An Australian medical research institute has warned the COVID-19 pandemic could undo decades of work driving down heart disease deaths.

A medical research facility has raised the alarm over Australian hospital data suggesting a large drop in attendance for serious heart conditions during the coronavirus crisis.

The Baker Heart and Diabetes Institute on Thursday warned the COVID-19 pandemic could undo decades of work driving down heart disease deaths.

Heart specialists around the world are concerned it could lead to under-treatment of heart disease and more deaths, as people falsely believe it is safer to stay home, the institute said.

The institute's director, Professor Tom Marwick, said heart muscle might not be saved if people suffering from acute coronary conditions didn't attend hospital.

"It also means medical therapy and cardiac rehabilitation will not be delivered, which could ultimately increase death rates from heart disease," Professor Marwick said in a statement on Thursday.

Dr Nick Cox, the director of cardiology at Melbourne's Sunshine Hospital, has seen cardiology patients decrease by almost half compared to average numbers in mid-February.

The number of serious heart attack cases requiring urgent stent procedures has dropped from about one a day to one every two to three days.

In Brisbane, the Queensland chair of the Cardiac Society, Dr Sudhir Wahi, has described a drop of nearly 30 per cent in acute presentations for heart conditions.

The Royal Hobart Hospital's Dr Andrew Black, meanwhile, has reported similar decreases along with patients presenting late - and sicker - to hospital.

Professor Marwick said it was important for people with symptoms of heart disease to seek help quickly, as heart muscle started to die within minutes when people developed chest pains over a blocked coronary artery.
"If enough heart muscle is lost, heart failure will ensue," he said.

He said the number of heart disease deaths from under-treatment could far exceed the number of patients dying from COVID-19.

"While it is possible that something may have happened to stop coronary plaque from rupturing or clots forming in the arteries, such as the reduction of physical activity during the shutdown causing fewer heart attacks, these explanations are unlikely," Professor Marwick said.

"A much more plausible explanation is that patients developing cardiac symptoms are reluctant to come to hospital.

"The consequences of this could be enormous."