title: Persistence of iatrogenic atrial septal defect after interventional mitral valve repair with the MitraClip system: a note of caution.
abstract: OBJECTIVE
  The purpose of this study was to investigate the persistence rates of iatrogenic atrial septal defect (iASD) after interventional edge-to-edge repair with serial transesophageal echocardiography examinations and close clinical follow-up (FU).
  
  
  BACKGROUND
  Transcatheter mitral valve repair (TMVR) with the MitraClip system (Abbott Vascular, Abbott Park, Illinois) is a therapeutic alternative to surgery in selected high-risk patients. Clip placement requires interatrial transseptal puncture and meticulous manipulation of the steerable sheath. The persistence of iASD after MitraClip procedures and its clinical relevance is unknown.
  
  
  METHODS
  A total of 66 patients (76.7% male, mean age 77.1 ± 7.9 years) with symptomatic mitral regurgitation (MR) at prohibitive surgical risk (EuroSCORE II 10.1 ± 6.1%) underwent MitraClip procedures and completed 6 months of FU.
  
  
  RESULTS
  Transesophageal echocardiography after FU showed persistent iASD in 50% of cases. Patients with iASD did not significantly differ from patients without ASD concerning baseline characteristics, New York Heart Association functional class, severity of MR, and acute procedural success rates (p > 0.05). When comparing procedural details and hemodynamic measures between groups, MitraClip procedures took longer in patients without iASD (82.4 ± 39.7 min vs. 68.9 ± 45.5 min; p = 0.05), and echocardiography after FU showed less decrease of systolic pulmonary artery pressures in the iASD group (-1.6 ± 14.1 mm Hg vs. 9.3 ± 17.4 mm Hg; p = 0.02). Clinically, patients with iASD presented more often with New York Heart Association functional classes >II after FU (57% vs. 30%; p = 0.04), showed higher levels of N-terminal pro-brain natriuretic peptide (6,667.3 ± 7,363.9 ng/dl vs. 4,835.9 ± 6,681.7 ng/dl; p = 0.05), and had less improvement in 6-min walking distances (20.8 ± 107.4 m vs. 114.6 ± 116.4 m; p = 0.001). Patients with iASD showed higher death rates during 6 months (16.6% vs. 3.3%; p = 0.05). Cox regression analysis found that only persistence of iASD (p = 0.04) was associated with 6-month survival.
  
  
  CONCLUSIONS
  The persistence rate of 50% iASD after MitraClip procedures is considerably high. Persistent interatrial shunting was associated with worse clinical outcomes and increased mortality. Further studies are warranted to investigate if persistent interatrial shunting is the mediator or marker of advanced disease in these patients.
authors.affiliation: Heart Centre Bonn, Department of Cardiology, University of Bonn, Bonn, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Schueler
authors.affiliation: Heart Centre Bonn, Department of Cardiology, University of Bonn, Bonn, Germany.
authors.forename: Can
authors.initials: C
authors.lastname: Öztürk
authors.affiliation: Asklepios Children's Hospital Sankt Augustin, Stankt Augustin, Germany.
authors.forename: Jan Arne
authors.initials: JA
authors.lastname: Wedekind
authors.affiliation: Heart Centre Bonn, Department of Cardiology, University of Bonn, Bonn, Germany.
authors.forename: Nikos
authors.initials: N
authors.lastname: Werner
authors.affiliation: Heart Centre Bonn, Department of Cardiology, University of Bonn, Bonn, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Stöckigt
authors.affiliation: Heart Centre Bonn, Department of Cardiac Surgery, University of Bonn, Bonn, Germany.
authors.forename: Fritz
authors.initials: F
authors.lastname: Mellert
authors.affiliation: Heart Centre Bonn, Department of Cardiology, University of Bonn, Bonn, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Nickenig
authors.affiliation: Heart Centre Bonn, Department of Cardiology, University of Bonn, Bonn, Germany. Electronic address: christoph.hammerstingl@ukb.uni-bonn.de.
authors.forename: Christoph
authors.initials: C
authors.lastname: Hammerstingl
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D054087:Atrial Septum / Q000000981:diagnostic imaging / Q000293:injuries*; D006328:Cardiac Catheterization / Q000009:adverse effects* / Q000295:instrumentation* / Q000401:mortality; D016009:Chi-Square Distribution; D018618:Echocardiography, Doppler, Color; D017548:Echocardiography, Transesophageal; D005260:Female; D005858:Germany; D006335:Heart Injuries / Q000000981:diagnostic imaging / Q000209:etiology* / Q000401:mortality; D006439:Hemodynamics; D006801:Humans; D007049:Iatrogenic Disease; D053208:Kaplan-Meier Estimate; D008297:Male; D008943:Mitral Valve / Q000503:physiopathology; D008944:Mitral Valve Insufficiency / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D013997:Time Factors
keywords: MitraClip; heart failure; iatrogenic ASD; prognosis