Cardioneuroablation Versus Pacemaker Implantation for the Treatment of Symptomatic Sinus Node Dysfunction

Endocardial Ablation of Ganglionated Plexi Versus Pacemaker Implantation in Patients With Symptomatic Sinus Node Dysfunction

Endocardial ganglion plexus ablation (cardioneuroablation) represents a promising therapeutic technique for the treatment of vasovagal syncope (VV), functional atrioventricular block (AVB) and sinus node dysfunction (SND) with a component of vagal hypertonia. Nevertheless, there is currently a paucity of literature about the results according to the type of presentation (VV, AVB or SND). The investigators aim to assess the safety and efficacy of cardioneuroablation for the treatment of symptomatic SND.

Sinus node dysfunction (SND), also known as sick sinus syndrome, comprises a wide spectrum of sinoatrial dysfunctions, ranging from sinus bradycardia, sinoatrial block, and sinus arrest to bradycardia tachycardia syndrome. An additional manifestation of SND is an inadequate chronotropic response to exercise, reported as chronotropic incompetence. Since the first cardiac denervation was reported in 2005, several registries and retrospective studies using this therapeutic approach for reflex syncope, SND and functional atrioventricular block have been published. However, due to the lack of randomized studies, current guidelines recommend permanent pacemaker implantation for patients with symptomatic SND in order to improve symptoms. Therefore, the purpose of the present study is to assess the safety and efficacy of cardioneuroablation versus permanent pacemaker implantation for the treatment of symptomatic SND.

This is a multicenter, randomized, open, interventional study. After being informed of the study and potential risks, participants will undergo a one week screening period to determine eligibility for the study entry. During this week, participants will undergo an exercise test, atropine test, and a 24 hour-holter electrocardiogram. Then, participants who meet the eligibility criteria, will be randomized 1:1 to receive permanent pacemaker implantation (control group) or cardioneuroablation (interventional group).

The primary endpoint (improve in quality of life assessed with 36-Item Short Form Survey (SF-36)) will be evaluated at six months since randomization.

Inclusion Criteria:

• Symptomatic sinus node dysfunction (dizziness, asthenia or syncope) clearly related to an abnormal electrocardiogram finding (sinus arrest, sinoatrial block, extreme bradycardia (<40 bpm) or chronotropic incompetence in the exercise test).
• Absence of structural cardiopathy

Exclusion Criteria:

• Left ventricular ejection fraction <50%
• Severe valvular disease
• Any type of cardiomyopathy such as hypertrophic cardiomyopathy
• Previous ischemic heart disease
• QRS interval >130 ms
• Atrioventricular conduction disorder with a former indication of pacemaker implantation (atrioventricular block Mobitz II, advanced atrioventricular block, complete atrioventricular block)
• Lifetime expectance <12 months