On December 14, 2011, the Food and Drug Administration (FDA) classified St. Jude Medical’s Riata defibrillator lead recall as a Class I recall, because of the “potential risk of serious injury or patient death if affected devices malfunction.”1 The affected lead model numbers are:
Riata (8 French) Silicone Endocardial Defibrillation Leads (Models 1560, 1561, 1562, 1570, 1571, 1572, 1580, 1581, 1582, 1590, 1591, and 1592), and Riata ST (7 French) Silicone Endocardial Defibrillation Leads (Models 7000, 7001, 7002, 7010, 7011, 7040, 7041, and 7042).
The Riata lead has a failure mechanism that differs from other defibrillator leads. The conductor cables can erode through their silicone insulation channel from the inside out and extrude from the body of the lead. Extrusion is usually located proximal to the distal coil and can occur at more than one site along the lead.
This lead is no longer being implanted, and St. Jude Medical’s newer ICD leads have an additional coating around the lead body that appears to prevent cable extrusion, but there are an estimated 79,000 patients who currently have an affected Riata lead in place. This problem was identified several years ago, and initially was felt to be infrequent. Previous communications from St. Jude Medical have suggested as of April 2011 that the rate of externalized conductors with the Riata and Riata ST leads was 0.094%. However, there is evidence that this is a much bigger problem. In a 2011 abstract from Northern Ireland, 15% of 165 patients with a Riata or Riata ST lead had an insulation breach during fluoroscopic screening.2 Although the conductor cables have their own additional layer of insulation, it is clear from data using the FDA Manufacturers and User Defined Experience (MAUDE) database that this does not always remain intact.3 An informative Riata Leads Issue Webinar was held by the Heart Rhythm Society on December 21, 2011.
The management of a patient with electrical failure of an ICD lead is usually fairly straightforward. However, the clinical implications of externalized conductors in a defibrillation lead without electrical anomalies are not clear. According to the FDA letter, St. Jude Medical has initiated a prospective study to evaluate the incidence rate and the long-term performance of leads with externalized conductors but without an associated electrical abnormality. Enrollment has reportedly already begun, and the study is expected to last for up to two years. In the meantime, as stated in the Advisory Letter, it is important to recognize that:
- The value of screening fluoroscopy for patients with leads that exhibit no electrical abnormalities is unknown at this time.
- The risk versus benefit of replacing a lead in an affected patient (with or without extraction of the affected lead) will vary from patient to patient.
- Prophylactic extraction or replacement of a lead without electrical dysfunction is not recommended.
All leads with an externalized conductor, with or without an associated electrical abnormality, should be reported to the company’s Technical Services Department at 1-800-722-3774. They should also be reported to the FDA’s MedWatch Program by phone at 1-800-FDA-1088, by fax at 1-800-FDA-0178, by mail at MedWatch, HF-2, FDA, 5600 Fishers Lane, Rockville, MD 20852-9787, or on the MedWatch website at www.fda.gov/medwatch.
- Meyer AJ, Weigelt JC. “FDA Classifies Voluntary Physician Advisory Letter on Riata and Riata ST Silicone Defibrillation Leads as Class I Recall (URGENT MEDICAL DEVICE ADVISORY).” U.S. Food and Drug Administration Home Page. 14 Dec. 2011. Accessed 16 Jan. 2012. <http://www.fda.gov/Safety/Recalls/ucm283879.htm>.
- Kodoth V, Cromie N, Lau E, et al. Riata lead failure; A report from Northern Ireland Riata lead screening programme (abstract P1838). Eur Heart J 2011;32:310.
- Hauser RG, McGriff D, Retel LK. Riata ICD Lead Failure: Analysis of Explanted Leads With A Unique Insulation Defect. Heart Rhythm 2011 Dec 28. [Epub ahead of print]