Acute and chronic reduction of functional mitral regurgitation in experimental heart failure by percutaneous mitral annuloplasty.
OBJECTIVE
We sought to determine acute and chronic efficacy of a percutaneous mitral annuloplasty (PMA) device in experimental heart failure (HF). Further, we evaluated the potential for adverse effects on left ventricular (LV) function and coronary perfusion.


BACKGROUND
Reduction of mitral annular dimension with a PMA device in the coronary sinus may reduce functional mitral regurgitation (MR) in advanced HF.


METHODS
Study 1: a PMA device was placed acutely in anesthetized open-chest dogs with rapid pacing-induced HF (n = 6) instrumented for pressure volume analysis. Study 2: in 12 anesthetized dogs with HF, fluoroscopic-guided PMA was performed, and dogs were followed for four weeks with continuing rapid pacing.


RESULTS
Study 1: percutaneous mitral annuloplasty reduced annular dimension and severity of MR at baseline and with phenylephrine infusion to increase afterload (MR jet/left atrial [LA] area 26 +/- 1% to 7 +/- 2%, p < 0.05). Pressure volume analysis demonstrated no acute impairment of LV function. Study 2: no device was placed in two dogs because of prototype size limitations. Attempted PMA impaired coronary flow in three dogs. Percutaneous mitral annuloplasty (n = 7) acutely reduced MR (MR jet/LA area 43 +/- 4% to 8 +/- 5%, p < 0.0001), regurgitant volume (14.7 +/- 2.1 ml to 3.1 +/- 0.5 ml, p < 0.05), effective regurgitant orifice area (0.130 +/- 0.010 cm(2) to 0.040 +/- 0.003 cm(2), p < 0.05), and angiographic MR grade (2.8 +/- 0.3 device to 1.0 +/- 0.3 device, p < 0.001). In the conscious state, MR was reduced at four weeks after PMA (MR jet/LA area 33 +/- 3% HF baseline vs. 11 +/- 4% four weeks after device, p < 0.05)


CONCLUSIONS
Percutaneous mitral annuloplasty results in acute and chronic reduction of functional MR in experimental HF.
Maniu
Calin V
CV
Division of Cardiovascular Disease, Mayo Clinic and Foundation, 200 First Street SW, Rochester, MN 55905, USA.
Patel
Jeetendra B
JB
Reuter
David G
DG
Meyer
Donna M
DM
Edwards
William D
WD
Rihal
Charanjit S
CS
Redfield
Margaret M
MM
D000818:Animals; D006328:Cardiac Catheterization; D002304:Cardiac Pacing, Artificial; D003326:Coronary Circulation / Q000502:physiology*; D004195:Disease Models, Animal; D004285:Dogs; D004452:Echocardiography; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D019918:Heart Valve Prosthesis Implantation; D006439:Hemodynamics / Q000502:physiology; D019060:Minimally Invasive Surgical Procedures; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D011474:Prosthesis Design; D016896:Treatment Outcome; D016277:Ventricular Function, Left / Q000502:physiology*