Current and future use of neuromodulation in heart failure

The proarrhythmogenic role of autonomics and emerging neuromodulation approaches to prevent sudden death in cardiac ion channelopathies

Ventricular arrhythmias in cardiac channelopathies are linked to autonomic triggers, which are sub-optimally targeted in current management strategies. Improved molecular understanding of cardiac channelopathies and cellular autonomic signalling could refine autonomic therapies to target the specific signalling pathways relevant to the specific aetiologies as well as the central nervous system centres involved in the cardiac autonomic regulation. This review summarizes key anatomical and physiological aspects of the cardiac autonomic nervous system and its impact on ventricular arrhythmias in primary inherited arrhythmia syndromes. Proarrhythmogenic autonomic effects and potential therapeutic targets in defined conditions including the Brugada syndrome, early repolarization syndrome, long QT syndrome, and catecholaminergic polymorphic ventricular tachycardia will be examined. Pharmacological and interventional neuromodulation options for these cardiac channelopathies are discussed. Promising new targets for cardiac neuromodulation include inhibitory and excitatory G-protein coupled receptors, neuropeptides, chemorepellents/attractants as well as the vagal and sympathetic nuclei in the central nervous system. Novel therapeutic strategies utilizing invasive and non-invasive deep brain/brain stem stimulation as well as the rapidly growing field of chemo-, opto-, or sonogenetics allowing cell-specific targeting to reduce ventricular arrhythmias are presented.

Neuromodulation interventions in the management of heart failure

Despite remarkable improvements in the management of heart failure (HF), HF remains one of the most rapidly growing cardiovascular condition resulting in a substantial burden on healthcare systems worldwide. In clinical practice, however, a relevant proportion of patients are treated with suboptimal combinations and doses lower than those recommended in the current guidelines. Against this background, it remains important to identify new targets and investigate additional therapeutic options to alleviate symptoms and potentially improve prognosis in HF. Therefore, non-pharmacological interventions targeting autonomic imbalance in HF have been evaluated. This paper aims to review the physiology, available clinical data, and potential therapeutic role of device-based neuromodulation in HF.

Cholinesterase inhibitors associated with lower rate of mortality in dementia patients with heart failure: a nationwide propensity weighting study

PURPOSE

This study investigates the potential impact of cholinesterase inhibitors (ChEIs) on patients with heart failure (HF) and dementia. ChEIs are known to boost acetylcholine levels and benefit cognition in patients with dementia; however, their effect on patients with HF is uncertain. This study aimed to assess whether cardiovascular events and mortality among patients with HF and dementia are altered by ChEI therapy.

METHODS

Data from the National Health Insurance Research Database in Taiwan were retrospectively analyzed. Dementia patients diagnosed with HF were followed for 5 years until all-cause mortality, cardiovascular mortality, hospitalization for worsening HF, or the end of the study. Multivariable Cox models and inverse probability of treatment weighting (IPTW) were employed.

RESULTS

Out of 20,848 patients with dementia, 5138 had HF. Among them, 726 were ChEI users and 4412 were non-users. Based on IPTW, the ChEI users had significantly lower estimated risks of all-cause mortality [hazard ratio (HR) 0.43; 95% confidence interval (CI) 0.38-0.49, p < 0.001] and cardiovascular mortality (HR 0.41; 95% CI 0.33-0.53, p < 0.001) compared with the non-users, but there was no significant difference in hospitalization for worsening HF (HR 0.73; 95% CI 0.51-1.05, p = 0.091) after 5 years. The survival benefits of ChEIs were consistent across subgroups.

CONCLUSIONS

The results of this retrospective cohort study suggest that ChEIs may be beneficial in reducing all-cause and cardiovascular mortality in patients with dementia with HF. Further research is needed to validate these findings and explore the potential benefits of ChEIs in all patients with HF, including those without dementia.

Cardiac Contractility Modulation for Heart Failure: Current and Future Directions

Cardiac contractility modulation (CCM) is a Food and Drug Administration-approved device-based therapy for patients with heart failure. The system delivers biphasic electric stimulation to the ventricular myocardium during the absolute refractory period to augment left ventricular contraction. CCM therapy promotes acute and chronic changes at the cellular level, leading to favorable remodeling throughout the myocardium. CCM improves quality of life, New York Heart Association class, left ventricular ejection fraction, peak oxygen uptake, and the composite end point of cardiovascular death and heart failure hospitalizations. This review will focus on the biological basis, indications, and evidence for CCM, as well as the future applications of this technology.

Antiarrhythmic effects of baroreceptor activation therapy in chronic heart failure: a case report

Background

Autonomic imbalance represents a keystone of chronic heart failure (HF) with substantial clinical and prognostic implications. Baroreceptor activation therapy (BAT) is a new therapeutic strategy to target the autonomic dysbalance by electrical stimulation of carotid baroreceptors. Besides its known beneficial effects on HF parameters, BAT is also supposed to trigger potential antiarrhythmic effects, which may additionally contribute to HF improvement.

Case summary

We report on a 70-year-old male with progredient shortness of breath and advanced HF in the context of an extensive cardiovascular history. After optimization of pharmacologic and device-related therapy, the decision was made to implant a BAT system (Barostim Neo, CVRx) to improve functional cardiac parameters and support symptomatic improvement. Implantation was associated with an overall clinical improvement assessed during outpatient visits every 6 months. Frequency of ventricular arrhythmic events declined, and atrial fibrillation ceased spontaneously. Echocardiography revealed an amelioration in left ventricular systolic function. Numbers of HF hospitalization decreased after Barostim implantation.

Discussion

We present a patient with an extensive cardiovascular history and fully exploited pharmacologic and device-related therapy, who showed improvement in New York Heart Association (NYHA) functional classification, left ventricular systolic function, and reduction of arrhythmic events following implantation of the BAT device. This case presents an additional positive potential of BAT for HF patients in terms of reduction of arrhythmia burden. These results should be confirmed by further clinical trials.

Protein kinase A: A potential marker of sympathovagal imbalance in heart failure

Mitigation of cardiac autonomic dysregulation by neuromodulation technologies is emerging as a new therapeutic modality of heart failure (HF). This recent progress has necessitated the identification of a biomarker for the quantification of sympathovagal balance, the potential target of 'neuromodulation' strategies. The currently available autonomic nervous system assessment parameters do not truly reflect the sympathovagal balance of the ventricle. Protein kinase A (PKA) is an intracellular enzyme that plays a major role in the pathophysiology of functional and structural ventricular remodeling in HF. Interestingly, sympathetic and parasympathetic activations exert reciprocal influence on the activity of PKA. The current review attempts to evaluate the potential concept and feasibility of using in vitro assessment of PKA activity as a marker of sympathovagal balance in HF.

A Comparative Review of Vagal Nerve Stimulation Versus Baroreceptor Activation Therapy in Cardiac Diseases

Sympathetic imbalance coupled with impairment of baroreceptor control is a key factor responsible for hemodynamic abnormalities in congestive heart failure. Vagal nerve stimulation (VNS) and baroreceptor activation therapy (BAT) are two novel interventions for the same. In this paper, we review the role of sympathovagal alterations in cardiac diseases like heart failure, arrhythmia, hypertension (HTN), etc. Studies like neural cardiac therapy for heart failure (NECTAR-HF), autonomic regulation therapy to enhance myocardial function and reduce progression of heart failure (ANTHEM-HF), and baroreflex activation therapy for heart failure (BEAT-HF), which comprise the history, efficacy, limitations, and current protocols, were extensively analyzed in contrast to one another. Vagal nerve stimulation reverses the reflex inhibition of cardiac vagal efferent activity, which is caused as a result of sympathetic overdrive during the course for heart failure. It has shown encouraging results in certain pre-clinical studies; however, there is also a possibility of serious cardiovascular adverse events if given in higher than the recommended dosage. Attenuated baroreflex sensitivity is attributed to cardiac arrhythmogenesis during heart failure. Baroreceptor activation therapy reverses this phenomenon. However, the surgical procedure for baroreceptor stimulation can have unwarranted complications, including worsening heart failure and hypertension. Considering the effectiveness of the given modalities and taking into account the inconclusive evidence of their adverse events, more clinical trials are needed for establishing the future prospects of these interventional approaches.

Device-based therapies for decompensated heart failure

PURPOSE OF REVIEW

Despite improvements in medical therapies, patients with heart failure continue to suffer significant morbidity and mortality. Acute decompensated heart failure (ADHF) remains a common and serious medical condition with a myriad of implications on patient survival and quality of life, and heart failure related readmissions persist [1-3].

RECENT FINDINGS

From the detection of prehospitalization decompensation and inpatient management of ADHF to stabilization of cardiogenic shock and durable mechanical circulatory support, device-based therapies are utilized across the spectrum of heart failure management. At present, there are numerous device-based therapies commonly used in clinical practice and many more devices in the early clinical-trial phase aimed at attenuation of ADHF.

SUMMARY

In this review, we examine recent updates in the breadth and use of devices-based therapies in these three main domains: ambulatory heart failure, acute decompensated heart failure, and cardiogenic shock. Device-based therapies for decompensated heart failure will continue to grow in number, indication, and complexity, making recognition and familiarity with available technologies of increased importance for research and clinical practice.

Neurogenic Hypertension, the Blood-Brain Barrier, and the Potential Role of Targeted Nanotherapeutics

Hypertension is a major health concern globally. Elevated blood pressure, initiated and maintained by the brain, is defined as neurogenic hypertension (NH), which accounts for nearly half of all hypertension cases. A significant increase in angiotensin II-mediated sympathetic nervous system activity within the brain is known to be the key driving force behind NH. Blood pressure control in NH has been demonstrated through intracerebrovascular injection of agents that reduce the sympathetic influence on cardiac functions. However, traditional antihypertensive agents lack effective brain permeation, making NH management extremely challenging. Therefore, developing strategies that allow brain-targeted delivery of antihypertensives at the therapeutic level is crucial. Targeting nanotherapeutics have become popular in delivering therapeutics to hard-to-reach regions of the body, including the brain. Despite the frequent use of nanotherapeutics in other pathological conditions such as cancer, their use in hypertension has received very little attention. This review discusses the underlying pathophysiology and current management strategies for NH, as well as the potential role of targeted therapeutics in improving current treatment strategies.