Ablation of persistent atrial fibrillation by using cryoballoon technique.
3 centers (Haukeland University Hospital, St Olavs Hospital in Trondheim and UNN in Tromsø) have participated this project. 40 patients have been enrolled and followed. Recurrences of atrial arrhythmias , quality of life, complications during procedure and data of atrial remodeling evaluated by echocardiography and CT have been recorded recorded.We registered the study I of our project on ClinicalTrials.gov with the title of “NOrwegian study of PERSistent Atrial Fibrillation treatment: cryoballoon versus radiofrequency catheter ablation (NO PERS-AF)”. The number is “NCT03008811”. Besides Haukeland University Hospital, two other centers (St Olavs Hospital in Trondheim and UNN in Tromsø) join this study. There have been so far total 40 patients, 22 patients in cryoballoon group and 18 patients in radiofrequency ablation(RFA) Group, enrolled and followed up . 3 months follow-up has been accomplised in 30 patients, 6 months follow-up has been accomplised in 27 patients, and 12 months follow-up has been accomplised in 13 patients. There was only one patient in cryoballoon group suffered phrenic nerve paralysis and recovered in 6 months. 24 patients in Haukeland university hospital with at least one follow-up were analyzed. The rate of atrial tachyarrhythmia-free in cryoballoon Group at 3, 6 and 12 months were 58.3%(7/12), 50.0%(6/12) and 50.0%(3/6), in RFA Group were 91.6%(11/12), 90.0%(9/10) and 71.4%(5/7). Quality of life were improved after ablation therapy. The study II is a substudy of patient follow-up in part I with Ultrasound and CT cor. Echocardiography examination is taken at 3, 6 and 12 months after the ablation procedure. CT cor is performed between 3 and 6 months. All data are recorded for further analysis. The study III is an investigation on energy delivery strategies of cryoballoon ablation. We have evaluated the data of cryoballoon ablation during earlier procedures. Several parallel studies on cryoballoon ablation have been conducted. Two abstracts have been presented at international Conferences last year, and one manuscript based on those findings has been finished and will be submitted in the near future.
We discuss the indication and risk of the ablation procedure, and they also observe their symptoms, but they are not involved in study design and how the study is conducted.
This project has been approved by REK on 25th Feb. 2016. , The study protocol has been registrated on www.ClinicalTrials.gov. So far two Norwegian centres (Haukeland University Hospital and St. Olavs Hospital) have participated in this study. 18 patients have been enrolled and followed up.This project has been registered on the ClinicalTrial.gov website as a two-center, prospective, randomized controlled clinical trial entitled “Norwegian study of persistent atrial fibrillation treatment: cryoballoon versus radiofrequency catheter (NO PERS-AF)”. The aim of this study is to compare the clinical outcome of ablation treatment for atrial fibrillation between cryoballoon and radiofrequency catheter ablation. So far 18 patients (16 from Haukeland University Hospital and 2 from St. Olavs Hospital) have been enrolled in this study. Nine patients underwent cryoablation and the other 9 patients underwent radiofrequency ablation. Pulmonary vein isolation was achieved in all patients. No serious adverse events or complications are reported. All patients are followed up according to study schedule without missing visit. Quality of life and the symptom burden of atrial fibrillation are evaluated. The heart rhythm of patient is recorded by 7-days Holter. We have presented the design of the study at regional and Nordic meetings. No paper has been published by now. We have two abstracts accepted and presented on HRS 2016, and we submit one abstract to EHRA/Cardiostom conference 2017. Names of abstracts are listed below. 1. Collective impacts of power, contact force and ablation time on ablation effect of atrial 2. Ablation index correlates with impedance drop during catheter ablation of atrial fibrillation. 3. Comparison of serum levels of troponin T and C-reactive protein following atrial fibrillation ablation with radiofrequency and cryo-energy.