A swab left inside a man after an operation was partly to blame for his death, an inquest has found.
Bernard Johnson, 64, from Lincolnshire, had surgery for heart disease at the Glenfield Hospital, Leicester, in 2009.
The inquest in Leicester heard the alarm was raised after the operation but Mr Johnson died from an infection.
Coroner Catherine Mason criticised staffing levels at the hospital, which said procedures had been strengthened.
Recording a narrative verdict, she said: "The evidence makes it clear to me that there were systems and procedures in place at the time of the surgery but these were not followed.
"In addition there were distractions in the theatre and staffing levels caused further pressure to an environment already dealing with a complex and lengthy procedure."
Ms Mason found that Mr Johnson died of multiple organ failure due to infection caused in part by the surgical swab which was left in his chest.
The hospital also apologised to Mr Johnson's family for the failings, adding it accepted the inquest's findings and had carried out a full review.
The inquest heard staff nurse Krishna Rungen had noticed the swab was missing but had not raised the alarm until the operation was over.
The surgeon, Mark Hickey, said it could easily have been removed if he had been warned at the time.
Mr Johnson then had to go back into theatre to have the swab removed but died nine days later.
His solicitor, Sally-Ann Robinson, said: "This could be repeated - it might happen again if they don't have adequate staffing levels, because they're under such pressure in the theatre.
"And that, obviously, is what needs tackling. Not just having the system in place, but making sure the staffing level's there to ensure that the systems can be followed."
Mr Johnson's widow, Sharon Groves-Johnson, said the family was considering further legal action.