced the risk of SCD.

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 &lt; 0.01) and the probability of arrhythmias (p &lt; 0.01). In addition, patient's plasma NTproBNP positively correlated with isoproterenol-induced contractile reserve in atrial tissue in vitro (r = 0.65; p &lt; 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 &lt; 0.05) and left ventricle (LV) NEP correlates inversely with left atrial (LA) volume (r = −0.691; p &lt; 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.

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.