title: Left Atrial Sphericity Index Predicts Early Recurrence of Atrial Fibrillation After Direct-Current Cardioversion: An Echocardiographic Study.
abstract: BACKGROUND
  Attempts to achieve rhythm control using direct-current cardioversion (DCC) are common in those with persistent atrial fibrillation (AF). Although often successful, AF recurs within 1 month in as many as 57% of patients. The aim of this study was to assess whether a baseline left atrial sphericity index (LASI) acquired by 2-dimensional transthoracic echocardiography (TTE) could be used as a predictor of AF recurrence after successful DCC.
  
  
  OBJECTIVE
  A baselline LASI assessed by 2D TTE can predict AF recurrence after successful DCC in patients with persistent AF.
  
  
  METHODS
  A total of 124 consecutive patients with persistent AF lasting <120 days underwent successful DCC. Other than β-blockers, no other antiarrhythmic treatment was administered. Prior to DCC, all patients underwent thorough TTE, and LASI was calculated as the fraction of the left atrial width/length of the largest possible left atrial volume in a 4-chamber view. The primary outcome was a TTE-estimated baseline LASI as a predictor of AF recurrence after successful DCC for persistent AF.
  
  
  RESULTS
  Anatomically, a more spherical shape of the left atrium (LASI >0.9) proved to be a strong and independent predictor of AF recurrence, with an odds ratio between 4.1 (95% confidence interval: 1.6-11.9, P = 0.005) and 7.6 (95% confidence interval: 3.3-19.7; P = 7.2 × 10(-6) ). The receiver operating characteristic curve indicated good power for distinguishing between recurring and nonrecurring AF, and we chose a cutoff of 0.9 because high specificity was a priority for clinical reasons.
  
  
  CONCLUSIONS
  In conclusion, baseline LASI >0.9 was associated with significantly greater AF recurrence throughout the 12-month follow-up period.
authors.affiliation: Department of Medical Research, Odense University Hospital Svendborg, Svendborg, Denmark.
authors.forename: Armin
authors.initials: A
authors.lastname: Osmanagic
authors.affiliation: Epidemiology, Biostatistics and Biodemography, Department of Public Health, University of Southern Denmark, Odense, Denmark.
authors.forename: Sören
authors.initials: S
authors.lastname: Möller
authors.affiliation: Department of Geriatric Medicine, Odense University Hospital, Odense, Denmark.
authors.forename: Azra
authors.initials: A
authors.lastname: Osmanagic
authors.affiliation: Department of Medical Research, Odense University Hospital Svendborg, Svendborg, Denmark.
authors.forename: Hussam M
authors.initials: HM
authors.lastname: Sheta
authors.affiliation: Department of Medical Research, Odense University Hospital Svendborg, Svendborg, Denmark.
authors.forename: Kristina H
authors.initials: KH
authors.lastname: Vinther
authors.affiliation: Department of Medical Research, Odense University Hospital Svendborg, Svendborg, Denmark.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Egstrup
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy; D004452:Echocardiography / Q000379:methods*; D004554:Electric Countershock / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D008297:Male; D012372:ROC Curve; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome