Impact of Left Ventricular Reshaping on Post-Infarction Functional Mitral Regurgitation in a Chronic Swine Model of Advanced Heart Failure

Objective To evaluate the efficacy and feasibility of left ventricular reshaping in a swine model of late-stage ischemic heart failure with marked left ventricular dilation and functional mitral regurgitation. Methods A chronic heart failure model with ischemic mitral regurgitation was established in eight Yorkshire swine via percutaneous injection of 100% ethanol into the left circumflex artery. The left ventricular reshaping device was implanted transapically at 6 months post-infarction and evaluated with echocardiography and pressure-volume loop analysis. Data from seven animals were analyzed. Results The device was successfully implanted and significantly reduced mitral regurgitation (regurgitant volume: 43.29 ± 14.47 vs. 9.90 ± 5.12 mL, p=0.0026). Posterior excursion angle (22.71 ± 6.92 vs. 39.14 ± 7.29°, p=0.0042) and coaptation length (2.72 ± 0.44 vs. 4.42 ± 0.76 mm, p=0.0033) increased significantly. Left ventricular volume significantly decreased after reshaping (indexed end-diastolic volume: 140.30 ± 28.28 vs. 84.68 ± 18.51 mL/m 2 , p=0.0019; indexed end-systolic volume: 91.54 ± 24.01 vs. 48.23 ± 16.25 mL/m 2 , p=0.0003). Ejection fraction significantly increased (33.71 ± 3.30 vs. 43.43 ± 7.12%, p=0.0046), whereas load-independent indices of systolic function and measures of diastolic function did not change significantly. Conclusions Transapical left ventricular reshaping demonstrated acute efficacy and feasibility at 6 months post-infarction in advanced heart failure by reducing left ventricular volume and mitral regurgitation.