title: Indexed left atrial volume predicts the recurrence of non-valvular atrial fibrillation after successful cardioversion.
abstract: OBJECTIVE
  Atrial fibrillation (AFib) induces remodelling of the left atrium (LA). Indexed LA volume (iLAV) as more accurate measure of LA size has not been evaluated as predictor of recurrence of AFib after cardioversion.
  
  
  RESULTS
  We identified 411 adults (mean age 64.1 ± 11.4 years, 34.5% women) who underwent successful cardioversion and with no history of other atrial arrhythmia, stroke, congenital heart disease, valvular dysfunction, surgery, thyroid dysfunction, acute or chronic inflammatory disease, and pacemaker. All echocardiographic data were retrieved from the laboratory database. iLAV was measured off-line using Simpson's method. Clinical characteristics and recurrence of clinical AFib were determined by review of medical records. Patients with scheduled follow-up of at least 6 months were included. About 250 patients (60.8%) developed AFib recurrence after a median (25th-75th percentile) follow-up of 345.0 (210.0-540.0) days. Patients with AFib recurrence had significantly greater iLAV than patients without AFib recurrence (39.7 ± 8.4 vs. 31.4 ± 4.6, P < 0.001). Each mL/m(2) increase in iLAV was associated with a 30% increased risk of AFib recurrence [odds ratio (OR) 1.30, confidence interval (CI) 1.23-1.38, P < 0.001]. In a multivariable model, each mL/m(2) increase in iLAV was independently associated with a 21% increase in the risk of AFib recurrence (OR 1.21, CI 1.11-1.30, P < 0.001). The areas under receiver operating characteristic curves, generated to compare LA diameter and iLAV as predictors of AFib recurrence, were 0.59 ± 0.3 and 0.85 ± 0.2, respectively (P < 0.001).
  
  
  CONCLUSIONS
  The present study is the first to show that larger iLAV before cardioversion, as a more accurate measure of LA remodelling than LA diameter, is strongly and independently associated with higher risks of AFib recurrence.
authors.affiliation: Cardiology Department, Modena University Hospital, Modena, Italy. procolo.marchese@gmail.com
authors.forename: Procolo
authors.initials: P
authors.lastname: Marchese
authors.forename: Francesca
authors.initials: F
authors.lastname: Bursi
authors.forename: Grazia
authors.initials: G
authors.lastname: Delle Donne
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Malavasi
authors.forename: Edoardo
authors.initials: E
authors.lastname: Casali
authors.forename: Andrea
authors.initials: A
authors.lastname: Barbieri
authors.forename: Francesco
authors.initials: F
authors.lastname: Melandri
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Modena
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000628:therapy*; D016279:Atrial Function, Left / Q000502:physiology*; D002302:Cardiac Output / Q000502:physiology; D002306:Cardiac Volume; D015331:Cohort Studies; D016001:Confidence Intervals; D004452:Echocardiography / Q000379:methods; D004554:Electric Countershock / Q000379:methods*; D004562:Electrocardiography; D005260:Female; D006325:Heart Atria / Q000473:pathology*; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D012372:ROC Curve; D012008:Recurrence; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D013318:Stroke Volume / Q000502:physiology