Polymer injection therapy to reverse remodel the papillary muscles: efficacy in reducing mitral regurgitation in a chronic ischemic model
| Autor: | Judy Hung, Robert A. Levine, Jorge Solis, Gus J. Vlahakes, Gavin J. C. Braithwaite, J. Luis Guerrero, Kaitlyn Lam, Benjamin Johnson, Jason Berlin, Mark D. Handschumacher, Orhun K. Muratoglu, Suzanne Sullivan |
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| Rok vydání: | 2010 |
| Předmět: |
medicine.medical_specialty
Polymers Echocardiography Three-Dimensional Myocardial Ischemia Hemodynamics Article Injections Coronary artery disease Internal medicine medicine Animals Circumflex cardiovascular diseases Papillary muscle Mitral regurgitation Vena contracta Sheep Ventricular Remodeling business.industry Injection therapy Mitral Valve Insufficiency Hydrogels Papillary Muscles medicine.disease medicine.anatomical_structure Polyvinyl Alcohol Models Animal Cardiology cardiovascular system Cardiology and Cardiovascular Medicine business Ligation |
| Zdroj: | Circulation. Cardiovascular interventions. 3(5) |
| ISSN: | 1941-7632 |
| Popis: | Background— Ischemic mitral regurgitation (MR) results from displacement of the papillary muscles caused by ischemic ventricular distortion. Progressive left ventricular (LV) remodeling has challenged therapy. Our hypothesis is that repositioning of the papillary muscles can be achieved by injection of polyvinyl-alcohol (PVA) hydrogel polymer into the myocardium in chronic MR despite advanced LV remodeling. Methods and Results— Ten sheep underwent ligation of the circumflex branches to produce chronic ischemic MR over 8 weeks. PVA was injected into the myocardium underlying the infarcted papillary muscle. Two-dimensional and 3D echocardiograms and hemodynamic data were obtained before infarct (baseline), before PVA (chronic MR), and after PVA. PVA injection significantly decreased MR from moderate to severe to trace (MR vena contracta, 5.8±1.2 to1.8±1.3 mm; chronic MR to post-PVA stage; P =0.0003). This was associated with a decrease in infarcted papillary muscle–to–mitral annulus tethering distance (30.3±5.7 to 25.9±4.6 mm, P =0.02), tenting volume (1.8±0.7 to 1.4±0.5 mL, P =0.01), and leaflet closure area (8.8±1.3 cm 2 to 7.6±1.3 cm 2 , P =0.004) from chronic MR to post-PVA stages. PVA was not associated with significant decreases in LV ejection fraction (41±3% versus 40±3%, P =NS), end-systolic elastance, τ (82±36 ms to 72±26, P =NS), or LV stiffness coefficient (0.05±0.04 to 0.03±0.01). Conclusions— PVA hydrogel injections improve coaptation and reduce remodeling in chronic MR without impairing LV systolic and diastolic function. This new approach offers a potential alternative for relieving tethering and ischemic MR by correcting papillary muscle position. |
| Databáze: | OpenAIRE |
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