However, two weeks after he was admitted, Mr Trolan's condition deteriorated and he experienced temperature spikes and a rapid heart rate.
The father of two was given new medication, but the coroner found there had been "undertreatment" with antibiotics which were not enough to kill off bacteria in a clot on his heart.
The coroner said the failure to identify this error in Mr Trolan's prescription was not entered into his records, describing this as "striking".
She said staff were aware of the error and it should have been discussed with the patient himself and with his family, but it was not. She said Mr Trolan's condition was not properly reviewed by staff at the Causeway Hospital.
In a statement following the verdict, the Northern Health Trust said: "We offer our sincere condolences to Mr Trolan's family and apologise unreservedly for the failings in care that have been highlighted.
"We fully accept the coroner's findings and will take time to reflect on the learning.
"The Trust has already undertaken an investigation into Mr Trolan's care and identified learning which has been shared with staff. This is a very tragic situation, and we are deeply sorry for the family's pain and loss."