Long-term outcomes of cardioneuroablation with and without extra-cardiac vagal stimulation confirmation in severe cardioinhibitory neurocardiogenic syncope

BACKGROUND

Cardioneuroablation (CNA) is a novel therapeutic approach for functional bradyarrhythmias, specifically neurocardiogenic syncope or atrial fibrillation, achieved through endocardial radiofrequency catheter ablation of vagal innervation, obviating the need for pacemaker implantation. Originating in the nineties, the first series of CNA procedures was published in 2005. Extra-cardiac vagal stimulation (ECVS) is employed as a direct method for stepwise denervation control during CNA.

OBJECTIVE

This study aimed to compare the long-term follow-up outcomes of patients with severe cardioinhibitory syncope undergoing CNA with and without denervation confirmation via ECVS.

METHOD

A cohort of 48 patients, predominantly female (56.3%), suffering from recurrent syncope (5.1 ± 2.5 episodes annually) that remained unresponsive to clinical and pharmacological interventions, underwent CNA, divided into two groups: ECVS and NoECVS, consisting of 34 and 14 cases, respectively. ECVS procedures were conducted with and without atrial pacing.

RESULTS

Demographic characteristics, left atrial size, and ejection fraction displayed no statistically significant differences between the groups. Follow-up duration was comparable, with 29.1 ± 15 months for the ECVS group and 31.9 ± 20 months for the NoECVS group (p = .24). Notably, syncope recurrence was significantly lower in the ECVS group (two cases vs. four cases, Log Rank p = .04). Moreover, the Hazard ratio revealed a fivefold higher risk of syncope recurrence in the NoECVS group.

CONCLUSION

This study demonstrates that concluding CNA with denervation confirmation via ECVS yields a higher success rate and a substantially reduced risk of syncope recurrence compared to procedures without ECVS confirmation.

Potential consequences of cardioneuroablation for vasovagal syncope: A call for appropriately designed, sham-controlled clinical trials

Cardioneuroablation (CNA) is being increasingly used to treat patients with vasovagal syncope (VVS). Bradycardia, in the cardioinhibitory subtype of VVS, results from transient parasympathetic overactivity leading to sinus bradycardia and/or atrioventricular block. By mitigating parasympathetic overactivity, CNA has been shown to improve VVS symptoms in clinical studies with relatively small sample sizes and short follow-up periods (<5 years) at selected centers. However, CNA may potentially tip the autonomic balance to a state of sympathovagal imbalance with attenuation of cardiac parasympathetic activity. A higher heart rate is associated with adverse cardiovascular events and increased mortality in healthy populations without cardiovascular diseases. Chronic sympathovagal imbalance may also affect the pathophysiology of spectra of cardiovascular disorders including atrial and ventricular arrhythmias. This review addresses potential long-term pathophysiological consequences of CNA for VVS.

Cardioneuroablation for reflex asystolic syncope: Mid-term safety, efficacy, and patient's acceptance

BACKGROUND

Cardioneuroablation (CNA) is a promising therapy for reflex asystolic syncope; however, convincing data on the mid-term safety and efficacy of this procedure are lacking.

OBJECTIVE

The purpose of this study was to assess the mid-term safety, efficacy, and patient acceptance of CNA.

METHODS

This prospective observational single-center study included 115 consecutive patients (mean age 39 ± 13 years; 58% female) treated between 2016 and 2022 who completed at least 1-year follow-up.

RESULTS

No significant procedure-related acute complications occurred. During median follow-up of 28 months (range 12-75), 95 (83%) remained free from syncope. Of the 20 patients (17%) with syncope recurrence, syncope burden decreased from a mean 17 (median 6.5) to 3.75 (median 2.5) episodes (P = .015). In 9 of 10 patients, pacing system removal was possible. Repeated CNA was needed in 3 patients (3%), whereas pacemaker implantation was performed in 5 (4%). The most frequent mid-term complication of CNA was sinus rhythm acceleration (from 60 ± 14 bpm to 90 ± 16 bpm; P <.0001), which was symptomatic in 31 patients (27%); 8 patients (7%) required chronic beta-blocker and/or ivabradine. Sinus node modification was necessary in 1 patient. Other complaints included dyspnea, chronic chest pain, and decreased exercise capacity, which were mild and reported by 16 patients (14%). Patient acceptance of CNA was very high: 96% stated that it was worth undergoing the procedure.

CONCLUSIONS

Mid-term efficacy of CNA exceeds 80%, and acute complications are absent. The most frequent mid-term chronic complication is inappropriate sinus tachycardia, which in 7% required chronic treatment. The procedure is well accepted by patients.

Cardioneuroablation for the Treatment of Vasovagal Syncope: Current Status and Impact on Quality of Life

PURPOSE OF REVIEW

Vasovagal syncope (VVS) is a common entity causing transient loss of consciousness and affecting quality of life. Guideline-recommended therapy involves conservative measures and pacing in selected patients. Cardioneuroablation (CNA) targeting the ganglionated plexi in the heart has been shown to reduce excessive vagal excitation, which plays a major role in the pathophysiology of VVS and functional bradycardia.

RECENT FINDINGS

The introduction of CNA has fueled research into its value for the treatment of VVS. Multiple observational studies and one randomized trial have demonstrated the safety and efficacy of CNA and the positive impact on quality of life. This review describes the rationale and CNA procedural techniques and outcomes. Patient selection and future directions have also been described. Cardioneuroablation is a promising treatment for patients with recurrent VVS and functional bradycardia. Further large-scale randomized studies are needed to further verify the safety and efficacy of this approach.

Cardioneuroablation for neurally-mediated syncope: Initial experience

Cardioneuroablation is an emerging alternative therapeutic modality for young patients with severe neurally-mediated syncope. We present two images of cardioneuroablation performed in young patients who suffered from recurrent neurally-mediated syncope with asystole and functional atrioventricular block. The patients remain syncope-free during follow-ups.

Endocardial ablation of epicardial ganglionated plexi: history, open questions and future prospects of cardioneuroablation

Neurocardiogenic syncope is the most common cause of transient loss of consciousness and considerably reduces quality of life. Pharmacological and pacing therapy may not be fully efficacious and complications related to implanted hardware must be considered. In this context, cardioneuroablation (CNA) has been proposed to attenuate the vagal reflex with elimination of cardioinhibition. It has been shown that CNA is able to eliminate recurrences of syncope in over 90% of cases and no major complications are reported in the current literature. Despite these encouraging findings, CNA is only mentioned in current guidelines as a possible alternative treatment and has no real indication class. The diversity of mapping techniques, the absence of direct denervation control, the lack of a precise endpoint, the possible placebo effect, the short follow-up, and the question of the learning curve represent the major limitations of this promising procedure. The aim of this review was to look over the existing literature, analysing the novelties, the limitations, the unresolved issues and the outcome of CNA.

Cardioneuroablation for severe neurocardiogenic syncope

INTRODUCTION AND OBJECTIVES

Cardioneuroablation (CNA), a technique based on radiofrequency ablation of cardiac vagal ganglia, was developed to treat recurrent vasovagal syncope (VVS) with a predominant cardioinhibitory component, as an alternative to pacemaker implantation. The aim of our study was to evaluate the safety and success rate of CNA guided by extracardiac vagal stimulation in patients with highly symptomatic cardioinhibitory VVS.

METHODS

Prospective study of patients who underwent anatomically guided CNA at two cardiology centers. All patients had a history of recurrent syncope with a predominant cardioinhibitory component and refractory to conventional measures. Acute success was determined by the absence or significant reduction of cardiac parasympathetic response to extracardiac vagal stimulation. The primary endpoint was the recurrence of syncope during follow-up.

RESULTS

In total, 19 patients (13 males; mean age 37.8±12.9 years) were included. Ablation was acutely successful in all patients. One patient had a convulsive episode after the procedure, which was deemed unrelated to the ablation, requiring admission to intensive care but without sequelae. No other complications occurred. At a mean follow-up of 21.0±13.2 months (range 3-42 months), 17 patients remained free of syncope. The remaining two patients had recurrence of syncope and, despite undergoing a new ablation procedure, required pacemaker implantation during follow-up.

CONCLUSION

Cardioneuroablation, confirmed by extracardiac vagal stimulation, appears to be an effective and safe treatment option for highly symptomatic patients with refractory VVS with a predominant cardioinhibitory component, providing a new potential approach as an alternative to pacemaker implantation.

Clinical impact of aging on outcomes of cardioneuroablation for reflex syncope or functional bradycardia: Results from the cardionEuroabLation: patiEnt selection, imaGe integrAtioN and outComEs-The ELEGANCE multicenter study

BACKGROUND

Cardioneuroablation (CNA) is a novel treatment for reflex syncope. The effect of aging on CNA efficacy is not fully understood.

OBJECTIVE

The purpose of this study was to assess the impact of aging on candidacy and efficacy of CNA for treating vasovagal syncope (VVS), carotid sinus syndrome (CSS), and functional bradyarrhythmia.

METHODS

The ELEGANCE (cardionEuroabLation: patiEnt selection, imaGe integrAtioN and outComEs) multicenter study assessed CNA in patients with reflex syncope or severe functional bradyarrhythmia. Patients underwent pre-CNA Holter electrocardiography (ECG), head-up tilt testing (HUT), and electrophysiological study. CNA candidacy and efficacy was assessed in 14 young (18-40 years), 26 middle-aged (41-60 years), and 20 older (>60 years) patients.

RESULTS

Sixty patients (37 men; mean age 51 ± 16 years) underwent CNA. The majority (80%) had VVS, 8% had CSS, and 12% had functional bradycardia/atrioventricular block. Pre-CNA Holter ECG, HUT, and electrophysiological findings did not differ across age groups. Acute CNA success was 93%, without differences between age groups (P = .42). Post-CNA HUT response was negative in 53%, vasodepressor in 38%, cardioinhibitory in 7%, and mixed in 2%, without differences across age groups (P = .59). At follow-up (8 months, interquartile range 4-15), 53 patients (88%) were free of symptoms. Kaplan-Meier curves did not show differences in event-free survival between age groups (P = .29). The negative predictive value of a negative HUT was 91.7%.

CONCLUSION

CNA is a viable treatment for reflex syncope and functional bradyarrhythmia in all ages, and is highly effective in mixed VVS. HUT is a key step in postablation clinical assessment.

Ganglionated Plexus Ablation Procedures to Treat Vasovagal Syncope

Vasovagal syncope (VVS) refers to a heterogeneous group of conditions whereby the cardiovascular reflexes normally controlling the circulation are interrupted irregularly in response to a trigger, resulting in vasodilation, bradycardia, or both. VVS affects one-third of the population at least once in their lifetime or by the age of 60, reduces the quality of life, and may cause disability affecting certain routines. It poses a considerable economic burden on society, and, despite its prevalence, there is currently no proven pharmacological treatment for preventing VVS. The novel procedure of ganglionated plexus (GP) ablation has emerged rapidly in the past two decades, and has been proven successful in treating syncope. Several parameters influence the success rate of GP ablation, including specific ablation sites, localization and surgical techniques, method of access, and the integration of other interventions. This review aims to provide an overview of the existing literature on the physiological aspects and clinical effectiveness of GP ablation in the treatment of VVS. Specifically, we explore the association between GPs and VVS and examine the impact of GP ablation procedures as reported in human clinical trials. Our objective is to shed light on the therapeutic significance of GP ablation in eliminating VVS and restoring normal sinus rhythm, particularly among young adults affected by this condition.

Selective anatomical catheter ablation of left atrial ganglionated plexus for vasovagal syncope: Left superior and right anterior ganglionated plexus ablation

BACKGROUND

Vasovagal syncope (VVS) is one of the most common causes of syncope. Traditional treatment has not achieved satisfactory results. The purpose of this study was to assess the feasibility and efficacy of selective anatomical catheter ablation of left atrial ganglionated plexus (GP) as a therapeutic strategy for the patients of symptomatic VVS.

METHODS

A total of 70 patients with at least once recurrent syncopal episode of VVS with a positive head-up tilt test were enrolled. They were divided into GP ablation group and control group. Patients in GP ablation group received anatomical catheter ablation of left superior ganglionated plexus (LSGP) and right anterior ganglionated plexus (RAGP). Patients in the control group were guideline-directed conventional therapy. The primary endpoint was VVS recurrences. The secondary endpoint was the recurrence of syncope and prodrome events.

RESULTS

There were no statistical differences in clinical characteristics between the ablation group (n = 35) and the control group (n = 35). Over a follow-up of 12 months, the ablation group had significantly lower syncope recurrence compared with the control group (5.7% vs. 25.7%, p = .02), and the ablation group had significantly lower syncope and prodrome recurrence compared with the control group (11.4% vs. 51.4%, p < .001). In GP ablation, 88.6% of the patients showed significant vagal response during LSGP ablation, and 88.6% of the patients showed significantly increased heart rate during RAGP ablation.

CONCLUSIONS

For patients with recurrent VVS, selective anatomical catheter ablation of LSGP and RAGP is superior to conventional therapy in reducing syncope recurrence.

Cardioneuroablation for vasovagal syncope: A systematic review and meta-analysis

BACKGROUND

Cardioneuroablation (CNA) has emerged as promising therapy for patients with refractory vasovagal syncope (VVS).

OBJECTIVE

The purpose of this study was to provide a freedom from syncope estimate for CNA, including subgroup analysis by method and target of ablation.

METHODS

A systematic search was performed in MEDLINE and EMBASE according to the PRISMA guidelines until February 14, 2022. Observational studies and clinical trials reporting freedom from syncope were included. Meta-analysis was performed with a random-effects model.

RESULTS

A total of 465 patients were included across 14 studies (mean age 39.8 ± 4.0 year; 53.5% female). Different techniques were used to guide CNA: 50 patients (10.8%) by mapping fractionated electrograms, 73 (15.7%) with the spectral method, 210 (45.2%) with high-frequency stimulation, 73 (15.7%) with a purely anatomically guided method, and 59 (12.6%) with a combination. The target was biatrial in 168 patients (36.1%), left atrium only in 259 (55.7%), and right atrium only in 38 (8.2%). The freedom from syncope was 91.9% (95% confidence interval [CI] 88.1%-94.6%; I2 = 6.9%; P = .376). CNA limited to right atrial ablation was associated with a significant lower freedom from syncope (81.5%; 95% CI 51.9%-94.7%; P <.0001) vs left atrial ablation only (94.0%; 95% CI 88.6%--6.9%) and biatrial ablation (92.7%; 95% CI 86.8%-96.1%). Subgroup analysis according to the technique used to identify ganglionated plexi did not show any significant difference in freedom from syncope (P = .206).

CONCLUSION

This meta-analysis suggests a high freedom from syncope after CNA in VVS. Well-designed, double-blind, multicenter, sham-controlled randomized clinical trials are needed to provide evidence for future guidelines.

Procedural Characteristics, Safety and Follow-up of Modified Right Sided Approach for Cardioneuroablation

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"Cardioneuroablation"--new treatment for neurocardiogenic syncope, functional AV block and sinus dysfunction using catheter RF-ablation

Cardiac neuroablation is a new technique for management of patients with dominantly adverse parasympathetic autonomic influence. The technique is based on radiofrequency (RF) ablation of autonomic connections in the three main ganglia around the heart. Their connections are identified by Fast-Fourier Transforms (FFTs) of endocardial signals: sites of autonomic nervous connections show fractionated signals with FFTs shifted to the right. In contrast, normal myocardium without these connections does not show these features. RF-ablation is thought to inflict permanent damage on the parasympathetic autonomic influence because its cells are adjacent to the heart whereas sympathetic cells are remote. Twenty-one patients with a mean age of 48 years, neurally mediated reflex syncope in six, functional high grade atrioventricular block in seven and sinus node dysfunction in 13 (there is overlap between the second and third groups) were treated. Follow-up for a mean of 9.2 months demonstrated success in all cases with relief of symptoms. No complications occurred.

Permanent cardiac pacing as primary therapy for neurocardiogenic (reflex) syncope

Recurrent reflex (or neurocardiogenic) syncope is a common clinical problem. Pacemaker therapy has been advocated as a potential therapy in severe or drug refractory cases of reflex syncope, while others have suggested that it may provide a benefit if employed as a primary therapeutic modality. The following paper reviews the concepts behind pacemaker therapy for reflex syncope and the results of various clinical trials that have evaluated its potential utility as a primary therapeutic modality.

Neurocardiogenic syncope: a case of prolonged asystole

We report the case of a 48-year-old woman with frequent episodes of loss of consciousness. The patient was submitted to head-up tilt testing that evoked a prolonged asystole associated with sphincteric incontinence and loss of urine. The patient was treated with dual-chamber pacemaker implantation; at a follow-up of 18 months no other episodes of syncope had occurred.