title: Two versus one repeat freeze-thaw cycle(s) after cryoballoon pulmonary vein isolation: the alster extra pilot study.
abstract: BACKGROUND
  Repeated freezing (bonus applications) during cryoballoon pulmonary vein isolation (PVI) has been suggested to improve lesion durability. However, the long-term clinical effects of repeated freezing have not been investigated.
  
  
  RESULTS
  A total of 51 patients (pts) with paroxysmal atrial fibrillation (AF) underwent PVI using the single big (28 mm) cryoballoon technique. One (27 pts, group I) or 2 bonus applications (24 pts, group II) were performed at all PVs subsequent to PVI. Clinical follow-up consisted of continuous rhythm monitoring by an implantable cardiac monitor (ICM, 24 pts) and serial 7-day Holter-ECG recording (7DH, 27 pts). The primary endpoint was defined as recurrent AF or atrial tachycardia. Acute PVI of all PVs was obtained in 50/51 pts (98%). The median (Q1;Q3) follow-up duration in this study was 384 (213;638) days. The primary endpoint occurred in 48% (group I, 15 pts ICM, 12 pts 7DH) and 46% (group II, 9 pts ICM, 15 pts 7DH), P = 0.84. Procedure- and fluoroscopy-time for group I versus group II was 193 ± 56 minutes versus 207 ± 27 and 33 ± 13 minutes versus 34 ± 11 minutes, respectively. Right phrenic nerve palsy (PNP) occurred in 3 pts (all group II, time to resolution: 128 ± 112 days). In 2 of these pts, PNP occurred during the second bonus application.
  
  
  CONCLUSIONS
  Application of 2 when compared to 1 freeze-thaw cycle(s) following cryoballoon PVI did not result in improved clinical success but was associated with a higher complication rate.
authors.affiliation: Department of Cardiology, Asklepios Klinik St. Georg, Hamburg, Germany.
authors.forename: Kyoung Ryul Julian
authors.initials: KR
authors.lastname: Chun
authors.forename: Alexander
authors.initials: A
authors.lastname: Fürnkranz
authors.forename: Ilka
authors.initials: I
authors.lastname: Köster
authors.forename: Andreas
authors.initials: A
authors.lastname: Metzner
authors.forename: Tobias
authors.initials: T
authors.lastname: Tönnis
authors.forename: Peter
authors.initials: P
authors.lastname: Wohlmuth
authors.forename: Erik
authors.initials: E
authors.lastname: Wissner
authors.forename: Boris
authors.initials: B
authors.lastname: Schmidt
authors.forename: Feifan
authors.initials: F
authors.lastname: Ouyang
authors.forename: Karl Heinz
authors.initials: KH
authors.lastname: Kuck
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D016009:Chi-Square Distribution; D003452:Cryosurgery / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D018572:Disease-Free Survival; D015716:Electrocardiography, Ambulatory; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D010243:Paralysis / Q000209:etiology; D059348:Peripheral Nerve Injuries / Q000209:etiology; D010791:Phrenic Nerve / Q000293:injuries; D010865:Pilot Projects; D011446:Prospective Studies; D011667:Pulmonary Veins / Q000503:physiopathology / Q000601:surgery*; D012008:Recurrence; D018570:Risk Assessment; D012307:Risk Factors; D013617:Tachycardia, Supraventricular / Q000209:etiology; D013686:Telemetry; D013997:Time Factors; D016896:Treatment Outcome