Group president Barry Robson is one of 120 patients with heart attack histories who attend programs twice a week to exercise and to get advice to avoid further attacks.

Maintenance program patients say they were told by Sydney West Area Health Service officials they could not replace a nurse when she goes on holidays next month.

The remaining nurse will focus on the six-week program for recent heart attack patients only.

This means the others will be stranded for three weeks.

A health service spokeswoman said other arrangements would be made for maintenance program patients.

''Options will include an individually tailored home exercise program or joining one of the phase two cardiac groups,'' she said.

But the 40 patients are angry because it may be impossible for them to use the gym equipment, for which they raised the money themselves.

They have raised $70,000 to buy gym equipment since the group started up in 2002.

``Out of 500 people who have been on the program since 2002, I can think of only one who has since died,'' Mr Robson said.

``The proof is in the pudding that it is a terrific preventive program.''

Three nurses were the staff for program up until 18 months ago.

``We've asked Professor Steven Boyages [area health service CEO] many times to give us back our three full-time nurses,'' Mr Robson said.

Mt Druitt nurses will give up their lunch hour or free time this Thursday to tell the community about the impact of hospital under-funding and staff shortages.

People are invited to join the NSW Nurses Association rally. It will start at noon in Zoe Place.