title: Assessment of mitral valve area during percutaneous mitral valve repair using the MitraClip system: comparison of different echocardiographic methods.
abstract: BACKGROUND
  Quantification of the mitral valve area (MVA) is important to guide percutaneous mitral valve repair using the MitraClip system. However, little is known about how to best assess MVA in this specific situation.
  
  
  RESULTS
  Immediately before and after MitraClip implantation, comprehensive 3-dimensional (3D) transesophageal echocardiography data were acquired for MVA assessment by the pressure half-time method and by two 3D quantification methods (mitral valve quantification software and 3D quantification software). In addition, transmitral gradients by continuous-wave Doppler (dPmeanCW) were measured to indirectly assess MVA. Data are given as median (interquartile range). Thirty-three patients (39% women) with a median age of 77.1 years (12.4 years) were studied. Before intervention, the median MVAs by the pressure half-time method, mitral valve quantification software, and 3D quantification software were 4.4 cm(2) (2.0 cm(2)), 4.7 cm(2) (2.4 cm(2)), and 6.2 cm(2) (2.4 cm(2)), respectively (P<0.001). After intervention, MVA was reduced to 1.9 cm(2) (0.7 cm(2)), 2.1 cm(2) (1.1 cm(2)), and 2.8 cm(2) (1.1 cm(2)), respectively (P=0.001). The median values for dPmeanCW before and after intervention were 1.0 mm Hg (1.0 mm Hg) and 3.0 mm Hg (3.0 mm Hg; P<0.001), respectively. At discharge, the median dPmeanCW was 4.0 mm Hg (3.0 mm Hg). In multivariate regression analyses including body surface area, the 3 different MVA methods, and dPmeanCW, a post-dPmeanCW ≥5 mm Hg was the best independent predictor of an elevated transmitral gradient at discharge.
  
  
  CONCLUSIONS
  Transmitral gradients by continuous-wave Doppler are quick, feasible in all patients, and superior to direct peri-interventional assessment of MVA. A postinterventional transmitral gradient by continuous-wave Doppler of ≥5 mm Hg best predicted elevated transmitral gradients at discharge.
authors.affiliation: Division of Echocardiography, Andreas Grüntzig Cardiac Catheterization Laboratories, Cardiology, Clinic for Cardiovascular Surgery, and Department of Anesthesiology, University Hospital Zurich, Zurich, Switzerland; and the Institute for Social and Preventive Medicine, University of Zurich, Zurich, Switzerland.
authors.forename: Patric
authors.initials: P
authors.lastname: Biaggi
authors.forename: Christian
authors.initials: C
authors.lastname: Felix
authors.forename: Christiane
authors.initials: C
authors.lastname: Gruner
authors.forename: Bernhard A
authors.initials: BA
authors.lastname: Herzog
authors.forename: Sabine
authors.initials: S
authors.lastname: Hohlfeld
authors.forename: Oliver
authors.initials: O
authors.lastname: Gaemperli
authors.forename: Barbara E
authors.initials: BE
authors.lastname: Stähli
authors.forename: Michaela
authors.initials: M
authors.lastname: Paul
authors.forename: Leonhard
authors.initials: L
authors.lastname: Held
authors.forename: Felix C
authors.initials: FC
authors.lastname: Tanner
authors.forename: Jürg
authors.initials: J
authors.lastname: Grünenfelder
authors.forename: Roberto
authors.initials: R
authors.lastname: Corti
authors.forename: Dominique
authors.initials: D
authors.lastname: Bettex
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006328:Cardiac Catheterization; D006348:Cardiac Surgical Procedures / Q000295:instrumentation*; D015150:Echocardiography, Doppler / Q000379:methods*; D017548:Echocardiography, Transesophageal; D004867:Equipment Design; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D008943:Mitral Valve / Q000000981:diagnostic imaging* / Q000601:surgery; D008946:Mitral Valve Stenosis / Q000000981:diagnostic imaging / Q000601:surgery*; D016896:Treatment Outcome
keywords: echocardiography, transesophageal; mitral valve insufficiency; mitral valve stenosis