Feasibility and Short-Term Efficacy of Percutaneous Mitral Annular Reduction for the Therapy of Heart Failure-Induced Mitral Regurgitation

Abstract

Background— Mitral regurgitation (MR) frequently accompanies congestive heart failure (CHF) and is associated with poorer prognosis and more significantly impaired symptomatic status. Although surgical mitral valve annuloplasty has the potential to offer benefit, concerns about the combined surgical risk and possible effects on ventricular performance have limited progress. We evaluated the feasibility and short-term efficacy of a novel device placed in the coronary sinus to reduce MR in the setting of CHF. Methods and Results— CHF and MR were induced in 9 adult sheep by rapid ventricular pacing for 5 to 8 weeks. A mitral annular constraint device was implanted percutaneously through the right internal jugular vein in the coronary sinus and great cardiac vein to create a short-term stable reduction (24.9±2.5%) in the mitral annular septal-lateral dimension as assessed echocardiographically. Right and left heart pressures and cardiac output were determined before and 15 minutes after device implantation. MR extent was examined echocardiographically and expressed as a ratio of left atrial area (MR/LAA). After device placement, MR was substantially reduced from an MR/LAA of 42+6% to 4±3% ( P <0.01). In association, mean pulmonary wedge pressure was significantly reduced (26±3 to 18±3 mm Hg; P <0.01) and mean cardiac output significantly increased (3.4±0.3 to 4.3±0.4 L/min; P =0.01). Conclusions— In this model of CHF, percutaneous placement of a mitral annular constraint device in the coronary sinus resulted in the short-term elimination or minimization of MR and was accompanied in the short term by favorable hemodynamic effects.