Increased rate of subacute lead complications with small-caliber implantable cardioverter-defibrillator leads

In Vivo Durability of Polyurethane Insulated Implantable Cardioverter Defibrillator (ICD) Leads

The 6935M Sprint Quattro Secure S and 6947M Sprint Quattro Secure are high voltage leads designed to administer a maximum of 40 joules of energy for terminating ventricular tachycardia or ventricular fibrillation. Both leads utilize silicone insulation and a polyurethane outer coating. The inner coil is shielded with polytetrafluoroethylene (PTFE) tubing, while other conductors are enveloped in ethylene tetrafluoroethylene (ETFE), contributing to the structural integrity and functionality of these leads. Polyurethane is a preferred material for the outer insulation of cardiac leads due to its flexibility and biocompatibility, while silicone rubber ensures chemical stability within the body, minimizing inflammatory or rejection responses. Thirteen implantable cardioverter defibrillator (ICD) leads were obtained from the Wright State University Anatomical Gift Program. The as-received devices exhibited varied in vivo implantation durations ranging from less than a month to 89 months, with an average in vivo duration of 41 ± 27 months. Tests were conducted using the Test Resources Q series system, ensuring compliance with ASTM Standard D 1708-02a and ASTM Standard D 412-06a. During testing, a load was applied to the intact lead, with careful inspection for surface defects before each test. Results of load to failure, percentage elongation, percentage elongation at 5 N, ultimate tensile strength, and modulus of elasticity were calculated. The findings revealed no significant differences in these parameters across all in vivo exposure durations. The residual properties of these ICD leads demonstrated remarkable stability and performance over a wide range of in vivo exposure durations, with no statistically significant degradation or performance changes observed.

EHRA expert consensus statement and practical guide on optimal implantation technique for conventional pacemakers and implantable cardioverter-defibrillators: endorsed by the Heart Rhythm Society (HRS), the Asia Pacific Heart Rhythm Society (APHRS), and the Latin-American Heart Rhythm Society (LAHRS)

With the global increase in device implantations, there is a growing need to train physicians to implant pacemakers and implantable cardioverter-defibrillators. Although there are international recommendations for device indications and programming, there is no consensus to date regarding implantation technique. This document is founded on a systematic literature search and review, and on consensus from an international task force. It aims to fill the gap by setting standards for device implantation.

Transvenous lead performance of implantable cardioverter-defibrillators and pacemakers

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 years 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 = .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.

Comparative study of the failure rates among 3 implantable defibrillator leads

BACKGROUND

After the introduction of the Biotronik Linox S/SD high-voltage lead, several cases of early failure have been observed.

OBJECTIVE

The purpose of this article was to assess the performance of the Linox S/SD lead in comparison to 2 other contemporary leads.

METHODS

We used the prospective Erasmus MC ICD registry to identify all implanted Linox S/SD (n = 408), Durata (St. Jude Medical, model 7122) (n = 340), and Endotak Reliance (Boston Scientific, models 0155, 0138, and 0158) (n = 343) leads. Lead failure was defined by low- or high-voltage impedance, failure to capture, sense or defibrillate, or the presence of nonphysiological signals not due to external interference.

RESULTS

During a median follow-up of 5.1 years, 24 Linox (5.9%), 5 Endotak (1.5%), and 5 Durata (1.5%) leads failed. At 5-year follow-up, the cumulative failure rate of Linox leads (6.4%) was higher than that of Endotak (0.4%; P < .0001) and Durata (2.0%; P = .003) leads. The incidence rate was higher in Linox leads (1.3 per 100 patient-years) than in Endotak and Durata leads (0.2 and 0.3 per 100 patient-years, respectively; P < .001). A log-log analysis of the cumulative hazard for Linox leads functioning at 3-year follow-up revealed a stable failure rate of 3% per year. The majority of failures consisted of noise (62.5%) and abnormal impedance (33.3%).

CONCLUSION

This study demonstrates a higher failure rate of Linox S/SD high-voltage leads compared to contemporary leads. Although the mechanism of lead failure is unclear, the majority presents with abnormal electrical parameters. Comprehensive monitoring of Linox S/SD high-voltage leads includes remote monitoring to facilitate early detection of lead failure.

Cable externalization and electrical failure of the Riata family of implantable cardioverter-defibrillator leads: A systematic review and meta-analysis

BACKGROUND

The Riata class of defibrillator leads were placed under US Food and Drug Association (FDA) advisory as of November 2011 because of high rates of cable externalization (CE) and electrical failure (EF). The overall rates of these complications remain unknown.

OBJECTIVE

The purpose of this study was to systematically search the literature for rates of Riata lead failure and to perform a meta-analysis to estimate failure rates.

METHODS

We conducted a meta-analysis of observational studies examining the rates of EF, CE, and the interaction of the two. We identified 23 English language manuscripts addressing 1 or more of these questions.

RESULTS

Across 23 studies, the overall CE rate was 23.1% (95% confidence interval [CI] 19.0%-27.6%). The overall EF rate was 6.3% (95% CI 4.7%-8.2%). The presence of CE was associated with a more than 6-fold increase in the rate of EF compared to no CE (17.3% [95% CI 11.2%-25.9%] vs 2.7% [95% CI 1.4%-5.2%], respectively). The rate of CE was 3-fold higher for 8Fr leads compared to 7Fr leads, but rates of EF were similar (4.6%; 95% CI 3.2-6.6] and 3.9%; 95% CI 2.4-6.1], respectively). Rates of both CE and EF were higher in dual coil vs single coil leads, but confidence intervals overlapped.

CONCLUSION

In clinical practice, rates of CE in Riata leads are substantial. While CE is associated with a significant increase in the risk of EF, the incidence of EF without externalization is not trivial.

Design of an Experimental Test System to Investigate Parameters Affecting Distal Tip Loads of Pacemaker and Defibrillator Leads

The purpose of this study was to design and evaluate a system to test the mechanical behavior of pacemaker and defibrillator leads. Over 300,000 pacemaker and implantable cardioverter defibrillator (ICD) procedures are performed every year in the U.S. for the treatment of cardiac arrhythmias, ventricular dysrhythmias, and congestive heart failure. These procedures require implanting transvenous leads into the interior wall of the heart. A serious and sometimes fatal complication that may occur during or after lead implantation is perforation of the lead tip through the heart wall. The factors that lead to perforation are not fully understood. This illustrates that the mechanical interactions between the lead tip and the cardiac tissue need to be further investigated to improve the outcome for pacemaker and ICD patients. To improve the performance of lead tips, the testing protocols must reproduce physiological and clinically relevant tip-tissue interactions. As a first step toward this goal, testing parameters that influence those interactions must be identified. We investigated the effect of test system parameters, which reproduce potentially critical physiological constraints, on the load experienced at the distal tip of thirteen pacemaker and defibrillator active-fixation leads. We evaluated the use of a constraint to simulate the effect of the right ventricle (RV constraint) in vivo, how and where the lead was fixed in the test configuration, location of the load cell in the test system, rotation and frequency of the test protocol, and the effect of stylets. Results showed the RV constraint and load cell placement had the largest impact on lead tip load, while rotation of the test setup and test frequency had a minimal impact. Recommendations are made for a test system and protocol for in vitro testing of leads that take into consideration in vivo conditions. Better approximations of the in vivo environment may lead to improved product development. The potential of this system to more effectively evaluate new pacemaker and defibrillator lead designs will require further study.

High prevalence of insulation failure with externalized cables in St. Jude Medical Riata family ICD leads: fluoroscopic grading scale and correlation to extracted leads

BACKGROUND

Inside-out abrasion with externalization of sensing ring or high-voltage cables in St Jude Medical Riata implantable cardioverter-defibrillator leads has been reported. The prevalence of extruded cables, rate of electrical abnormalities, and predictors of failure in Riata leads are unknown.

OBJECTIVES

To estimate the incidence of lead failure in the St Jude Medical Riata implantable cardioverter-defibrillator leads and to propose a standard for the fluoroscopic assessment of insulation breakdown.

METHODS

Patients undergoing cine-fluoroscopy on Riata implantable cardioverter-defibrillator leads at our institution before January 25, 2012, were included (n = 87). Leads were graded as types 0-3 (0 = normal, 1 = abnormal conductor spacing, 2 ≤1 cm cable extrusion, 3 = >1 cm length extrusion). Comparison to extracted leads (n = 15) was documented. Device interrogation data were used for electrical analysis.

RESULTS

The mean time from implant was 5.9 ± 3.45 years. Structural lead failure with externalized cables was seen in 33.3% (29 of 87) of the patients. Thirty-one percent (9 of 29) of the leads with exposed cables showed electrical failure, and 29.7% (19 of 64) of the leads with normal electrical data contained externalized cables. Time from implant ≥5 years predicted structural lead failure (P < 0.05). X-ray grade compared with extracted leads demonstrated a sensitivity and specificity of 86% and 100%, respectively.

CONCLUSIONS

Cine-fluoroscopy using a simple scale correlated with the structural integrity of extracted Riata leads. A high percentage of leads with extrusion showed electrical failure. Leads ≥5 years from implant showed a high rate of externalized cables. A large independent multicenter study to determine the prevalence and clinical sequelae of Riata lead failures is warranted.

Conductor externalization of the Riata internal cardioverter defibrillator lead: tip of the iceberg? Report of three cases and review of literature

AIMS

Recently, concerns about St Jude's Riata lead family have come to light. We present three cases of patients with Riata internal cardioverter defibrillator (ICD) leads with externalized conductors.

METHODS AND RESULTS

All patients had the same insulation defect, with externalized conductors, but differed in presentation and symptoms. These cases, which form 3 of 179 (1.68%) of our total Riata lead population, presented four or more years after implantation. This may be an indication that the problem with the Riata lead may well be greater than reported in the recent St Jude Medical device advisory letter.

CONCLUSION

The management of the Riata lead problem is discussed as, up until now, management of patients with an implanted Riata lead has been based on detecting electric abnormalities on regular ICD interrogation only.

Delayed perforation of the right ventricular wall by a single standard-caliber implantable cardioverter-defibrillator lead detected by multidetector computed tomography

We present an unusual case of a delayed right ventricular perforation by a single standard-caliber implantable cardioverter-defibrillator lead, which manifested 14 days after implantation. Multidetector computed tomography could clearly display the lead perforation, and allow for identification of the associated sequelae such as pericardial effusion and planning the lead extraction strategy.

[Sprint fidelis defibrillation lead: a nine-center experience in Spain]

INTRODUCTION AND OBJECTIVES

Sprint Fidelis defibrillation leads are prone to early failure. Most of the reported series come from a single institution. This paper describes the clinical experience in nine Spanish hospitals.

METHODS

Clinical, implant, and follow-up data of all patients with a Sprint Fidelis lead were analyzed. All cases of lead failure were identified, medium-term lead survival was calculated, and possible predictors for lead failure were determined.

RESULTS

In total, 378 leads in 376 patients were studied. The mean age (male 85.7%) was 64.9 ± 13.6 years. The majority of patients (59.8%) had ischemic heart disease. Mean left ventricular ejection fraction was 33.4% ± 14.5%. Left subclavian vein puncture was used in 74.8%. During a mean follow-up of 30.9 ± 14 months, 16 lead failures have occurred, with a lead survival of 96.1% at 36 months after implantation. Eleven of 16 lead failures were caused by failure of pace/sense conductors, 3 by defects in the high-voltage conductor, and 2 by defects in both types of conductors. A less depressed left ventricular ejection fraction was associated with an increased probability of lead failure (42.4% ± 16% vs. 33% ± 14.3%; P =.011). Three hospitals presented a rate of lead failure higher than 10%; the rate was less than 5% in the remaining 6 hospitals.

CONCLUSIONS

In this multicenter series of 378 leads, the 3-year estimated survival was higher than that reported in prior series. Clinical presentation of lead failures was similar to that reported previously. Left ventricular ejection fraction and hospital of implantation were variables associated to lead failure.

ICD Lead Design and the Management of Patients with Lead Failure

The implantable cardioverter defibrillator (ICD) lead is critical to the function of the ICD system. The mortality reduction associated with ICDs implanted for primary prevention indications has been made possible by the development of effective and reliable transvenous ICD leads. Mortality rates for implantation of transvenous ICD lead systems are currently less than 0.5%. The reliability and functional characteristics of a lead are often not known until it has been in widespread use. An understanding of the mechanism of lead failure is essential for proper patient management. This article describes the design and construction of ICD leads, discusses lead failure, and reviews subsequent management of patients.