title: Tethering symmetry reflects advanced left ventricular mechanical dyssynchrony in patients with ischemic mitral regurgitation undergoing restrictive mitral valve repair.
abstract: BACKGROUND
  We evaluated the papillary muscle systolic dyssynchrony (DYS-PAP) using two-dimensional speckle tracking echocardiography (2D-STE) in patients with chronic ischemic mitral regurgitation (CIMR) showing different preoperative leaflet pattern and investigated the impact of baseline tethering pattern in the prediction of significant post-repair desynchronized papillary muscle contraction.
  
  
  METHODS
  We recruited 152 CIMR consecutive patients (64.4% male, mean age 65.9 ± 7.1 years) who survived coronary artery bypass grafting (CABG) and (undersized mitral ring annuloplasty, performed between 2001and 2010. The assessment of DYS-PAP was performed preoperatively and at follow-up (median 41.5 months [IQR 23-61]) by 2D-STE in the apical 4-chamber view for anterolateral papillary muscle and apical long-axis view for posteromedial papillary muscle). Based on the cutoff value (anterior-posterior tethering angle ratio α/β ≥ 0.76) patients were classified in 2 groups; symmetrical (group 1, n = 73, mean α/β = 0.81 ± 0.6) and asymmetrical preoperative tethering pattern (group 2, n = 79, mean α/β = 0.66 ± 0.4).
  
  
  RESULTS
  Recurrent MR occurred in 67.1% (n = 49) in group 1 versus 3.8% (n = 3) in group 2 (p < 0.001). Comparing both groups at baseline, patients in group 1 had higher DYS-PAP (57.7 ± 5.3 vs 29.8 ± 2.4 ms in group 2, p < 0.001) that significantly worsened at follow-up (78.1 ± 8.8 ms, p < 0.001 versus baseline), whereas in group 2 it improved (26.6 ± 6.0 ms, p < 0.001 versus baseline). Tethering symmetry significantly correlated with DYS-PAP (r = 0.90, p < 0.001) and it was a strong multivariable predictor of significant postoperative DYS-PAP (odds ratio 4.2; 95% confidence level 3.4 to 5.2, p < 0.001).
  
  
  CONCLUSIONS
  Tethering symmetry is an easy and immediate tool to identify CIMR patients with advanced DYS-PAP who are unlikely to benefit from mitral repair with undersized mitral ring annuloplasty.
authors.affiliation: Department of Cardiothoracic Surgery, University Hospital, Maastricht, The Netherlands.
authors.forename: Leen
authors.initials: L
authors.lastname: van Garsse
authors.forename: Sandro
authors.initials: S
authors.lastname: Gelsomino
authors.forename: Emile
authors.initials: E
authors.lastname: Cheriex
authors.forename: Fabiana
authors.initials: F
authors.lastname: Lucà
authors.forename: Carmelo Massimiliano
authors.initials: CM
authors.lastname: Rao
authors.forename: Orlando
authors.initials: O
authors.lastname: Parise
authors.forename: Gian Franco
authors.initials: GF
authors.lastname: Gensini
authors.forename: Jos
authors.initials: J
authors.lastname: Maessen
mesh_terms: D000368:Aged; D004452:Echocardiography; D005260:Female; D006801:Humans; D007511:Ischemia / Q000150:complications / Q000601:surgery; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000150:complications* / Q000601:surgery*; D010210:Papillary Muscles / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D012189:Retrospective Studies