Baroreflex Activation Therapy for the Treatment of Heart Failure With a Reduced Ejection Fraction

Treating heart failure by targeting the vagus nerve

Increased sympathetic and reduced parasympathetic nerve activity is associated with disease progression and poor outcomes in patients with chronic heart failure. The demonstration that markers of autonomic imbalance and vagal dysfunction, such as reduced heart rate variability and baroreflex sensitivity, hold prognostic value in patients with chronic heart failure despite modern therapies encourages the research for neuromodulation strategies targeting the vagus nerve. However, the approaches tested so far have yielded inconclusive results. This review aims to summarize the current knowledge about the role of the parasympathetic nervous system in chronic heart failure, describing the pathophysiological background, the methods of assessment, and the rationale, limits, and future perspectives of parasympathetic stimulation either by drugs or bioelectronic devices.

Baroreflex activation therapy in advanced heart failure: A long-term follow-up

AIMS

Baroreceptor activation therapy (BAT) is a promising new treatment strategy for patients with heart failure with reduced ejection fraction (HFrEF). It provides symptomatic relief, improvement in left ventricular function and reduction of cardiac biomarkers. Data regarding the long-term effect of BAT on HFrEF are scarce. This retrospective, monocentric study aimed to assess long-term outcome in patients who underwent BAT.

METHODS

Patients with HFrEF who received BAT at Hannover Medical School between 2014 and 2023 were followed until the latest available follow-up. Symptom burden, echocardiography and laboratory testing were assessed before BAT implantation and in subsequent follow-ups.

RESULTS

Twenty-three patients (mean age 66 ± 10 years, 83% male) with HFrEF were included in the study. Aetiology of heart failure was ischaemic in 70%. The majority of patients (96%) suffered from New York Heart Association (NYHA) III with a mean left ventricular ejection fraction (LVEF) of 23 ± 8% and N-terminal pro-B-type natriuretic peptide (NT-proBNP) of 2463 ± 2922 pg/mL. A complication occurred in one patient during BAT implantation (4%). The mean follow-up was 3 ± 2 (max. 7.5) years. BAT reduced NYHA classification in 12 patients (52%) after 1 year, of which one patient remained in ameliorated NYHA for 7.5 years. Echocardiographic evaluation revealed significant improvement in LVEF by 9 ± 9% after 1 year (P < 0.001) and by 11 ± 9% (P = 0.005) after 2 years. In addition, BAT mildly reduced NT-proBNP in the first 2 years [non-significantly after 1 year by 396 ± 1006 pg/mL and significantly after 2 years by 566 ± 651 pg/mL (P = 0.039)]. Seven patients reaching the recommended replacement time underwent device exchange. Four patients died during observation time.

CONCLUSIONS

BAT resulted in a substantial reduction in NYHA classification and improvement in LVEF that lasted over long-term follow-up in many patients. NT-proBNP level decreased interim in long-term follow-up. These findings highlight the long-term efficacy and potential benefits of BAT as a therapeutic intervention for patients with HFrEF.

Effects of baroreflex activation therapy on cardiac function and morphology

AIMS

Arterial hypertension (aHTN) plays a fundamental role in the pathogenesis and prognosis of heart failure with preserved ejection fraction (HFpEF). The risk of heart failure increases with therapy-resistant arterial hypertension (trHTN), defined as inadequate blood pressure (BP) control ≥140/90 mmHg despite taking ≥3 antihypertensive medications including a diuretic. This study investigates the effects of the BP lowering baroreflex activation therapy (BAT) on cardiac function and morphology in patients with trHTN with and without HFpEF.

METHODS

Sixty-four consecutive patients who had been diagnosed with trHTN and received BAT implantation between 2012 and 2016 were prospectively observed. Office BP, electrocardiographic and echocardiographic data were collected before and after BAT implantation.

RESULTS

Mean patients' age was 59.1 years, 46.9% were male, and mean body mass index (BMI) was 33.2 kg/m2. The prevalence of diabetes mellitus was 38.8%, atrial fibrillation was 12.2%, and chronic kidney disease (CKD) stage ≥3 was 40.8%. Twenty-eight patients had trHTN with HFpEF, and 21 patients had trHTN without HFpEF. Patients with HFpEF were significantly older (64.7 vs. 51.6 years, P < 0.0001), had a lower BMI (30.0 vs. 37.2 kg/m2, P < 0.0001), and suffered more often from CKD-stage ≥3 (64 vs. 20%, P = 0.0032). After BAT implantation, mean office BP dropped in patients with and without HFpEF (from 169 ± 5/86 ± 4 to 143 ± 4/77 ± 3 mmHg [P = 0.0019 for systolic BP and 0.0403 for diastolic BP] and from 170 ± 5/95 ± 4 to 149 ± 6/88 ± 5 mmHg [P = 0.0019 for systolic BP and 0.0763 for diastolic BP]), while a significant reduction of the intake of calcium-antagonists, α2-agonists and direct vasodilators, as well as a decrease in average dosage of ACE-inhibitors and α2-agonists could be seen. Within the study population, a decrease in heart rate from 74 ± 2 to 67 ± 2 min-1 (P = 0.0062) and lengthening of QRS-time from 96 ± 3 to 106 ± 4 ms (P = 0.0027) and QTc-duration from 422 ± 5 to 432 ± 5 ms (P = 0.0184) were detectable. The PQ duration was virtually unchanged. In patients without HF, no significant changes of echocardiographic parameters could be seen. In patients with HFpEF, posterior wall diameter decreased significantly from 14.0 ± 0.5 to 12.7 ± 0.3 mm (P = 0.0125), left ventricular mass (LVM) declined from 278.1 ± 15.8 to 243.9 ± 13.4 g (P = 0.0203), and e' lateral increased from 8.2 ± 0.4 to 9.0 ± 0.4 cm/s (P = 0.0471).

CONCLUSIONS

BAT reduced systolic and diastolic BP and was associated with morphological and functional improvement of HFpEF.

Baroreflex Function in Cardiovascular Disease

The baroreflex system is involved in modulating several physiological functions of the cardiovascular system and can directly and indirectly modulate cardiac output, blood pressure, and cardiac electrophysiology. In addition, it is involved in regulating neurohormonal pathways involved in the cardiovascular function, such as the renin-angiotensin-aldosterone system (RAAS) and vasopressin release. Baroreflex dysfunction is characterized by sympathetic overactivation and parasympathetic withdrawal and is associated with several cardiovascular diseases, such as hypertension, heart failure (HF), and coronary artery disease (CAD). Targeting the baroreflex system via invasive (e.g., baroreflex activation therapy and endovascular baroreceptor amplification) and non-invasive approaches (e.g., slow breathing exercises and exercise training) has emerged as a novel pathway to manage cardiovascular diseases. Studies examining the long-term safety and efficacy of such interventions in various cardiovascular diseases are needed.

HFSA Scientific Statement: Update on Device Based Therapies in Heart Failure

Heart failure (HF) is 1 of the major challenges of our time, given its increase in prevalence and related mortality rates. Foundational pharmacological therapies, including angiotensin receptor neprilysin inhibitors (ARNIs), beta-blockers, mineralocorticoid receptor antagonists (MRAs), and sodium-glucose co-transporter inhibitors (SGLTis), have been established for HF with reduced ejection fraction (HFrEF). Moreover, recent trials have established the role of SGLTis in patients with HF with preserved ejection fraction (HFpEF). However, even with these therapies, a substantial residual risk persists in both HFrEF and HFpEF. Alongside pharmacological advancements, device-based therapies have shown efficacy in HF management, including implantable cardioverter-defibrillators (ICDs) and cardiac resynchronization therapy (CRT). More recently, devices such as cardiac contractility modulation (CCM) and baroreflex activation therapy (BAT) have been approved by the FDA, although they lack comprehensive guideline recommendations. This scientific statement outlines the unmet needs in chronic HF, reviews contemporary data and provides a framework for integrating novel device-based therapies into current clinical workflows. It emphasizes the importance of early diagnosis and phenotyping, proper patient stratification and a personalized approach to combining pharmacological and device therapies. The document also highlights the need for further research into device interactions and patient selection to optimize outcomes, while recognizing the need for a more integrated approach to treatment so as to address the unmet needs and residual risks in HF management.

Pharmacologic, Surgical, and Device-Based Cardiac Neuromodulation

The cardiac autonomic nervous system plays a key role in maintaining normal cardiac physiology, and once disrupted, it worsens the cardiac disease states. Neuromodulation therapies have been emerging as new treatment options, and various techniques have been introduced to mitigate autonomic nervous imbalances to help cardiac patients with their disease conditions and symptoms. In this review article, we discuss various neuromodulation techniques used in clinical settings to treat cardiac diseases.

[Advances in heart failure management]

Heart failure is a pathological condition characterized by substantial prevalence and mortality, particularly in the Western world. Over recent decades, both pharmacological and non-pharmacological interventions have emerged, significantly enhancing patient survival and overall quality of life. Moreover, advancements in diverse imaging modalities facilitate precise diagnosis and comprehensive investigation into the fundamental etiology, enabling the development of more precise therapeutic approaches. Nonetheless, discernible gaps persist in comprehending specific facets of this condition, albeit persistent research endeavors seek to elucidate these inquiries.

Sex-related similarities and differences in responses to heart failure therapies

Although sex-related differences in the epidemiology, risk factors, clinical characteristics and outcomes of heart failure are well known, investigations in the past decade have shed light on an often overlooked aspect of heart failure: the influence of sex on treatment response. Sex-related differences in anatomy, physiology, pharmacokinetics, pharmacodynamics and psychosocial factors might influence the response to pharmacological agents, device therapy and cardiac rehabilitation in patients with heart failure. In this Review, we discuss the similarities between men and women in their response to heart failure therapies, as well as the sex-related differences in treatment benefits, dose-response relationships, and tolerability and safety of guideline-directed medical therapy, device therapy and cardiac rehabilitation. We provide insights into the unique challenges faced by men and women with heart failure, highlight potential avenues for tailored therapeutic approaches and call for sex-specific evaluation of treatment efficacy and safety in future research.

Beyond Medical Therapy-An Update on Heart Failure Devices

Heart failure (HF) is a complex and progressive disease marked by substantial morbidity and mortality rates, frequent episodes of decompensation, and a reduced quality of life (QoL), with severe financial burden on healthcare systems. In recent years, several large-scale randomized clinical trials (RCTs) have widely expanded the therapeutic armamentarium, underlining additional benefits and the feasibility of rapid titration regimens. This notwithstanding, mortality is not declining, and hospitalizations are constantly increasing. It is widely acknowledged that even with guideline-directed medical therapy (GDMT) on board, HF patients have a prohibitive residual risk, which highlights the need for innovative treatment options. In this scenario, groundbreaking devices targeting valvular, structural, and autonomic abnormalities have become crucial tools in HF management. This has led to a full-fledged translational boost with several novel devices in development. Thus, the aim of this review is to provide an update on both approved and investigated devices.

[Treatment with cardiac electronic implantable devices]

Cardiac device therapy provides not only treatment options for bradyarrhythmia but also advanced treatment for heart failure and preventive measures against sudden cardiac death. In heart failure treatment it enables synergistic reverse remodelling and reduces pharmacological side effects. Cardiac resynchronization therapy (CRT) has revolutionized the treatment of reduced left ventricular ejection fraction (LVEF) and left bundle branch block by decreasing the mortality and morbidity with improvement of the quality of life and resilience. Conduction system pacing (CSP) as an alternative method of physiological stimulation can improve heart function and reduce the risk of pacemaker-induced cardiomyopathy. Leadless pacers and subcutaneous/extravascular defibrillators offer less invasive options with lower complication rates. The prevention of infections through preoperative and postoperative strategies enhances the safety of these therapies.

Advances in device-based treatment of heart failure with preserved ejection fraction: evidence from clinical trials

Heart failure with preserved ejection fraction (HFpEF) is a group of clinical syndromes that exhibit a remarkably heterogeneous phenotype, characterized by symptoms and signs of heart failure, left ventricular diastolic dysfunction, elevated levels of natriuretic peptides, and an ejection fraction greater than or equal to 50%. With the aging of the population and the escalating prevalence of hypertension, obesity, and diabetes, the incidence of HFpEF is progressively rising. Drug therapy options for HFpEF are currently limited, and the associated high risk of cardiovascular mortality and heart failure rehospitalization significantly impact patients' quality of life and longevity while imposing a substantial economic burden on society. Recent research indicates that certain device-based therapies may serve as valuable adjuncts to drug therapy in patients with specific phenotypes of HFpEF, effectively improving symptoms and quality of life while reducing the risk of readmission for heart failure. These include inter-atrial shunt and greater splanchnic nerve ablation to reduce left ventricular filling pressure, implantable heart failure monitor to guide diuresis, left atrial pacing to correct interatrial dyssynchrony, cardiac contractility modulation to enhance cardiac calcium handling, as well as renal denervation, baroreflex activation therapy, and vagus nerve stimulation to restore the autonomic imbalance. In this review, we provide a comprehensive overview of the mechanisms and clinical evidence pertaining to these devices, with the aim of enhancing therapeutic strategies for HFpEF.

Non-pharmacologic autonomic neuromodulation for treatment of heart failure: A systematic review and meta-analysis of randomized controlled trials

Treatment strategies that modulate autonomic tone through interventional and device-based therapies have been studied as an adjunct to pharmacological treatment of heart failure with reduced ejection fraction (HFrEF). The main objective of this study was to perform a meta-analysis of randomized controlled trials which evaluated the efficacy of device-based autonomic modulation for treatment of HFrEF. All randomized-controlled trials testing autonomic neuromodulation device therapy in HFrEF were included in this trial-level analysis. Autonomic neuromodulation techniques included vagal nerve stimulation (VNS), baroreflex activation (BRA), spinal cord stimulator (SCS), and renal denervation (RD). The prespecified primary endpoints included mean change and 95% confidence intervals (CI) of left ventricular ejection fraction (LVEF), NT pro-B-type natriuretic peptide (NT-proBNP), and quality of life (QOL) measures including 6-minute hall walk distance (6-MHWD), and Minnesota Living with Heart Failure Questionnaire (MLHFQ). New York Heart Association (NYHA) functional class improvement was reported as odds ratios and 95% CI of improvement by at least 1 functional class. Eight studies were identified that included 1037 participants (2 VNS, 2 BRA, 1 SCS, and 3 RD trials). This included 6 open-label, 1 single-blind, and 1 sham-controlled, double-blind study. The mean age (±SD) was 61 (±9.3) years. The mean follow-up time was 7.9 months. Twenty percent of the total patients were female, and the mean BMI (±SD) was 29.86 (±4.12). Autonomic neuromodulation device therapy showed a statistically significant improvement in LVEF (4.02%; 95% CI 0.24,7.79), NT-proBNP (-219.80 pg/ml; 95% CI -386.56, -53.03), NYHA functional class (OR 2.32; 95% CI 1.76, 3.07), 6-MHWD (48.39 m; 95% CI 35.49, 61.30), and MLHFQ (-12.20; 95% CI -19.24, -5.16) compared to control. In patients with HFrEF, the use of autonomic neuromodulation device therapy is associated with improvement in LVEF, reduction in NT-proBNP, and improvement in patient-centered QOL outcomes in mostly small open-label trials. Large, double-blind, sham-controlled trials designed to detect differences in hard cardiovascular outcomes are needed before widespread use and adoption of autonomic neuromodulation device therapies in HFrEF.

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.

Baroreflex activation therapy for heart failure with reduced ejection fraction: A comprehensive systematic review and meta-analysis

Background

In recent years, baroreflex activation therapy (BAT) has been utilized to treat heart failure with reduced ejection fraction (HFrEF). However, the supporting literature on its efficacy and safety is still limited. This investigation elucidates the effects of BAT in HFrEF patients to provide a reference for future clinical applications.

Methods

This investigation follows Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) 2020 guidelines. Relevant investigations on the use of BAT in HFrEF patients were searched and selected from 5 databases, including Web of Science, MEDLINE, PubMed, Embase, and Cochrane Library, from inception to December 2022. The methodological quality of eligible articles was assessed via the Cochrane risk of bias tool, and for meta-analysis, RevMan (5.3) was used.

Results

Randomized controlled trials comprising 343 participants were selected for the meta-analysis, which revealed that in HFrEF patients, BAT enhanced the levels of LVEF (MD: 2.97, 95 % CI: 0.53 to 5.41), MLHFQ (MD: -14.81, 95 % CI: -19.57 to -10.06) and 6MWT (MD: 68.18, 95 % CI: 51.62 to 84.74), whereas reduced the levels of LVEDV (MD: -15.79, 95 % CI: -32.96 to 1.37) and DBP (MD: -2.43, 95 % CI: -4.18 to -0.68).

Conclusion

It was concluded that BAT is an efficient treatment option for HFrEF patients. However, to validate this investigation, further randomized clinical trials with multiple centers and large sample sizes are needed.

Current Approaches to Worsening Heart Failure: Pathophysiological and Molecular Insights

Worsening heart failure (WHF) is a severe and dynamic condition characterized by significant clinical and hemodynamic deterioration. It is characterized by worsening HF signs, symptoms and biomarkers, despite the achievement of an optimized medical therapy. It remains a significant challenge in cardiology, as it evolves into advanced and end-stage HF. The hyperactivation of the neurohormonal, adrenergic and renin-angiotensin-aldosterone system are well known pathophysiological pathways involved in HF. Several drugs have been developed to inhibit the latter, resulting in an improvement in life expectancy. Nevertheless, patients are exposed to a residual risk of adverse events, and the exploration of new molecular pathways and therapeutic targets is required. This review explores the current landscape of WHF, highlighting the complexities and factors contributing to this critical condition. Most recent medical advances have introduced cutting-edge pharmacological agents, such as guanylate cyclase stimulators and myosin activators. Regarding device-based therapies, invasive pulmonary pressure measurement and cardiac contractility modulation have emerged as promising tools to increase the quality of life and reduce hospitalizations due to HF exacerbations. Recent innovations in terms of WHF management emphasize the need for a multifaceted and patient-centric approach to address the complex HF syndrome.

Emerging devices for heart failure management

There have been significant advances in the treatment of heart failure (HF) in recent years, driven by significant strides in guideline-directed medical therapy (GDMT). Despite this, HF is still associated with high levels of morbidity and mortality, and most patients do not receive optimal medical therapy. In conjunction with the improvement of GDMT, novel device therapies have been developed to better treat HF. These devices include technology capable of remotely monitoring HF physiology, devices that modulate the autonomic nervous system, and those that structurally change the heart with the ultimate aim of addressing the root causes of HF physiology As these device therapies gradually integrate into the fabric of HF patient care, it becomes increasingly important for modern cardiologists to become familiar with them. Hence, the objective of this review is to shed light on currently emerging devices for the treatment of HF.

Baroreflex Activation Therapy in Patients with Heart Failure with a Reduced Ejection Fraction

A randomized, controlled trial of baroreflex activation therapy (BAT) in patients with heart failure and reduced ejection fraction demonstrated that BAT was safe and significantly improved patient-centered symptomatic outcomes, increasing exercise capacity, improving quality of life, decreasing n-terminal pro B-type natriuretic peptide (NT-proBNP), and improving functional class. BAT was approved by the FDA for improvement of symptoms of heart failure for patients who remain symptomatic despite treatment with guideline-directed management, are New York Heart Association Class III or Class II (with a recent history of Class III), have a left ventricular ejection fraction ≤ 35%, an NT-proBNP < 1600 pg/mL and excluding patients indicated for cardiac resynchronization therapy.

Baroreflex activation therapy in patients with heart failure with reduced ejection fraction: a single-centre experience

AIMS

Heart failure with reduced ejection fraction (HFrEF) is associated with excessive sympathetic and impaired parasympathetic activity. The Barostim Neo™ device is used for electronical baroreflex activation therapy (BAT) to counteract autonomic nervous system dysbalance. Randomized trials have shown that BAT improves walking distance and reduces N-terminal prohormone of brain natriuretic peptide (NT-proBNP) levels at least in patients with only moderate elevation at baseline. Its impact on the risk of heart failure hospitalization (HFH) and death is not yet established, and experience in clinical routine is limited.

METHODS AND RESULTS

We report on patient characteristics and clinical outcome in a retrospective, non-randomized single-centre registry of BAT in HFrEF. Patients in the New York Heart Association (NYHA) Classes III and IV with a left ventricular ejection fraction (LVEF) <35% despite guideline-directed medical therapy were eligible. Symptom burden, echocardiography, and laboratory testing were assessed at baseline and after 12 months. Clinical events of HFH and death were recorded at routine clinical follow-up. Data are shown as number (%) or median (inter-quartile range). Between 2014 and 2020, 30 patients were treated with BAT. Median age was 67 (63-77) years, and 27 patients (90%) were male. Most patients (83%) had previous HFH. Device implantation was successful in all patients. At 12 months, six patients had died and three were alive but did not attend follow-up. NYHA class was III/IV in 26 (87%)/4 (13%) patients at baseline, improved in 19 patients, and remained unchanged in 5 patients (P < 0.001). LVEF improved from 25.5 (20.0-30.5) % at baseline to 30.0 (25.0-36.0) % at 12 months (P = 0.014). Left ventricular end-diastolic diameter remained unchanged. A numerical decrease in NT-proBNP [3165 (880-8085) vs. 1001 (599-3820) pg/mL] was not significant (P = 0.526). Median follow-up for clinical events was 16 (10-33) months. Mortality at 1 (n = 6, 20%) and 3 years (n = 10, 33%) was as expected by the Meta-Analysis Global Group in Chronic Heart Failure risk score. Despite BAT, event rate was high in patients with NYHA Class IV, NT-proBNP levels >1600 pg/mL, or estimated glomerular filtration rate (eGFR) <30 mL/min at baseline. NYHA class and eGFR were independent predictors of mortality.

CONCLUSIONS

Patients with HFrEF who are selected for BAT are in a stage of worsening or even advanced heart failure. BAT appears to be safe and improves clinical symptoms and-to a modest degree-left ventricular function. The risk of death remains high in advanced disease stages. Patient selection seems to be crucial, and the impact of BAT in earlier disease stages needs to be established.

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.

Percutaneous Strategies in Structural Heart Diseases: Focus on Chronic Heart Failure

BACKGROUND

Central Illustration : Percutaneous Strategies in Structural Heart Diseases: Focus on Chronic Heart Failure Transcatheter devices for monitoring and treating advanced chronic heart failure patients. PA: pulmonary artery; LA: left atrium; AFR: atrial flow regulator; TASS: Transcatheter Atrial Shunt System; VNS: vagus nerve stimulation; BAT: baroreceptor activation therapy; RDN: renal sympathetic denervation; F: approval by the American regulatory agency (FDA); E: approval by the European regulatory agency (CE Mark).

BACKGROUND

Innovations in devices during the last decade contributed to enhanced diagnosis and treatment of patients with cardiac insufficiency. These tools progressively adapted to minimally invasive strategies with rapid, widespread use. The present article focuses on actual and future directions of device-related diagnosis and treatment of chronic heart failure.

Neuromodulation Therapies in Heart Failure: A State-of-the-Art Review

Heart failure (HF) continues to impact the population globally with increasing prevalence. While the pathophysiology of HF is quite complex, the dysregulation of the autonomic nervous system, as evident in heightened sympathetic activity, serves as an attractive pathophysiological target for newer therapies and HF. The degree of neurohormonal activation has been found to correlate to the severity of symptoms, decline in functional capacity, and mortality. Neuromodulation of the autonomic nervous system aims to restore the balance between sympathetic nervous system and the parasympathetic nervous system. Given that autonomic dysregulation plays a major role in the development and progression of HF, restoring this balance may potentially have an impact on the core pathophysiological mechanisms and various HF syndromes. Autonomic modulation has been proposed as a potential therapeutic strategy aimed at reduction of systemic inflammation. Such therapies, complementary to drug and device-based therapies may lead to improved patient outcomes and reduce disease burden. Most professional societies currently do not provide a clear recommendation on the use of neuromodulation techniques in HF. These include direct and indirect vagal nerve stimulation, spinal cord stimulation, baroreflex activation therapy, carotid sinus stimulation, aortic arch stimulation, splanchnic nerve modulation, cardiopulmonary nerve stimulation, and renal sympathetic nerve denervation. In this review, we provide a comprehensive overview of neuromodulation in HF.

Efficacy and safety of baroreflex activation therapy for heart failure with reduced ejection fraction: systematic review

Baroreflex activation therapy (BAT) is a possible adjuvant treatment for patients with heart failure with reduced ejection fraction (HFrEF) who remain symptomatic despite optimal medical therapy and may be an alternative therapy in patients with contraindications or drug intolerance. Our aim was to evaluate the efficacy and safety of BAT in patients with HFrEF. The protocol for this study was registered with PROSPERO (CRD42022349175). Searches were conducted using MEDLINE, preMedLine (via PubMed), EMBASE, Cochrane Library, Web of Science, Trip Medical Database, WHO International Clinical Trials Registry, and ClinicalTrials.gov. We included randomized controlled trials that compared the effects of BAT with pharmacological treatment. We assessed the risk of bias of each study using the Cochrane RoB2 tool and the certainty of the results using the GRADE approach. We performed a meta-analysis of treatment effects using a fixed-effects or random-effects model, depending on the heterogeneity observed. Two studies were included in the meta-analysis (HOPE4HF and BeAT-HF). The results showed that BAT led to statistically significant improvements in New York Heart Association functional class (relative risk 2.13; 95% confidence interval [CI, 1.65 to 2.76]), quality of life (difference in means -16.97; 95% CI [-21.87 to -12.07]), 6 min walk test (difference in means 56.54; 95% CI [55.67 to 57.41]) and N-terminal probrain natriuretic peptide (difference in means -120.02; 95% CI [-193.58 to -46.45]). The system- and procedure-related complication event-free rate varied from 85.9% to 97%. The results show that BAT is safe and improves functional class, quality of life and congestion in selected patients with HFrEF. Further studies and long-term follow-up are needed to assess efficacy in reducing cardiovascular events and mortality.

Autonomic control of ventricular function in health and disease: current state of the art

PURPOSE

Cardiac autonomic dysfunction is one of the main pillars of cardiovascular pathophysiology. The purpose of this review is to provide an overview of the current state of the art on the pathological remodeling that occurs within the autonomic nervous system with cardiac injury and available neuromodulatory therapies for autonomic dysfunction in heart failure.

METHODS

Data from peer-reviewed publications on autonomic function in health and after cardiac injury are reviewed. The role of and evidence behind various neuromodulatory therapies both in preclinical investigation and in-use in clinical practice are summarized.

RESULTS

A harmonic interplay between the heart and the autonomic nervous system exists at multiple levels of the neuraxis. This interplay becomes disrupted in the setting of cardiovascular disease, resulting in pathological changes at multiple levels, from subcellular cardiac signaling of neurotransmitters to extra-cardiac, extra-thoracic remodeling. The subsequent detrimental cycle of sympathovagal imbalance, characterized by sympathoexcitation and parasympathetic withdrawal, predisposes to ventricular arrhythmias, progression of heart failure, and cardiac mortality. Knowledge on the etiology and pathophysiology of this condition has increased exponentially over the past few decades, resulting in a number of different neuromodulatory approaches. However, significant knowledge gaps in both sympathetic and parasympathetic interactions and causal factors that mediate progressive sympathoexcitation and parasympathetic dysfunction remain.

CONCLUSIONS

Although our understanding of autonomic imbalance in cardiovascular diseases has significantly increased, specific, pivotal mediators of this imbalance and the recognition and implementation of available autonomic parameters and neuromodulatory therapies are still lagging.

Beyond Conventional Cardiac Resynchronisation Therapy: A Review of Electrophysiological Options in the Management of Chronic Heart Failure

The incidence of heart failure (HF) continues to grow and burden our health care system. Electrophysiological aberrations are common amongst patients with heart failure and can contribute to worsening symptoms and prognosis. Targeting these abnormalities with cardiac and extra-cardiac device therapies and catheter ablation procedures augments cardiac function. Newer technologies aimed to improvement procedural outcomes, address known procedural limitations and target newer anatomical sites have been trialled recently. We review the role and evidence base for conventional cardiac resynchronisation therapy (CRT) and its optimisation, catheter ablation therapies for atrial arrhythmias, cardiac contractility and autonomic modulation therapies.

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.

Auricular Vagal Neuromodulation and its Application in Patients with Heart Failure and Reduced Ejection Fraction

BACKGROUND

The autonomic nervous system (ANS) imbalance in heart failure (HF) creates a vicious cycle, excess sympathetic activity, and decreased vagal activity contributing to the worsening of HF. Low-intensity transcutaneous electrical stimulation of the auricular branch of the vagus nerve (taVNS) is well tolerated and opens new therapeutic possibilities.

OBJECTIVES

To hypothesize the applicability and benefit of taVNS in HF through intergroup comparison of echocardiography parameters, 6-minute walk test, Holter heart rate variability (SDNN and rMSSD), Minnesota quality of life questionnaire, and functional class by the New York Heart Association. In comparisons, p values <0.05 were considered significant.

METHODS

Prospective, double-blind, randomized clinical study with sham methodology, unicentric. Forty-three patients were evaluated and divided into 2 groups: Group 1 received taVNS (frequencies 2/15 Hz), and Group 2 received sham. In comparisons, p values <0.05 were considered significant.

RESULTS

In the post-intervention phase, it was observed that Group 1 had better rMSSD (31 x 21; p = 0.046) and achieved better SDNN (110 vs. 84, p = 0.033). When comparing intragroup parameters before and after the intervention, it was observed that all of them improved significantly in group 1, and there were no differences in group 2.

CONCLUSION

taVNS is a safe to perform and easy intervention and suggests a probable benefit in HF by improving heart rate variability, which indicates better autonomic balance. New studies with more patients are needed to answer the questions raised by this study.

Transcatheter interventions for heart failure

Despite significant advances in the medical management of patients living with heart failure, there continues to be significant morbidity and mortality associated with the condition. There is a growing need for research and development of additional modalities to fill the management and treatment gaps, reduce hospitalisations and improve the quality of life for patients living with heart failure. In the last decade, there has been a rapid rise in the use of non-valvular catheter-based therapies for the management of chronic heart failure to complement existing guideline-directed management. They target well-defined mechanistic and pathophysiological processes critical to the progression of heart failure including left ventricular remodelling, neurohumoral activation, and congestion. In this review, we will explore the physiology, rationale, and current stages of the clinical development of the existing procedures.

Baroreflex activation therapy in advanced heart failure therapy: insights from a real-world scenario

AIMS

Baroreflex activation therapy (BAT) is an innovative treatment option for advanced heart failure (HFrEF). We analysed patients' BAT acceptance and the outcome of BAT patients compared with HFrEF patients solely treated with a guideline-directed medical therapy (GDMT) and studied effects of sacubitril/valsartan (ARNI).

METHODS

In this prospective study, 40 HFrEF patients (71 ± 3 years, 20% female) answered a questionnaire on the acceptance of BAT. Follow-up visits were performed after 3, 6, and 12 months. Primary efficacy endpoints included an improvement in QoL, NYHA class, LVEF, HF hospitalization, NT-proBNP levels, and 6MHWD.

RESULTS

Twenty-nine patients (73%) showed interest in BAT. Ten patients (25%) opted for implantation. BAT and BAT + ARNI patients developed an increase in LVEF (BAT +10%, P-value (P) = 0.005*; BAT + ARNI +9%, P = 0.049*), an improved NYHA class (BAT -88%, P = 0.014*, BAT + ARNI -90%, P = 0.037*), QoL (BAT +21%, P = 0.020*, BAT + ARNI +22%, P = 0.012*), and reduced NT-proBNP levels (BAT -24%, P = 0.297, BAT + ARNI -37%, P = 0.297). BAT HF hospitalization rates were lower (50%) compared with control group patients (83%) (P = 0.020*).

CONCLUSIONS

Although BAT has generated considerable interest, acceptance appears to be ambivalent. BAT improves outcome with regard to LVEF, NYHA class, QoL, NT-proBNP levels, and HF hospitalization rates. BAT + ARNI resulted in more pronounced effects than ARNI alone.

Potential Neuromodulation of the Cardio-Renal Syndrome

The cardio-renal syndrome (CRS) type 2 is defined as a progressive loss of renal function following a primary insult to the myocardium that may be either acute or chronic but is accompanied by a decline in myocardial pump performance. The treatment of patients with CRS is difficult, and the disease often progresses to end-stage renal disease that is refractory to conventional therapy. While a good deal of information is known concerning renal injury in the CRS, less is understood about how reflex control of renal sympathetic nerve activity affects this syndrome. In this review, we provide insight into the role of the renal nerves, both from the afferent or sensory side and from the efferent side, in mediating renal dysfunction in CRS. We discuss how interventions such as renal denervation and abrogation of systemic reflexes may be used to alleviate renal dysfunction in the setting of chronic heart failure. We specifically focus on a novel cardiac sensory reflex that is sensitized in heart failure and activates the sympathetic nervous system, especially outflow to the kidney. This so-called Cardiac Sympathetic Afferent Reflex (CSAR) can be ablated using the potent neurotoxin resinferitoxin due to the high expression of Transient Receptor Potential Vanilloid 1 (TRPV1) receptors. Following ablation of the CSAR, several markers of renal dysfunction are reversed in the post-myocardial infarction heart failure state. This review puts forth the novel idea of neuromodulation at the cardiac level in the treatment of CRS Type 2.

Reflecting on the advancements of HFrEF therapies over the last two decades and predicting what is yet to come

What was once considered a topic best avoided, managing heart failure with reduced ejection fraction (HFrEF) has become the focus of many drug and device therapies. While the four pillars of guideline-directed medical therapies have successfully reduced heart failure hospitalizations, and some have even impacted cardiovascular mortality in randomized controlled trials (RCTs), patient-reported outcomes have emerged as important endpoints that merit greater emphasis in future studies. The prospect of an oral inotrope seems more probable now as targets for drug therapies have moved from neurohormonal modulation to intracellular mechanisms and direct cardiac myosin stimulation. While we have come a long way in safely providing durable mechanical circulatory support to patients with advanced HFrEF, several percutaneous device therapies have emerged, and many are under investigation. Biomarkers have shown promise in not only improving our ability to diagnose incident heart failure but also our potential to implicate specific pathophysiological pathways. The once-forgotten concept of discordance between pressure and volume, the forgotten splanchnic venous and lymphatic compartments, have all emerged as promising targets for diagnosing and treating heart failure in the not-so-distant future. The increase in heart failure-related cardiogenic shock (CS) has revived interest in defining optimal perfusion targets and designing RCTs in CS. Rapid developments in remote monitoring, telemedicine, and artificial intelligence promise to change the face of heart failure care. In this state-of-the-art review, we reminisce about the past, highlight the present, and predict what might be the future of HFrEF therapies.

Endovascular Baroreflex Amplification With the MobiusHD Device in Patients With Heart Failure and Reduced Ejection Fraction: Interim Analysis of the First-in-Human Results

Background

Endovascular baroreflex amplification with the MobiusHD, a self-expanding stent-like device that is implanted in the internal carotid artery, was designed to reduce the sympathetic overactivity that contributes to progressive heart failure with reduced ejection fraction.

Methods

Symptomatic patients (New York Heart Association class III) with heart failure with reduced ejection fraction (left ventricular ejection fraction [LVEF] ≤40%) despite guideline directed medical therapy and n-terminal pro-B type natriuretic peptide (NT-proBNP) levels ≥400 pg/mL in whom carotid ultrasound and computed tomographic angiography demonstrated absence of carotid plaque were enrolled. Baseline and follow-up measures included 6-minute walk distance (6MWD), Kansas City Cardiomyopathy Questionnaire overall summary score (KCCQ OSS), and repeat biomarkers and transthoracic echocardiography.

Results

Twenty-nine patients underwent device implantation. The mean age was 60.6 ± 11.4 years, and all had New York Heart Association class III symptoms. Mean KCCQ OSS was 41.4 ± 12.7, mean 6MWD was 216.0 ± 43.7 m, median NT-proBNP was 1005.9 pg/mL (894, 1294), and mean LVEF was 34.7 ± 2.9%. All device implantations were successful. Two patients died (161 days and 195 days) and one stroke occurred (170 days) during follow-up. For the 17 patients with 12-month follow-up, mean KCCQ OSS improved by 17.4 ± 9.1 points, mean 6MWD increased by 97.6 ± 51.1 meters, a mean 28.4% reduction from the baseline NT-proBNP concentration was found, and mean LVEF improved by 5.6% ± 2.9 (paired data).

Conclusion

Endovascular baroreflex amplification with the MobiusHD device was safe and effected positive changes in quality of life, exercise capacity, and LVEF, consistent with observed reductions in NT-proBNP levels.

Carotid Artery Revascularization Improves Cardiac Sympathetic Nerve Activity in Patients With Carotid Artery Stenosis

BACKGROUND

The carotid sinus baroreceptor reflex controls the neural regulation of blood pressure. Baroreceptor disorders due to carotid sinus atherosclerosis have detrimental cardiovascular effects. This study investigated the medium-term effects of carotid artery revascularization (CAR) on sympathetic and cardiac function and systemic blood pressure variability in patients with carotid artery stenosis.

METHODS

This study included 21 consecutive patients (median age 70 years, 18 men) with carotid artery stenosis scheduled for CAR. ¹²³I metaiodobenzylguanidine (MIBG) scintigraphy, echocardiography, brain natriuretic peptide levels, 24-h Holter electrocardiography (ECG), and ambulatory blood pressure monitoring assessed approximately 3 months postoperatively were compared to preoperative data.

RESULTS

All 21 enrolled patients underwent CAR. Carotid artery stenting was done in three patients with cardiovascular risk or anatomical difficult for carotid endarterectomy. The mean common carotid artery end-diastolic velocity improved significantly (P < 0.01) by 1.6-fold, from 10.8 ± 3.2 to 16.1 ± 7.1 cm/s. In ¹²³I-MIBG scintigraphy, the heart-to-mediastinum (H/M) count ratio was significantly higher than preoperatively (from 2.66 ± 0.48 to 2.86 ± 0.56, P = 0.03). Holter ECG analysis revealed a significant decrease in the low-frequency/high-frequency (LF/HF) ratio compared to preoperatively (from 2.17 ± 1.20 to 1.62 ± 0.68, P = 0.04). These findings suggest decreased myocardial sympathetic activation. In echocardiography, the tissue Doppler-derived e' increased, and E/e' decreased significantly (P < 0.05) from 11.7 ± 5.1 to 10.1 ± 4.0, suggesting an improved left ventricular diastolic capacity. The mean 24-h and nighttime blood pressures were unchanged.

CONCLUSIONS

CAR in patients with carotid stenosis may provide medium-term improvement in cardiac sympathetic nerve activity and left ventricular diastolic dysfunction.

The plasticity of cardiac sympathetic nerves and its clinical implication in cardiovascular disease

The heart is electrically and mechanically controlled by the autonomic nervous system, which consists of both the sympathetic and parasympathetic systems. It has been considered that the sympathetic and parasympathetic nerves regulate the cardiomyocytes’ performance independently; however, recent molecular biology approaches have provided a new concept to our understanding of the mechanisms controlling the diseased heart through the plasticity of the autonomic nervous system. Studies have found that cardiac sympathetic nerve fibers in hypertrophic ventricles strongly express an immature neuron marker and simultaneously cause deterioration of neuronal cellular function. This phenomenon was explained by the rejuvenation of cardiac sympathetic nerves. Moreover, heart failure and myocardial infarction have been shown to cause cholinergic trans-differentiation of cardiac sympathetic nerve fibers via gp130-signaling cytokines secreted from the failing myocardium, affecting cardiac performance and prognosis. This phenomenon is thought to be one of the adaptations that prevent the progression of heart disease. Recently, the concept of using device-based neuromodulation therapies to attenuate sympathetic activity and increase parasympathetic (vagal) activity to treat cardiovascular disease, including heart failure, was developed. Although several promising preclinical and pilot clinical studies using these strategies have been conducted, the results of clinical efficacy vary. In this review, we summarize the current literature on the plasticity of cardiac sympathetic nerves and propose potential new therapeutic targets for heart disease.

Modeling the physiological roles of the heart and kidney in heart failure with preserved ejection fraction during baroreflex activation therapy

Heart failure (HF) is a leading cause of death and is increasing in prevalence. Unfortunately, therapies that have been efficacious in patients with HF with reduced ejection fraction (HFrEF) have not convincingly shown a reduction in cardiovascular mortality in patients with HF with preserved ejection fraction (HFpEF). It is thought that high sympathetic nerve activity (SNA) in the heart plays a role in HF progression. Clinical trials demonstrate that baroreflex activation therapy reduces left ventricular (LV) mass and blood pressure (BP) in patients with HFpEF and hypertension; however, the mechanisms are unclear. In the present study, we used HumMod, a large physiology model to simulate HFpEF and predict the time-dependent changes in systemic and cardiac hemodynamics, SNA, and cardiac stresses during baroreflex activation. The baseline HFpEF model was associated with elevations in systolic BP, diastolic dysfunction, and LV hypertrophy and stiffness similar to clinical HFpEF. Simulating 12 mo of baroreflex activation resulted in reduced systolic BP (-25 mmHg) and LV mass (-15%) similar to clinical evidence. Baroreflex activation also resulted in sustained decreases in cardiac and renal SNA (-22%) and improvement in LV β1-adrenergic function. However, the baroreflex-induced reductions in BP and improvements in cardiac stresses, mass, and function were mostly attenuated when renal SNA was clamped at baseline levels. These simulations suggest that the suppression of renal SNA could be a primary determinant of the cardioprotective effects from baroreflex activation in HFpEF.NEW & NOTEWORTHY Treatments that are efficacious in patients with HFrEF have not shown a significant impact on cardiovascular mortality in patients with HFpEF. We believe these simulations offer novel insight into the important roles of the cardiac and renal nerves in HFpEF and the potential mechanisms of how baroreflex activation alleviates HFpEF disease progression.

Current and future use of neuromodulation in heart failure. Eur Heart J Suppl 2022;24:E28-E34. [PMID: 35991620 PMCID: PMC9385118 DOI: 10.1093/eurheartjsupp/suac031]

Autonomic imbalance is a common finding in heart failure (HF) with reduced ejection fraction (HFrEF). Addressing different targets within the autonomic nervous systems has been evaluated in patients with HF, including renal sympathetic denervation, vagal nerve stimulation, and baroreceptor activation therapy (BAT). Although all are pathophysiologically plausible and promising, only BAT shows sufficient evidence for implementation into clinical practice in randomized controlled trials. Baroreceptor activation therapy can be used in patients with symptomatic HFrEF despite optimal guideline-directed medication and device therapy. This article reviews the current and future use of neuromodulation in HF and provides an overview on current guideline recommendations and clinical practice.

Baroreflex activation therapy with the Barostim™ device in patients with heart failure with reduced ejection fraction: a patient level meta-analysis of randomized controlled trials

AIMS

Heart failure with reduced ejection fraction (HFrEF) remains associated with high morbidity and mortality, poor quality of life (QoL) and significant exercise limitation. Sympatho-vagal imbalance has been shown to predict adverse prognosis and symptoms in HFrEF, yet it has not been specifically targeted by any guideline-recommended device therapy to date. Barostim™, which directly addresses this imbalance, is the first Food and Drug Administration approved neuromodulation technology for HFrEF. We aimed to analyse all randomized trial evidence to evaluate the effect of baroreflex activation therapy (BAT) on heart failure symptoms, QoL and N-terminal pro-brain natriuretic peptide (NT-proBNP) in HFrEF.

METHODS AND RESULTS

An individual patient data (IPD) meta-analysis was performed on all eligible trials that randomized HFrEF patients to BAT + guideline-directed medical therapy (GDMT) or GDMT alone (open label). Endpoints included 6-month changes in 6-min hall walk (6MHW) distance, Minnesota Living With Heart Failure (MLWHF) QoL score, NT-proBNP, and New York Heart Association (NYHA) class in all patients and three subgroups. A total of 554 randomized patients were included. In all patients, BAT provided significant improvement in 6MHW distance of 49 m (95% confidence interval [CI] 33, 64), MLWHF QoL of -13 points (95% CI -17, -10), and 3.4 higher odds of improving at least one NYHA class (95% CI 2.3, 4.9) when comparing from baseline to 6 months. These improvements were similar, or better, in patients who had baseline NT-proBNP &lt;1600 pg/ml, regardless of the cardiac resynchronization therapy indication status.

CONCLUSION

An IPD meta-analysis suggests that BAT improves exercise capacity, NYHA class, and QoL in HFrEF patients receiving GDMT. These clinically meaningful improvements were consistent across the range of patients studies. BAT was also associated with an improvement in NT-proBNP in subjects with a lower baseline NT-proBNP.

Neuromodulation devices for heart failure

Autonomic imbalance with a sympathetic dominance is acknowledged to be a critical determinant of the pathophysiology of chronic heart failure with reduced ejection fraction (HFrEF), regardless of the etiology. Consequently, therapeutic interventions directly targeting the cardiac autonomic nervous system, generally referred to as neuromodulation strategies, have gained increasing interest and have been intensively studied at both the pre-clinical level and the clinical level. This review will focus on device-based neuromodulation in the setting of HFrEF. It will first provide some general principles about electrical neuromodulation and discuss specifically the complex issue of dose-response with this therapeutic approach. The paper will thereafter summarize the rationale, the pre-clinical and the clinical data, as well as the future prospectives of the three most studied form of device-based neuromodulation in HFrEF. These include cervical vagal nerve stimulation (cVNS), baroreflex activation therapy (BAT), and spinal cord stimulation (SCS). BAT has been approved by the Food and Drug Administration for use in patients with HfrEF, while the other two approaches are still considered investigational; VNS is currently being investigated in a large phase III Study.

What Have We Learned in the Last 20 Years About CRT Non-Responders?

Although cardiac resynchronization therapy (CRT) has become well established in the treatment of heart failure, the management of patients who do not respond after CRT remains a key challenge. This review will summarize what we have learned about non-responders over the last 20 years and discuss methods for optimizing response, including the introduction of novel therapies.

CE: Guideline-Directed Cardiac Devices for Patients with Heart Failure

ABSTRACT

Heart failure affects over 6.2 million adults in the United States and is expected to affect over 8 million by 2030. The U.S. one-year mortality rate is almost 30% among Medicare beneficiaries. Technological advances have produced several new cardiac devices that are available for therapy and symptom management. This article reviews current device therapies for heart failure and uses a composite case to demonstrate how bedside nurses can help patients understand treatment options related to their disease process and care for them through this experience.

Research Opportunities in Autonomic Neural Mechanisms of Cardiopulmonary Regulation: A Report From the National Heart, Lung, and Blood Institute and the National Institutes of Health Office of the Director Workshop

This virtual workshop was convened by the National Heart, Lung, and Blood Institute, in partnership with the Office of Strategic Coordination of the Office of the National Institutes of Health Director, and held September 2 to 3, 2020. The intent was to assemble a multidisciplinary group of experts in basic, translational, and clinical research in neuroscience and cardiopulmonary disorders to identify knowledge gaps, guide future research efforts, and foster multidisciplinary collaborations pertaining to autonomic neural mechanisms of cardiopulmonary regulation. The group critically evaluated the current state of knowledge of the roles that the autonomic nervous system plays in regulation of cardiopulmonary function in health and in pathophysiology of arrhythmias, heart failure, sleep and circadian dysfunction, and breathing disorders. Opportunities to leverage the Common Fund's SPARC (Stimulating Peripheral Activity to Relieve Conditions) program were characterized as related to nonpharmacologic neuromodulation and device-based therapies. Common themes discussed include knowledge gaps, research priorities, and approaches to develop novel predictive markers of autonomic dysfunction. Approaches to precisely target neural pathophysiological mechanisms to herald new therapies for arrhythmias, heart failure, sleep and circadian rhythm physiology, and breathing disorders were also detailed.

2021 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure: Developed by the Task Force for the diagnosis and treatment of acute and chronic heart failure of the European Society of Cardiology (ESC). With the special contribution of the Heart Failure Association (HFA) of the ESC

Document Reviewers: Rudolf A. de Boer (CPG Review Coordinator) (Netherlands), P. Christian Schulze (CPG Review Coordinator) (Germany), Magdy Abdelhamid (Egypt), Victor Aboyans (France), Stamatis Adamopoulos (Greece), Stefan D. Anker (Germany), Elena Arbelo (Spain), Riccardo Asteggiano (Italy), Johann Bauersachs (Germany), Antoni Bayes-Genis (Spain), Michael A. Borger (Germany), Werner Budts (Belgium), Maja Cikes (Croatia), Kevin Damman (Netherlands), Victoria Delgado (Netherlands), Paul Dendale (Belgium), Polychronis Dilaveris (Greece), Heinz Drexel (Austria), Justin Ezekowitz (Canada), Volkmar Falk (Germany), Laurent Fauchier (France), Gerasimos Filippatos (Greece), Alan Fraser (United Kingdom), Norbert Frey (Germany), Chris P. Gale (United Kingdom), Finn Gustafsson (Denmark), Julie Harris (United Kingdom), Bernard Iung (France), Stefan Janssens (Belgium), Mariell Jessup (United States of America), Aleksandra Konradi (Russia), Dipak Kotecha (United Kingdom), Ekaterini Lambrinou (Cyprus), Patrizio Lancellotti (Belgium), Ulf Landmesser (Germany), Christophe Leclercq (France), Basil S. Lewis (Israel), Francisco Leyva (United Kingdom), AleVs Linhart (Czech Republic), Maja-Lisa Løchen (Norway), Lars H. Lund (Sweden), Donna Mancini (United States of America), Josep Masip (Spain), Davor Milicic (Croatia), Christian Mueller (Switzerland), Holger Nef (Germany), Jens-Cosedis Nielsen (Denmark), Lis Neubeck (United Kingdom), Michel Noutsias (Germany), Steffen E. Petersen (United Kingdom), Anna Sonia Petronio (Italy), Piotr Ponikowski (Poland), Eva Prescott (Denmark), Amina Rakisheva (Kazakhstan), Dimitrios J. Richter (Greece), Evgeny Schlyakhto (Russia), Petar Seferovic (Serbia), Michele Senni (Italy), Marta Sitges (Spain), Miguel Sousa-Uva (Portugal), Carlo G. Tocchetti (Italy), Rhian M. Touyz (United Kingdom), Carsten Tschoepe (Germany), Johannes Waltenberger (Germany/Switzerland) All experts involved in the development of these guidelines have submitted declarations of interest. These have been compiled in a report and published in a supplementary document simultaneously to the guidelines. The report is also available on the ESC website www.escardio.org/guidelines For the Supplementary Data which include background information and detailed discussion of the data that have provided the basis for the guidelines see European Heart Journal online.

Reverse re-modelling chronic heart failure by reinstating heart rate variability

Heart rate variability (HRV) is a crucial indicator of cardiovascular health. Low HRV is correlated with disease severity and mortality in heart failure. Heart rate increases and decreases with each breath in normal physiology termed respiratory sinus arrhythmia (RSA). RSA is highly evolutionarily conserved, most prominent in the young and athletic and is lost in cardiovascular disease. Despite this, current pacemakers either pace the heart in a metronomic fashion or sense activity in the sinus node. If RSA has been lost in cardiovascular disease current pacemakers cannot restore it. We hypothesized that restoration of RSA in heart failure would improve cardiac function. Restoration of RSA in heart failure was assessed in an ovine model of heart failure with reduced ejection fraction. Conscious 24 h recordings were made from three groups, RSA paced (n = 6), monotonically paced (n = 6) and heart failure time control (n = 5). Real-time blood pressure, cardiac output, heart rate and diaphragmatic EMG were recorded in all animals. Respiratory modulated pacing was generated by a proprietary device (Ceryx Medical) to pace the heart with real-time respiratory modulation. RSA pacing substantially increased cardiac output by 1.4 L/min (20%) compared to contemporary (monotonic) pacing. This increase in cardiac output led to a significant decrease in apnoeas associated with heart failure, reversed cardiomyocyte hypertrophy, and restored the T-tubule structure that is essential for force generation. Re-instating RSA in heart failure improves cardiac function through mechanisms of reverse re-modelling; the improvement observed is far greater than that seen with current contemporary therapies. These findings support the concept of re-instating RSA as a regime for patients who require a pacemaker.

Cardiopulmonary function during exercise in heart failure with reduced ejection fraction following baroreflex activation therapy

PURPOSE

Baroreflex activation therapy has favorable effects in heart failure patients. We report the results of a single-center study of baroreflex activation therapy in heart failure with reduced ejection fraction including cardiopulmonary exercise testing for the first time to show the effect on exercise capacity.

METHODS

A total of 17 patients were treated with baroreflex activation therapy. Eligibility criteria were the New York Heart Association class ⩾III and ejection fraction ⩽35% on guideline-directed medical and device therapy. The New York Heart Association class, quality of life, and 6-min hall walk distance were assessed in all patients. Twelve patients underwent cardiopulmonary exercise testing before and 8.9 ± 6.4 months after initiation of baroreflex activation therapy.

RESULTS

The New York Heart Association class and 6-min hall walk distance improved after baroreflex activation therapy, while quality of life remained stable. Weight-adapted peak oxygen uptake increased significantly from 10.1 (8.2-12.9) ml/min/kg to 12.1 (10.4-14.6) ml/min/kg (p = 0.041). Maximal heart rate was stable. Maximal oxygen pulse increased from 9.7 (5.5-11.3) to 9.9 (7.1-12.1) ml/heartbeat (p = 0.047) in 10 patients with low maximal oxygen pulse at baseline (<16.5 ml/heartbeat). There was no significant change in maximal oxygen pulse in the whole cohort. Ventilatory efficiency remained stable.

CONCLUSION

Weight-adapted peak oxygen uptake improved after baroreflex activation therapy, pointing to an enhanced exercise capacity. Ventilatory efficiency and heart rate did not change, while oxygen pulse increased in patients with low oxygen pulse at baseline, indicating an improvement in circulatory efficiency, that is, a beneficial effect on stroke volume and peripheral oxygen extraction.

Diagnostic Tools, Biomarkers, and Treatments in Diabetic polyneuropathy and Cardiovascular Autonomic Neuropathy

The various manifestations of diabetic neuropathy, including distal symmetric sensorimotor polyneuropathy (DSPN) and cardiovascular autonomic neuropathy (CAN), are among the most prevalent chronic complications of diabetes. Major clinical complications of diabetic neuropathies, such as neuropathic pain, chronic foot ulcers, and orthostatic hypotension, are associated with considerable morbidity, increased mortality, and diminished quality of life. Despite the substantial individual and socioeconomic burden, the strategies to diagnose and treat diabetic neuropathies remain insufficient. This review provides an overview of the current clinical aspects and recent advances in exploring local and systemic biomarkers of both DSPN and CAN assessed in human studies (such as biomarkers of inflammation and oxidative stress) for better understanding of the underlying pathophysiology and for improving early detection. Current therapeutic options for DSPN are (I) causal treatment, including lifestyle modification, optimal glycemic control, and multifactorial risk intervention, (II) pharmacotherapy derived from pathogenetic concepts, and (III) analgesic treatment against neuropathic pain. Recent advances in each category are discussed, including non-pharmacological approaches, such as electrical stimulation. Finally, the current therapeutic options for cardiovascular autonomic complications are provided. These insights should contribute to a broader understanding of the various manifestations of diabetic neuropathies from both the research and clinical perspectives.

Novel Non-pharmaceutical Advancements in Heart Failure Management: The Emerging Role of Technology

PURPOSE OF REVIEW

To summarise and discuss the implications of recent technological advances in heart failure care.

RECENT FINDINGS

Heart failure remains a significant source of morbidity and mortality in the US population despite multiple classes of approved pharmacological treatments. Novel cardiac devices and technologies may offer an opportunity to improve outcomes. Baroreflex Activation Therapy and Cardiac Contractility Remodelling may improve myocardial contractility by altering neurohormonal stimulation of the heart. Implantable Pulmonary Artery Monitors and Biatrial Shunts may prevent heart failure admissions by altering the trajectory of progressive congestion. Phrenic Nerve Stimulation offers potentially effective treatment for comorbid conditions. Smartphone applications offer an intriguing strategy for improving medication adherence.

SUMMARY

Novel heart failure technologies offer promise for reducing this public health burden. Randomized controlled studies are indicated for assessing the future role of these novel therapies.

Vagal Neuromodulation in Chronic Heart Failure With Reduced Ejection Fraction: A Systematic Review and Meta-Analysis

Objectives: The aim of this study was to evaluate the effects of invasive vagal nerve stimulation (VNS) in patients with chronic heart failure (HF) and reduced ejection fraction (HFrEF).

Background: Heart failure is characterized by autonomic nervous system imbalance and electrical events that can lead to sudden death. The effects of parasympathetic (vagal) stimulation in patients with HF are not well-established.

Methods: From May 1994 to July 2020, a systematic review was performed using PubMed, Embase, and Cochrane Library for clinical trials, comparing VNS with medical therapy for the management of chronic HFrEF (EF ≤ 40%). A meta-analysis of several outcomes and adverse effects was completed, and GRADE was used to assess the level of evidence.

Results: Four randomized controlled trials (RCT) and three prospective studies, totalizing 1,263 patients were identified; 756 treated with VNS and 507 with medical therapy. RCT data were included in the meta-analysis (fixed-effect distribution). Adverse effects related to VNS were observed in only 11% of patients. VNS was associated with significant improvement (GRADE = High) in the New York Heart Association (NYHA) functional class (OR, 2.72, 95% CI: 2.07–3.57, p < 0.0001), quality of life (MD −14.18, 95% CI: −18.09 to −10.28, p < 0.0001), a 6-min walk test (MD, 55.46, 95% CI: 39.11–71.81, p < 0.0001) and NT-proBNP levels (MD −144.25, 95% CI: −238.31 to −50.18, p = 0.003). There was no difference in mortality (OR, 1.24; 95% CI: 0.82–1.89, p = 0.43).

Conclusions: A high grade of evidence demonstrated that vagal nerve stimulation improves NYHA functional class, a 6-min walk test, quality of life, and NT-proBNP levels in patients with chronic HFrEF, with no differences in mortality.