title: Paroxysmal AF catheter ablation with a contact force sensing catheter: results of the prospective, multicenter SMART-AF trial.
abstract: BACKGROUND
  Catheter ablation is important for treatment of paroxysmal atrial fibrillation (PAF). Limited animal and human studies suggest a correlation between electrode-tissue contact and radiofrequency lesion generation.
  
  
  OBJECTIVE
  The study sought to assess the safety and effectiveness of an irrigated, contact force (CF)-sensing catheter in the treatment of drug refractory symptomatic PAF.
  
  
  METHODS
  A prospective, multicenter, nonrandomized study was conducted. Enrollment criteria included: ≥3 symptomatic episodes of PAF within 6 months of enrollment and failure of ≥1 antiarrhythmic drug (Class I to IV). Ablation included pulmonary vein isolation with confirmed entrance block as procedural endpoint.
  
  
  RESULTS
  A total of 172 patients were enrolled at 21 sites, where 161 patients had a study catheter inserted and 160 patients underwent radiofrequency application. Procedural-related serious adverse events occurring within 7 days of the procedure included tamponade (n = 4), pericarditis (n = 3), heart block (n = 1, prior to radiofrequency application), and vascular access complications (n = 4). By Kaplan-Meier analyses, 12-month freedom from atrial fibrillation/atrial flutter/atrial tachycardia recurrence was 72.5%. The average CF per procedure was 17.9 ± 9.4 g. When the CF employed was between investigator selected working ranges ≥80% of the time during therapy, outcomes were 4.25 times more likely to be successful (p = 0.0054; 95% confidence interval: 1.53 to 11.79).
  
  
  CONCLUSIONS
  The SMART-AF trial demonstrated that this irrigated CF-sensing catheter is safe and effective for the treatment of drug refractory symptomatic PAF, with no unanticipated device-related adverse events. The increased percent of time within investigator-targeted CF ranges correlates with increased freedom from arrhythmia recurrence. Stable CF during radiofrequency application increases the likelihood of 12-month success. (THERMOCOOL® SMARTTOUCH® Catheter for Treatment of Symptomatic Paroxysmal Atrial Fibrillation; NCT01385202).
authors.affiliation: Texas Cardiac Arrhythmia Institute at St. David's Medical Center, Austin, Texas; Division of Cardiology, Stanford University, Stanford, California; Case Western Reserve University, Cleveland, Ohio; EP Services, California Pacific Medical Center, San Francisco, California; Interventional Electrophysiology, Scripps Clinic, San Diego, California; Department of Biomedical Engineering, University of Texas, Austin, Texas. Electronic address: dr.natale@gmail.com.
authors.forename: Andrea
authors.initials: A
authors.lastname: Natale
authors.affiliation: Icahn School of Medicine at Mount Sinai, New York, New York.
authors.forename: Vivek Y
authors.initials: VY
authors.lastname: Reddy
authors.affiliation: Florida Hospital Cardiovascular Institute, Orlando, Florida.
authors.forename: George
authors.initials: G
authors.lastname: Monir
authors.affiliation: Loyola University, Maywood, Illinois.
authors.forename: David J
authors.initials: DJ
authors.lastname: Wilber
authors.affiliation: Cleveland Clinic Foundation, Cleveland, Ohio.
authors.forename: Bruce D
authors.initials: BD
authors.lastname: Lindsay
authors.affiliation: University of Alabama at Birmingham; Birmingham, Alabama.
authors.forename: H Thomas
authors.initials: HT
authors.lastname: McElderry
authors.affiliation: Piedmont Heart Institute, Atlanta, Georgia.
authors.forename: Charan
authors.initials: C
authors.lastname: Kantipudi
authors.affiliation: Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Moussa C
authors.initials: MC
authors.lastname: Mansour
authors.affiliation: Minneapolis Heart Institute Foundation, Minneapolis, Minnesota.
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Melby
authors.affiliation: Mayo Clinic, Rochester, Minnesota.
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Packer
authors.affiliation: University of Oklahoma Health Science Center, Oklahoma City, Oklahoma.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakagawa
authors.affiliation: Biosense Webster, Inc., Diamond Bar, California.
authors.forename: Baohui
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Biosense Webster, Inc., Diamond Bar, California.
authors.forename: Robert B
authors.initials: RB
authors.lastname: Stagg
authors.affiliation: Biosense Webster, Inc., Diamond Bar, California.
authors.forename: Lee Ming
authors.initials: LM
authors.lastname: Boo
authors.affiliation: Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Francis E
authors.initials: FE
authors.lastname: Marchlinski
mesh_terms: D001281:Atrial Fibrillation / Q000503:physiopathology / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D057785:Catheters; D004562:Electrocardiography; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011667:Pulmonary Veins / Q000601:surgery; D012008:Recurrence; D013614:Tachycardia, Paroxysmal / Q000503:physiopathology / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome
keywords: atrial fibrillation; catheter ablation; contact force; radiofrequency