Effects of catheter-based renal denervation on heart failure with reduced ejection fraction: a systematic review and meta-analysis

Catheter-based renal artery denervation: facts and expectations

Catheter-based renal artery denervation (RAD) is entering a new era. After the disappointing results of SYMPLICITY-HTN 3 trial in year 2014, several technical and methodological advancements led to execution of important SHAM-controlled randomized trials with promising results. Now, the 2023 ESH Guidelines give RAD a class of recommendation II with a Level of Evidence B. Currently, catheter-based RAD has two main areas of application: (a) Hypertensive patients who are still untreated, in whom RAD is a sort of a first-line treatment; (b) Difficult-to-control or true resistant hypertensive patients. Notably, randomized SHAM-controlled trials met their primary end-point in both these conditions. So far, we do not dispose of established predictors of the antihypertensive response to RAD. Some data suggest that younger patients with systo-diastolic hypertension, absence of diffuse atherosclerosis and evidence of sympathetic nervous system overactivity experience a better BP response to the procedure. We reviewed the available data on catheter-based RAD and included an updated meta-analysis of the results of the available SHAM-controlled trials. Overall, the reduction in 24-h systolic blood pressure (BP) after RAD exceeded that after SHAM by 4.58 mmHg (95% CI 3.07-6.10) in untreated patients, and by 3.82 mmHg (95% CI 2.46-5.18) in treated patients, without significant heterogeneity across trials, patient phenotype (untreated versus treated patients) and technique (radiofrequency versus ultrasound). There were no important safety signals related to the procedure. Notably, some data suggest that RAD could be an effective additional approach in patients with atrial fibrillation and other conditions characterized by sympathetic nervous system overactivity.

Brain-heart communication in health and diseases

Tight connections between the brain and heart have attracted a considerable amount of attention. This review focuses on the anatomical (extrinsic cardiac autonomic nervous system and intrinsic cardiac autonomic nervous system) and functional (neuroendocrine-heart axis and neuroimmune-heart axis) connections between the brain and heart, the linkage between central nervous system diseases and cardiovascular diseases, the harm of sympathetic hyperactivity to the heart, and current neuromodulation therapies. Depression is a comorbidity of cardiovascular diseases, and the two are causally related. This review summarizes the mechanisms and treatment of depression and cardiovascular diseases, providing theoretical evidence for basic research and clinical studies to improve treatment options.

A Japan nationwide web-based survey of patient preference for renal denervation for hypertension treatment

Renal denervation is a potential alternative to antihypertensive drug therapy. However, data on patient preference for this treatment option are limited and there are no data specifically from Asian patients. This study evaluated patient preference for renal denervation in patients with hypertension from Japan. Patients were a subset of those who participated in a March 2020 online electronic survey of patients with hypertension who had regularly visited medical institutions for treatment, were receiving antihypertensive drug therapy and had home blood pressure recordings available. The survey included a question about patient preference for treatment with renal denervation. A total of 2,392 patients were included (66% male, mean age 59.8 ± 11.6 years, mean duration of hypertension 11.4 ± 9.5 years). Preference for renal denervation was expressed by 755 patients (31.6%), and was higher in males than in females, in younger compared with older patients, in those with higher versus lower blood pressure, in patients who were less adherent versus more adherent to antihypertensive drug therapy, and in those who did rather than did not have antihypertensive drug-related side effects. Significant predictors of preference for renal denervation on logistic regression analysis were younger patient age, male sex, higher home or office systolic blood pressure, poor antihypertensive drug adherence, the presence of heart failure, and the presence of side effects during treatment with antihypertensive drugs. Overall, a relevant proportion of Japanese patients with hypertension expressed a preference for renal denervation. This should be taken into account when making shared decisions about antihypertensive drug therapy.

Systematic review of renal denervation for the management of cardiac arrhythmias

Background

In the wake of the controversy surrounding the SYMPLICITY HTN-3 trial and data from subsequent trials, this review aims to perform an updated and more comprehensive review of the impact of renal sympathetic denervation on cardiac arrhythmias.

Methods and results

A systematic search was performed using the Medline, Scopus and Embase databases using the terms “Renal Denervation” AND “Arrhythmias or Atrial or Ventricular”, limited to Human and English language studies within the last 10 years. This search yielded 19 relevant studies (n = 6 randomised controlled trials, n = 13 non-randomised cohort studies) which comprised 783 patients. The studies show RSD is a safe procedure, not associated with increases in complications or mortality post-procedure. Importantly, there is no evidence RSD is associated with a deterioration in renal function, even in patients with chronic kidney disease. RSD with or without adjunctive pulmonary vein isolation (PVI) is associated with improvements in freedom from atrial fibrillation (AF), premature atrial complexes (PACs), ventricular arrhythmias and other echocardiographic parameters. Significant reductions in ambulatory and office blood pressure were also observed in the majority of studies.

Conclusion

This review provides evidence based on original research that ‘second generation’ RSD is safe and is associated with reductions in short-term blood pressure and AF burden. However, the authors cannot draw firm conclusions with regards to less prominent arrhythmia subtypes due to the paucity of evidence available. Large multi-centre RCTs investigating the role of RSD are necessary to comprehensively assess the efficacy of the procedure treating various arrhythmias.

Graphic abstract

Cardiovascular Prognosis in Drug-Resistant Hypertension Stratified by 24-Hour Ambulatory Blood Pressure: The JAMP Study

[Figure: see text].

Renal, Cardiac, and Autonomic Effects of Catheter-Based Renal Denervation in Ovine Heart Failure

[Figure: see text].

Nocturnal Hypertension and Heart Failure: Mechanisms, Evidence, and New Treatments

Heart failure (HF) is a common condition with an increasing prevalence. Despite a variety of evidence-based treatments for patients with HF with reduced ejection fraction, morbidity and mortality rates remain high. Furthermore, there are currently no treatments that have yet been shown to reduce complication and death rates in patients who have HF with preserved ejection fraction. Hypertension is a common comorbidity in patients with HF, contributing to disease development and prognosis. For example, hypertension is closely associated with the development of left ventricular hypertrophy, which an important precursor of HF. In particular, nighttime blood pressure (BP) appears to be an important, modifiable risk factor. Both nighttime BP and an abnormal circadian pattern of nighttime BP dipping have been shown to predict development of HF and the occurrence of cardiovascular events, independent of office BP. Key mechanisms for this association include sodium handling/salt sensitivity and increased sympathetic activation. These pathogenic mechanisms are targeted by several new treatment options, including sodium-glucose cotransporter 2 inhibitors, angiotensin receptor neprilysin inhibitors, mineralocorticoid receptor antagonists, and renal denervation. All of these could form part of antihypertensive strategies designed to control nighttime BP and contribute to the goal of achieving perfect 24-hour BP management. Nevertheless, additional research is needed to determine the effects of reducing nighttime BP and improving the circadian BP profile on the rate of HF, other cardiovascular events, and mortality.

Impact of renal sympathetic denervation on cardiac magnetic resonance-derived cardiac indices in hypertensive patients - A meta-analysis

BACKGROUND

Renal sympathetic denervation (RDN) is a safe device-based option for the treatment of hypertension although current guidelines do not recommend its use in routine clinical practice. In this meta-analysis, we investigated the effects of RDN in cardiac magnetic resonance (CMR)-derived cardiac indices.

METHODS

This meta-analysis was performed in accordance with the PRISMA statement. A comprehensive systematic search of MEDLINE database and Cochrane library through to January 2021 was performed. The inclusion criteria were studies that enrolled patients undergoing RDN in whom CMR data were provided for left ventricular end-diastolic volume indexed to body surface area (BSA) (LVEDVI), left ventricular end-systolic volume indexed (LVESVI), left ventricular mass indexed (LVMI), and left ventricular ejection fraction (LVEF) pre and post RDN. A random effects model was used for the analyses.

RESULTS

Our search strategy revealed 9 studies that were finally included in the meta-analysis (n=300 patients, mean age: 60 years old, males: 59%). Compared to control group, RDN patients showed significantly lower values in the attained volumes (LVEDVI: -6.70 ml/m², p=0.01; LVESVI: -3.63 ml/m², p=0.006). Moreover, RDN group achieved a statistically significant higher attained LVEF (3.49%, p=0.01). A non-significant difference was found in the attained LVMI between RDN and control groups (-2.59 g/m², p=0.39). Compared to pre-RDN values, RDN reduces significantly the LVMI, the LVEDVI, and the LVESVI while a non-significant change of LVEF was found.

CONCLUSIONS

In conclusion, the current study demonstrates the potential beneficial role of RDN in CMR-derived cardiac indices that reflect adverse remodeling. However, large, randomized studies are needed to elucidate the role of RDN in cardiac remodeling in hypertension, heart failure, and other clinical settings.

AT II Receptor Blockade and Renal Denervation: Different Interventions with Comparable Renal Effects?

BACKGROUND

Angiotensin II (Ang II) and the renal sympathetic nervous system exert a strong influence on renal sodium and water excretion. We tested the hypothesis that already low doses of an Ang II inhibitor (candesartan) will result in similar effects on tubular sodium and water reabsorption in congestive heart failure (CHF) as seen after renal denervation (DNX).

METHODS

Measurement of arterial blood pressure, heart rate (HR), renal sympathetic nerve activity (RSNA), glomerular filtration rate (GFR), renal plasma flow (RPF), urine volume, and urinary sodium. To assess neural control of volume homeostasis, 21 days after the induction of CHF via myocardial infarction rats underwent volume expansion (0.9% NaCL; 10% body weight) to decrease RSNA. CHF rat and controls with or without DNX or pretreated with the Ang II type-1 receptor antagonist candesartan (0.5 ug i.v.) were studied.

RESULTS

CHF rats excreted only 68 + 10.2% of the volume load (10% body weight) in 90 min. CHF rats pretreated with candesartan or after DNX excreted from 92 to 103% like controls. Decreases of RSNA induced by volume expansion were impaired in CHF rats but unaffected by candesartan pointing to an intrarenal drug effect. GFR and RPF were not significantly different in controls or CHF.

CONCLUSION

The prominent function of increased RSNA - retaining salt and water - could no longer be observed after renal Ang II receptor blockade in CHF rats.

Effects of sympathectomy on myocardium remodeling and function

OBJECTIVES

To evaluate the effects of sympathectomy on the myocardium in an experimental model.

METHODS

The study evaluated three groups of male Wistar rats: control (CT; n=15), left unilateral sympathectomy (UNI; n=15), and bilateral sympathectomy (BIL; n=31). Sympathectomy was performed by injection of absolute alcohol into the space of the spinous process of the C7 vertebra. After 6 weeks, we assessed the chronotropic properties at rest and stress, cardiovascular autonomic modulation, myocardial and peripheral catecholamines, and beta-adrenergic receptors in the myocardium. The treadmill test consisted of an escalated protocol with a velocity increment until the maximal velocity tolerated by the animal was reached.

RESULTS

The bilateral group had higher levels of peripheral catecholamines, and consequently, a higher heart rate (HR) and blood pressure levels. This suggests that the activation of a compensatory pathway in this group may have deleterious effects. The BIL group had basal tachycardia immediately before the exercise test and increased tachycardia at peak exercise (p<0.01); the blood pressure had the same pattern (p=0.0365). The variables related to autonomic modulation were not significantly different between groups, with the exception of the high frequency (HF) variable, which showed significant differences in CT vs UNI. There was no significant difference in beta receptor expression between groups. There was a higher concentration of peripheral norepinephrine in the BIL group (p=0.0001), and no significant difference in myocardial norepinephrine (p=0.09).

CONCLUSION

These findings suggest that an extra cardiac compensatory pathway increases the sympathetic tonus and maintains a higher HR and higher levels of peripheral catecholamines in the procedure groups. The increase in HF activity can be interpreted as an attempt to increase the parasympathetic tonus to balance the greater sympathetic activity.

Contemporary Strategies to Manage High Blood Pressure in Patients with Coexistent Resistant Hypertension and Heart Failure With Reduced Ejection Fraction

Resistant hypertension (RH) represents an advanced subtype of hypertension that is complex to diagnose and treat. Compared with general hypertension, RH increases the risk patients will develop more advanced cardiovascular complications, including heart failure with reduced ejection fraction (HFrEF). As expected, the prevalence of RH has increased since the introduction of lower blood pressure targets included in the recent 2017 American blood pressure guidelines. The array of pharmacotherapies available to treat both hypertension and HFrEF has also expanded within the past decade. However, the efficacy of these cutting-edge pharmacotherapies has not come without a more advanced understanding of the important adjunct role non-pharmacological therapies play in helping with the management of both hypertension and HFrEF. In this review, we provide a summary of the latest pharmacological and non-pharmacological strategies that can be used to initiate treatment and optimize long-term blood pressure control in patients with coexistent RH and HFrEF.

Renal Denervation: History and Current Status

This review examines the early roots of renal denervation from its conceptualization and the creation of a percutaneous catheter system from a start-up company. As excitement began to grow with early animal experiments and human trials, renal denervation began to focus on the treatment of hypertension, culminating in a disappointing pivotal trial. Lessons learned from this trial are pushed forward, and renal denervation begins to gain clinical momentum as a new set of successful clinical trials emerge. The future for renal denervation eventually may extend beyond hypertension.

Autonomic Control of the Heart and Its Clinical Impact. A Personal Perspective

This essay covers several aspects of the autonomic control of the heart, all relevant to cardiovascular pathophysiology with a direct impact on clinical outcomes. Ischemic heart disease, heart failure, channelopathies, and life-threatening arrhythmias are in the picture. Beginning with an overview on some of the events that marked the oscillations in the medical interest for the autonomic nervous system, our text explores specific areas, including experimental and clinical work focused on understanding the different roles of tonic and reflex sympathetic and vagal activity. The role of the baroreceptors, not just for the direct control of circulation but also because of the clinical value of interpreting alterations (spontaneous or induced) in their function, is discussed. The importance of the autonomic nervous system for gaining insights on risk stratification and for providing specific antiarrhythmic protection is also considered. Examples are the interventions to decrease sympathetic activity and/or to increase vagal activity. The non-invasive analysis of the RR and QT intervals provides additional information. The three of us have collaborated in several studies and each of us contributes with very specific and independent areas of expertise. Here, we have focused on those areas to which we have directly contributed and hence speak with personal experience. This is not an attempt to provide a neutral and general overview on the autonomic nervous system; rather, it represents our effort to share and provide the readers with our own personal views matured after many years of research in this field.

The effect of multiple-inflation balloon aortic valvuloplasty

Recent improvements of balloon aortic valvuloplasty (BAV) devices and procedures have provided improved outcomes, but it is not clear whether the multiple-inflation BAV technique is effective in patients with symptomatic severe aortic valve stenosis (AS). We conducted an analysis of the impact of multiple-inflation BAV (at least 6 times inflation) on the mean aortic valve area (AVA) and mean aortic valve pressure gradient (AV-PG) in patients with symptomatic severe aortic stenosis as compared with conventional BAV (from single to three times inflation). We identified two studies of multiple-inflation BAV with antegrade approach using Inoue-balloon catheter (425 patients) and four studies of conventional BAV (170 patients) with retrograde approach. Using a random intercept model, we found that multiple-inflation BAV significantly increased mean AVA (mean difference (MD) [95% indicates confidence interval (CI)] = 0.25 [0.16-0.34], P < 0.001) and significantly decreased mean AV-PG (MD [95% CI] =  - 20.2 [- 27.8, - 12.70], P < 0.001) as compared with the conventional BAV. Furthermore, despite an extremely high Society of Thoracic Surgeons (STS) score (9.2-14.5), the all-cause mortality rate at one year of multiple-inflation BAV was 16-17%. The results of our analyses indicate that the multiple-inflation BAV technique seem to be effective for patients with symptomatic severe AS as compared with conventional BAV.

Effects of catheter-based renal denervation on heart failure with reduced ejection fraction: a meta-analysis of randomized controlled trials

Despite the major progress in the treatment of heart failure, the burden of heart failure is steadily increasing in the Western world. Heart failure is characterized by increased sympathetic activity, and chronic sympathetic activation is involved in the maintenance of the pathological state. Recent studies have shown that catheter-based renal denervation (RDN) presents a safe and minimally invasive treatment option for uncontrolled hypertension, a condition that is driven by increased sympathetic activity. Although randomized controlled trials (RCTs) have examined the effect of RDN in heart failure patients, results are inconsistent due partly to limited power with small sample sizes. We aimed to conduct a meta-analysis of RCTs on the effect of RDN in heart failure patients with reduced left ventricular (LV) ejection fraction (EF). Electronic search identified 5 RCTs including 177 patients. In the pooled analysis, RDN increased LVEF (weighted mean difference (WMD) [95% CI] = 6.289 [1.883, 10.695]%) and 6-min walk distance (61.063 [24.313, 97.813] m) and decreased B-type natriuretic peptide levels (standardized mean difference [95% CI] = - 1.139 [- 1.824, - 0.454]) compared with control. In contrast, RDN did not significantly change estimated glomerular filtration rate (WMD [95% CI] = 5.969 [- 2.595, 14.533] ml/min/1.73 m²) and systolic (- 1.991 [- 15.639, 11.655] mmHg) or diastolic (- 0.003 [- 10.325, 10.320] mmHg) blood pressure compared with control. Our meta-analysis suggests that RDN may improve LV function and exercise capacity in heart failure patients with reduced EF, providing the rationale to conduct large-scale multicenter trials to confirm the observed potential benefits of RDN.

Renal iodine123-metaiodobenzylguanidine scintigraphy relates to muscle sympathetic nervous activity in heart failure with reduced ejection fraction

BACKGROUND

Renal denervation is effective for modulating augmented sympathetic nerve activity (SNA) in heart failure with reduced ejection fraction (HFrEF). We have demonstrated that renal iodine¹²³-metaiodobenzylguanidine (¹²³I-MIBG) scintigraphy is associated with muscle sympathetic nerve activity (MSNA) in patients with hypertension. However, it is unclear whether renal ¹²³I-MIBG scintigraphy is useful for assessment of SNA in HFrEF.

METHODS

The study population consisted of 24 HFrEF patients and 11 healthy subjects as controls. Patients with HFrEF underwent ¹²³I-MIBG scintigraphy and hemodynamics using a Swan-Ganz catheter (SGC). HFrEF was defined as echocardiography with left ventricular ejection fraction (LVEF) < 50%. MSNA was measured from the peroneal nerve for direct evaluation of SNA. Renal ¹²³I-MIBG scintigraphy was performed simultaneously with cardiac scintigraphy. The early and delayed kidney-to-mediastinum ratio (K/M), early and delayed heart-to-mediastinum ratio (H/M), and washout rate (WR) were calculated.

RESULTS

LVEFs were 35% ± 11% in patients with HFrEF and 63% ± 10% in the controls (p < 0.01). The WR of cardiac ¹²³I-MIBG showed no relation to MSNA, but was related to stroke volume (r = 0.45, p < 0.05). In contrast, the WR of renal ¹²³I-MIBG scintigraphy (average of both sides) showed a strong correlation with MSNA (BI, r = 0.70, p < 0.01; BF, r = 0.66, p < 0.01); however, no significant correlations were detected between renal ¹²³I-MIBG scintigraphy and SGC results.

CONCLUSIONS

The WR of renal ¹²³I-MIBG scintigraphy may reflect MSNA. Further studies are needed to clarify the relationship between renal ¹²³I-MIBG imaging and renal SNA.

Renal denervation in patients with heart failure secondary to Chagas' disease: A pilot randomized controlled trial

INTRODUCTION

Chagas disease is one of the most relevant endemic parasitic diseases in Latin America, affecting approximately 6 million people. Overt Chagas heart disease is an ominous condition, occurring in 20-30% of infected individuals, which has besides the persistent myocarditis a peculiar intracardiac ganglionic neuronal depletion and dysautonomy. This study aims to evaluate the safety and feasibility of renal denervation for patients with advanced symptomatic Chagas cardiomyopathy.

METHODS

Open-label prospective pilot study that randomized patients with Chagas heart disease to either renal denervation or conservative treatment (2:1 ratio). The primary endpoint was the incidence of major adverse events at 9 months, defined as a composite of all-cause death, myocardial infarction, stroke, need for renal artery invasive treatment, or worsening renal function.

RESULTS

A total of 17 patients were allocated for renal denervation (n = 11) or conservative treatment (n = 6). Included patients had severe symptomatic heart disease, with markedly depressed left ventricular function (average ejection fraction 26.7 ± 4.9%). For patients randomized to renal denervation, the procedure was performed successfully and uneventfully. After 9 months, the primary endpoint occurred in 36.4% of patients in the renal denervation group and 50.0% in the control arm (p = .6). After 9 months, clinical, laboratory, functional, echocardiographic, and quality of life parameters were similar between groups.

CONCLUSIONS

This pilot study suggests that renal denervation is safe and feasible in patients with Chagas cardiomyopathy, warranting future studies to better evaluate the clinical efficacy of the interventional strategy in improving the prognosis of this high-risk population.

Novel approaches to the management of chronic systolic heart failure: future directions and unanswered questions

Despite improvements in outcomes in the last few decades for heart failure (HF) with reduced ejection fraction (HFrEF), there still remains a need for novel therapies as many patients incompletely recover with existing therapies and progress to advanced HF. In this review, we will discuss recent advances in the management of HFrEF with a focus on upcoming therapies that hold the greatest promise for clinical use. We will discuss novel pharmacological therapies and areas of uncertainty with existing therapies. We will also discuss the potential utility and controversy surrounding novel interventions for HF such as percutaneous mitral valve repair, atrial fibrillation ablation, and other emerging interventions with positive signals for benefit in HFrEF. Finally, we will summarize the current state of stem cell and gene therapy for HFrEF and future directions.

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Beyond pharmacological treatment: an insight into therapies that target specific aspects of heart failure pathophysiology

Heart failure is a common syndrome associated with substantial morbidity and mortality. The management of symptoms and the strategies for improving prognosis have largely been based on pharmacological treatments. The pathophysiology of heart failure is complex because of the multiple causes responsible for this syndrome. This Series paper presents some examples of advances in heart failure management, in which the treatment specifically targets the underlying pathophysiological mechanisms responsible for the symptoms. These treatments include treatment of electromechanical dyssynchrony and dysrhythmia by cardiac resynchronisation and implantable cardioverter-defibrillators; neurohumoral modification by baroreflex and vagal stimulation; prevention of adverse cardiac remodelling by interatrial shunts; and finally targeting the myocardium directly by cell therapy in an attempt to regenerate new myocardial cells.

Sympathetic nervous system in age-related cardiovascular dysfunction: Pathophysiology and therapeutic perspective

Cardiovascular diseases such as heart failure and metabolic syndrome have high prevalence in the elderly population and are leading causes of death, disability, hospitalization, driving high healthcare costs worldwide. To reduce this social and economic burden there is urgency to find effective therapeutic targets. Several studies have linked the dysfunction of the Sympathetic Nervous System and β-adrenergic receptor signaling with the pathogenesis of age-related cardiovascular diseases. Therapeutic treatments that restore their functions have been shown to be effective in subjects with cardiovascular comorbidities. In fact, lifestyle interventions (such as exercise training and diet) as well as pharmacologic treatments (e.g. β-blockers or moxonidine) and mini-invasive interventions (renal sympathetic denervation) have beneficial effects on age-related cardiovascular diseases. In the current "Medicine in focus" article we will discuss the pathogenic role of the Sympathetic Nervous System in age-related cardiovascular diseases as well as current and new therapeutic approaches.

Devices and interventions for the prevention of adverse outcomes of tachycardia on heart failure

Heart failure (HF) is the leading cause of hospitalization in the USA. Despite advances in pharmacologic management, the incidence of HF is on the rise and survivability is persistently reduced. Sympathetic overdrive is implicated in the pathophysiology of HF, particularly HF with reduced ejection fraction (HFrEF). Tachycardia can be particularly deleterious and thus has spurred significant investigation to mitigate its effects. Various modalities including vagus nerve stimulation, baroreceptor activation therapy, spinal cord stimulation, renal sympathetic nerve denervation, left cardiac sympathetic denervation, and carotid body removal will be discussed. However, the effects of these modalities on tachycardia and its outcomes in HFrEF have not been well-studied. Further studies to characterize this are necessary in the future.