Optimizing outcomes after a heart attack

It’s estimated that about 700,000 Canadians are living with heart failure, a serious condition that erodes quality of life due to symptoms like shortness of breath, swelling, fatigue and weakness and a rapid or irregular heartbeat. Heart failure also increases the risk of sudden death, which occurs when the heart suddenly stops beating.

Although therapies can help, in some cases, heart transplant may be the only option for patients with heart failure, which often develops after a heart attack, when scars form on the heart tissue, affecting the heart’s electrical system and ultimately making it less efficient at pumping blood around the body.   

Dr. Justin Deniset, PhD, a researcher at the University of Calgary’s Cumming School of Medicine, is focused on finding a way to prevent heart failure before it develops. He recently received a John R. Evans Leader’s Fund (JELF) award from the Canada Foundation for Innovation to investigate how the immune system tries to repair the initial damage after a heart attack, and how this process may influence how the heart fails and the speed at which this happens. 

“We have ideas about how certain types of immune system cells may contribute to heart failure, but we aren’t sure of the mechanisms they use. We also don’t know specifically where they do these jobs,” says Deniset.  “Knowing the roles of these specific cells in and around the heart may lead to new treatments to prevent the damaged heart from failing.”

Deniset developed special imaging techniques using high-powered microscopes that allow his team to visualize, in real time, the immune and heart cells interacting in the beating heart. The lab is one of just a handful of research labs in the world, and the only team in Canada, using this unique technology.

The technology allows Deniset’s team to track how specific cells in the blood or pericardial fluid, found in the sac surrounding the heart, interact with cells found in the heart following a heart attack.

Specifically, the team will selectively block certain cells from reaching the heart after injury to see the results. They will also block the molecules that allow these immune cells to influence their local environment.

The hope is that the research will reveal the inner workings of the immune cells in repairing the heart, allowing researchers to develop therapies and pinpoint the target areas to deliver those therapies to delay the development of heart failure following a heart attack.   

“Ultimately, our goal is to increase survival and maintain a better quality of life for patients that have suffered a heart attack,” says Deniset. “There are a lot of things to explore, but it is very exciting.”

Justin Deniset is an assistant professor and a member of the Dept. of Physiology and Pharmacology and the Dept. of Cardiac Sciences at the University of Calgary’s Cumming School of Medicine. He is a member of the Libin Cardiovascular Institute.