Cryoballoon Isolation of Superior Vena Cava in Paroxysmal Atrial Fibrillation

Study Overview
=================
Brief Summary
-----------------
There is still unresolved question whether isolation of superior vena cava (SVC) in conjunction to conventional pulmonary vein isolation (PVI) improves outcomes in the treatment of paroxysmal atrial fibrillation. The investigators are conducting a randomized study to determine if SVC isolation (in addition to pulmonary vein isolation) with the cryoballoon technology can improve freedom from atrial arrhythmias in one year follow up after the ablation.

Detailed Description
-----------------
Paroxysmal atrial fibrillation can be triggered by non-pulmonary vein foci, like the superior vena cava. There are some older publications showing improved result in terms of freedom from atrial tachycardias when electrical isolation of this vessel utilizing radiofrequency energy is achieved. Recent retrospective studies showed that isolation of superior vena cava by the means of cryoballoon technology is safe and feasible procedure. Furthermore, one retrospective cohort study showed improved outcomes of SVC insolation + PVI versus PVI only strategy. To our knowledge there is still no randomized data that compared SVC isolation + PVI vs PVI only strategy when using cryoballoon technology. The investigators want to determine if SVC isolation by the means of cryoballoon technology in conjunction with PVI can improve the patients outcomes. Also, there will be focus on the safety of the procedure, especially regarding the right sided phrenic nerve palsy. The primary objective of the study is freedom from atrial arrhythmias defined by standard postprocedural monitoring by ECG and Holter monitors. The investigators are conducting a randomized study with 1:1 randomization and planning to enroll around 100 participants with 1 year follow up. One group will receive conventional cryoballoon pulmonary vein isolation, and other group will receive SVC isolation after the PVI procedure.

Official Title
-----------------
Cryoballoon Isolation of Superior Vena Cava in Paroxysmal Atrial Fibrillation - a Randomized Study

Conditions
-----------------
Atrial Fibrillation

Intervention / Treatment
-----------------
* Device: superior vena cava isolation
* Device: pulmonary vein isolation


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: paroxysmal atrial fibrillation scheduled for cryoballoon the ablation of atrial fibrillation (indication not related to the study) Exclusion Criteria: persistent atrial fibrillation renal failure contrast allergy

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: SVC arm<br>Patients who will receive SVC isolation by the means of cryoballoon after the PVI procedure | Device: superior vena cava isolation<br>* SVC isolation by the means of cryoballoon<br>|
| Active Comparator: PVI arm<br>Patients who will receive convectional cryoballoon PVI procedure | Device: pulmonary vein isolation<br>* conventional pulmonary vein isolation by the means of cryoballoon<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| efficacy | number of patients free of any atrial arrhythmias during the one year of follow up (occurrence of any atrial arrhythmia longer than 30 seconds, detected by Holter EKG or 12 lead EKG will be considered as treatment failure) | one year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| feasibility | the success rates of SVC isolation. percentage of patients in whom successful SVC isolation was performed. SVC isolation will be verified by the circular mapping catheter, after the application of cryoballoon lesion. The absence of electrical signals in SVC after the ablation is considered as a successful isolation. | during the procedure | 
| safety | adverse events during the procedure (specials consideration on phrenic nerve palsy) and after the procedure (groin hematoma, pericardial effusion, etc) | one year | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
pulmonary vein isolation, superior vena cava isolation, cryoballoon ablation