Nearly 30 percent of cardiac arrest patients transported by ambulance to a D.C. hospital in the past five months arrived alive, more than double the percentage only four years ago, city emergency medical services officials say.

Mayor Adrian Fenty on Thursday joined Fire and Emergency Medical Services Chief Dennis Rubin to tout progress in EMS since Rubin took the helm two years ago. Their claims come as the department faces a slate of public relations challenges, including reports of cheating on an emergency medical technician exam, flunked assessments and a heart attack victim who died hours after a paramedic diagnosed him with acid reflux.