When Implanted Heart Devices Fail
The Odds -- and Consequences -- of Pacemaker, ICD Breakdowns
The Risk of Pacemaker, ICD Failure continued...
There is good news, however. New data from 2003 and 2004 show what Maisel
calls "a reassuring decline in the ICD malfunction rate, almost back down
to the lowest levels seen in the 1990s."
Does the risk of a breakdown mean you should think twice about getting a
pacemaker or ICD device? Maisel doesn't think so -- if your doctor says you
really need one.
"The chance someone will be saved by one of these device about a
thousand times greater than the chance the device will fail when they need
it," Maisel says.
He notes that there were 30 deaths due to pacemaker malfunction and 31
deaths due to ICD malfunction among the 2.7 million patients who had one of
ICD Replacement Risks
ICD breakdown isn't the only risk of getting one of these implants, find
cardiologist Andrew D. Krahn, MD, of University of Western Ontario in London,
Canada, and colleagues.
When a device breaks down, manufacturers sometimes discover a design flaw or
manufacturing error. That leads to product "advisories" that warn
patients of potential problems. This puts the patient in a major dilemma.
Should patients risk device failure, or should they risk the operation to have
the device removed and replaced?
"We saw the other side of the coin: not devices failing, but patients
suffering due to recall of devices," Krahn tells WebMD.
Getting an ICD implant isn't a major operation. But replacement can be
tricky. The patient is older, there may be scar tissue, and there is more risk
of a deadly infection after surgery. How dangerous is it? Krahn's team surveyed
nearly all the doctors in Canada who do these procedures.
"We were surprised by the high risk of infection and the number of
replacement procedures that required a second operation," Krahn says.
"We reported a 6% major complication rate. And 2% of patients with major
complications required a major surgical procedure. That is a compelling risk.
Our concern about the device has to cap that threshold for us to advocate
So what should you do if you've received an "advisory" warning that
your ICD might fail? This is a tough question, and the answer may be not to
have the device removed.
"The majority of advisories had a 1-in-10,000 to a 1-in-100 risk of
device failure," Krahn says. "And for some manufacturer advisories, you
can detect problems by monitoring the device. So the vast majority of the time,
you detect a problem before the patient feels anything. On the other hand, some
advisories warn of abrupt loss of function. Some patients suffer sudden
It's an unusual risk-vs.-benefit decision. Patients, Krahn says, should
first look at their own medical condition, then at the risk estimated for the
specific device they have implanted.