Splanchnic Nerve Block for Chronic Heart Failure

Interventional therapies for chronic heart failure: An overview of recent developments

Heart failure (HF), the final manifestation of most cardiovascular diseases, has become a major global health concern, affecting millions of individuals. Despite basic drug treatments, patients present with high morbidity and mortality rates. However, recent advancements in interventional therapy have shown promising results in improving the prognosis of patients with HF. These advancements include transcatheter aortic valve replacement for severe aortic stenosis, transcatheter mitral valve repair for chronic mitral regurgitation, neuromodulation therapy for multiple targets and measures in the treatment of chronic HF and left ventricular assist device implantation for advanced HF (Figure 1). In this review, we aimed to provide an overview of the current progress in interventional therapies for chronic HF.

Device therapies for heart failure with reduced ejection fraction: a new era

Even with significant advancements in the treatment modalities for patients with heart failure (HF), the rates of morbidity and mortality associated with HF are still high. Various therapeutic interventions, including cardiac resynchronization therapy, Implantable Cardiovascular-Defibrillators, and left ventricular assist devices, are used for HF management. Currently, more research and developments are required to identify different treatment modalities to reduce hospitalization rates and improve the quality of life of patients with HF. In relation to this, various non-valvular catheter-based therapies have been recently developed for managing chronic HF. These devices target the pathophysiological processes involved in HF development including neurohumoral activation, congestion, and left ventricular remodeling. The present review article aimed to discuss the major transcatheter devices used in managing chronic HF. The rationale and current clinical developmental stages of these interventions will also be addressed in this review.

Endovascular Ablation of the Greater Splanchnic Nerve in Heart Failure With Preserved Ejection Fraction: The REBALANCE-HF Randomized Clinical Trial

Importance

Greater splanchnic nerve ablation may improve hemodynamics in patients with heart failure and preserved ejection fraction (HFpEF).

Objective

To explore the feasibility and safety of endovascular right-sided splanchnic nerve ablation for volume management (SAVM).

Design, Setting, and Participants

This was a phase 2, double-blind, 1:1, sham-controlled, multicenter, randomized clinical trial conducted at 14 centers in the US and 1 center in the Republic of Georgia. Patients with HFpEF, left ventricular ejection fraction of 40% or greater, and invasively measured peak exercise pulmonary capillary wedge pressure (PCWP) of 25 mm Hg or greater were included. Study data were analyzed from May 2023 to June 2024.

Intervention

SAVM vs sham control procedure.

Main Outcomes and Measures

The primary efficacy end point was a reduction in legs-up and exercise PCWP at 1 month. The primary safety end point was serious device- or procedure-related adverse events at 1 month. Secondary efficacy end points included HF hospitalizations, changes in exercise function and health status through 12 months, and baseline to 1-month change in resting, legs-up, and 20-W exercise PCWP.

Results

A total of 90 patients (median [range] age, 71 [47-90] years; 58 female [64.4%]) were randomized at 15 centers (44 SAVM vs 46 sham). There were no differences in adverse events between groups. The primary efficacy end point did not differ between SAVM or sham (mean between-group difference in PCWP, -0.03 mm Hg; 95% CI, -2.5 to 2.5 mm Hg; P = .95). There were also no differences in the secondary efficacy end points. There was no difference in the primary safety end point between the treatment (6.8% [3 of 44]) and sham (2.2% [1 of 46]) groups (difference, 4.6%; 95% CI, -6.1% to 15.4%; P = .36). There was no difference in the incidence of orthostatic hypotension between the treatment (11.4% [5 of 44]) and sham (6.5% [3 of 46]) groups (difference, 4.9%; 95% CI, -9.2% to 18.8%; P = .48).

Conclusions and Relevance

Results show that SAVM was safe and technically feasible, but it did not reduce exercise PCWP at 1 month or improve clinical outcomes at 12 months in a broad population of patients with HFpEF.

Trial Registration

ClinicalTrials.gov Identifier: NCT04592445.

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.

Endovascular Ablation of the Right Greater Splanchnic Nerve in Heart Failure With Preserved Ejection Fraction: Rationale, Design and Lead-in Phase Results of the REBALANCE-HF Trial

OBJECTIVE

Splanchnic vasoconstriction augments transfer of blood volume from the abdomen into the thorax, which may increase filling pressures and hemodynamic congestion in patients with noncompliant hearts. Therapeutic interruption of splanchnic nerve activity holds promise to reduce hemodynamic congestion in patients with heart failure with preserved ejection fraction (HFpEF). Here we describe (1) the rationale and design of the first sham-controlled, randomized clinical trial of splanchnic nerve ablation for HFpEF and (2) the 12-month results of the lead-in (open-label) trial's participants.

METHODS

REBALANCE-HF is a prospective, multicenter, randomized, double-blinded, sham-controlled clinical trial of endovascular, transcatheter, right-sided greater splanchnic nerve ablation for volume management (SAVM) in patients with HFpEF. The primary objectives are to evaluate the safety and efficacy of SAVM and identify responder characteristics to inform future studies. The trial consists of an open-label lead-in phase followed by the randomized, sham-controlled phase. The primary efficacy endpoint is the reduction in pulmonary capillary wedge pressure (PCWP) at 1-month follow-up compared to baseline during passive leg raise and 20W exercise. Secondary and exploratory endpoints include health status (Kansas City Cardiomyopathy Questionnaire), 6-minute walk test distance, New York Heart Association class, and NTproBNP levels at 3, 6 and 12 months. The primary safety endpoint is device- or procedure-related serious adverse events at the 1-month follow-up.

RESULTS

The lead-in phase of the study, which enrolled 26 patients with HFpEF who underwent SAVM, demonstrated favorable safety outcomes and reduction in exercise PCWP at 1 month post-procedure and improvements in all secondary endpoints at 6 and 12 months of follow-up. The randomized phase of the trial (n = 44 SAVM; n = 46 sham) has completed enrollment, and follow-up is ongoing.

CONCLUSION

REBALANCE-HF is the first sham-controlled randomized clinical trial of greater splanchnic nerve ablation in HFpEF. Initial 12-month open-label results are promising, and the results of the randomized portion of the trial will inform the design of a future pivotal clinical trial. SAVM may offer a promising therapeutic option for patients with HFpEF.

TRIAL REGISTRATION

NCT04592445.

Role of splanchnic circulation in the pathogenesis of heart failure: State-of-the-art review

A hallmark of heart failure (HF), whether it presents itself during rest or periods of physical exertion, is the excessive elevation of intracardiac filling pressures at rest or with exercise. Many mechanisms contribute to the elevated intracardiac filling pressures, and notably, the concept of volume redistribution has gained attention as a cause of the elevated intracardiac filling pressures in patients with HF, particularly HF with preserved ejection fraction, who often present without symptoms at rest, with shortness of breath and fatigue appearing only during exertion. This phenomenon suggests cardiopulmonary system non-compliance and inappropriate volume distribution between the stressed and unstressed blood volume components. A substantial proportion of the intravascular blood volume is in the splanchnic vascular compartment in the abdomen. Preclinical and clinical investigations support the critical role of the sympathetic nervous system in modulating the capacitance and compliance of the splanchnic vascular bed via modulation of the greater splanchnic nerve (GSN). The GSN activation by stressors such as exercise causes excessive splanchnic vasoconstriction, which may contribute to the decompensation of chronic HF via volume redistribution from the splanchnic vascular bed to the central compartment. Accordingly, for example, GSN ablation for volume management has been proposed as a potential therapeutic intervention to increase unstressed blood volume. Here we provide a comprehensive review of the role of splanchnic circulation in the pathogenesis of HF and potential novel treatment options for redistributing blood volume to improve symptoms and prognosis in patients with HF.

Splanchnic Nerve Block: An Emerging Treatment for Heart Failure

Heart failure (HF) is a disease syndrome whose management is increasingly challenging given the aging population and efficacious management of acute cardiac events. The current treatment options within our armamentarium incompletely address the unmet needs of HF. Splanchnic nerve block (SNB) is a novel technique that targets the greater splanchnic nerve, a potential therapeutic target in HF. However, the technique confers potential adverse side effects and complications that warrant further investigations. In this review paper, we aim to discuss the inextricable role of splanchnic nerve in HF by highlighting their physiological interplay, clinical studies that have exhibited favorable hemodynamic parameters in the context of acute and chronic HF, and common side effects and possible complications from SNB.

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.

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.

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.

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.

Splanchnic Nerve Modulation Effects on Surrogate Measures of Venous Capacitance

Background Splanchnic nerve modulation (SNM) is an emerging procedure to reduce cardiac filling pressures in heart failure. Although the main contributor to reduction in cardiac preload is thought to be increased venous capacitance in the splanchnic circulation, supporting evidence is limited. We examined changes in venous capacitance surrogates pre- and post-SNM. Methods and Results This is a prespecified analysis of a prospective, open-label, single-arm interventional study evaluating the effects of percutaneous SNM with ropivacaine in chronic heart failure with elevated filling pressures at rest and with exercise. Patients underwent cardiopulmonary exercise testing with invasive hemodynamic assessment pre- and post-SNM. Blood pressure changes with modified Valsalva maneuver and hemoconcentration, pre- and post-SNM were compared using a repeated measures model. Inferior vena cava diameter and collapsibility (>50% decrease in size with inspiration), and presence of bendopnea pre- and post-SNM were also compared. Fifteen patients undergoing SNM (age 58 years, 47% women, 93% with left ventricular ejection fraction ≤35%) were included. After SNM, changes in systolic blood pressure during Valsalva (peak-to-trough) were greater (41 versus 48 mm Hg, P=0.025). Exercise-induced hemoconcentration was unchanged (0.63 versus 0.43 g/dL, P=0.115). Inferior vena cava diameter was reduced (1.59 versus 1.30 cm, P=0.034) with higher collapsibility (33% versus 73%, P=0.014). Bendopnea was less (47% versus 13%, P=0.025). Conclusions SNM resulted in increased venous capacitance, associated decreased cardiac preload, and decreased bendopnea. Minimally invasive measures of venous capacitance could serve as markers of successful SNM. Long-term effects of SNM on venous capacitance warrant further investigation for heart failure management. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03453151.

Effects of the obstruction of erector spinae plane in affected people undergoing percutaneous vertebroplasty

BACKGROUND

We aimed to compare the difference between the therapeutic effects of percutaneous vertebroplasty (PVP) as well as PVP combined with erector spinae plane blocked (ESPB) in osteoporotic vertebral compression fractures (OVCFs) therapy.

METHODS

After the reception, 100 affected people to OVCFs were randomly divided into the PVP group as a control as well as the PVP + ESPB group as the observation, which included fifty affected people per group. The visual analog scale (VAS) for pain as well as the Oswestry Disability Index (ODI) per group was assessed before the operation, two hours after the operation, and when patients were discharged from the hospital. Operating time was also evaluated on the charged bulk of bone cement during the surgery, blood loss during the surgery, as well as operating costs for each group. Additionally, to assess differences, comparisons have been done among available groups in terms of ambulation as well as defecation or stool after the operation at the earlier time.

RESULTS

The PVP + ESPB category acquired lower VAS and ODI scores when assessments were processed 2 h after the operation and when they were discharged from a hospital. They also had earlier postoperative ambulation and defecation time than the category of PVP (p < 0.05). Regarding the other indicators, there did not show significant differences. Besides, no complications occurred within both group, either after the operation or when they discharge from the hospital.

CONCLUSION

PVP + ESPB for OVCF is related to less VAS, further effective alleviation of pain, and fewer ODI values in affected people after the operation than only PVP. Besides, affected people can involve in ambulation more swiftly. The PVP + ESPB therapy improves the quicker recuperation of intestinal function as well as helps to improve the overall life quality of patients.

Advances in novel devices for the treatment of heart failure

Heart failure (HF) is one of the leading causes of global health impairment. Current drugs are still limited in their effectiveness in the treatment and reversal of HF: for example, drugs for acute HF (AHF) help to reduce congestion and relieve symptoms, but they do little to improve survival; most conventional drugs for HF with preserved ejection fraction (HFpEF) do not improve the prognosis; and drugs have extremely limited effects on advanced HF. In recent years, progress in device therapies has bridged this gap to a certain extent. For example, the availability of the left ventricular assist device has brought new options to numerous advanced HF patients. In addition to this recognizable device, a range of promising novel devices with preclinical or clinical trial results are emerging that seek to treat or reverse HF by providing circulatory support, repairing structural abnormalities in the heart, or providing electrical stimulation. These devices may be useful for the treatment of HF. In this review, we summarized recent advances in novel devices for AHF, HFpEF, and HF with reduced ejection fraction (HFrEF) with the aim of providing a reference for clinical treatment and inspiration for novel device development.

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.

Effect of nitroglycerin on splanchnic and pulmonary blood volume

BACKGROUND

Sublingual nitroglycerin (SL NTG) is useful for treating acute decompensated heart failure, possibly by increasing splanchnic capacitance and reducing left ventricular (LV) preload. We evaluated a radionuclide method to study these effects, initially in subjects without heart failure.

METHODS AND RESULTS

Red blood cells were labelled by an in vitro method. Abdominal and chest images were obtained at rest, showing relative regional blood volumes. The abdomen was then re-imaged during progressive escalation of intrathoracic pressure using continuous positive airway pressure to assess baseline splanchnic capacitance (pressure-volume relationship, PVR) and compliance (slope of PVR). The procedure was repeated after 0.6 mg SL NTG, followed by chest images. Relative splanchnic blood volume increased at rest after SL NTG (P < .002), signifying an increase in splanchnic capacitance. The slope of the splanchnic PVR decreased in proportion to the baseline PVR (P = .0014), signifying increased compliance. The relative pulmonary blood volume decreased in proportion to the increase in splanchnic blood volume (P = .01).

CONCLUSIONS

A semi-quantitative radionuclide method demonstrated the effect of SL NTG for increasing splanchnic capacitance and compliance, with a proportional decrease in pulmonary blood volume. These data may be applied to quantitatively evaluate the importance of splanchnic vasodilation as a mechanism of LV preload reduction in the treatment of heart failure.

CLINICAL TRIALS REGISTRATION

NCT02425566.

Device-based therapy for decompensated heart failure: An updated review of devices in development based on the DRI2P2S classification

Congestive heart failure (HF) is a devastating disease leading to prolonged hospitalization, high morbidity and mortality rates, and increased costs. Well-established treatments for decompensated or unstable patients include medications and mechanical cardiac support devices. For acute HF decompensation, new devices are being developed to help relieve symptoms and recover heart and renal function in these patients. A recent device-based classification scheme, collectively classified as DRI2P2S, has been proposed to better describe these new device-based therapies based on their mechanism: dilators (increase venous capacitance), removers (direct removal of sodium and water), inotropes (increase left ventricular contractility), interstitials (accelerate removal of lymph), pushers (increase renal arterial pressure), pullers (decrease renal venous pressure), and selective (selective intrarenal drug infusion). In this review, we describe the new class of medical devices with the most current results reported in preclinical models and clinical trials.

Fluid Volume Homeostasis in Heart Failure: A Tale of 2 Circulations

Fluid volume homeostasis in health and heart failure (HF) requires a complex interaction of 2 systems, the intravascular and interstitial-lymphatic circulations. With the development of HF both the intravascular and interstitial compartments undergo variable degrees of volume remodeling which can include significant expansion. This reflects the impact of multiple pathophysiologic mechanisms on both fluid compartments which initially play a compensatory role to stabilize intravascular circulatory integrity but with progression in HF can evolve to produce the various manifestations of volume overload and clinical HF congestion. The intent of this review is to help enhance recognition of the pathophysiologic and clinical importance of the interlinked roles of these 2 circulatory systems in volume regulation and chronic HF. It would also be hoped that a better understanding of the interacting functions of the intravascular and interstitial-lymphatic fluid compartments can potentially aid development of novel management strategies particularly addressing the generally undertargeted interstitial-lymphatic system and help bring such approaches forward through a more integrated view of these 2 circulatory systems.

Applications of the ultrasound-guided nerve block technique for nonanalgesic effects

The nerve block technique guided by ultrasound has been able to accurately block tiny nerves throughout the body in recent years. It has been increasingly used to treat multisystem diseases or analgesia in surgical patients, but the latter accounted for the vast majority of cases. The nonanalgesic effect of nerve blocks is also in wide demand. After searching ultrasound-guided nerve block works on the PubMed database, we systematically summarized the current clinical application of the nerve block technique and the unique role and related mechanism of nerve block in the prevention and treatment of multi-system diseases or symptoms, including disorders of the circulatory and respiratory systems, postoperative cognitive dysfunction, immune function, posttraumatic stress disorder, and postoperative digestive system, to put forward the potential prospective application in future and serve as a reference for future research of nerve block therapy in these diseases mentioned.

Catheter-Based Management of Heart Failure: Pathophysiology and Contemporary Data

Device therapy for severe heart failure (HF) has shown efficacy both in acute and chronic settings. Recent percutaneous device innovations have pioneered a field known as interventional HF, providing clinicians with a variety of options for acute decompensated HF that are centered on nonsurgical mechanical circulatory support. Other structural-based therapies are aimed at the pathophysiology of chronic HF and target the underlying etiologies such as functional mitral regurgitation, ischemic cardiomyopathy, and increased neurohumoral activity. Remote hemodynamic monitoring devices have also been shown to be efficacious for the ambulatory management of HF. We review the current data on devices and investigational therapies for HF management whereby pharmacotherapy falls short.

Endovascular Ablation of the Right Greater Splanchnic Nerve in Heart Failure with Preserved Ejection Fraction: Early Results of the REBALANCE-HF Trial Roll-in Cohort

Aims

In heart failure (HF) with preserved ejection fraction (HFpEF), excessive redistribution of blood volume into the central circulation leads to elevations of intracardiac pressures with exercise limitations. Splanchnic ablation for volume management (SAVM) has been proposed as a therapeutic intervention. Here we present preliminary safety and efficacy data from the initial roll‐in cohort of the REBALANCE‐HF trial.

Methods and results

The open‐label (roll‐in) arm of REBALANCE‐HF will enrol up to 30 patients, followed by the randomized, sham‐controlled portion of the trial (up to 80 additional patients). Patients with HF, left ventricular ejection fraction (LVEF) ≥50%, and invasive peak exercise pulmonary capillary wedge pressure (PCWP) ≥25 mmHg underwent SAVM. Baseline and follow‐up assessments included resting and exercise PCWP, New York Heart Association (NYHA) class, Kansas City Cardiomyopathy Questionnaire (KCCQ), 6‐min walk test, and N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP). Efficacy and safety were assessed at 1 and 3 months. Here we report on the first 18 patients with HFpEF that have been enrolled into the roll‐in, open‐label arm of the study across nine centres; 14 (78%) female; 16 (89%) in NYHA class III; and median (interquartile range) age 75.2 (68.4–81) years, LVEF 61.0 (56.0–63.2)%, and average (standard deviation) 20 W exercise PCWP 36.4 (±8.6) mmHg. All 18 patients were successfully treated. Three non‐serious moderate device/procedure‐related adverse events were reported. At 1‐month, the mean PCWP at 20 W exercise decreased from 36.4 (±8.6) to 28.9 (±7.8) mmHg (p < 0.01), NYHA class improved by at least one class in 33% of patients (p = 0.02) and KCCQ score improved by 22.1 points (95% confidence interval 9.4–34.2) (p < 0.01).

Conclusion

The preliminary open‐label results from the multicentre REBALANCE‐HF roll‐in cohort support the safety and efficacy of SAVM in HFpEF. The findings require confirmation in the ongoing randomized, sham‐controlled portion of the trial.

Targeting Preload in Heart Failure: Splanchnic Nerve Blockade and Beyond

Preload augmentation represents a critical mechanism for the cardiovascular system to increase effective circulating blood volume to increase cardiac filling pressures and, subsequently, for the heart to increase cardiac output. The splanchnic vascular compartment is the primary source of vascular capacity and thus the primary target for preload recruitment in humans. Under normal conditions, sympathetic stimulation of these primary venous vessels promotes the shift of blood from the splanchnic to the thoracic compartment and elevates preload and cardiac output. However, in heart failure, since filling pressures may be elevated at rest due to decreased venous capacitance, incremental recruitment of preload to enhance cardiac output may exacerbate congestion and limit exercise capacity. Accordingly, recent attention has focused on therapies designed to regulate splanchnic vascular redistribution to improve cardiac filling pressures and patient-centered outcomes such as quality of life and exercise capacity in patients with heart failure. In this review, we discuss the relevance of splanchnic circulation as a venous reservoir, the contribution of stressed blood volume to heart failure pathogenesis, and the implications for pharmacological therapeutic interventions to prevent heart failure decompensation. Further, we review emerging device-based approaches for cardiac preload reduction such as partial/complete occlusion of the superior vena cava or the inferior vena cava.

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.

Early Hemodynamic Changes following Surgical Ablation of the Right Greater Splanchnic Nerve for the Treatment of Heart Failure with Preserved Ejection Fraction

Background: Permanent ablation of the right greater splanchnic nerve (GSN) has previously been demonstrated to improve quality of life and functional outcomes, as well as reduce abnormally high intracardiac filling pressures, in patients with heart failure with preserved ejection fraction (HFpEF) at 1, 3 and 12 months following the procedure. We hypothesize that hemodynamic changes that ensue from surgical right GSN ablation would be apparent as early as 24 h after the medical intervention. Methods and Results: This is a prespecified analysis of a single-arm, two-center, open-label study evaluating the effects of right GSN ablation via thoracoscopic surgery in HFpEF patients with pulmonary capillary wedge pressure (PCWP) ≥15 mmHg at rest or ≥25 mmHg with supine cycle ergometry. A total of seven patients (median age 67 years, 29% female) underwent GSN removal followed by invasive right heart catheterization within 24 h. GSN ablation resulted in a significant reduction in PCWP 24 h after the procedure compared to baseline for both 20 W exercise (baseline (28.0 ± 4.3 mmHg) to 24 h (19.6 ± 6.9 mmHg); p = 0.0124) and peak exercise (baseline (25.6 ± 2.4 mmHg) to 24 h (17.4 ± 5.9 mmHg); p = 0.0025). There were no significant changes in resting or leg-up hemodynamics. Conclusions: Permanent right GSN ablation leads to a reduction in intracardiac filling pressures during exercise, apparent as early as 24 h following the procedure.

A Glimpse Into the Future of Transcatheter Interventional Heart Failure Therapies

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HF affects millions of patients every year, adding a significant financial burden to global health care systems.

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This review discusses the role of novel transcatheter-based therapies for the management of HF.

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Ongoing clinical trials will provide answers on the potential clinical benefits of these technologies in HF outcomes.

Chronic heart failure is one of the most debilitating chronic conditions affecting millions of people and adding a significant financial burden to health care systems worldwide. Despite the significant therapeutic advances achieved over the last decade, morbidity and mortality remain high. Multiple catheter-based interventional therapies targeting different physiological and anatomical targets are already under different stages of clinical investigation. The present paper provides a technical overview of the most relevant catheter-based interventional therapies under clinical investigation.

Autonomic Testing Optimizes Therapy for Heart Failure and Related Cardiovascular Disorders

PURPOSE OF REVIEW

Cardiovascular autonomic control is an intricately balanced dynamic process. Autonomic dysfunction, regardless of origin, promotes and sustains the disease processes, including in patients with heart failure (HF). Autonomic control is mediated through the two autonomic branches: parasympathetic and sympathetic (P&S). HF is arguably the disease that stands to most benefit from P&S manipulation to reduce mortality risk. This review article briefly summarizes some of the more common types of autonomic dysfunction (AD) that are found in heart failure, suggests a mechanism by which AD may contribute to HF, reviews AD involvement in common HF co-morbidities (e.g., ventricular arrhythmias, AFib, hypertension, and Cardiovascular Autonomic Neuropathy), and summarizes possible therapy options for treating AD in HF.

RECENT FINDINGS

Autonomic assessment is important in diagnosing and treating CHF, and its possible co-morbidities. Autonomic assessment may also have importance in predicting which patients may be susceptible to sudden cardiac death. This is important since most CHF patients with sudden cardiac death have preserved left ventricular ejection fraction and better discriminators are needed. Many life-threatening cardiovascular disorders will require invasive testing for precise diagnoses and therapy planning when modulating the ANS is important. In cases of non-life-threatening disorders, non-invasive ANS testing techniques, especially those that individually assess both ANS branches simultaneously and independently, are sufficient to diagnose and treat serially.

Levosimendan-induced venodilation is mediated by opening of potassium channels

Unique vascular responses adhere to the cardiovascular efficacy of the inodilator levosimendan. In particular, selective venodilation appears to explain its clinical benefit during pulmonary hypertension complicated by heart failure with preserved ejection fraction. Vasodilators increase vessel diameter in various parts of the vascular system to different degrees and thereby influence blood pressure, its distribution, and organ perfusion depending on their mechanisms of action. Levosimendan and its long‐lived active metabolite OR‐1896 mobilize a set of vasodilatory mechanisms, that is, the opening of the ATP‐sensitive K⁺ channels and other K⁺ channels on top of a highly selective inhibition of the phosphodiesterase III enzyme. A vessel‐specific combination of the above vasodilator mechanisms—in concert with cardiac effects and cardiovascular reflex regulations—illustrates the pharmacological profile of levosimendan in various cardiovascular disorders. While levosimendan has been known to be an inotrope, its properties as an activator of ATP‐sensitive K⁺ channels have gone largely ignored with respect to clinical applications. Here, we provide a summary of what is known about the ATP‐sensitive K⁺ channel properties in preclinical studies and now for the first time, its ATP‐sensitive K⁺ channel properties in a clinical trial.

Surgical ablation of the right greater splanchnic nerve for the treatment of heart failure with preserved ejection fraction: first-in-human clinical trial

AIMS

Inappropriate control of blood volume redistribution may be a mechanism responsible for exercise intolerance in heart failure with preserved ejection fraction (HFpEF). We propose to address this underlying pathophysiology with selective blockade of sympathetic signalling to the splanchnic circulation by surgical ablation of the right greater splanchnic nerve (GSN).

METHODS AND RESULTS

In a single-arm, prospective, two-centre trial, 10 patients with HFpEF (50% male, mean age 70 ± 3 years) all with New York Heart Association (NYHA) class III, left ventricular ejection fraction >40%, pulmonary capillary wedge pressure (PCWP) ≥15 mmHg at rest or ≥25 mmHg with supine cycle ergometry, underwent ablation of the right GSN via thoracoscopic surgery. Patients were evaluated at baseline, 1, 3, 6 and 12 months after the procedure. The primary endpoint was a reduction in exercise PCWP at 3 months. There were no adverse events related to the blockade of the nerve during 12-month follow-up but three patients had significant peri-procedural adverse events related to the surgical procedure itself. At 3 months post-GSN ablation, patients demonstrated a reduction in 20 W exercise PCWP when compared to baseline [-4.5 mmHg (95% confidence interval, CI -14 to -2); P = 0.0059], which carried over to peak exercise [-5 mmHg (95% CI -11 to 0; P = 0.016). At 12 months, improvements were seen in NYHA class [3 (3) vs. 2 (1, 2); P = 0.0039] and quality of life assessed with the Minnesota Living with Heart Failure Questionnaire [60 (51, 71) vs. 22 (16, 27); P = 0.0039].

CONCLUSION

In this first-in-human study, GSN ablation in HFpEF proved to be feasible, with a suggestion of reduced cardiac filling pressure during exercise, improved quality of life and exercise capacity.

The 2021 Carl Ludwig Lecture. Unsympathetic autonomic regulation in heart failure: patient-inspired insights

Defined as a structural or functional cardiac abnormality accompanied by symptoms, signs, or biomarkers of altered ventricular pressures or volumes, heart failure also is a state of autonomic disequilibrium. A large body of evidence affirms that autonomic disturbances are intrinsic to heart failure; basal or stimulated sympathetic nerve firing or neural norepinephrine (NE) release more often than not exceed homeostatic need, such that an initially adaptive adrenergic or vagal reflex response becomes maladaptive. The magnitude of such maladaptation predicts prognosis. This Ludwig lecture develops two theses: the elucidation and judiciously targeted amelioration of maladaptive autonomic disturbances offers opportunities to complement contemporary guideline-based heart failure therapy, and serendipitous single-participant insights, acquired in the course of experimental protocols with entirely different intent, can generate novel insight, inform mechanisms, and launch entirely new research directions. I précis six elements of our current synthesis of the causes and consequences of maladaptive sympathetic disequilibrium in heart failure, shaped by patient-inspired epiphanies: arterial baroreceptor reflex modulation, excitation stimulated by increased cardiac filling pressure, paradoxical muscle sympathetic activation as a peripheral neurogenic constraint on exercise capacity, renal sympathetic restraint of natriuresis, coexisting sleep apnea, and augmented chemoreceptor reflex sensitivity and then conclude by envisaging translational therapeutic opportunities.

Splanchnic nerve modulation in heart failure: mechanistic overview, initial clinical experience, and safety considerations

Volume recruitment from the splanchnic compartment is an important physiological response to stressors such as physical activity and blood loss. In the setting of heart failure (HF), excess fluid redistribution from this compartment leads to increased cardiac filling pressures with limitation in exercise capacity. Recent evidence suggests that blocking neural activity of the greater splanchnic nerve (GSN) could have significant benefits in some patients with HF by reducing cardiac filling pressures and improving exercise capacity. However, to date the long-term safety of splanchnic nerve modulation (SNM) in the setting of HF is unknown. SNM is currently used in clinical practice to alleviate some forms of chronic abdominal pain. A systematic review of the series where permanent SNM was used as a treatment for chronic abdominal pain indicates that permanent SNM is well tolerated, with side-effects limited to transient diarrhoea or abdominal colic and transient hypotension. The pathophysiological role of the GSN in volume redistribution, the encouraging findings of acute and chronic pilot SNM studies and the safety profile from permanent SNM for pain provides a strong basis for continued efforts to study this therapeutic target in HF.

Obesity, venous capacitance, and venous compliance in heart failure with preserved ejection fraction

AIMS

Circulating blood volume is functionally divided between the unstressed volume, which fills the vascular space, and stressed blood volume (SBV), which generates vascular wall tension and intravascular pressure. With decreases in venous capacitance, blood functionally shifts to the SBV, increasing central venous pressure and pulmonary venous pressures. Obesity is associated with both elevated venous pressure and heart failure with preserved ejection fraction (HFpEF). To explore the mechanisms underlying this association, we evaluated relationships between blood volume distribution, venous compliance, and body mass in patients with and without HFpEF.

METHODS AND RESULTS

Subjects with HFpEF (n = 62) and non-cardiac dyspnoea (NCD) (n = 79) underwent invasive haemodynamic exercise testing with echocardiography. SBV was estimated (eSBV) from measured haemodynamic variables fit to a comprehensive cardiovascular model. Compared to NCD, patients with HFpEF displayed a leftward-shifted central venous pressure-dimension relationship, indicating reduced venous compliance. eSBV was 81% higher at rest and 69% higher during exercise in HFpEF than NCD (both P < 0.0001), indicating reduced venous capacitance. Despite greater augmented eSBV with exercise, the increase in cardiac output was reduced in HFpEF, suggesting operation on the plateau of the Starling curve. Exercise eSBV was directly correlated with higher body mass index (r = 0.77, P < 0.0001) and inversely correlated with right ventricular-pulmonary arterial coupling (r = -0.57, all P < 0.0001).

CONCLUSIONS

Patients with HFpEF display reductions in systemic venous compliance and increased eSBV related to reduced venous capacitance, abnormalities in right ventricular-pulmonary artery interaction, and increased body fat. These data provide new evidence supporting an important role of venous dysfunction in obesity-related HFpEF and suggest that therapies that improve venous function may hold promise to improve clinical status in this cohort.

Extra-cardiac targets in the management of cardiometabolic disease: Device-based therapies

Heart failure (HF) does not occur in a vacuum and is commonly defined and exacerbated by its co‐morbid conditions. Neurohormonal imbalance and systemic inflammation are some of the key pathomechanisms of HF but also commonly encountered co‐morbidities such as arterial hypertension, diabetes mellitus, cachexia, obesity and sleep‐disordered breathing. A cornerstone of HF management is neurohormonal blockade, which in HF with reduced ejection fraction has been tied to a reduction in morbidity and mortality. Pharmacological treatment effective in patients with HF with reduced ejection fraction did not show substantial effects in HF with preserved ejection fraction. Here, we review novel device‐based therapies using neuromodulation of extra‐cardiac targets to treat cardiometabolic disease.

Quantitative Assessment of the Incidence of Persistent Orthostatic Hemodynamic Changes After Celiac Plexus Neurolysis: A Prospective Case Series

Celiac plexus neurolysis has been associated with orthostatic hypotension but has not been quantified prospectively or evaluated for persistence after the immediate postprocedural period. Our objective was to quantify persistent hemodynamic changes induced by celiac plexus neurolysis. In this case series of 16 patients with cancer, 8 (50%) had orthostatic hypotension alone, 3 (18.75%) developed an exaggerated postural heart rate increase (>30 beats per min), and 1 (6.25%) had both orthostatic hypotension and an increased heart rate. While the analgesic benefit of celiac plexus neurolysis is clear, the observed hemodynamic changes may be poorly tolerated in some individuals.

Novelties in Therapy of Chronic Heart Failure

In recent decades, considerable advances have been made in the treatment of heart failure. The main target of heart failure therapy is the inhibition of the sympathetic nervous system and renin-angiotensin-aldosterone system. The angiotensin receptor blockers represent a breakthrough in the treatment of heart failure with a demonstrated effect on reduction of cardiovascular events. However, new perspectives derive from latest drugs developed for diabetes, iron deficiency, and hyperkalemia. New frontiers are also opened to the development of neurohormonal therapies, antagonists of inflammatory mediators, inotropic agents, and cell-based treatments.

Extracardiac Abnormalities of Preload Reserve: Mechanisms Underlying Exercise Limitation in Heart Failure with Preserved Ejection Fraction, Autonomic Dysfunction, and Liver Disease

While many of the cardiac limitations to exercise performance are now well-characterized, extracardiac limitations to exercise performance have been less well recognized but are nevertheless important. We propose that abnormalities of cardiac preload reserve represents an under-recognized but common cause of exercise limitations. We further propose that mechanistic links exist between conditions as seemingly disparate as heart failure with preserved ejection fraction, nonalcoholic fatty liver disease, and pelvic venous compression/obstruction syndromes (eg, May-Thurner). We conclude that extracardiac abnormalities of preload reserve serve as a major pathophysiologic mechanism underlying these and other disease states.