title: Outcomes of myocardial infarction hydrogel injection therapy in the human left ventricle dependent on injectate distribution.
abstract: Myocardial infarction therapies involving biomaterial injections have shown benefits in inhibiting progression towards heart failure. However, the underlying mechanisms remain unclear. A finite element model of the human left ventricle was developed from magnetic resonance images. An anteroapical infarct was represented at acute (AI) and fibrotic (FI) stage. Hydrogel injections in the infarct region were modelled with layered (L) and bulk (B) distribution. In the FI, injectates reduced end-systolic myofibre stresses from 291.6% to 117.6% (FI-L) and 115.3% (FI-B) of the healthy value, whereas all AI models exhibited sub-healthy stress levels (AI: 90.9%, AI-L: 20.9%, AI-B: 30.5%). Reduction in end-diastolic infarct stress were less pronounced for both FI (FI: 294.1%, FI-L: 176.5%, FI-B: 188.2%) and AI (AI: 94.1%, AI-L: 35.3%, AI-B: 41.2%). In the border zone, injectates reduced end-systolic fibre stress by 8-10% and strain from positive (AI) and zero (FI) to negative. Layered and bulk injectates increased ejection fraction by 7.4% and 8.4% in AI and 14.1% and 13.7% in FI. The layered injectate had a greater impact on infarct stress and strain at acute stage, whereas the bulk injectate exhibited greater benefits at FI stage. These findings were confirmed by our previous in vivo results.
authors: Cardiovascular Research Unit, Chris Barnard Division of Cardiothoracic Surgery, University of Cape Town, Observatory, South Africa.
authors: Renee
authors: R
authors: Miller
authors: Neil H
authors: NH
authors: Davies
authors: Jeroen
authors: J
authors: Kortsmit
authors: Peter
authors: P
authors: Zilla
authors: Thomas
authors: T
authors: Franz
mesh_terms: D003198:Computer Simulation; D020342:Finite Element Analysis; D006321:Heart / Q000503:physiopathology; D006352:Heart Ventricles / Q000473:pathology / Q000503:physiopathology; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000493:pharmacokinetics* / Q000627:therapeutic use*; D021621:Imaging, Three-Dimensional; D007267:Injections; D019028:Magnetic Resonance Imaging, Cine; D008955:Models, Cardiovascular; D009203:Myocardial Infarction / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D020257:Ventricular Remodeling
chemical_list: D020136:Hydrogel, Polyethylene Glycol Dimethacrylate
keywords: adverse remodelling; finite element analysis; heart failure; intra-myocardial injectate; myocardial infarction; myocardial stress