Mitral cerclage annuloplasty, a novel transcatheter treatment for secondary mitral valve regurgitation: initial results in swine.
OBJECTIVE
We developed and tested a novel transcatheter circumferential annuloplasty technique to reduce mitral regurgitation in porcine ischemic cardiomyopathy.


BACKGROUND
Catheter-based annuloplasty for secondary mitral regurgitation exploits the proximity of the coronary sinus to the mitral annulus, but is limited by anatomic variants and coronary artery entrapment.


METHODS
The procedure, "cerclage annuloplasty," is guided by magnetic resonance imaging (MRI) roadmaps fused with live X-ray. A coronary sinus guidewire traverses a short segment of the basal septal myocardium to re-enter the right heart where it is exchanged for a suture. Tension is applied interactively during imaging and secured with a locking device.


RESULTS
We found 2 feasible suture pathways from the great cardiac vein across the interventricular septum to create cerclage. Right ventricular septal re-entry required shorter fluoroscopy times than right atrial re-entry, which entailed a longer intramyocardial traversal but did not cross the tricuspid valve. Graded tension progressively reduced septal-lateral annular diameter, but not end-systolic elastance or regional myocardial function. A simple arch-like device protected entrapped coronary arteries from compression even during supratherapeutic tension. Cerclage reduced mitral regurgitation fraction (from 22.8 +/- 12.7% to 7.2 +/- 4.4%, p = 0.04) by slice tracking velocity-encoded MRI. Flexible cerclage reduced annular size but preserved annular motion. Cerclage also displaced the posterior annulus toward the papillary muscles. Cerclage introduced reciprocal constraint to the left ventricular outflow tract and mitral annulus that enhanced leaflet coaptation. A sample of human coronary venograms and computed tomography angiograms suggested that most have suitable venous anatomy for cerclage.


CONCLUSIONS
Transcatheter mitral cerclage annuloplasty acutely reduces mitral regurgitation in porcine ischemic cardiomyopathy. Entrapped coronary arteries can be protected. MRI provided insight into the mechanism of cerclage action.
Kim
June-Hong
JH
Translational Medicine Branch, Division of Intramural Research, National Heart Lung and Blood Institute, NIH, Bethesda, MD 20892-1538, USA.
Kocaturk
Ozgur
O
Ozturk
Cengizhan
C
Faranesh
Anthony Z
AZ
Sonmez
Merdim
M
Sampath
Smita
S
Saikus
Christina E
CE
Kim
Ann H
AH
Raman
Venkatesh K
VK
Derbyshire
J Andrew
JA
Schenke
William H
WH
Wright
Victor J
VJ
Berry
Colin
C
McVeigh
Elliot R
ER
Lederman
Robert J
RJ
D000818:Animals; D006328:Cardiac Catheterization / Q000379:methods*; D003331:Coronary Vessels / Q000033:anatomy & histology; D005471:Fluoroscopy; D006346:Heart Septum / Q000033:anatomy & histology; D008279:Magnetic Resonance Imaging; D008943:Mitral Valve / Q000033:anatomy & histology / Q000601:surgery*; D008944:Mitral Valve Insufficiency / Q000209:etiology / Q000601:surgery*; D017202:Myocardial Ischemia / Q000150:complications; D025321:Surgery, Computer-Assisted; D013536:Suture Techniques; D013552:Swine; D014656:Vascular Surgical Procedures / Q000379:methods