Between 1990 and 2000, more than 500,000 pacemakers and implantable cardioverter defibrillators (ICDs) in the US were subject to manufacturer safety alerts or recalls.
During the 10-year period, there were 52 safety alerts or product recalls involving 408,500 pacemakers and 114,645 ICDs out of more than 1.3 million device checks and analyses.
Most of the advisories (95 per cent) were due to either hardware or software problems, and the total cost of these advisories resulted in about $870.2 million, with ICDs making up 76 per cent of the cost, while accounting for only 22 per cent of the advisories.
As the devices become more technologically advanced, the number of recalls per year increases. In 1990, there were no safety alerts or recalls but, in 1999, there were advisories involving 182,647 devices. In fact, say the researchers, 65 per cent of all devices recalled have occurred since January 1999 (J Am Med Assoc, 2001; 286: 793-9, 843-4).
* The incidence of infection in implanted pacemakers or ICDs among patients with Staphylococcus aureus bacteraemia may also be higher than previously thought, according to a small study.
US researchers estimate that about 70 per cent of S. aureus bacteraemia patients who have an implanted cardiac device may also have a device infection. Of 33 patients with implanted pacemakers or ICDs and S. aureus bacteraemia over a six-year period, device infection was confirmed in 15. Infection was suspected in a further nine patients, but these died of sepsis before device infection could be confirmed.
Researchers warn that any suspicion of infection should be followed-up thoroughly with a full blood test, as device infection results in more illness and an increased risk of death. However, they also found that cardiac device infection does not always produce symptoms - 60 per cent of those with confirmed device infection had no clinically detectable signs of infection (Circulation, 2001; 104: 1029-33).