More and more Australians are having defibrillators surgically inserted each year.

Thousands of people are now having implantable cardioverter defibrillators (ICDs) – life-saving devices that prevent sudden cardiac death – implanted each year, according a new study on the technology.

Researchers, led by Dr Jodie Ingles from Sydney University, found that the number of ICD procedures increased from 1,844 in 2002–03 to 6,504 in 2014–15. More than 75 per cent of procedures were in men.

“In 2014–15, the ICD insertion rate for people aged 70 or more was 78.1 per 100,000 population, 22 per 100,000 for those aged 35–69 years, and 1.40 per 100,000 people under 35,” Ingles and colleagues wrote.

“The reported complication rate decreased from 45 per cent in 2002–03 to 19 per cent in 2014–15, partly because of a change in the coding of complications [from ‘severe and catastrophic’ to ‘catastrophic’ only]. The number of removals corresponded to at least 4 per cent of the number of insertions each year.”

The researchers say it is unclear whether the overall increase in procedure rates reflected an increasing need for ICD therapy, or was a direct result of increased awareness of risk factors for sudden death.

“A patient-centred approach to care, including discussing the benefits and risks of ICD therapy with the patient and their family, is essential,” the paper states.

“The proportion of women among patients undergoing ICD procedures is relatively small (about 20 per cent); the possibility that ICD therapy is underused in female patients should be investigated.”

The authors were surprised by one set of results in particular – the increased rate of ICD removals.

“The most frequent reasons for ICD removal are post-surgical infection (clinically accepted infection rate: 1 per cent), device malfunction, misdiagnosis of a heart condition, or lack of clinical benefit,” they wrote.

“The unexpectedly high rate of removals we found should be a priority for investigation.”

The full report is accessible here.