Edmonton’s Mazankowski Heart Institute celebrated its fifth anniversary on Thursday but some say the much-heralded health facility is underused.

About 100,000 cardiac patients have been treated since the institute started taking patients in 2009, but the building’s top three floors remain empty.

Sandra Azocar, executive director of health care advocacy group Friends of Medicare, thinks that’s a problem –especially since other Edmonton hospitals are overcrowded.

Azocar would like to see those floors used to relieve some of pressure.

“If you have spaces that are not being utilized and yet we have people sitting in hallways, it doesn't make sense,” she said.

Liberal leader Raj Sherman says the Mazankowski Institute is a world-class facility which is being underused, particularly in terms of access to urgent and elective surgery.

Sherman is concerned that lack of staff is hampering the facility from reaching its full potential.

"It's not enough people to do the work. More nurses, more O.R.time, more support staff for these amazing cardiologists and health care teams that we have there.”

The Mazankowski Institute had a troubled start. The building, named for former deputy prime minister Don Mazankowski, was originally scheduled for completion in the fall of 2007.

Prime Minister Stephen Harper attended the official opening in May 2008 but construction delays prevented the facility from accepting first patients until July 2009.

The project also ran over its original $193 million dollar budget, forcing the Alberta government to spend another $36.5 million to get the building completed.

Alberta Health Services eventually plans to use the institute’s top three floors but no date has been set.