Heart attack deaths rising among young Americans Fox News senior medical analyst Dr. Marc Siegel joins 'America's Newsroom' to discuss a dramatic increase in fatal heart attacks among people under the age of 55 and how to keep the heart healthy. NEW You can now listen to Fox News articles! Scientists have developed a new therapy designed to repair cardiac damage after a heart attack . The study, led by researchers at Columbia University and published in the journal Nature Biomedical Engineering,