Efficiency Study Evaluating the Use of the PVAC Catheter Technology for Performing Ablation in Patients With Atrial Fibrillation (CAPCOST)
Atrial fibrillation (AF) is the most common arrhythmia affecting the Canadian population. AF is associated with increased risk of stroke, heart failure, and even mortality1. AF can also cause debilitating symptoms and adversely affect a patient's quality of life and functional status. These are amongst several reasons why a strategy of sinus rhythm may be pursued over a strategy of allowing AF to persist2-6.
Percutaneous catheter ablation has emerged as an effective alternative to antiarrhythmic drugs (AAD) for maintaining sinus rhythm7. The cornerstone of AF ablation procedures today is electrical disconnection or "isolation" of the pulmonary vein (PV) antra from the rest of the left atrium (LA)8-13. In experienced hands, the success rate of PV isolation off AAD is about 80-90% in patients with paroxysmal AF, but repeat procedures are required in up to 40% of patients14-18. Thus, after one ablation, the success rate may only be 50-70% off drugs.
Current standard ablation procedures for PV antral isolation employ mapping systems with which reconstructions of the LA and PV anatomy can be created. Visualization may be supplemented by integration of CT or MRI images and/or intracardiac echocardiography. Robotic navigation systems have also been employed to assist in ablation. The result is that ablation technology has become very complex and costly. Furthermore, all of these technologies are based on a single point unipolar radiofrequency (RF) ablation catheter where lesions are created point-by-point around the PVs to eventually obtain electrical isolation. This results in a lengthy procedure, often more than 4 hours, which requires a high degree of operator skill. Creation of contiguous, transmural lesions is also challenging with standard single-point RF.
Recently, a novel multipolar catheter ablation system has been evaluated for achieving PV isolation (PVAC catheter, Ablation Frontiers, Medtronic Inc., Minneapolis, MN). Based on an over-the-wire circular mapping and ablation design, the catheter can be advanced into the PV antrum, and multiple lesions around the circumference of the catheter can be delivered simultaneously using duty-cycled unipolar and bipolar RF energy. In early reports, the system can achieve complete PV isolation with reduced fluoroscopy and procedural times and uses lower powers to achieve more reliable lesion sets19-21. Long-term efficacy also seems comparable to standard RF ablation22,23.
This novel technology has the potential to broaden the application of AF ablation, by making the procedures less time-consuming and less complex without compromising on procedural efficacy. However, published data on outcomes related to use of PVAC technology are limited to studies with relatively small sample sizes ranging from 12 to 102 patients20-25. Data has been restricted to experiences from a small number of European centers performing moderate numbers of PVAC procedures and there is no prospective, multicenter data. The investigators therefore know little about the efficiency of PVAC procedures, which in turn, may allow for an assessment of the cost-effectiveness of using this technology.
|Study Design:||Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||The Prospective, Multicenter Canadian Atrial Fibrillation PVAC Cohort Study|
- Procedure Duration and Fluoroscopy time [ Time Frame: At the time of the initial ablation procedure and repeat ablations. ]
- Incidence of emergency room visits, hospitalizations and urgent clinic visits. [ Time Frame: 1 year follow-up post ablation ]Incidence of emergency room visits, hospitalizations and urgent clinic visits one year prior to ablation and 3, 6, 9, and 12 months post ablation.
- Quality of Life measurements (CCS-SAF, AFEQT and SF-12) [ Time Frame: 1 year post ablation ]Quality of Life measurements (CCS-SAF , AFEQT and SF-12) questionnaires at baseline, 3, 6 , 9 and 12 months.
- Total ablation procedure costs. [ Time Frame: 1 year post ablation ]
|Study Start Date:||February 2012|
|Estimated Study Completion Date:||August 2017|
|Estimated Primary Completion Date:||June 2017 (Final data collection date for primary outcome measure)|
Active Comparator: Control
Subjects who are undergoing AF ablation with traditional ablation technology at the same centers by the same operators. Control patients will be enrolled in a 1:2 ratio compared to the PVAC cohort.
Device: Radiofrequency Ablation Procedure
Application of radiofrequency energy will be delivered during PV antral isolation procedure and should be performed with a standard, open irrigated ablation catheter and a mapping system as the investigator would perform the procedure normally.
Experimental: PVAC Cohort
The PVAC is deployed in the left atrium over a 0.032-inch guidewire inside the PV and advanced until it is wedged within the antrum proximal to the ostium. Energy is delivered through selected electrode pairs with local potentials as well as adjacent electrode pairs, allowing bipolar current to flow to the target electrode(s) from both sides. Each application lasts for 60 seconds. When the temperature does not rise above 50°C within 15 seconds, the application should be discontinued to improve position. The PVAC may be manipulated within the antrum to ablate in a pattern of overlapping circular lesions.
Device: Radiofrequency Ablation Procedure
Application of radiofrequency energy with the Pulmonary Vein Ablation Catheter(PVAC)to eliminate potentials arising from the pulmonary veins.
Other Name: PVAC Catheter, Medtronic Inc., Ablation Frontiers
Please refer to this study by its ClinicalTrials.gov identifier: NCT01562912
|Hamilton Health Sciences|
|Hamilton, Ontario, Canada|
|London Health Sciences Center|
|London, Ontario, Canada, N6A 5A5|
|Southlake Regional Health Centre|
|Newmarket, Ontario, Canada, L3Y 2P9|
|McGill University Health Centre|
|Montreal, Quebec, Canada, H3G 1A4|
|Hôpital Sacré-Coeur de Montréal|
|Montreal, Quebec, Canada, H4J 1C5|
|Institut universitaire de cardiologie et de pneumologie de Québec|
|Quebec City, Quebec, Canada, G1V 4G5|
|Principal Investigator:||Atul Verma, MD||Newmarket Electrophysiology Research Group|