On a communication released on 16 August, the Food and Drug Administration (FDA) recommended physicians to closely monitor patients who have been implanted with a Riata or Riata ST lead (St Jude Medical) due to “an increase in frequency of reported Riata insulation failures, beginning approximately four years after implant.” The FDA also recommends notifying patients if they have a recalled lead.
The leads are used with implantable cardioverter defibrillators (ICD’s) and cardiac resyncronisation therapy (CRT) defibrillators.
According to the FDA’s release, “Insulation failure may cause some of the electrical conductors inside Riata leads to move within (migrate), or move entirely outside (externalise), the outer lead insulation. These changes may be detectable on X-ray or fluoroscopic imaging.”
Lead insulation failure is characterized by the premature erosion of the insulation around the electrical conductor wires. Insulation failure may cause abnormal sensing or pacing, or delivery of inappropriate or no shock therapy, which could result in serious adverse events, including death. St Jude Medical recalled the Riata and Riata St leads on November 2011 due to insulation failure.
The company stopped selling these leads in late 2010 but more than 227,000 Riata leads had been distributed worldwide. According to St Jude Medical, as of 2011, approximately 79,000 Riata leads remained implanted in patients in the United States.
The FDA recommends that patients who have not had a recent evaluation and device interrogation should undergo X-ray exams or fluoroscopic imaging to assess for any electrical abnormalities. Physicians should consider remote monitoring for patients with a recalled lead to better detect electrical abnormalities.
St Jude Medical recommends reprogramming the device to increase the chance for detection of a lead abnormality. The patient alert and remote monitoring alerts should also be turned on.
The FDA encourages physicians to file a voluntary report to the FDA’s MedWatch Safety Information and Adverse Event Reporting Program, for any suspicion of premature lead insulation failure, externalised or migrated conductors, electrical malfunction, or other abnormal function.