Impact of left ventricular reshaping on postinfarction functional mitral regurgitation in a chronic swine model of...

The study objective was 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.

A chronic heart failure model with ischemic mitral regurgitation was established in 8 Yorkshire swine via percutaneous injection of 100% ethanol into the left circumflex artery. The left ventricular reshaping device was implanted transapically at 6 months postinfarction and evaluated with echocardiography and pressure-volume loop analysis. The final efficacy analysis included 7 animals.

The device was successfully implanted and significantly reduced mitral regurgitation (regurgitant volume: 43.29 ± 14.47 mL vs 9.90 ± 5.12 mL, P = .0026). Posterior excursion angle (22.71 ± 6.92° vs 39.14 ± 7.29°, P = .0042) and coaptation length (2.72 ± 0.44 mm vs 4.42 ± 0.76 mm, P = .0033) increased significantly. Left ventricular volume significantly decreased after reshaping (indexed end-diastolic volume: 140.30 ± 28.28 mL/m² vs 84.68 ± 18.51 mL/m², P = .0019; indexed end-systolic volume: 91.54 ± 24.01 mL/m² vs 48.23 ± 16.25 mL/m², P = .0003). Ejection fraction significantly increased (33.71% ± 3.30% vs 43.43% ± 7.12%, P = .0046), whereas load-independent indices of systolic function and measures of diastolic function did not change significantly.

Transapical left ventricular reshaping demonstrated acute efficacy and feasibility at 6 months postinfarction in advanced heart failure by reducing left ventricular volume and mitral regurgitation.