title: The mechanism of mitral regurgitation assessed by preprocedural echocardiography is associated with the outcome of catheter ablation in patients with paroxysmal atrial fibrillation.
abstract: BACKGROUND
  Mitral regurgitation (MR) is generally classified as either primary (organic) or secondary (functional). Although patients with atrial fibrillation (AF) often exhibit MR, the relation between the etiology of MR and the outcome of catheter ablation (CA) remains unknown. We conducted this study in order to elucidate this association.
  
  
  METHODS
  Among 1330 consecutive paroxysmal AF patients who underwent initial catheter ablation in our institution, 92 patients (62 men, mean age 65 ± 7 years) who had moderate or severe MR were included in this study; 46 were classified to have primary and the remaining 46 to have secondary MR by preoperative echocardiography. These patients were prospectively monitored after the CA.
  
  
  RESULTS
  During a mean follow-up period of 27.9 ± 28.8 months, AF recurred in 26/46 (56.6 %) of primary MR patients and in 15/46 (32.6 %) of those with secondary MR (P < 0.02). Although univariate analysis found that diabetes, left atrial volume indexed by body surface area (LAVI), and primary MR were significantly associated with AF recurrence, primary MR (hazard ratio (HR), 2.47; 95 % confidence interval (CI), 1.30-4.88; P = 0.006) and LAVI (HR, 1.03/1 mL/m(2) increase; 95 % CI, 1.00-1.06; P = 0.03) remained significant predictors on multivariate analysis. The AF recurrence-free rate was lower in patients with primary MR after both the initial and final CA.
  
  
  CONCLUSIONS
  In patients with paroxysmal AF and moderate or severe MR, primary MR may increase the risk of AF recurrence after the initial and final CA.
authors.affiliation: Cardiovascular Centre, Yokosuka Kyosai Hospital, 1-16 Yonegahama-Street, Yokosuka, 238-8558, Japan. teru.takigawa@gmail.com.|Heart Rhythm Centre, Tokyo Medical and Dental University, Tokyo, Japan. teru.takigawa@gmail.com.|Department of Cardiovascular Medicine, Tokyo Medical and Dental University, Tokyo, Japan. teru.takigawa@gmail.com.
authors.forename: Masateru
authors.initials: M
authors.lastname: Takigawa
authors.affiliation: Cardiovascular Centre, Yokosuka Kyosai Hospital, 1-16 Yonegahama-Street, Yokosuka, 238-8558, Japan.
authors.forename: Taishi
authors.initials: T
authors.lastname: Kuwahara
authors.affiliation: Cardiovascular Centre, Yokosuka Kyosai Hospital, 1-16 Yonegahama-Street, Yokosuka, 238-8558, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Takahashi
authors.affiliation: Cardiovascular Centre, Yokosuka Kyosai Hospital, 1-16 Yonegahama-Street, Yokosuka, 238-8558, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Okubo
authors.affiliation: Cardiovascular Centre, Yokosuka Kyosai Hospital, 1-16 Yonegahama-Street, Yokosuka, 238-8558, Japan.
authors.forename: Emiko
authors.initials: E
authors.lastname: Nakashima
authors.affiliation: Cardiovascular Centre, Yokosuka Kyosai Hospital, 1-16 Yonegahama-Street, Yokosuka, 238-8558, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Watari
authors.affiliation: Cardiovascular Centre, Yokosuka Kyosai Hospital, 1-16 Yonegahama-Street, Yokosuka, 238-8558, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Yamao
authors.affiliation: Cardiovascular Centre, Yokosuka Kyosai Hospital, 1-16 Yonegahama-Street, Yokosuka, 238-8558, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Nakajima
authors.affiliation: Cardiovascular Centre, Yokosuka Kyosai Hospital, 1-16 Yonegahama-Street, Yokosuka, 238-8558, Japan.
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Tanaka
authors.affiliation: Cardiovascular Centre, Yokosuka Kyosai Hospital, 1-16 Yonegahama-Street, Yokosuka, 238-8558, Japan.
authors.forename: Katsumasa
authors.initials: K
authors.lastname: Takagi
authors.affiliation: Cardiovascular Centre, Yokosuka Kyosai Hospital, 1-16 Yonegahama-Street, Yokosuka, 238-8558, Japan.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Kimura
authors.affiliation: Cardiovascular Centre, Yokosuka Kyosai Hospital, 1-16 Yonegahama-Street, Yokosuka, 238-8558, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Hikita
authors.affiliation: Heart Rhythm Centre, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Kenzo
authors.initials: K
authors.lastname: Hirao
authors.affiliation: Department of Cardiovascular Medicine, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Isobe
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000601:surgery*; D017115:Catheter Ablation / Q000706:statistics & numerical data*; D015897:Comorbidity; D018572:Disease-Free Survival; D004452:Echocardiography / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D011300:Preoperative Care / Q000379:methods / Q000706:statistics & numerical data; D015995:Prevalence; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome
keywords: Atrial fibrillation; Catheter ablation; Mechanism; Mitral regurgitation; Recurrence