This is important. They've successfully used human stem cells to regenerate
monkey hearts after heart attacks. Human trials likely within a few years.
Over a period of three months, the hearts were shown to have regenerated dead tissue by up to 40% and achieved electromechanical coupling with the original host heart. However, it’s unclear from the study whether a full recovery would be possible via stem cell treatment.
I expect human stem cells will be at least as compatible with human hearts. It's hard to see how this could fail. Ideally, they'd sample cells from the patient, turn them back into stem cells, and completely avoid the rejection / immuno suppressants problem.
Hopefully the eventual human trial will include some antisocial but otherwise-healthy people.