GARNETT Allan Mickelo was serving a life sentence for murder when he was found dead in his cell at Woodford Correctional Centre.
The 48-year-old, who was born in Cherbourg, had been discharged from hospital two days earlier after undergoing surgery for a heart condition.
When stumbling across Mr Mickelo's body on November 24, 2012, the prison nurse who found him dead did not perform CPR.
But in findings released on Wednesday following an inquest into Mr Mickelo's death, Queensland Deputy State Coroner John Lock said CPR would not have helped the man.
He said the nurse's examination was "cursory" but that nurse was certain Mr Mickelo had been dead for some time and that CPR would have been futile.
Mr Lock also said investigations into Mr Mickelo's death showed his death was natural.
Mr Mickelo had been in jail since he was about 17 years old, when he was sentenced to life in jail for murder.
He had ongoing health issues and had had heart attacks in 1996 and 2009.
In early November 2012, he was taken to Caboolture Hospital and later transferred to Princess Alexandra Hospital where he underwent surgery - coronary stenting - to improve blood flow to his heart.
A day after being discharged, Mr Mickelo complained about chest heaviness. The nurse who examined him said he appeared to have no cardiac issues and that he remained settled that night.
At 7.30pm the next day, it was recorded that Mr Mickelo was in his cell and settled and had been given access to the toilet. He was then found dead about 10.20pm.
Mr Lock's findings said an autopsy found Mr Mickelo had extensive heart disease. The doctor who performed the autopsy told the inquest it was one of the worst hearts he had seen.
In his findings, Mr Lock also said there was a problem with Mr Mickelo's medication.
He was discharged from hospital without a supply of new medication and this medication was not available at the prison until the next day.
"The issue of some prescribed medications not being in stock at (the prison) remains somewhat of a problem," Mr Lock said.
But he said the process now was for the prison to request hospitals to supply a prisoner with five days of discharge medication.
"I am satisfied that, whilst there were inadequacies in the care provided to Mr Mickelo in terms of medication management and chest pain management, that these have been addressed," Mr Lock said in his findings.
He found Mr Mickelo died of a heart attack.