Abstract and Introduction
Abstract
Background. Point-to-point focal radiofrequency (RF) catheter ablation for aberrant pulmonary vein triggers that manifest into atrial fibrillation (AF) is the traditional method for treating symptomatic drug-resistant paroxysmal AF (PAF) when an ablation procedure is warranted. More recently, pulmonary vein isolation (PVI) using the cryoballoon has been demonstrated to be safe and effective (STOP AF clinical trial). Currently, two small studies have reviewed the procedural efficiency when comparing cryoballoon to focal RF catheter ablation procedures; however, no multicenter study has yet reported on this comparison of the two types of ablation catheters.
Methods. A multicenter retrospective chart extraction and evaluation was conducted at seven geographically mixed cardiac care centers. The study examined procedural variables during ablation for PVI in PAF patients.
Results. In several procedural measurements, the two modalities were comparable in efficiencies, including: acute PVI >96%; length of hospital stay at approximately 27 hours; and about 30% usage of adenosine after procedural testing. However, when compared to RF catheters, the cryoballoon procedure demonstrated a 13% reduction in laboratory occupancy time (247 min vs 283 min), a 13% reduction in procedure time (174 min vs 200 min), and a 21% reduction in fluoroscopy time (33 min vs 42 min). Additionally, when comparing the material usage of both cryoballoon and RF catheters, the cryoballoon used more radiopaque contrast agent (78 cc vs 29 cc) while using less intraprocedural saline (1234 cc vs 2386 cc), intracardiac echocardiography (88% vs 99%), three-dimensional electroanatomic mapping (30% vs 87%), and fewer transseptal punctures (1.5 vs 1.9).
Conclusion. This study is the first United States multicenter examination to report the procedural comparisons between the cryoballoon and focal RF catheters when used for the treatment of PAF patients. In this hospital chart review study, potential advantages were found when operating the cryoballoon with regard to hospital resource allocation. There was no statistical difference between cryoballoon and RF catheters for acute PVI success during the ablation procedure.
Introduction
Pulmonary vein isolation (PVI) has been demonstrated to be one of the cornerstones of the ablation strategy during the therapeutic treatment of atrial fibrillation (AF).[1] The original work done by Haïssaguerre established the presence and importance of spontaneous ectopic beats that originated in the pulmonary vein (PV).[2] Based upon this clinical research, there have been a variety of tools developed to isolate these asynchronous triggers. In the United States (US), there are two types of commercially available ablation catheters that are Food and Drug Administration (FDA) approved: the cryoballoon (Medtronic, Inc), and a variety of focal radiofrequency (RF) catheters. In our study, the examination of RF catheters included the family of open irrigated RF catheters (ThermoCool and ThermoCool SF, Biosense Webster; and Safire BLU, St Jude Medical) and non-irrigated catheters (Blazer, Boston Scientific).
Historically, when paroxysmal AF (PAF) patients are symptomatic and refractory to antiarrhythmic drug (AAD) therapy, focal RF ablation catheters have been used to deliver heat energy and ablate cardiac tissue.[1] In the cryoballoon system, ultra-cold therapy is delivered to the PV antrum and heat is removed from the contacting tissue. The completion of the STOP AF clinical trial has established the safety and efficacy profile of the cryoablation system.[3] Yet, only a few single-center studies have examined the procedural efficiencies of the cryoballoon system in any detail.[4–6]
Currently, larger multicenter evaluations are being conducted that will directly compare the cryoballoon to focal RF catheters. FIRE AND ICE (ClinicalTrials.gov NCT01490814), FREEZE cohort (ClinicalTrials.gov NCT01360008), and FreezeAF (ClinicalTrials.gov NCT00774566) are all prospective multicenter evaluations that will evaluate cryoballoon and RF catheters with regard to safety, efficacy, and efficiency. CABANA (ClinicalTrials.gov, NCT00911508) is an international, multicenter study designed to prospectively compare ablation therapy to antiarrhythmic medical therapy in the treatment of AF, and includes both cryoablation and RF catheter ablation. However, until these larger clinical studies are completed, there is still a need to examine cryoballoon and focal RF ablation catheters in a multicenter comparison of procedural efficiencies. In the current study, experienced users of both cryoballoon and RF catheters compared their hospital experience with both catheters.
J Invasive Cardiol. 2014;26(6):268-272. © 2014 HMP Communications, LLC
