Article

A new insulation material for cardiac leads with potential for improved performance

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... 3 A coating with silicone-polyurethane copolymer (Optim) may prevent exteriorized cables. 4,5 In a study by Jenney et al, Optim insulation was clearly superior in abrasion resistance to silicone. 5 However, the Optim layer does not cover the silicone elastomer insulation under the shock coils. ...
... 4,5 In a study by Jenney et al, Optim insulation was clearly superior in abrasion resistance to silicone. 5 However, the Optim layer does not cover the silicone elastomer insulation under the shock coils. Recent reports have described insulation failure of the Durata lead. ...
... The 96%-98% reduction in externalized conductors in Durata leads compared to Riata/Riata ST leads is attributable to the design changes in the Durata lead, including a 50% increase in the insulation thickness from the inner cables to the outer edge of the lead and the addition of the Optim insulation layer, which results in a 50-fold improvement in abrasion resistance. 18 Our finding of only rare instances of externalized conductors in the Durata leads is consistent with an independent analysis of 11,155 Optim-insulated Durata leads and the similarly constructed Riata ST Optim leads enrolled in prospective, multicenter registries of Optim-insulated leads, which demonstrated 100% freedom from externalized conductors and 99.7% freedom from all-cause insulation abrasion through 4.6 years implant duration. 19 ...
Article
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Background The Cardiac Lead Assessment Study (CLAS) was a large prospective, multi-center, international post-market surveillance study conducted at 45 sites. Objective CLAS examined the prevalence and incidence of externalized conductors and electrical dysfunction in subjects with selected St. Jude Medical defibrillator and left ventricular leads. Methods Cinefluoroscopy was used to determine the presence of externalized conductors at enrollment and 12, 24, and 36-month follow-up visits. Lead electrical measurements were also collected systematically. Results The study enrolled 2,216 subjects with a total of 2,847 study leads. The prevalence of externalized conductors through 36 months for Riata leads was 30.9%, Riata ST leads 12.6%, Durata leads 0.5%, and QuickSite/QuickFlex leads 4.7%. The prevalence of electrical dysfunction through 36 months for Riata was 4.0%, Riata ST 3.3%, Durata 2.4%, and QuickSite/QuickFlex 0.3%. In Riata and Riata ST leads with externalized conductors there was a low risk of electrical dysfunction; none of the Durata or QuickSite/QuickFlex leads with externalized conductors developed electrical dysfunction. There was no evidence of an electrical short in a high voltage shocking circuit leading to failed shock. Conclusion A high prevalence of externalized conductors was found in Riata and Riata ST defibrillator leads, with a higher risk of externalization for 8F Riata leads than for 7F Riata ST leads. The 98% reduction in prevalence of externalized conductors in Durata leads compared to Riata/Riata ST leads confirms that the design improvements culminating in Durata leads significantly improved abrasion resistance and durability. (ClinicalTrials.gov Identifier: NCT01507987).
... 4 In a custom bench test, Optim had an abrasion resistance >2,500,000 cycles to failure compared with >125,000 cycles to failure for highperformance silicone. 5 The extracted lead in this case had been implanted more than six years in comparison to the 1 year of material analysis conducted by Simmons et al. It is therefore possible, it had been exposed to more extensive degradation. ...
... Optim R is composed by a silicon-polyurethan co-polymer with better abrasion resistance that could help to avoid or reduce the risk of these insulation defects. 10 ...
Article
Long-term lead failure is a known complication of ICD therapy. The precise incidence and sequelae of insulation defects at the tricuspid level, however, are not well characterized. Objective: This study determined the risk of lead failure, with particular emphasis on insulation defects at the level of the tricuspid valve, in a large series of consecutive ICD recipients. Data from 357 consecutive patients, who had received transvenous 7 and 8 French ICD-leads (St. Jude Medical, Riata family) and were followed at our center, formed the basis of this study. During a mean follow-up of 42 ± 24 months, 30 of 357 (8%) patients required surgical intervention due to lead failure. For overall lead defects, lead access via the subclavian vein and subpectoral device placement were independent predictors of overall lead failure (OR 3.47, 95% CI 1.38-8.72, P = 0.013 and OR 3.83, 95% CI 1.77-8.27, P = 0.001, respectively). Lead insulation defects at the level of the tricuspid valve accounted for 20% of all lead failures. Diagnosis of this specific insulation defect could only be established by fluoroscopy, while electrical parameters were within normal limits in all of these patients. On univariate but not on multivariate analysis the presence of nonischemic cardiomyopathy was a predictor of this lead complication (OR 8.2, CI 1.5-46.1, P = 0.02). Insulation defects of 7 and 8 French ICD leads at the tricuspid level represent an important complication of device therapy. Even moderate changes in lead impedance within the normal limits at follow-up should prompt careful fluoroscopic evaluation to avoid spurious shocks.
... Newer bipolar leads, even though larger than earlier models (5.8 ± 0.4 vs 4.8 ± 0.7 F; P < 0.001), have features that may account for less tissue ingrowth. Some insulation technology, including materials such as polyurethane 14 or Optim, 15 now widely used, may be less traumatic and less thrombogenic for the vasculature wall. 16 Similarly, a large steroid collar between the lead tip and distal electrode may reduce tissue inflammation inside the CS. 17 In addition, new bipolar leads with a more isodiametric design may reduce the risk of fibrous entrapment during retrieval, allowing easier extraction with MT. 18 Finally, on multivariate analysis, an interesting trend was observed between MD and previous open-chest surgery: it is not unreasonable to suspect that after open-chest surgery, positioning of a central venous line for fluid/medication administration, major vessel/heart manipulation, or CS cannulation for retrograde cardioplegia may promote tissue ingrowth and development of fibrous adherence, thus increasing the need for MD. ...
Article
The aim of this study was to evaluate procedural outcomes of coronary sinus (CS) lead extraction, focusing on predictors and need for mechanical dilatation (MD) in the event that manual traction (MT) is ineffective. The study assessed results in 145 consecutive patients (age 69 ± 10 years; 121 men)--a total of 147 CS pacing leads--who underwent transvenous CS lead removal between January 2000 and March 2010. All leads but one (99%) (implantation time 29 ± 25 months) were successfully removed. MT was effective in 103 (70%), and MD was necessary in the remaining 44 (30%) procedures. In multivariate analyses, unipolar design (odds ratio [OR] 3.22, 95% confidence interval [CI] 1.43-7.7; P = 0.005) and noninfective indication (OR 4.8, 95% CI 1.8-13, P = 0.002) were independent predictors for MD (P < 0.0001), with a predictive trend for prior cardiac surgery (OR 2.2, 95% CI 0.98-5.26; P = 0.06). Five (3.4%) complex procedures required a transfemoral vein approach (TFA) or repeat procedure. No deaths occurred, and there was one major complication (0.7%), cardiac tamponade, after MT. No complication predictors were identified. CS leads were safely and effectively removed in nearly all patients, and 70% were removed with MT alone; 30% required MD. Preoperative predictors suggesting the need for MD or TFA were noninfective indication and unipolar lead design. Complications were rare, and there was no predictable pattern among MT or MD removal techniques.
... Their results encouraged the development of Optim TM (also known as SJM SPC TM ) for cardiovascular applications. In 2005, Jenney et al. 5 reported that Optim had an abrasion resistance .2 500 000 cycles to failure on a custom bench test compared with .125 000 cycles to failure for high-performance silicone; similarly, Optim TM 's tear and tensile strengths were found to be much greater than high-performance silicone. ...
Article
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Aim The purpose of this study was to determine if Optim™, a unique copolymer of silicone and polyurethane, protects Riata ST Optim and Durata implantable cardioverter-defibrillator (ICD) leads (SJM, St Jude Medical Inc., Sylmar, CA, USA) from abrasions that cause lead failure. Methods and results We searched the US Food and Drug Administration's (FDA's) Manufacturers and User Device Experience (MAUDE) database on 13 April 2012 using the simple search terms ‘Riata ST Optim™ abrasion analysis’ and ‘Durata abrasion analysis’. Lead implant time was estimated by subtracting 3 months from the reported lead age. The MAUDE search returned 15 reports for Riata ST Optim™ and 37 reports for Durata leads, which were submitted by SJM based on its analyses of returned leads for clinical events that occurred between December 2007 and January 2012. Riata ST Optim™ leads had been implanted 29.1 ± 11.7 months. Eight of 15 leads had can abrasions and three abrasions were caused by friction with another device, most likely another lead. Four of these abrasions resulted in high-voltage failures and one death. One failure was caused by an internal insulation defect. Durata leads had been implanted 22.2 ± 10.6 months. Twelve Durata leads had can abrasions, and six leads had abrasions caused by friction with another device. Of these 18 can and other device abrasions, 13 (72%) had electrical abnormalities. Low impedances identified three internal insulation abrasions. Conclusions Riata ST Optim™ and Durata ICD leads have failed due to insulation abrasions. Optim™ did not prevent these abrasions, which developed ≤4 years after implant. Studies are needed to determine the incidence of these failures and their clinical implications.
... The latter is prevalently observed in the presence of poor biostability, as for polyurethane leads. The Optim © silicone/ polyurethane co-polymer effectively combines the flexibility and bio- stability of silicone insulator with the lubricity, toughness, and strength of traditional polyurethanes [7][8][9][10], reducing physical damage relat- ed to body trauma and chemical damage following biodegradation. If our preliminary data will be confirmed on larger studies, Optim © could become an attractive insulator material to improve cardiac lead extraction profile. ...
... This new hybrid material, manufactured by AorTech International (Elast-Eon TM E2A), has been reported to exhibit a better abrasion resistance than silicone and could help avoid or reduce the risk of insulation failures. 12 Nevertheless, to date, these aspects are still controversial. Durata's internal design shares many design elements with the Riata ST. ...
Article
Serious concerns have been recently raised about the reliability of the silicone-polyurethane copolymer (Optim™) lead insulation system. We sought to identify insulation defects and Optim-lead failures by systematic fluoroscopic and electrical assessment in a prospectively defined cohort of implantable cardioverter-defibrillator (ICD) patients.METHODS AND RESULTS: Between July 2007 and December 2011, 234 patients were implanted with 413 optim-coated leads as part of an ICD system at a single centre. Fluoroscopic screening with high-resolution cine-fluoroscopy at 30 frames per second was offered to all patients. In addition, the electrical integrity of all implanted leads was assessed. Durata, Riata ST Optim, and low-voltage Optim leads were implanted in 199, 26, and 188 cases, respectively. During a total follow-up of 10 036 lead-months, there were 7 Optim-lead failures (defined as electrical malfunction resulting in lead replacement) and 31 deaths; no cases of electrical noises were encountered. The overall incidence of lead failure was 1.2 vs. 0.3 per 100 lead-years, for high- and low-voltage leads, respectively (P = 0.1). One hundred fifty-one patients agreed to undergo fluoroscopy screening; none of the 264 analysed Optim leads were found to have any fluoroscopically visible structural defects after an average of 31 months post-implant.CONCLUSION: This study represents the first systematic screening of Optim-coated leads in a large unselected cohort of ICD patients. Over a 5-year period few lead failures were observed and normal fluoroscopic appearance was present in all patients.
... Polymer–polymer tribology has not been studied as extensively as metal-on-polymer tribology [14] . Furthermore, tribological studies of materials used in cardiac lead applications are rare [15]. Other discussions of cardiac lead use conditions as related to insulation wear have not been found. ...
... It is a thin (0.09 mm) overlay that covers the lead silicone body except for the part beneath the shocking coils. Optim is 50 times more abrasion-resistant than silicone with > 2,500,000 cycles to failure in comparison to > 125,000 cycles to failure high-performance silicone, on a custom bench test, with superior tear and tensile strengths [20]. Optim also revealed significantly more biostable than Pellethane 55D and Pellethane 80A in animal tests. ...
... This failure analysis will focus mainly on the lead, assuming that pulse generator and program do not fail. A lead has four major components, terminal pin, insulation, conductor coil and tip-electrode [13]. The specifications for both leads were provided by Medtronic. ...
Article
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A neurostimulator was investigated in this paper posthumously. Device was presented to our anatomical gift program. Investigation was multi-fold and contained visual inspection, using an optical microscope, and mechanical and electrical testing of leads and its insulator. It was concluded that the device could have been damaged during implantation, in vivo, during removal, and/or during transportation to author’s laboratories. The damage observed on the lead insulation is similar to that which can occur due to anchoring of the lead and hardening due to oxidation. Insulation stiffness was determined to be 1/10 of new insulator. The results reported here on the insulation may or may not have affected the electrical operation of the neurostimulator.
... Two and half million cycles in a custom bench test comparison with other polymers in 2005 proved that Optim had abrasion resistance. 23 Its superior properties compared to high-performance silicone, especially in terms of tear and tensile strengths, have been substantiated. It was reported that Optim lead insulation was significantly more biostable in animal tests than the polyurethanes Pellethane 55D and Pellethane 80A; ultimately, in 2011, investigations revealed in post-market monitoring that incidences of lead abrasion in certain cases of Optim use led to can friction after four years of implantation, so placement of the lead under the can requires critical management. ...
Article
In 1986, the European Society of Biomaterials Consensus Conference gave a simplified definition of biomaterials as “a non-viable material used in a medical device intended to interact with biological systems”. This seems to be more appropriate when we look into the versatility of applications of biomaterials in the health sector, especially in cardiovascular practice. This field has expanded exponentially in every direction, with multifunctional capability. Heart valves have undergone an evolution in biomaterials and design. Patches and conduits have been developed to correct anatomical deficits, and solutions have been found for narrowing or ballooning of the arteries. Research is ongoing to find replacements for every part of this system by creating replicas made of various materials. To investigate problems pertaining to the cardiovascular system, catheters have undergone an astounding leap in material optimization. In these three sectors, the trends, successes, and failures are worth discussing. This review mainly focuses on the types of biomaterial used for making cardiovascular devices and their advantages and limitations.
... While polyurethane has moderate resistance to cold [10], silicone can withstand extremely low temperatures of −100°C and below [11]. Optim®, a co-polymer of both materials, demonstrated superior biostability compared to polyurethane [12] while carrying a higher abrasion resistance compared to silicone [13]. ...
Article
Full-text available
Intorduction: Medical societies and cardiac implantable electronic devices (CIED) manufacturers recommend avoiding close or direct contact between the body of transvenous leads and ablation catheters used to treat cardiac arrhythmias. These recommendations are made despite the lack of clinical studies. However, the target myocardium for successful ablation can be contiguous to CIED leads. Methods and results: We examine in vitro the effects of direct application of radiofrequency (RF) and cryo-ablation energy on the integrity and functionality of CIED leads (excluding the pacing electrodes and defibrillation coils). A saline bath was created to mimic the body milieu. CIED leads, including all commercially available lead insulation materials, were connected to a CIED pulse generator and placed in direct contact with ablation catheter in the tissue bath. RF and cryo-ablation energy were delivered under various conditions, including maximal ablation power, temperature and impedance via the RF generator. CIED lead functionality, reflective of conductor integrity, was evaluated through lead impedance monitoring during ablation. CIED leads were then visually inspected, and examined with optic and electron microscopy as per protocol. A total of 42 leads were studied. All leads showed absence of insulation damage at the site of ablation visually and with microscopy. Lead functionality was also preserved in all leads. Conclusion: Catheter ablation in contact with CIED leads using radiofrequency or cryo-ablation in vitro did not affect lead body integrity and function despite aggressive ablation settings. It may be reasonable to perform ablation in contact with the body of CIED leads when clinically necessary. This article is protected by copyright. All rights reserved.
... One material is silicone-polyurethane copolymer, which is also known as Optim (trademark of Abbott). Optim has shown more abrasion resistance than silicone in more than 278,000 implanted lead with 99.9% survival after 5 years [46]. Hauser et al [44], have studied 15 Riata ST Optim (trademark of Abbott) and 37 Durata leads (trademark of Abbott). ...
Thesis
Approximately, 92.1 million patients in the US suffer from cardiovascular diseases with an estimated healthcare cost of over $300 billion; out of which at least one million patients have Cardiac Implantable Electronics Devices (CIED). CIED represented by pacemakers, Implantable Cardioversion Defibrillator (ICD), and Cardiac Resynchronization Therapy (CRT) are exposed to in-vivo damage. These damages are complex and composed on multiple levels and present challenges while assessing their combined extent. Since 2004, more than one hundred recalls were reported for cardiac devices. ICD devices had the majority with 40.8% recalls, pacemaker recall percentage was 14.5%, CRT recall percentage was12.7%, leads recalls were 9.7%, and others (stents and LVAD) with 22.3% recalls. The objective of this research is to investigate the damage of the cardiac devices and the changes in the residual properties after in vivo implantation, such knowledge will lend insight into the common damage patterns, controlling the probability of failure in the design of future devices, and improve reliability. In vivo damage assessment was performed on 65 retrieved cardiac devices and 136 leads from different manufacturers (Medtronic, St. Jude Medical-Abbott and Boston Scientific). The examined damage features were surface deformation, burnishing, pitting, scratching, discoloration, delamination, insulation defects, coil damage, and abrasion.
Article
Since Albert Hyman in 1932 presented the first external pacemaker, we have seen a furious evolution of pacemaker and lead technology. Today the endocardial implantation of pacemaker leads is standard; an epimyocardial approach is reserved for children, patients with thrombosis of the superior vena cava and for left ventricular pacing leads, if it is impossible to find a target vein using the coronary sinus. Atrial leads have to be always active fixation leads, for right ventricular leads also a passive fixation can be used. The prior position for atrial pacing is the right atrial appendix; the ventricular lead should be placed near the right ventricular apex. Intraoperative measurement should be standardized and only sensing and pacing threshold in accordance to the guidelines is acceptable. Minor complications like lead dislocation can be treated also in not specialized hospitalities, severe complications like perforation, myocardial injury or pericardial effusion should be treated in heart centres with the opportunity of thoracotomy and heart-lung-machine. To avoid such severe complications it is necessary, that the implantation team performs at least 50 to 100 procedures/year.
Article
Background : After the reports of recalled leads, several technological improvements have been introduced and the durability of implantable cardioverter defibrillator (ICD) leads has improved. The incidence of lead failures is now less than in the previous studies. However, there are few reports that have shown the long‐term durability of ICD leads as compared to pacemaker (PM) leads. This study analyzed the medium to long‐term performance of transvenous ICD leads as compared to PM leads. Methods We retrospectively studied 1227 cases from April 2007 to December 2017 who underwent an initial transvenous ICD or PM implantation. The number of lead failures and patient background characteristics were analyzed. Results During a median 3‐3.5 year follow up period, 1 (0.3%) ICD lead and 18 (2.4%) PM leads failed. The incidence of lead failures was significantly higher in the PM group than ICD group (p = 0.019). Males were associated with a higher incidence of lead failures in the PM group. Conclusion Since the era of recalled ICD leads, the durability of ICD leads has remarkably improved and the incidence of lead failures with non‐recalled ICD leads has been less than that for PM leads. This article is protected by copyright. All rights reserved
Chapter
The implantable cardiac pacemaker (PM)/defibrillator is a technically sophisticated system composed of a generator connected to one or more leads. Pacemaker/defibrillator leads play a pivotal role for system function, delivering the output pulse or the endocardial shock from the generator to the myocardium and acquiring spontaneous intracardiac electrogram from the heart to the device. Leads are also the most frequently involved component in case of system malfunction, and when a generator-pocket infection is present, their extraction — always necessary to guarantee complete resolution — is a challenge. The success of lead extraction is highly influenced by lead characteristics; for that reason, this chapter is dedicated to lead technology, i.e., polarity, electrodes, fixation mechanisms, electrode-tissue interaction, conductors, insulators, and connectors, with particular attention to aspects that may interfere with the extraction procedure. We discuss separately cardiac PM and defibrillator leads to emphasize their different technology.
Article
The patented Optim coating was designed to prevent insulation abrasions on the Durata lead (St Jude Medical, St Paul, Minnesota) and avoid the problems that had afflicted its predecessor, the Riata silicone lead (St Jude Medical). We report a case of external insulation failure 8 months after implantation of a dual-coil Durata lead and consider the potential causes of the failure.
Article
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Defibrillatorelektroden der Firma St. Jude Medical vom Typ Riata® und Riata ST® zeigen ein erhöhtes Auftreten von Isolationsdefekten, wobei die inneren, separat isolierten Leiter durch den Elektrodenkörper nach außen treten können („inside-out fracture“). Die genaue Inzidenz von Riata®-Elektrodenproblemen ist nicht klar. Nach neuen Daten von US-amerikanischen und kanadischen Registern scheint sie bei 2–4% pro Jahr in den ersten 5 Jahren zu liegen und höher für Riata®-8F-Elektroden zu sein. Wir empfehlen eine Information und Aufklärung sowie folgendes Vorgehen bei Patienten mit Riata®- und Riata-ST®-Elektroden: 1. Aktivierung der automatischen Alarme des ICD-Aggregats, 2. Versorgung des Patienten mit einem Gerät zum Telemonitoring falls möglich, 3. ICD-Kontrollen monatlich bei hohem Patientenrisiko (Schrittmacherabhängigkeit, stattgehabte Kammertachyarrhythmien) und hohem/mittlerem Elektrodenrisiko (8F, 7F „single-coil“), 3-monatlich bei mittlerem Patienten- und Elektrodenrisiko, 3- bis 6-monatlich bei geringem Patienten- und Elektrodenrisiko. Bei den Kontrollen sollte speziell auf Oversensing-Artefakte in gespeicherten Elektrogrammen (EGM) anhaltender und nichtanhaltender Kammertachykardien geachtet und das EGM bei Provokationsmanövern (Pektoralisaktivität, Armbewegungen) analysiert werden. Bei elektrischen Abnormalitäten sollte primär ein Elektrodenersatz durchgeführt werden. Eine Extraktion sollte nur dann erfolgen, wenn eine Indikation nach den aktuellen Leitlinien besteht. Eine Durchleuchtung sollte nur bei elektrischen Auffälligkeiten und durch einen erfahrenen Elektrophysiologen durchgeführt (15 Bilder pro Sekunde) und beurteilt werden. Das Vorgehen bei fluoroskopischen Auffälligkeiten ohne elektrische Abnormalitäten ist unklar, so dass keine routinemäßige Durchleuchtung bei Patienten mit elektrisch einwandfreien Riata®-Elektroden empfohlen wird.
Chapter
Implantation of cardiac rhythm devices is relatively safe. Nevertheless, it is still an invasive procedure fraught with complications even in for the most experienced implanter. Knowledge of the potential complications possible at every step of the procedure is critical for a safe implant. This chapter will review implant related complications, device and lead related failures and their management and lead extraction techniques and risks.
Article
Introduction: Data on long-term durability of St. Jude Medical DurataTM defibrillation leads compared to its previous model, the St. Jude Medical RiataTM leads in clinical practice are missing. Aim of the study was to analyze the long-term performance of the DurataTM defibrillation leads compared to the RiataTM leads in clinical practice. Methods and results: A total of 1407 consecutive patients of a prospective single-centre implantable cardioverter defibrillator (ICD)-registry were analyzed who underwent ICD implantation with a DurataTM (n = 913) or RiataTM (n = 494) ICD lead between 2002 and 2017. Most of the leads were implanted via a subclavian vein access. The estimated lead defect rates after 5 and 10 years were not different between the DurataTM (11% and 36%) and RiataTM leads (13% and 38%). Among DurataTM leads single coil - and DF-4 connector ICD leads had a lower incidence of lead failure. Major causes of lead failure were compression of the lead in the clavicular region, generator to lead friction and distal fatigue fracture whereas lead defect due to externalization was a rare cause of lead defect in RiataTM leads (3%). Conclusion: Among ICD leads implanted via the subclavian vein access the lead defect rate of DurataTM leads after 10 years is similar to that of RiataTM leads. Single coil and DF-4 ICD leads are associated with a lower lead failure rate. Mechanical stress represents a major cause of lead failure mechanism whereas externalization might only play a minor role in clinical practice. This article is protected by copyright. All rights reserved.
Article
The St. Jude Medical Riata family of implantable cardioverter defibrillator (ICD) leads has demonstrated a high rate of externalized conductors and electrical failure. Given similar design elements to Riata, we sought to assess the rate of failure of the Riata-ST-Optim and Durata lead families in Canada. All Canadian ICD-implanting centres were invited to submit follow-up information on all Optim-coated ICD leads implanted. Electrical failure was defined as a rapid change in impedance or pacing capture threshold leading to lead revision, or over-sensing due to noise. Externalized conductors were defined as appearance of conductor wires outside the lead body. Systematic fluoroscopic screening for externalized conductors was not performed. As of December 1, 2012, fifteen of 25 centres provided data on 3981 leads (44% of those sold in Canada during the same timeframe); 3477 Durata and 504 Riata-ST-Optim leads. The most common model numbers were 7122 (1516 leads; 38%), 7121 (707 leads; 18%) and 7120 (622 leads; 16%). The mean follow up duration from implant to December 1, 2012 was 4.47± 0.48 years for Riata-ST-Optim leads and 2.00±1.10 years for Durata leads. The annual rate of lead failure was 0.27%/year for Riata-ST-Optim leads and 0.24%/year for Durata leads. There were no instances of externalized conductors identified in the failed leads. No deaths were attributed to lead failure; however, 2 patients experienced inappropriate shocks due to lead failure. The overall electrical failure rate of the Riata-ST-Optim and Durata leads appears low, and no instances of externalized conductors were observed.
Article
Aims: The high rate of implantable cardioverter defibrillator (ICD) lead failures related to the Sprint Fidelis' and Riata's design have raised serious concerns about the reliability of ICD leads. The St. Jude Medical Durata family of leads replaced the preceding Riata line following increased rates of lead failure (1.17% per year). The aim of our study was to evaluate the long-term performance of the Durata lead. Methods: Eight hundred and eighteen Durata ICD leads were implanted in 11 Italian centers. The incidence of lead failure, defined as a sudden rise in long-term pacing or defibrillation impedance and/or a sudden change in R-wave amplitude and capture thresholds, was assessed. The incidences of lead dislodgment and lead perforation were also evaluated. Results: During a median follow-up of 1353 days (3.7 years; 25-75th interquartile range 806-1887 days) lead failure occurred in 16/818 leads (0.54%/year). The overall survival, free of lead failure, was 98.9% at 3 years, 98.2% at 4 years and 97.5% at 5 years. Lead dislodgment occurred in 12/818 leads with an incidence of 0.4%/year. No cases of cardiac perforation were reported. No major adverse events were reported except for two cases of inappropriate shocks as a consequence of failure or dislodgment. Conclusion: Our study suggests that the Durata lead does not engender a higher risk of failure. Overall survival, free from lead failure, was found to be higher than previously reported for the Riata lead.
Article
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Riata® and Riata ST® implantable cardioverter defibrillator (ICD) leads (St. Jude Medical, Sylmar, CA) show an increased incidence of insulation defects, particularly "inside-out" lead fracture where inner, separately insulated cables penetrate through the surrounding silicone of the lead body. The exact incidence of Riata® lead problems is not clear and seems to range between 2-4% per year in the first 5 years after implantation according to new registry data. We recommend beyond a detailed information the following care of patients with Riata® and Riata ST® leads: 1) Activation of automatic ICD alerts, 2) remote monitoring with automatic daily alerts whenever possible, 3) monthly ICD controls in patients at high risk (pacemaker dependency, history of ventricular tachyarrhythmias) and high or moderate lead-related risk (8F, 7F single coil), 3-monthly controls in moderate patient and lead-related risk, 3 to 6-monthly controls in low patient and lead-related risk (no bradycardia, no history of ventricular tachyarrhythmia). Every ICD control should include meticulous analysis of oversensing artifacts in stored electrograms (EGMs) of sustained and non-sustained ventricular tachyarrhythmias and registration of EGMs during provocation testing (pectoral muscle activity, arm movements). If electrical abnormalities are observed, reoperation with addition of a new ICD lead is recommended; lead extraction only if indicated according to current guidelines. Fluoroscopy should only be performed if electrical abnormalities are found by an experienced electrophysiologist and a high frame rate and resolution. Management of fluoroscopic abnormalities in the absence of electrical abnormalities is not clear. Therefore, routine fluoroscopy of patients with Riata® leads without electrical abnormalities is not recommended.
Technical Report
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Pacemakers have undeniably bestowed heart patients with a new lease of life. The number of pacemakers implanted annually is growing by manifolds and it is expanding into newer demographics. However, this demand surge comes with an increase in pacemaker design complexity and technological advancement-related complications. This report begins by capturing all the failure modes afflicting present-day leadless and lead-based pacemakers. Thereafter, it delves into three primary mechanical problems observed in lead-based pacemakers, namely, conductor fracture, insulation breaches and polymer degradation. Furthermore, through an extensive literature survey, the report compiles a vast array of electro-mechanical properties of the multi-material, multi-component and multi-functional systems that together comprise the pacemaker leads. Finally, the regulatory challenges are addressed, and areas of improvement suggested to segue into the futuristic landscape the pacemaker industry is heading towards.
Article
The prognostic benefit of the implantable cardioverter-defibrillator (ICD) has been well established in multiple settings and its use is consequently widespread. Modern-day ICD systems use transvenous high-voltage leads to act as the interface between the heart and the generator, allowing for the sensing of a cardiac activity and the delivery of both bradycardia and tachycardia therapy, including high-voltage, high-current shocks. The ICD lead is in many ways the most fragile and critical component of the ICD system, and is subjected to more stress than any other implanted medical device. It has similar components to a pacing lead including tip and ring electrodes, fixation mechanism, conductors, insulators, and connector pins. In addition, it also contains the high-voltage shock coils that allow the delivery of defibrillation therapy to the cardiac tissue. The materials used to manufacture each of these components have undergone little evolution from their initial pacing lead-derived origin, but promising progress in this area is now occurring and better conductors and insulators have been developed. Lead body design continues to be multiluminal rather than coaxial, but various iterations of this basic paradigm continue to be investigated. In addition to miniaturization of the entire ICD lead, new industry standard lead connectors will also be introduced to reduce complexity and pocket bulk. However, long-term failure rates have been considerable, with lead failure related to both conductor and insulator malfunction. It is hoped that recent improvements in an ICD lead design and manufacture will result in a good functionality with a reliable long-term performance.
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