title: Transseptal Approach versus Left Atrial Approach to Mitral Valve: A Propensity Score Matching Study.
abstract: BACKGROUND
  Many patients with mitral valve diseases need surgical procedures for the repair or replacement of their mitral valve. There is a great deal of controversy over the outcomes of the transseptal (TS) and left atrial (LA) approaches to the mitral valve. We sought to evaluate the outcomes of each approach more accurately by eliminating the possible biases in case selection and matching.
  
  
  METHODS
  This retrospective study included patients who had surgery for mitral valve diseases via either the TS approach or the LA approach between 2004 and 2011 in Tehran Heart Center. Patients with surgical approaches other than the TS and LA were excluded. To control for the confounding effects, a propensity score matching technique was applied and the patients were matched for 14 demographic and preoperative variables. After the selection of controls, the effect of the TS approach (163 patients) versus the LA approach (652 patients) on the outcomes was presented through odds ratio (OR) with 95% confidence intervals (CI).
  
  
  RESULTS
  The mean age of the patients was 53.15 ± 12.02 years in the TS group and 52.93 ± 13.56 years in the LA group. Females comprised 119 (73.0%) patients in the TS group and 462 (70.9%) in the LA group. There was a significant association in the prevalence of new postoperative atrial fibrillation in the two groups (OR = 1.539, 95%CI: 1.072-2.210; p value = 0.019). Temporary pacemaker placement had no statistically significant difference between the two groups (p value = 0.418). The TS patients had significantly longer pump (p value < 0.001) and cross-clamp (p value < 0.001) times. The mortality rate was 4.1% (27 patients) in the LA group and 6.1% (10 patients) in the TS group (p value = 0.274).
  
  
  CONCLUSIONS
  In our study population, the TS approach was associated with higher pump and cross-clamp times as well as risk of postoperative atrial fibrillation, but it did not increase the rates of permanent pacemaker placement, re-operations, and mortality.
authors.affiliation: Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Omid
authors.initials: O
authors.lastname: Rezahosseini
authors.affiliation: Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mohamadreza
authors.initials: M
authors.lastname: Rezaei
authors.affiliation: Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Seyed Hossein
authors.initials: SH
authors.lastname: Ahmadi Tafti
authors.affiliation: Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Arash
authors.initials: A
authors.lastname: Jalali
authors.affiliation: Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Payvand
authors.initials: P
authors.lastname: Bina
authors.affiliation: Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Atefeh
authors.initials: A
authors.lastname: Ghiasi
authors.affiliation: Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Abbasali
authors.initials: A
authors.lastname: Karimi
authors.affiliation: Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Kiomars
authors.initials: K
authors.lastname: Abbasi
authors.affiliation: Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mahmood
authors.initials: M
authors.lastname: Shirzad
authors.affiliation: Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Saeed
authors.initials: S
authors.lastname: Davoodi
authors.affiliation: Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Abbas
authors.initials: A
authors.lastname: Salehi Omran
keywords: Atrial fibrillation; Heart atria; Heart septum; Mitral valve