Failure-free survival of the Riata implantable cardioverter-defibrillator lead after a very long-term follow-up

Aims

Riata^® implantable cardioverter-defibrillator (ICD) leads from St. Jude Medical are prone to malfunction. This study aimed to describe the rate of this lead's malfunction in a very long-term follow-up.

Methods

This single-centre observational study included 50 patients who received a Riata 7Fr dual-coil lead between 2003 and 2008. Follow-up was conducted both in person and remotely, and analysed at 8-month intervals. We evaluated the rates of cable externalization (CE), electrical failure (EF), and the interaction of these two complications. Structural lead failure was defined as radiographic CE. Oversensing of non-cardiac signal or sudden changes in impedance, sensing, or pacing thresholds constituted EF.

Results

During a mean follow-up of 10.2 ± 2.9 years, 16 patients (32%) died. We observed lead malfunction in 13 patients (26%): three (23%) due to CE, six (46%) to EF and four (31%) to both complications. Of the malfunctioning leads, 77% failed after seven years of follow-up. The incidence rate (IR) of overall malfunction per 100 patients per year was 0.9 during the first seven years post-implantation, increased to 7.0 after the 7th year and more than doubled (to 16.7) after 10 years. Beyond seven years post-implantation, IR per 100 patient-years increased in both EF and CE (from 0.6 to 5.6 vs. 0.3 to 4.2, respectively). Presence of CE was associated with a 4-fold increase in the proportion of EF.

Conclusion

The incidence of Riata ICD lead malfunction, both for EF and CE, increased dramatically after seven years and then more than doubled after 10 years post-implantation.

Prospective Assessment of Linox Implantable Cardioverter Defibrillator Leads for Structural or Electrical Abnormalities

INTRODUCTION

Insulation failure leading to conductor externalization (CE) of a Linox (Biotronik, Berlin, Germany) implantable cardioverter defibrillator (ICD) lead has recently been reported. The aim of this study was to assess prospectively all Linox family ICD leads implanted at our center for evidence of CE or an electrical abnormality.

METHODS

All patients with a Linox family ICD lead implanted at our center, between November 2007 and March 2015, were identified and all living patients were invited to attend for fluoroscopic screening and electrical assessment of the lead.

RESULTS

A total of 183 patients had a Linox family ICD lead implanted at our center. Of these, 5 patients (2.7%) had the lead extracted because of electrical failure and 2 of these leads had evidence of CE. Out of 158 living patients with a Linox family ICD lead, 111 patients attended for screening (mean age 63.1 years, 22.5% female). In this group of patients, no cases of CE or electrical abnormalities of the lead were identified.

CONCLUSION

In this study evaluating 183 patients with a Linox family ICD lead implanted at a single center, 5 leads (2.7%) were explanted because of electrical failure and 2 of these leads had evidence of CE. Prospective fluoroscopic assessment of 111 Linox family ICD leads, with a mean dwell time of 31.5 months, revealed no further cases of CE.

The Incidence of Riata Defibrillator Lead Failure: a Single-Center Experience

Riata defibrillator leads were recalled due to a high failure rate. This study measured the incidence of externalized conductor (EC) and electrical dysfunction (ED) and sought to determine the predictors of ED with Riata defibrillator leads. We enrolled patients who received Riata® or Riata® ST silicone defibrillator leads at our center between January 2003 and December 2010. The presence of EC was evaluated with chest radiography. The incidence rates were measured at < 3 years, 3-5 years, and > 5 years after lead implantation. We also investigated the rates of ED and other clinical events during the follow-up period. A total of 44 patients were analyzed. The total cumulative incidence of EC was 27.3%. During the median dwell time (80 months), the incidence of ED was 22.7%. Patients with ED were younger (46.5 vs. 56.5 years, P = 0.018) and had a higher prevalence of cardiomyopathy than those without ED (60.0% vs. 20.6%, P = 0.043). ECs were most frequently detected in patients who underwent X-ray analysis 3-5 years after lead implantation (44.4%). In contrast, ED had a bimodal incidence pattern, with peaks at 5 years (7.0%) and 9 years (5.3%). There was no difference in ED-free survival rate between patients with and without EC (P = 0.628). Given the delayed occurrence of EC and ED after implantation of Riata defibrillator leads, long-term close monitoring is critically important.

Venous access and long-term pacemaker lead failure: comparing contrast-guided axillary vein puncture with subclavian puncture and cephalic cutdown

Aims

Existing data on the relationship between venous access and long-term pacemaker lead failure (PLF) are scarce and inconsistent. We aim to study the hypothesis that contrast-guided axillary vein puncture (AP) is better than subclavian puncture (SP) and similar to cephalic vein cutdown (CV) in the incidence of PLF and the success rate of AP is higher than CV.

Methods and results

The case records of 409 patients with 681 implantable pacemaker leads were reviewed. Two hundred and fifty-two, 217, and 212 leads were implanted via AP, CV, and SP, respectively. With a mean follow-up of 73.6 ± 33.1 months, 20 (2.9%) PLF occurred. Three (1.2%), 5 (2.3%), and 12 (5.6%) PLF occurred in the AP, CV, and SP groups, respectively. On multivariate Cox regression analysis, the only independent predictor for PLF was the use of SP instead of AP (AP vs. SP; hazard ratio: 0.261; 95% confidence interval: 0.071-0.954, P = 0.042). The success rate of CV (78.2%) was significantly lower than those of AP (97.6%) and SP (96.8%) (P < 0.001).

Conclusion

Compared with SP, the use of AP but not CV independently predicted a lower risk of PLF. The success rates in achieving venous accesses were similar between AP and SP, but significantly lower for CV. Axillary vein puncture may thus be considered the venous access of choice for pacemaker lead implantation.

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.

Insight into the mechanism of failure of the Riata lead under advisory

BACKGROUND

Cable externalization and insulation abrasion are known to occur with the St Jude Medical Riata leads under advisory. The distribution of these abnormalities and how they relate to clinical presentation have not been well described.

OBJECTIVE

In this study, we sought to determine the relationship between structural lead failure and clinical presentation by using the analysis of returned Riata products in Canada.

METHODS

The analyses of returned Riata products in Canada were obtained from St Jude Medical, Sylmar, CA. These data were correlated with the clinical presentation of patients just before lead removal from service.

RESULTS

As of May 1, 2013, there were 263 returned Riata leads in Canada. Of these, 43 (16.8%) were found to have insulation abrasion that was due to either lead-can or lead-other device interaction (70%) or inside-out abrasion (27.9%). The predilection of lead-to-can abrasion was seen in the Riata 7-F leads (84.2% vs 58.4%; P = .07), while inside-out abrasion was more common in the Riata 8-F leads (37.5% vs 15.8%; P = .12). Electrical abnormalities were frequent (20 of 31 [65.4%]) and most often due to electrical noise (45.2%), although inappropriate shocks were present (25.8%). Death occurred in 1 of 43 (2.3%) of those patients with an insulation defect in the lead-can abrasion group.

CONCLUSION

Lead-can abrasion is the most common form of insulation defect in the Riata group of leads under advisory. Management of this group of leads under advisory should not neglect the issue of lead-can abrasion, in addition to detection of cable externalization.

Longitudinal follow-up of Riata leads reveals high annual incidence of new conductor externalization and electrical failure

BACKGROUND AND PURPOSE

Riata(TM) defibrillation leads are susceptible to conductor externalization. The point prevalence of insulation defect in Riata(TM) leads is up to 33 %, but prospective data concerning incidence of new lead abnormalities are lacking. The purpose of our study was to determine the annual incidence of new conductor externalizations and electrical lead failure.

METHODS

A prospective observational study was conducted at a single tertiary center. One hundred forty-one patients were followed over 12 months. A posterior-anterior (PA)/lateral chest x-ray (CXR) with zooming was performed at baseline and at 12 months to screen for conductor externalization. Electrical abnormalities and clinical outcome were also assessed.

RESULTS

The overall incidence of new insulation defects was 8.5 % at 12 months. High-risk leads for new conductor externalization were lead models 1580, 1582, and 1590 with an annual rate of 11.9, 11.1, and 10 %, respectively. New conductor externalizations were three times more common in 8 Fr leads compared to 7 Fr leads. The overall incidence of new electrical dysfunction was 6.4 % at 12 months. Electrical dysfunction was significantly higher in abnormal leads (25 % [3/12], 4.7 % [6/129]; p = 0.03) and mostly driven by high ventricular pacing thresholds. There was no difference in inappropriate shock or failure of high-voltage therapy.

CONCLUSION

The annual incidence of new insulation defects in Riata(TM) leads is much higher than previously reported. Lead models 1580, 1582, and 1590 are at highest risk for new conductor externalization. Electrical dysfunction in Riata(TM) leads is also much higher than reported and is associated with conductor externalization.

Mechanical and electrical dysfunction of Riata implantable cardioverter-defibrillator leads

AIM

Riata implantable cardioverter-defibrillator leads are prone to failure by conductor externalization and/or electrical dysfunction. The objectives of this study were to determine the predictors of the Riata lead failure, to assess the association of conductor externalization and electrical lead failure, and to analyse the rates of lead failure over time.

METHODS AND RESULTS

Of 273 implanted Riata leads in our centre, 197 were investigated according to the Riata recall protocol, including electrical measurements by device interrogation and annually fluoroscopy. During a mean follow-up period of 5.6 ± 1.4 years, Riata lead failure was 18.8% (37 of 197) for externalization and 17.3% (34 of 197) for electrical lead failure. Electrical lead failure was correlated with time after implant. Externalization and electrical dysfunction co-existed in only 6 of 197 (3%) patients and were not related (Phi's coefficient -0.013, P = 0.85). During the second annual screening, 145 (73.6%) patients underwent fluoroscopy and 9 patients had novel externalizations resulting in an incidence of 6.72%/patient/year which was higher than expected based on cross-sectional analysis. Besides, there was a significant increase in the extent of externalization (17.65 ± 11.14 mm vs. 21.77 ± 11.95 mm, P = 0.001). In multivariate Cox regression analysis, non-ischaemic cardiomyopathy and impaired LVEF were independent predictors of externalization, and 7 Fr lead was a predictor of electrical lead failure.

CONCLUSION

Riata leads show progressive and high externalization rates without correlation between externalization and electrical lead failure. Non-ischaemic cardiomyopathy and impaired LVEF are independent predictors of structural lead failure in cross-sectional analysis, whereas 7 Fr lead is a predictor of electrical lead failure.

Prevalence of externalized conductors in Riata and Riata ST silicone leads: results from the prospective, multicenter Riata Lead Evaluation Study

BACKGROUND/OBJECTIVE

Following a class I recall of St. Jude Medical Riata/Riata ST silicone implantable cardioverter-defibrillator leads, we report on the phase I results of the Riata Lead Evaluation Study, a prospective, multicenter investigation to assess the prevalence of externalized conductors (ECs) and the electrical dysfunction in these leads.

METHODS

We enrolled patients previously implanted with Riata/Riata ST leads and performed cinefluoroscopy using multiple views. A physician panel adjudicated the images for the presence of EC. The prevalence of EC was stratified and compared by lead model and patient characteristics. Upon occurrence of a lead revision, another physician panel determined whether electrical dysfunction had occurred based on predefined criteria.

RESULTS

Seven hundred seventy six patients with Riata/Riata ST silicone leads (8Fr/7Fr = 66.6%/33.4%; single-/dual-coil = 12.9%/87.1%) across 23 centers were analyzed. Implant duration was 4.8 ± 0.9 years for 7Fr and 6.5 ± 1.6 years for 8Fr leads (P <.001). The prevalence of EC was significantly lower in 7Fr compared with 8Fr leads for the entire study population (9.3% vs 24.2%, P < .001) and for leads implanted ≤6 years (9.4% vs 18.8%, P = .006). Other than lead size, there were no significant differences in lead, patient, or electrical characteristics between leads with and without EC. Over a period of 9.8 ± 2.0 months, the overall prevalence of electrical dysfunction was 1.3% (confidence interval 0.49%-2.1%), with only 3 of 10 cases occurring in leads with EC.

CONCLUSION

Larger-diameter Riata leads were more prone to EC than smaller-diameter Riata ST leads. The prevalence of electrical dysfunction was not associated with EC.