PO-03-073 CARDIONEUROABLATION FOR THE MANAGEMENT OF PATIENTS WITH RECURRENT VASOVAGAL SYNCOPE AND SYMPTOMATIC BRADYARRHYTHMIAS: THE CNA-FWRD CROSS-OVER TRIAL AND PROSPECTIVE REGISTRY

Abstract

Cardioneuroablation (CNA) has been introduced as a potential alternative treatment strategy in appropriately selected patients for prevention of recurrent cardioinhibitory vasovagal syncope (VVS) and functional atrioventricular block (AVB). The Cardioneuroablation for the Management of Patients with Recurrent Vasovagal Syncope and Symptomatic Bradyarrhythmias (CNA-FWRD) Registry is a multicenter prospective registry and Cross-Over Trial with the objective of examining acute and long-term outcomes of CNA in appropriately selected patients with recurrent VVS and AVB. The main study will be a prospective cross-over design with patients randomized to two groups receiving 6-month treatment interventions in alternate order: Medical therapy followed by CNA (Group 1) or CNA followed by Medical therapy (group 2). Patients declining the cross-over study will be eligible for inclusion in a parallel prospective registry. Details of inclusion and exclusion criteria are provided in Table 1. Functional AVB is defined as sudden change from physiologic atrioventricular conduction to transient second- or third-degree AVB resulting in symptomatic pauses longer than 2 seconds. All fragmented EGMs that demonstrated 3 or more deflectionsin the regions that are known to be consistent with probable localization of ganlionated plexus (GP) will be identified and tagged (Figure 1). In each VVS patient, the GPs will be targeted in the following order: the superior left atrial GP, the Marshall tract GP (MTGP), the inferior left atrial GP, the superior right atrial GP (RSGP), and finally the inferior right atrial GP. Additional right atrial ablation on the superior aspect on the interatrial septum will be performed for RSGP. In patients with AVB, the posteromedial left atrial GP, MTGP and RSGP will be ablated, respectively. The primary outcome is 12-month syncope recurrence post catheter ablation. Secondary outcomes include procedure-related complications, freedom from syncope at 12 months, freedom from AVB at 12 months, need for repeat GP ablation, quality of life at 12 months. Study enrollment began for (8) sites on June 20, 2022. So far, 59 patients have been enrolled into the registry. There remains lack of procedural standardization CNA as a treatment strategy and limited long-term data for key outcomes including recurrence of syncope, durable impact of disruption of the autonomic nervous system and long-term complications. CNA-FWRD has the potential to help fill this information gap.Tabled 1Inclusion and Exclusion Criteria for Study Cohort (PO-03-073)DiagnosisInclusion criteriaExclusion criteriaVVSAt least 3 vasovagal syncope episodes in the preceding 12 monthsPresence of arrhythmic conditions that can cause syncopeAge < 60 yearsPresence of evidence related to structural heart disease> 3s asystole on head-up tilt testingPrevious history of catheter ablation> 3s asystole on ambulatory ECG monitoringPresence of inheritable arrhythmic conditionsPositive response to atropine testOrthostatic hypotension on Head-up tilt table testUnresponsiveness to conventional treatment modalitiesPseudo-syncopePresence of proven indication for Pacemaker implantationAbnormal thyroid function levelsUsage of negative chronotropic drugsChronotropic incompetence at exercise stress testAVBAll AVB casesHistorySymptomatic bradycardiaUse of negative chronotropic or dromotropic drugsLaboratoryassessmentNormal thyroid function testsThyroid function abnormalitySuspicionof obstructive sleep apneaNegative polysomnogramPositive polysomnogramBaselineECGLeft bundle brunch blockExerciseStress TestChronotropic incompetenceOccurrence or worsening of AVB with exerciseEPSSupra-Hisian AVBIntra/infra-Hisian AVBParoxysmal AVBBaselineECGNormal PR interval or first degree AVBSecond or third degree AVBHolter RecordingPR prolongation before second or third degree AVB episodeConstant PR before second or third degree AVB episodeDecrease in sinus rate during or just prior to second or third degree AVB episodeIncrease in sinus rate during second or third degree AVB episodeResolution of AVB with an increase in sinus rateResolution of AVB with a constant sinus rateEPSBaseline H-V interval <55msecBaseline H-V interval ≥55 msecIntra/infra-Hisian AVB by atrial pacing at rates of 150 bpm or lessPersistent AVBBaselineECGSecond or third degree AVBAtropine responseComplete resolution of atrioventricular conduction or conversion to first degree AVB with atropine infusionAVB unresponsive to atropine testExercise stress testComplete resolution of AVB or conversion to first degree AVB with exercise testAVB unresponsive to exercise stress testEPSBaseline H-V interval <55msecBaseline H-V interval ≥55 msecIntra/infra-Hisian AVB by atrial pacing at rates of 150 bpm or less Open table in a new tab