Effects And Mechanisms Of Direct Cardiac Compression In Interruption Of Myocardial Remodelling In Chronic Heart Failure.
Funder
National Health and Medical Research Council
Funding Amount
$392,250.00
Summary
Heart failure (HF) is a disease where the heart pumping function is insufficient to provide adequate blood supply to the rest of the body. It is a highly debilitating disease affecting nearly 10 million people worldwide and has a <50% one-year survival in severe cases. Despite significant advances in pharmacotherapy, heart transplant is the only alternative for severe HF but is restricted by lack of donor organs to only ~ 5% of those requiring it. Research has shown that progression of HF is ....Heart failure (HF) is a disease where the heart pumping function is insufficient to provide adequate blood supply to the rest of the body. It is a highly debilitating disease affecting nearly 10 million people worldwide and has a <50% one-year survival in severe cases. Despite significant advances in pharmacotherapy, heart transplant is the only alternative for severe HF but is restricted by lack of donor organs to only ~ 5% of those requiring it. Research has shown that progression of HF is related to many subsequent changes after an initial insult. In addition to pumping failure, HF is associated with deranged compensatory responses such as neurohumoral over-activation, heart chamber enlargement, loss of functional cells, increase of inflammatory mediators and changes in cardiac skeleton (extracellular matrix). The changes in the heart are collectively known as remodelling. Mechanical heart assist is now considered a potential destination therapy for severe HF, superior to pharmacotherapy alone. Improvement of cardiac pumping function and even successful weaning from devices has been reported, along with observations of reverse remodelling. The success of this approach has been limited however, particularly with HF due to coronary disease, the most prevalent form. We developed a novel HeartPatch mechanical assist device to compress the heart from its outer surface. It gives support to both main chambers and avoids blood contact, a feature of currently available devices associated with complications such as blood clotting and infection. Our device has proved effective in animals with acute HF and even with cardiac arrest. We propose to study the effects of our device on the process of remodelling in HF with coronary disease in a controlled manner. The project will enhance understanding of the mechanisms involved in reverse remodelling and further the development of a device which may potentially benefit many severe HF patients.Read moreRead less
Remodelling In Cardiac Hypertrophy: Implications For Arrhythmogenesis
Funder
National Health and Medical Research Council
Funding Amount
$48,361.00
Summary
High blood pressure (HBP) affects 1 in 3 adults. Cardiac hypertrophy (thickened heart muscles) is a common condition seen in HBP. This research seeks to study the underlying changes in electrical, structural and molecular properties of the heart that may contribute to the increased sudden death and atrial fibrillation (irregular heart rhythm) associated with both HBP and cardiac hypertrophy. The new understanding may identify new treatment targets to reduce these life-threatening conditions.
MYOCARDIAL NEOVASCULARIZATION FOR ISCHEMIC HEART DISEASE USING BONE MARROW-DERIVED ANGIOBLASTS
Funder
National Health and Medical Research Council
Funding Amount
$577,400.00
Summary
Congestive heart failure remains a major public health problem. In Western societies heart failure is primarily the consequence of a previous myocardial infarction. We have recently identified certain cells in the bone marrow of adult humans that can cause new blood vessel development in the heart after infarction, protecting the heart muscle cells against death and preventing heart failure. Since the cardiovascular diseases that are most likely to benefit from treatments utilizing adult bone ma ....Congestive heart failure remains a major public health problem. In Western societies heart failure is primarily the consequence of a previous myocardial infarction. We have recently identified certain cells in the bone marrow of adult humans that can cause new blood vessel development in the heart after infarction, protecting the heart muscle cells against death and preventing heart failure. Since the cardiovascular diseases that are most likely to benefit from treatments utilizing adult bone marrow-derived endothelial progenitors, or angioblasts, predominantly affect aging individuals, critical questions that must be addressed are whether advanced age and-or progression of cardiovascular disease reduce the total numbers and-or the functional activity of such cells. In the current proposal we will investigate the relationship between increasing age or progression of ischemic heart disease and changes in the number and in vivo biologic properties of human angioblasts. Patients at various ages and stage of cardiovascular disease will be studied. Angioblast numbers will be quantitated in freshly obtained bone marrow cells. The ability of purified angioblasts to be targeted to the ischemic heart will be studied by labeling the angioblasts with a radioactive tracer and measuring tracer uptake in the heart at various time points after intravenous infusion of the cells. Finally, angioblast functional capacity will be evaluated using standard measurements of heart function before and at various time points after reinfusion of cells into the donor. In Aims 2 and 3 of this proposal we will focus our investigations on the potential use of angioblast therapy for reversal of established chronic heart failure in our animal models. Specifically, we will investigate whether induction of neovascularization results in cardiomyocyte regeneration and explore novel strategies to augment heart muscle regeneration by increasing angioblast trafficking to the damaged myocardium .Read moreRead less
I am a translational, human physiologist which places me in a unique position to address important clinical questions. My current interests centre on: • Identification of novel predictors of unstable coronary heart disease • Novel treatment approaches in:
Myeloperoxidase-catalysed Damage To Arterial Extracellular Matrix And Its Consequences
Funder
National Health and Medical Research Council
Funding Amount
$384,750.00
Summary
A heme enzyme (myeloperoxidase) has been shown to be present in the lesions present in diseased human arteries, and it has been reported that this enzyme contributes to the development of arterial disease via its ability to catalyse the formation of highly reactive oxidants. Recent studies have shown that the level of this enzyme correlate strongly with the presence of coronary artery disease, and that this enzyme may play a role in plaque rupture, a leading cause of sudden coronary death. It ha ....A heme enzyme (myeloperoxidase) has been shown to be present in the lesions present in diseased human arteries, and it has been reported that this enzyme contributes to the development of arterial disease via its ability to catalyse the formation of highly reactive oxidants. Recent studies have shown that the level of this enzyme correlate strongly with the presence of coronary artery disease, and that this enzyme may play a role in plaque rupture, a leading cause of sudden coronary death. It has also been reported that elevated levels of metal ions are present in advanced human atherosclerotic lesions. In recent experiments we have shown that products generated by myeloperoxidase can interact with metal ions and superoxide radicals, and that this process results in an exacerbation of damage. This synergism between the oxidants generated by myeloperoxidase and metal ions may explain, at least in part, the complex mixture of products detected in human lesions and be responsible for the weakening of lesion structure and contribute to an enhanced likelihood of plaque rupture. This study will examine the potential effects and mechanisms of damage to extracellular matrix materials from normal arteries and cultured cells We will examine under what circumstances interactions occur and whether these reactions may play a key role in plaque rupture. We will also examine how materials arising from damage to the extracellular matrix may affect the cells whic grow upon this scaffolding, and whether this may be partly responsible for altered behaviour of cells within dveloping atherosclerotic lesions. A detailed knowledge of which processes are important in plaque rupture is an essential pre-requisite to the development of new therapeutic strategies.Read moreRead less
The Role Of Dysregulated VEGFs In Lymphatic And Non-lymphatic Vascular Malformations
Funder
National Health and Medical Research Council
Funding Amount
$389,486.00
Summary
Vascular malformations are abnormal growths of blood vessels that affect hundreds of children born in Australia every year. They range from small birthmarks to large destructive growths that cause chronic pain, bleeding and major deformity. This is the largest ever study to systematically look for the biological drivers that cause these growths so that drug treatments will ultimately be able to replace surgery as the first line treatment.