Long-term electrical survival analysis of Riata and Riata ST silicone leads: National Veterans Affairs experience
ABSTRACT BACKGROUND: A medical device advisory issued by St Jude Medical in November 2011 estimated 0.63% all-cause abrasion rate on their Riata and Riata ST silicone high-voltage lead families (Riata/ST), leading to Food and Drug Administration class I recall. We performed an independent comparative, long-term electrical survival analysis of Riata/ST and 3 other high-voltage lead families in a large national cohort of patients. OBJECTIVE: To evaluate long-term electrical survival of Riata/ST leads relative to other commonly evaluated high-voltage leads. METHODS: Failure rates of Riata/ST, Sprint Quattro Secure (Quattro), Sprint Fidelis (Fidelis), and Endotak Reliance G/SG (Endotak) leads from the Veterans Administration's National Cardiac Device Surveillance Center database, consisting of 24,145 patients with remote transmissions since 2003, were analyzed. Survival probability was determined with Kaplan-Meier survival analysis with the log-rank test. RESULTS: Of 1403 Riata/ST, 5608 Quattro, 5076 Fidelis, and 2401 Endotak leads identified, 5-year survival probability of Riata/ST leads (97.5%) was significantly lower than that of Quattro (99.2%) and Endotak (99.5%) leads (P <.0001) but higher than that of Fidelis leads (89.6%) (P <.0001). Riata ST leads showed a 6-year survival of 91.4% (95% confidence interval 81.3-96.2) compared to 97.0% (95% confidence interval 92.2-98.1) in Riata leads (P = .003). CONCLUSIONS: There is decreased survival probability of Riata/ST leads compared to other contemporary high-voltage leads, with decreased survival of Riata ST silicone compared to Riata lead series. Careful long-term follow-up should be maintained in patients with Riata/ST leads in order to prevent inappropriate shocks or failed device interventions. Our results were determined in advance of Food and Drug Administration class I recall, which suggested that large-scale remote monitoring may be an effective tool for continued implantable cardioverter-defibrillator system surveillance.
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ABSTRACT: The Medtronic Sprint Fidelis lead (SFL; Medtronic Inc., Minneapolis, MN, USA) has a significantly impaired long-term survival, and active fixation leads fare worse than passive leads. The goal of this study was to present data of a series of passive SFL only with very long mean follow-up of more than 6 years. Patients in whom a passive SFL was implanted in two large Swiss centers were followed. We excluded eight (5.5%) patients with a follow-up of <6 months. Patients who died or were lost during follow-up were censored at death or last device check, all others on January 31, 2014. We employed two different definitions of failure: strict = fracture with inappropriate discharge; sudden increase in impedance >1,500 or high-voltage impedance >100 Ohm; >300 nonphysiological short interventricular-intervals. Lenient = any of the above plus a linear increase in impedance >1,500 Ohm or a linear decrease in sensing to a level that treating cardiologists considered inappropriate. We included 137 patients. Age was 60 ± 12 years. Mean and median follow-up were 6.2 ± 2.1 and 6.8 (interquartile range 4.8-7.8) years. Applying the strict definition, 12 leads (8.8%) were replaced after 4.9 ± 2.4 years (range 1.2-8.1). Applying the lenient definition, 14 leads (10.2%) failed. Cumulative lead survival was 98.5% at 3, 96.9% at 4, 94.2% at 5, and 93.1% at 6 years. Leads "at risk" were: n = 122 (89%), 115 (84%), 101 (74%), and 88 (64%). In this population with passive SFLs, 5-year lead survival is impaired with 94.2% based on 74% of leads "at risk" at this time point. ©2015 Wiley Periodicals, Inc.Pacing and Clinical Electrophysiology 01/2015; 38(3). DOI:10.1111/pace.12578 · 1.25 Impact Factor
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ABSTRACT: Abrasion-induced insulation breach is a common failure mode of silicone-body, transvenous, implantable cardioverter defibrillator leads. It is caused either by external compression or internal motion of conducting cables. The present method of monitoring lead integrity measures low frequency conductor impedance. It cannot detect insulation failures until both the silicone lead body and inner fluoropolymer insulation have been breached completely, exposing conductors directly to blood or tissue. Thus the first clinical presentation may be either failure to deliver a life-saving shock or painful, inappropriate shocks in normal rhythm. We present a new method for identifying lead failure based on high frequency impedance measurements. This method was evaluated in 3D electromagnetic simulation and bench testing to identify insulation defects in the St. Jude Medical Riata® lead, which is prone to insulation breach.
Circulation Arrhythmia and Electrophysiology 12/2014; 7(6):1237-61. DOI:10.1161/CIRCEP.114.002344 · 5.42 Impact Factor