"Paramedics were forced to fend off angry males who eventually forced them to stop treating the patient who was in cardiac arrest and subsequently died," APA secretary Steve Pearce said.
"We had the outrageous situation where a violent mob demanded paramedics hand over a defibrillator and drugs, saying they would treat the patient."
The paramedics barricaded themselves inside the unit as the violent mob demanded a defibrillator and drugs believing they could treat the young man, Pearce added.
About 20 police officers arrived at the scene, including the Public Order Riot Squad, to rescue the paramedics at about 7.45am.
However, the male patient died at the scene.
"On this occasion the stupidity of these people have taken the life of their family member," Pearce said.
"We don't want any more people to face the horrifying situation of their loved ones dying because paramedics are unable to treat patients after threats of violence.
"Paramedics are being subjected to this type of aggression all too often and it is time those who think it is acceptable to attack paramedics woke up to themselves.
"This just has to stop and we need more intervention by police much earlier to make sure our paramedics and our patients are safe.
"Those who think it is acceptable to stop paramedics while they are trying to save a life ought to consider the consequences of their actions."
A Campsie duty officer told news.com.au police got involved when a group of people outside the home had become "agitated"
"Police provided assistance to the paramedics due the behaviour of the crowd," he said.
He added that no police officers were injured and the death is not being treated as suspicious.
Pearce called for faster intervention by police and said attacks on paramedics in the Bankstown area had become a regular occurrence.
The incident comes just weeks after a paramedic was assaulted and others were threatened when they were treating an unconscious woman at a Sydney bar in Darling Harbour.
A riot squad was called in to escort the crew and patient to a waiting ambulance after a group of people with the 22-year-old woman became "agitated and aggressive" at the King Street Wharf bar.
In February, this year, paramedics took part in a roundtable on occupational violence with NSW Health Minister Brad Hazzard where measures to keep paramedics safe were put on the table.
The APA, however, says the state government and NSW Ambulance "have failed to implement strategies to keep paramedics safe".
Pearce said they are "more and more frequently being impeded from doing their work or accessing the sick person, or while they're trying to treat the person, they encounter violent aggressors".