Grant: Operating Grant

Acute myocardial infarction (heart attack) remains the number one cause of death and reduced quality of life of all heart diseases. The number of heart attack survivors is increasing, but the factors that determine how the heart will heal after the heart attack are not well known. Some individuals will develop significantly worsening heart function over time, which can lead to heart failure, while others will not. There is a need for better clinically applicable tools to determine which individuals are at risk after their heart attack. The goals of this program are to develop new magnetic resonance imaging (MRI) methods to measure the properties of the heart muscle, following a heart attack, which will accurately predict worsening heart function, early in disease progression. Our proposed tools will help us to develop new therapies (by understanding the disease mechanisms) and to determine which individuals should receive therapy and to measure how they respond to therapy. From animal studies, it is known that early changes in the heart muscle outside of the heart attack region (also called the "remote region") are strongly predictive of future remodeling of the heart, or dilation of heart and reduced pumping function. A characteristic feature of these early changes in the heart muscle is the formation of "diffuse fibrosis", which is the accumulation of new tissue around the muscle cells that is similar to a scar that forms on a healing cut. Our hypothesis is that new MRI methods can measure diffuse fibrosis following heart attack and that the amount of diffuse fibrosis will predict which individuals will be likely to develop new heart problems after their heart attack. In our proposed program, we will validate our newly developed MRI methods to detect diffuse fibrosis using numerical simulations and animal experiments and we will study human subjects at several time points after their heart attack to further validate our proposed methods.