title: Pulmonary vein measurements on pre-procedural CT/MR imaging can predict difficult pulmonary vein isolation and phrenic nerve injury during cryoballoon ablation for paroxysmal atrial fibrillation.
abstract: OBJECTIVE
  We tested the hypothesis that pulmonary vein (PV) measurements on pre-procedural CT/MR imaging can predict difficulty in isolation and phrenic nerve (PN) injury during cryoballoon ablation for paroxysmal atrial fibrillation (AF).
  
  
  METHODS
  Consecutive patients with paroxysmal AF who had pre-procedural CT/MRI and underwent cryoballoon ablation as part of a randomized trial were studied. Imaging was anonymized for blinded analysis of: (1) maximum ostial diameter, (2) minimum ostial diameter, (3) ostial area and (4) ratio of maximum over minimum ostial diameter (eccentricity index). Veins that required more than 2 freezes of at least 200 s duration to isolate or not isolated were defined as difficult to isolate. Loss of PN pacing during right-sided ablation was defined as PN injury. Logistic regression was used to analyze the predictive effect of the measurements on the 2 outcomes.
  
  
  RESULTS
  148 PVs in 38 patients (aged 60 ± 11 years, 76% male) were analyzed. Left inferior PV (LIPV) was most difficult to isolate with 23 out of 37 PVs (62%), and PN injury occurred in 3 of 38 (8%) right superior PV (RSPV). Greater eccentricity index predicted difficulty in isolating LIPV, OR 40.33 (95% CI 1.40 to 1160, p = 0.03) and smaller eccentricity index predicted PN injury in RSPV, OR 0.01 (95% CI 0.01-0.16, p = 0.001).
  
  
  CONCLUSIONS
  Eccentricity index measured from pre-procedural CT/MR imaging can predict difficulty of PV isolation and PN injury during cryoballoon ablation for paroxysmal AF.
authors.affiliation: Barts Heart Centre, St Bartholomew's Hospital, Bart's & The London NIHR Cardiovascular Biomedical Research Unit, William Harvey Research Institute, Queen Mary University of London, UK. Electronic address: richardang@mac.com.
authors.forename: Richard
authors.initials: R
authors.lastname: Ang
authors.affiliation: Barts Heart Centre, St Bartholomew's Hospital, Bart's & The London NIHR Cardiovascular Biomedical Research Unit, William Harvey Research Institute, Queen Mary University of London, UK.
authors.forename: Ross J
authors.initials: RJ
authors.lastname: Hunter
authors.affiliation: Barts Heart Centre, St Bartholomew's Hospital, Bart's & The London NIHR Cardiovascular Biomedical Research Unit, William Harvey Research Institute, Queen Mary University of London, UK.
authors.forename: Victoria
authors.initials: V
authors.lastname: Baker
authors.affiliation: Barts Heart Centre, St Bartholomew's Hospital, Bart's & The London NIHR Cardiovascular Biomedical Research Unit, William Harvey Research Institute, Queen Mary University of London, UK.
authors.forename: Laura
authors.initials: L
authors.lastname: Richmond
authors.affiliation: Barts Heart Centre, St Bartholomew's Hospital, Bart's & The London NIHR Cardiovascular Biomedical Research Unit, William Harvey Research Institute, Queen Mary University of London, UK.
authors.forename: Mehul
authors.initials: M
authors.lastname: Dhinoja
authors.affiliation: Barts Heart Centre, St Bartholomew's Hospital, Bart's & The London NIHR Cardiovascular Biomedical Research Unit, William Harvey Research Institute, Queen Mary University of London, UK.
authors.forename: Simon
authors.initials: S
authors.lastname: Sporton
authors.affiliation: Barts Heart Centre, St Bartholomew's Hospital, Bart's & The London NIHR Cardiovascular Biomedical Research Unit, William Harvey Research Institute, Queen Mary University of London, UK.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Schilling
authors.affiliation: Barts Heart Centre, St Bartholomew's Hospital, Bart's & The London NIHR Cardiovascular Biomedical Research Unit, William Harvey Research Institute, Queen Mary University of London, UK.
authors.forename: Francesca
authors.initials: F
authors.lastname: Pugliese
authors.affiliation: Barts Heart Centre, St Bartholomew's Hospital, Bart's & The London NIHR Cardiovascular Biomedical Research Unit, William Harvey Research Institute, Queen Mary University of London, UK.
authors.forename: Ceri
authors.initials: C
authors.lastname: Davies
authors.affiliation: Barts Heart Centre, St Bartholomew's Hospital, Bart's & The London NIHR Cardiovascular Biomedical Research Unit, William Harvey Research Institute, Queen Mary University of London, UK. Electronic address: mark.earley@bartshealth.nhs.uk.
authors.forename: Mark
authors.initials: M
authors.lastname: Earley
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000601:surgery*; D003452:Cryosurgery / Q000009:adverse effects / Q000379:methods; D005260:Female; D006801:Humans; D007431:Intraoperative Complications / Q000517:prevention & control*; D016015:Logistic Models; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D059348:Peripheral Nerve Injuries / Q000209:etiology / Q000517:prevention & control; D010791:Phrenic Nerve / Q000293:injuries*; D011300:Preoperative Care / Q000379:methods; D011667:Pulmonary Veins / Q000000981:diagnostic imaging / Q000601:surgery; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome
keywords: Atrial fibrillation; CT; Cryoballoon; MRI