title: One-year clinical success of a 'no-bonus' freeze protocol using the second-generation 28 mm cryoballoon for pulmonary vein isolation.
abstract: OBJECTIVE
  Studies on the use of the second-generation 28 mm cryoballoon (CB) for the treatment of atrial fibrillation (AF) have reported superior 1-year clinical outcome. Customarily, a bonus freeze cycle is applied after pulmonary vein isolation (PVI). The purpose of the present study was to assess the 1-year clinical outcome following PVI foregoing a bonus freeze cycle.
  
  
  RESULTS
  Patients with drug-refractory paroxysmal AF (PAF) or persistent AF underwent PVI using the second-generation 28 mm CB. The freeze cycle duration was set at 240 s. No bonus freeze cycle was applied. Clinical follow-up (FU) included 12-lead ECGs and 24h-Holter ECGs at 3, 6, and 12 months. A total of 45 patients (age 60 ± 11 years, mean LA diameter 42.1 ± 8.6 mm, n = 38 [84%] PAF) underwent CB-based PVI. Of 177 pulmonary veins (PVs) identified, 176/177 (99%) PVs were successfully isolated. The mean number of CB applications was 1.2 ± 0.4, 1.5 ± 0.8, 1.4 ± 0.7, 1.1 ± 0.3 and 1.7 ± 1.2 for the right superior PVs, right inferior PVs, left superior PVs, left inferior PVs, and left common PVs, respectively. Mean procedure and fluoroscopy times were 113 ± 32 and 19 ± 7 min, respectively. Phrenic nerve palsy occurred in 1/45 (2%) patients. One of 45 (2%) patients was lost to FU. After a mean FU period of 392 ± 58 (267-522) days including a 3-month blanking period, 36 of 44 (82%) patients remained in stable sinus rhythm. Five out of eight patients with arrhythmia recurrence underwent a second procedure. Only those PVs isolated with a single freeze cycle (5/11 PVs, 45%) demonstrated PV reconduction. In contrast, no PV reconnection was found in PVs initially treated with multiple freeze cycles.
  
  
  CONCLUSIONS
  A 'no-bonus'-freeze protocol for PVI using the second-generation 28 mm CB resulted in an 82% 1-year clinical success rate. A bonus freeze cycle following successful PVI may not be essential to superior clinical outcome.
authors: Department of Cardiology, Asklepios Klinik St. Georg, Lohmühlenstraße 5, Hamburg 20099, Germany e.wissner@asklepios.com.
authors: Erik
authors: E
authors: Wissner
authors: Department of Cardiology, Asklepios Klinik St. Georg, Lohmühlenstraße 5, Hamburg 20099, Germany.
authors: Christian-Hendrik
authors: CH
authors: Heeger
authors: Department of Cardiology, Asklepios Klinik St. Georg, Lohmühlenstraße 5, Hamburg 20099, Germany.
authors: Hanno
authors: H
authors: Grahn
authors: Department of Cardiology, Asklepios Klinik St. Georg, Lohmühlenstraße 5, Hamburg 20099, Germany.
authors: Bruno
authors: B
authors: Reissmann
authors: Department of Cardiology, Asklepios Klinik St. Georg, Lohmühlenstraße 5, Hamburg 20099, Germany.
authors: Peter
authors: P
authors: Wohlmuth
authors: Department of Cardiology, Asklepios Klinik St. Georg, Lohmühlenstraße 5, Hamburg 20099, Germany.
authors: Christine
authors: C
authors: Lemes
authors: Department of Cardiology, Asklepios Klinik St. Georg, Lohmühlenstraße 5, Hamburg 20099, Germany.
authors: Peter
authors: P
authors: Rausch
authors: Department of Cardiology, Asklepios Klinik St. Georg, Lohmühlenstraße 5, Hamburg 20099, Germany.
authors: Shibu
authors: S
authors: Mathew
authors: Department of Cardiology, Asklepios Klinik St. Georg, Lohmühlenstraße 5, Hamburg 20099, Germany.
authors: Andreas
authors: A
authors: Rillig
authors: Department of Cardiology, Asklepios Klinik St. Georg, Lohmühlenstraße 5, Hamburg 20099, Germany.
authors: Sebastian
authors: S
authors: Deiss
authors: Department of Cardiology, Asklepios Klinik St. Georg, Lohmühlenstraße 5, Hamburg 20099, Germany.
authors: Tillman
authors: T
authors: Maurer
authors: Department of Cardiology, Asklepios Klinik St. Georg, Lohmühlenstraße 5, Hamburg 20099, Germany.
authors: Tina
authors: T
authors: Lin
authors: Department of Cardiology, Asklepios Klinik St. Georg, Lohmühlenstraße 5, Hamburg 20099, Germany.
authors: Roland Richard
authors: RR
authors: Tilz
authors: Department of Cardiology, Asklepios Klinik St. Georg, Lohmühlenstraße 5, Hamburg 20099, Germany.
authors: Feifan
authors: F
authors: Ouyang
authors: Department of Cardiology, Asklepios Klinik St. Georg, Lohmühlenstraße 5, Hamburg 20099, Germany.
authors: Karl-Heinz
authors: KH
authors: Kuck
authors: Department of Cardiology, Asklepios Klinik St. Georg, Lohmühlenstraße 5, Hamburg 20099, Germany.
authors: Andreas
authors: A
authors: Metzner
mesh_terms: D001281:Atrial Fibrillation / Q000175:diagnosis / Q000601:surgery*; D017115:Catheter Ablation / Q000295:instrumentation* / Q000379:methods; D003452:Cryosurgery / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D006329:Heart Conduction System / Q000601:surgery*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011667:Pulmonary Veins / Q000601:surgery*; D016896:Treatment Outcome
keywords: Ablation; Atrial fibrillation; Cryoballoon; Outcome; Pulmonary vein isolation