Cardiology Division, Department of Medicine, Massachusetts General Hospital, Boston, Mass.
Cardiac Surgery Division, Department of Surgery, Massachusetts General Hospital, Boston, Mass.
J Thorac Cardiovasc Surg. 2018 Apr;155(4):1485-1493. doi: 10.1016/j.jtcvs.2017.11.006. Epub 2017 Nov 14.
Ischemic mitral regurgitation (IMR) results from ischemic left ventricular (LV) distortion and remodeling, which displaces the papillary muscles and tethers the mitral valve leaflets apically. The aim of this experimental study was to examine efficacy of an adjustable novel polymer filled mesh (poly-mesh) device to reverse LV remodeling and reduce IMR.
Acute (N = 8) and chronic (8 weeks; N = 5) sheep models of IMR were studied. IMR was produced by ligation of circumflex branches to create myocardial infarction. An adjustable poly-mesh device was attached to infarcted myocardium in acute and chronic IMR models and compared with untreated sham sheep. Two- and 3-dimensional echocardiography and hemodynamic measurements were performed at baseline, post IMR, and post poly-mesh (humanely killed).
In acute models, moderate IMR developed in all sheep and decreased to trace/mild (vena contracta: 0.50 ± 0.09 cm to 0.26 ± 0.12 cm; P < .01) after poly-mesh. In chronic models, IMR decreased in all sheep after poly-mesh, and this reduction persisted over 8 weeks (vena contracta: 0.42 ± 0.09 cm to 0.08 ± 0.12 cm; P < .01) with significant increase in the slope of end-systolic pressure-volume relationship (1.1 ± 0.5 mm Hg/mL to 2.9 ± 0.7 mm Hg/mL; P < .05). There was a significant reduction in LV volumes from chronic IMR to euthanasia stage with poly-mesh compared with sham group (%end-diastolic volume change -20 ± 11 vs 15% ± 16%, P < .01; %end-systolic volume change -14% ± 19% vs 22% ± 22%, P < .05; poly-mesh vs sham group) consistent with reverse remodeling.
An adjustable polymer filled mesh device reduces IMR and prevents continued LV remodeling during chronic follow-up.
缺血性二尖瓣反流（IMR）是由缺血性左心室（LV）变形和重塑引起的，其导致乳头肌移位并将二尖瓣叶顶部系紧。本实验研究的目的是检验一种可调新型聚合物填充网（poly-mesh）装置的疗效，以逆转 LV 重塑并减少 IMR。
研究了急性（N=8）和慢性（8 周；N=5）羊 IMR 模型。通过结扎回旋支支创建心肌梗死以产生 IMR。将可调poly-mesh 装置附于急性和慢性 IMR 模型的梗死心肌上，并与未治疗的假羊进行比较。在基线、IMR 后和 poly-mesh 后（人道处死）进行二维和三维超声心动图和血流动力学测量。
在急性模型中，所有羊均出现中度 IMR，在 poly-mesh 后降至微量/轻度（收缩末期射血分数：0.50±0.09cm 至 0.26±0.12cm；P<.01）。在慢性模型中，所有羊的 IMR 在 poly-mesh 后均降低，这种降低在 8 周内持续存在（收缩末期射血分数：0.42±0.09cm 至 0.08±0.12cm；P<.01），同时收缩末期压力-容积关系斜率显著增加（1.1±0.5mm Hg/mL 至 2.9±0.7mm Hg/mL；P<.05）。与 sham 组相比，慢性 IMR 至安乐死阶段的 LV 容积有明显减少（与 sham 组相比，%舒张末期容积变化-20±11% vs 15%±16%，P<.01；%收缩末期容积变化-14%±19% vs 22%±22%，P<.05；poly-mesh 组与 sham 组相比），与逆转重塑一致。
一种可调聚合物填充网装置可减少 IMR，并在慢性随访期间防止 LV 重塑的持续进行。
