Fasting prior to surgery isn’t about heart health. It’s about not having you choke on your own vomit or have issues with intimation should that become necessary.
Not being NPO might not be a problem, until you tear something that requires open heart surgery right now, and , whoops you have a full stomach. Hopefully the stress won’t cause them to vomit and using cricoid pressure and suxx you can get a tube in without them aspirating some of their last meal. Intubating through vomit is no bueno.