title: Predicting atrial fibrillation ablation outcome: The CAAP-AF score.
abstract: Patients with a variety of clinical presentations undergo atrial fibrillation (AF) ablation. Long-term ablation success rates can vary considerably.
  
  
  
  The purpose of this study was to develop a clinical scoring system to predict long-term freedom from AF after ablation.
  
  
  
  We retrospectively derived the scoring system on a development cohort (DC) of 1125 patients undergoing AF ablation and tested it prospectively in a test cohort (TC) of 937 patients undergoing AF ablation.
  
  
  
  The demographics of the DC patients were as follows: age 62.3 ± 10.3 years, male sex 801 (71.2%), left atrial size 4.30 ± 0.69 cm, paroxysmal AF 348 (30.9%), number of drugs failed 1.3 ± 1.1, hypertension 525 (46.7%), diabetes 100 (8.9%), prior stroke/transient ischemic attack 78 (6.9%), prior cardioversion 528 (46.9%), and CHADS2 score 0.87 ± 0.97. Multivariate analysis showed 6 independent variables predicting freedom from AF after final ablation: coronary artery disease (P = .021), atrial diameter (P = .0003), age (P = .004), persistent or long-standing AF (P < .0001), number of antiarrhythmic drugs failed (P < .0001), and female sex (P = .0001). We created a scoring system (CAAP-AF) using these 6 variables, with scores ranging from 0 to 13 points. The 2-year AF-free rates by CAAP-AF scores were as follows: 0 = 100%, 1 = 95.7%, 2 = 96.3%, 3 = 83.1%, 4 = 85.5%, 5 = 79.9%, 6 = 76.1%, 7 = 63.4%, 8 = 51.1%, 9 = 53.6%, and ≥10 = 29.1%. Ablation success decreased as CAAP-AF scores increased (P < .0001). The CAAP-AF score also predicted freedom from AF in the TC. The 2-year Kaplan-Meier AF-free rates by CAAP-AF scores were as follows: 0 = 100%, 1 = 87.0%, 2 = 89.0%, 3 = 91.6%, 4 = 90.5%, 5 = 84.4%, 6 = 70.1%, 7 = 71.0%, 8 = 60.7%, 9 = 68.9%, and ≥10 = 51.3%. As CAAP-AF scores increased, 2-year freedom from AF in the TC decreased (P < .0001).
  
  
  
  An easily determined clinical scoring system was derived retrospectively and applied prospectively. The CAAP-AF score predicted freedom from AF after ablation in both a DC and a TC of patients undergoing AF ablation. The CAAP-AF score provides a realistic AF ablation outcome expectation for individual patients.
authors.affiliation: Silicon Valley Cardiology, E. Palo Alto, California; Sequoia Hospital, Redwood City, California. Electronic address: rawinkle@aol.com.
authors.forename: Roger A
authors.initials: RA
authors.lastname: Winkle
authors.affiliation: Royal Brompton Hospital, London, United Kingdom.
authors.forename: Julian W E
authors.initials: JW
authors.lastname: Jarman
authors.affiliation: Silicon Valley Cardiology, E. Palo Alto, California; Sequoia Hospital, Redwood City, California.
authors.forename: R Hardwin
authors.initials: RH
authors.lastname: Mead
authors.affiliation: Silicon Valley Cardiology, E. Palo Alto, California; Sequoia Hospital, Redwood City, California.
authors.forename: Gregory
authors.initials: G
authors.lastname: Engel
authors.affiliation: Silicon Valley Cardiology, E. Palo Alto, California; Sequoia Hospital, Redwood City, California.
authors.forename: Melissa H
authors.initials: MH
authors.lastname: Kong
authors.affiliation: Silicon Valley Cardiology, E. Palo Alto, California; Sequoia Hospital, Redwood City, California.
authors.forename: William
authors.initials: W
authors.lastname: Fleming
authors.affiliation: Silicon Valley Cardiology, E. Palo Alto, California; Sequoia Hospital, Redwood City, California.
authors.forename: Rob A
authors.initials: RA
authors.lastname: Patrawala
mesh_terms: D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology / Q000601:surgery; D017115:Catheter Ablation / Q000009:adverse effects / Q000379:methods; D015897:Comorbidity; D005260:Female; D006801:Humans; D000069451:Long Term Adverse Effects / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D010043:Outcome and Process Assessment, Health Care; D011237:Predictive Value of Tests; D012008:Recurrence; D012107:Research Design; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D000889:Anti-Arrhythmia Agents
keywords: Ablation outcomes; Atrial fibrillation; Atrial fibrillation ablation; Catheter ablation; Radiofrequency ablation