Fluoroscopic investigation of Riata® transvenous defibrillator leads.
BACKGROUND
Implantable cardioverter-defibrillator leads from Riata® family (St. Jude Medical Inc., Sylmar, CA, USA) have been recently recalled by Food and Drug Administration for concerns of a unique type of "inside-out" insulation failure leading to conductor externalization. The objective of this study was to evaluate the prevalence and predictors of conductor externalization in patients implanted with Riata 8 French (Fr) and 7 Fr leads.


METHODS
Patients implanted with Riata® and Riata ST® who were actively followed up in our institution were scheduled for high resolution 3 view fluoroscopy and device interrogation including high voltage (HV) lead impedance testing. Fluoroscopic images were graded as presence of externalization or no externalization.


RESULTS
Of the 90 patients who underwent screening fluoroscopy, majority had dual coil leads (62.5%) and median duration from the implant time to screening was 79.5 months. Twenty four (26.7%) patients exhibited evidence of lead externalization with 10 (41.6%) of these showing electrical abnormalities at the time of screening. No externalization was seen in the 7 Fr leads. Pacing thresholds were significantly elevated in the externalized cohort compared to non-externalized group (1.42 ± 1.23 vs. 0.93 ± 0.53; p = 0.01). Time since lead implant and lead diameter emerged as significant predictors of lead externalization on univariate analysis with only lead diameter being significant on multivariate analysis (odds ratio 30.68; 4.95-∞, p = 0.001).


CONCLUSIONS
Prevalence of insulation failure exhibiting as conductor externalization is high (26.7%) among the large diameter 8 Fr Riata® leads with a significant proportion of patients manifesting electrical failure. High resolution 3 view fluoroscopy is a reasonable approach to screen for this unique type of insulation failure.
Department of Cardiac Electrophysiology, Henry Ford Hospital, Detroit, MI, United States. dr_gurjit@yahoo.com.
Gurjit
G
Singh
Marc K
MK
Lahiri
Arfaat
A
Khan
Kan D
KD
Fang
Claudio D
CD
Schuger
D000368:Aged; D000369:Aged, 80 and over; D016009:Chi-Square Distribution; D016208:Databases, Factual; D016757:Death, Sudden, Cardiac / Q000209:etiology / Q000517:prevention & control*; D017147:Defibrillators, Implantable / Q000009:adverse effects*; D004554:Electric Countershock / Q000009:adverse effects* / Q000295:instrumentation; D017097:Electric Impedance; D005260:Female; D005471:Fluoroscopy; D005548:Foreign-Body Migration / Q000000981:diagnostic imaging* / Q000453:epidemiology; D006801:Humans; D008297:Male; D057052:Medical Device Recalls; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D015995:Prevalence; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States; D014486:United States Food and Drug Administration