Fluoroscopic Screening of Asymptomatic Patients Implanted With the Recalled Riata Lead Family
The Food and Drug Administration recently issued a class I recall of the St. Jude Medical Riata implantable cardioverter-defibrillator (ICD) lead because of increased risk of electrical failure presumably and mechanical separation via “inside-out abrasion.” What is the failure rate of the Riata leads?
Two hundred forty-five patients (mean age 71 years) underwent fluoroscopic and electrical screening of a Riata ICD lead (mean dwell time 5.7 years). Cine fluoroscopy was performed in three projections, and ICD interrogation was performed within 1 week of fluoroscopy.
Externalization of the conductor was observed by fluoroscopy in 21.6% of leads. Externalization was time-dependent, being more common with dwell times >5.6 years (29.3%) than with dwell times ≤5.6 years (14%). Externalization was seen in 80%, 75%, and 84% of right anterior oblique, posterior-anterior, and left anterior oblique views, respectively. A >25% reduction in R-wave amplitude was significantly more common in externalized leads (29%) than in normal leads (7%). Only one patient with an externalized lead demonstrated noise on the near-field channel with isometric maneuvers.
The authors concluded that the failure rate of the Riata lead is approximately 30% at >5.6 years post-implantation.
The lead failure rate in this study was higher than in prior studies, probably because high-resolution cine fluoroscopy was used for screening instead of conventional radiography. The mechanism of lead failure is breach of the silicone insulation by the conductor cable, and this is more likely to occur as the dwell time increases. How often an externalized lead develops electrical lead failure still is unclear, and the decision to closely monitor the patient or to prophylactically replace the lead must be individualized.
Keywords: Defibrillators, Fluoroscopy, Embryo Implantation, United States Food and Drug Administration, Cardiology, Silicones, Pacemaker, Artificial, United States, Mental Recall
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