Medtronic’s (NYSE:MDT) precedent-setting Sprint Fidelis recall isn’t aging well, according to researchers.
Looking at numbers for nearly half of all Sprint Fidelis implants in Canada, the rate of failure appears to be climbing, prompting some doctors to recommend that the devices be replaced before they show signs of failure.
"The rate of Fidelis failure continues to increase over time, with failures approaching 17% at 5 years," the researchers wrote in the January issue of Circulation. "Our data suggests that Fidelis replacement should be strongly considered, at the time of generator replacement."
Medtronic’s physician guidelines, last updated in April 2011, recommend that surgeons take no action on functioning leads in normal circumstances. In the event of a device change-out or upgrade procedure, however, the Minneapolis-based med-tech giant recommends that surgeons consider patient factors and device model failure rates in determining whether to leave the functioning leads intact or replace them.
"Medtronic’s Independent Physician Quality panel routinely reviews external publications related to Fidelis, as well as our own information to ensure that their patient management recommendations remain up to date," company spokesman Chris Garland told MassDevice in an email. "At this time, there are no changes to our patient management recommendations."
The new study, funded but not designed by Medtronic, estimates that around 268,000 Fidelis leads were implanted in patients worldwide before Medtronic suspended shipments in October 2007.
All 23 Canadian centers licensed to perform implantable cardioverter-defibrillator procedures in Canada reported their data to the Canadian Heart Rhythm Society Device Committee. The researchers looked at more than 3,000 Sprint Fidelis implants performed at 11 of the centers in Canada, Cardiovascular Business reported.
Failure rates for the implants grew from 0.2% at 1 year, to 2.1% at 2 years, 5.3% at 3 years, 10.6% at 4 years and 16.8% at 5 years for the total population, data showed.
"The failure rate in this study and other reports is higher than Medtronic has reported from their own data," according to the researchers. "This is possibly explained, at least in part, by variable center failure rates and perhaps bias toward reporting data from centers with higher rates. In the current study we controlled for this by selecting centers from high and low strata of failure rate."
Researchers also found that failure rates were higher in female patients, patients who received the implant via the subclavian or axillary pathways and patients who had had lead failure in the past.
"These data support the widespread anecdote that there are a group of patients, whom for unknown reasons, have recurrent ICD lead failures," researchers wrote. "The explanation is unclear but needs further investigation."
Medtronic pulled the Sprint Fidelis leads, used to connect pacemakers to the heart’s muscle, from shelves worldwide in October 2007 when it was announced that they were prone to fracture – meaning they could either fail to deliver the shock needed to regulate a haywire heartbeat or else send unneeded shocks.
The defective leads are implicated in more than 100 deaths, although Medtronic has said that only 13 fatalities had the leads as a "possible or likely contributing factor."
Medtronic settled lawsuits related to the recall for $268 million in October 2010.
