title: Targeting systolic anterior motion and left ventricular outflow tract obstruction in hypertrophic obstructed cardiomyopathy with a MitraClip.
abstract: OBJECTIVE
  Hypertrophic obstructive cardiomyopathy (HOCM) with left ventricular outflow tract obstruction frequently involves a systolic anterior motion (SAM) of the anterior mitral leaflet. We hypothesised that SAM could be a new target for MitraClip therapy.
  
  
  RESULTS
  Three patients with HOCM were chosen for MitraClip therapy, due to significant SAM with subsequent mitral regurgitation. Invasive haemodynamic studies (right heart catheterisation, simultaneous transaortic pressure recording, and administration of nitroglycerine) were performed before and after MitraClip implantation, and a six-week follow-up was undertaken. MitraClip implantation was successfully performed with significant reduction of mitral regurgitation and SAM in all patients. Basal peak gradients (before clip: 65±25.5 mmHg; after clip: 7.7±5.0 mmHg) as well as provoked pressure gradients (before clip: 145.3±8.1 mmHg; after clip: 23.2±7.6 mmHg) were significantly reduced after MitraClip implantation. Right heart catheterisation data did not reveal major changes. At six-week follow-up, all patients presented in a persistently improved clinical state (NYHA Class I-II) with insignificant residual MR and continuously reduced LVOT gradients.
  
  
  CONCLUSIONS
  This is the first catheter-based study targeting primarily a SAM in HOCM to reduce LVOT obstruction. The results prove the concept that SAM is more than an epiphenomenon in HOCM. Thus, SAM-induced obstruction might be a valuable target for the MitraClip.
authors.affiliation: Department of Cardiology, Asklepios Clinic St. Georg, Hamburg, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Schäfer
authors.forename: Christian
authors.initials: C
authors.lastname: Frerker
authors.forename: Thomas
authors.initials: T
authors.lastname: Thielsen
authors.forename: Dimitry
authors.initials: D
authors.lastname: Schewel
authors.forename: Ralf
authors.initials: R
authors.lastname: Bader
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Kuck
authors.forename: Felix
authors.initials: F
authors.lastname: Kreidel
mesh_terms: D000368:Aged; D006328:Cardiac Catheterization / Q000295:instrumentation*; D002312:Cardiomyopathy, Hypertrophic / Q000150:complications* / Q000175:diagnosis; D018618:Echocardiography, Doppler, Color; D017548:Echocardiography, Transesophageal; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008944:Mitral Valve Insufficiency / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D013599:Systole; D013997:Time Factors; D016896:Treatment Outcome; D016277:Ventricular Function, Left; D014694:Ventricular Outflow Obstruction / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*