NHS Lothian contacted 186 patients who had heart aortic valve replacement operations in the last six months to advise them of a possible infection risk.
The decision was taken by an Incident Management Team following a case of heart valve infection – known as endocarditis.
The team studied records of thousands of patients who had many different types of surgery carried out since the beginning of 2015.
They discovered that six who underwent cardio thoracic surgery over 18 months were affected by micro organisms, possibly acquired during open heart surgery.
In a statement, NHS Lothian confirmed: “Of the small number of patients affected, some later died. No cases were found prior to March 2017 and there have been no known cases in patients operated on since November 2018.
“As a precaution however, four planned surgeries have been cancelled this week to allow for specialist cleaning and disinfection of the theatres used for this type of procedure. Enhanced infection control measures have also been put in place.”
Prof Alex McMahon, NHS Lothian Executive Lead for Infection Control said: “We extend our sincere apologies and deepest condolences to the families of the patients who died, all of whom were informed at the time of their treatment that they had an unusual and difficult to treat infection.”
He added: “We know this will be a worrying time for those who have received letters but we have contacted patients purely as a precaution.
“The risk is very low and we do not anticipate any more cases, however we know that it can take up to six months for these infections to materialise. We want to make sure those patients know what symptoms to be aware of and to contact NHS Inform if they have any concerns. Many patients receiving this type of surgery are already very ill and vulnerable to infection so we place the highest importance on a stringent infection prevention and control regime.”
Endocarditis occurs in 0.5 per cent of patients per year and can have many different causes – usually the source is the patient’s own body. These cases are unusual because the micro-organisms which have caused the endocarditis are more commonly found in the environment.
A Scottish Government spokesperson said: “Our thoughts and condolences are with the families and friends of those patients who have sadly died. We know this will be a worrying time for those who have received letters, and while the risk of infection is low, it is important that they follow the advice given by NHS Lothian.
“NHS Lothian is undertaking specialist cleaning and disinfection of the theatres used for this type of procedure and have stated that enhanced infection control measures have also been put in place. “Scottish Government officials remain in close contact with the health board on this incident.”