Percutaneous mitral annular reduction provides continued benefit in an ovine model of dilated cardiomyopathy.
BACKGROUND
Functional mitral valve regurgitation plays a key role in the symptomatic severity and progression of heart failure. In an ovine model of dilated cardiomyopathy, we examined the chronic functional consequences of mitral regurgitation reduction using a recently developed novel percutaneous mitral annular reduction (PMAR) device.


RESULTS
Fourteen adult sheep were paced right ventricularly at 180 to 190 bpm for 5 weeks, leading to the development of moderate mitral valve regurgitation. After echocardiographic, hemodynamic, and neurohormonal analysis, 9 animals underwent PMAR. All animals were subsequently paced for another 28 days, and a final echocardiographic and hemodynamic study was conducted. Animals that had undergone PMAR showed significantly increased negative and positive dP/dt, whereas pulmonary capillary wedge pressure and mitral valve regurgitation were significantly reduced compared with those at device implant despite continued pacing. In conjunction, significant improvements in plasma norepinephrine and brain natriuretic peptide were apparent.


CONCLUSIONS
The application of PMAR in animals with pacing-induced dilated cardiomyopathy and functional mitral valve regurgitation resulted in continued improvements in hemodynamic and neurohormonal parameters.
Byrne
Melissa J
MJ
Department of Applied Cardiovascular Research, Baker Heart Research Institute, Melbourne, Victoria, Australia.
Kaye
David M
DM
Mathis
Mark
M
Reuter
David G
DG
Alferness
Clif A
CA
Power
John M
JM
D000818:Animals; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects; D002311:Cardiomyopathy, Dilated / Q000097:blood / Q000000981:diagnostic imaging / Q000209:etiology / Q000601:surgery*; D005500:Follow-Up Studies; D006439:Hemodynamics; D008943:Mitral Valve / Q000601:surgery*; D008944:Mitral Valve Insufficiency / Q000097:blood / Q000209:etiology / Q000601:surgery; D020097:Natriuretic Peptide, Brain / Q000097:blood; D009638:Norepinephrine / Q000097:blood; D019736:Prostheses and Implants; D011669:Pulmonary Wedge Pressure; D011897:Random Allocation; D012756:Sheep; D014463:Ultrasonography
D020097:Natriuretic Peptide, Brain; D009638:Norepinephrine