title: Cryoballoon vs. radiofrequency ablation for paroxysmal atrial fibrillation: an updated meta-analysis of randomized and observational studies.
abstract: OBJECTIVE
  Radiofrequency (RF) ablation represents a standard of care for pulmonary vein isolation in patients with drug-refractory paroxysmal atrial fibrillation (AF). In this setting, cryoballoon (CB) ablation has emerged as alternative therapy. However, the efficacy and safety of CB vs. RF ablation in patients with paroxysmal AF remain a matter of debate.
  
  
  RESULTS
  We searched electronic scientific databases for studies of CB vs. RF ablation in patients with paroxysmal AF. Aggregate data were pooled to perform a meta-analysis. The primary efficacy and safety outcomes were the recurrence of any atrial arrhythmia and procedure-related complications, respectively. A total of 6473 participants from 10 studies (CB, n = 2232 vs. RF, n = 4241) were studied. After a median follow-up of 16 months, the risk of any atrial arrhythmia recurrence (risk ratio, RR 95% confidence interval [95% CI] = 1.01 [0.90-1.14], P = 0.83) and procedure-related complications (RR [95% CI] = 0.92 [0.66-1.28], P = 0.61) were comparable between CB vs. RF ablation. Cryoballoon ablation led to a higher risk of persistent phrenic nerve palsy (RR [95% CI] = 13.60 [3.87-47.81], P < 0.01) and a lower risk of cardiac tamponade (RR [95% CI] = 0.48 [0.25-0.89], P = 0.02) compared with RF ablation. There was a trend of statistically significant interaction between the type of CB and the duration of ablation (P for interaction = 0.09).
  
  
  CONCLUSIONS
  In patients with paroxysmal AF, ablation therapy with CB is associated with efficacy and safety comparable to that of RF. Second-generation CB catheters seem to reduce procedure duration. Further studies are warranted to disclose the impact of second-generation CB catheters compared with RF for ablation of paroxysmal AF.
authors.affiliation: I. Medizinische Klinik, Klinikum rechts der Isar, Technische Universität München, Ismaninger Strasse 22, 81675 Munich, Germany.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Buiatti
authors.affiliation: I. Medizinische Klinik, Klinikum rechts der Isar, Technische Universität München, Ismaninger Strasse 22, 81675 Munich, Germany.
authors.forename: Gesa
authors.initials: G
authors.lastname: von Olshausen
authors.affiliation: I. Medizinische Klinik, Klinikum rechts der Isar, Technische Universität München, Ismaninger Strasse 22, 81675 Munich, Germany.
authors.forename: Petra
authors.initials: P
authors.lastname: Barthel
authors.affiliation: I. Medizinische Klinik, Klinikum rechts der Isar, Technische Universität München, Ismaninger Strasse 22, 81675 Munich, Germany.
authors.forename: Simon
authors.initials: S
authors.lastname: Schneider
authors.affiliation: Medizinische Klinik IV, Städtisches Klinikum Karlsruhe, Academic Teaching Hospital of the University of Freiburg, Karlsruhe, Germany.
authors.forename: Armin
authors.initials: A
authors.lastname: Luik
authors.affiliation: Deutsches Herzzentrum München, Technische Universität München and Medizinische Klinik I, St. Josefs-Hospital, Wiesbaden, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Kaess
authors.affiliation: I. Medizinische Klinik, Klinikum rechts der Isar, Technische Universität München, Ismaninger Strasse 22, 81675 Munich, Germany.|DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich, Germany.
authors.forename: Karl-Ludwig
authors.initials: KL
authors.lastname: Laugwitz
authors.affiliation: I. Medizinische Klinik, Klinikum rechts der Isar, Technische Universität München, Ismaninger Strasse 22, 81675 Munich, Germany.
authors.forename: Petra
authors.initials: P
authors.lastname: Hoppmann
mesh_terms: D001281:Atrial Fibrillation / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D062906:Cardiac Catheters; D017115:Catheter Ablation / Q000009:adverse effects; D016009:Chi-Square Distribution; D003452:Cryosurgery / Q000009:adverse effects / Q000295:instrumentation*; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D064887:Observational Studies as Topic; D016017:Odds Ratio; D011667:Pulmonary Veins / Q000503:physiopathology / Q000601:surgery*; D016032:Randomized Controlled Trials as Topic; D012008:Recurrence; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome
keywords: Atrial fibrillation; Catheter ablation; Cryoballoon; Meta-analysis; Radiofrequency