title: Mitral inflow patterns after MitraClip implantation at rest and during exercise.
abstract: BACKGROUND
  MitraClip implantation reduces mitral regurgitation effectively but decreases mitral valve area, creating iatrogenic mitral stenosis. Evaluation with transesophageal echocardiography intraprocedurally is necessary to measure mitral regurgitation and mitral valve pressure gradient (MVPG) to determine whether it is necessary and safe to place more clips. The aim of this study was to investigate whether these intraprocedural hemodynamics represent postprocedural measurements and whether exercise is affected by the stenosis.
  
  
  METHODS
  In this retrospective single-center study, 51 patients who underwent MitraClip implantation were included. Measurements were performed intraprocedurally using transesophageal echocardiography and postprocedurally using transthoracic echocardiography. In 23 of these patients, exercise echocardiography was performed at follow-up.
  
  
  RESULTS
  Intraprocedural mean MVPG was 3.0 ± 1.6 mm Hg and increased to 4.3 ± 2.2 mm Hg postprocedurally (P < .001). During exercise, mean MVPG increased significantly compared with rest conditions (from 3.6 ± 1.7 to 6.3 ± 2.7 mm Hg, P < .001). Six patients had mean resting MVPGs ≥ 5 mm Hg at follow-up and had higher systolic pulmonary artery pressure (sPAPs) than patients with mean MVPGs < 5 mm Hg (47 ± 7 vs 35 ± 12 mm Hg, P = .035). Higher MVPG and sPAP did not lead to more symptoms of heart failure. Receiver operating characteristic curve analysis showed an estimated cutoff point for intraprocedural pressure half-time of 91 msec to identify patients with mitral stenosis and sPAP ≥ 50 mm Hg postprocedurally.
  
  
  CONCLUSIONS
  Mean MVPG during MitraClip implantation measured by TEE underestimates the hemodynamics in daily life, of which operators should be aware when deciding on placing one or more clips. Pressure half-time seems to be the most robust parameter compared with mean and maximum MVPG and may contribute to this decision. Patients with higher mean MVPGs after MitraClip implantation have higher sPAPs at follow-up. However, more symptoms of heart failure were not detected at follow-up.
authors.affiliation: Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Boerlage-van Dijk
authors.affiliation: Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Annelieke C M J
authors.initials: AC
authors.lastname: van Riel
authors.affiliation: Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Rianne H A C M
authors.initials: RH
authors.lastname: de Bruin-Bon
authors.affiliation: Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Esther M A
authors.initials: EM
authors.lastname: Wiegerinck
authors.affiliation: Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Karel T
authors.initials: KT
authors.lastname: Koch
authors.affiliation: Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: M Marije
authors.initials: MM
authors.lastname: Vis
authors.affiliation: Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Paola G
authors.initials: PG
authors.lastname: Meregalli
authors.affiliation: Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Navin R
authors.initials: NR
authors.lastname: Bindraban
authors.affiliation: Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Barbara J M
authors.initials: BJ
authors.lastname: Mulder
authors.affiliation: Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Jan J
authors.initials: JJ
authors.lastname: Piek
authors.affiliation: Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Berto J
authors.initials: BJ
authors.lastname: Bouma
authors.affiliation: Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. Electronic address: j.baan@amc.nl.
authors.forename: Jan
authors.initials: J
authors.lastname: Baan
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity; D058385:Cardiac Valve Annuloplasty / Q000295:instrumentation*; D017548:Echocardiography, Transesophageal; D019544:Equipment Failure Analysis; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D019060:Minimally Invasive Surgical Procedures / Q000295:instrumentation*; D008943:Mitral Valve / Q000503:physiopathology*; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery*; D011474:Prosthesis Design; D012146:Rest; D012189:Retrospective Studies; D013525:Surgical Instruments; D016896:Treatment Outcome
keywords: HR; Heart rate; MR; MS; MVA; MVPG; MitraClip; Mitral regurgitation; Mitral stenosis; Mitral valve area; Mitral valve pressure gradient; NYHA; New York Heart Association; PHT; Pressure half-time; ROC; Receiver operating characteristic; Systolic pulmonary artery pressure; TEE; TTE; Transesophageal echocardiography; Transthoracic echocardiography; Transthoracic exercise echocardiography; sPAP