The Food and Drug Administration is calling for additional studies regarding
the safety of recalled heart devices made by St. Jude Medical. As we previously
reported on this blog, the
medical devices have been linked to at least 20 deaths.
The concerns involve leads that connect an implantable cardioverter defibrillator
(ICD) to the heart in order to monitor heart rhythms. As detailed by the
FDA, ICDs are used to detect life-threatening heart rhythms and send an electrical
shock from the ICD through the lead to the heart.
ICD leads typically have layers of insulation that protect electrical conductor
wires inside the lead. However, St. Jude’s Rialta leads were recalled
on Nov. 28, 2011, due to premature erosion of the insulation around the
electrical conductor wires.
This premature insulation failure can impact the lead’s ability to
function properly. As highlighted by the FDA, defective devices can cause
abnormal sensing or pacing, or delivery of inappropriate or no shock therapy,
which could result in serious adverse events, including death.
Although St. Jude issued a recall, approximately 79,000 Riata leads remained
implanted in patients in the United States as of 2011. Therefore, the
FDA has elected to take a more proactive approach. It now recommends that
patients who have implantable heart defibrillators with Riata and Riata
ST leads should have X-rays or other imaging alternatives to check for
abnormalities in the insulation surrounding the lead.
The FDA highlights that its recommendation is supported by several studies
that have demonstrated that routine imaging of the leads may detect previously
unrecognized abnormalities with the insulation. In addition, x-rays or
other imaging techniques can help health care providers develop individualized
patient treatment plans. The FDA is also cautioning against routine removal
of leads without careful evaluation of benefits and risks to the individual patient.