Deaths caused by the failure of Riata and Riata ST implantable cardioverter-defibrillator leads

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1 Deaths caused by the failure of Riata and Riata ST implantable cardioverter-defibrillator leads Robert G. Hauser, MD, FHRS, Raed Abdelhadi, MD, Deepa McGriff, BS, Linda Kallinen Retel, BS, FHRS From the Minneapolis Heart Institute Foundation, Minneapolis, Minnesota. BACKGROUND Riata and Riata ST leads (St Jude Medical, Sylmar, CA) were recalled in These leads are prone to externalized conductors. However, it is electrical s that may result in serious adverse events, including death. OBJECTIVE To assess the deaths of patients with Riata and Riata ST leads that have been reported to the Food and Drug Administration to determine whether they were due to lead. A similar analysis was performed for Quattro Secure leads (Medtronic, Inc, Minneapolis, MN). METHODS In February 2012, we searched the Food and Drug Administration s Manufacturers and User Facility Device Experience database for deaths associated with Riata, Riata ST, and Quattro Secure leads. A lead-related death was a sudden or unexpected death accompanied by evidence of lead ; an indeterminate death was a death that was nonsudden or evidence of lead was not provided; a not leadrelated death was a death that was nonsudden and/or there was no evidence that the lead contributed to the patient s demise. RESULTS The Manufacturers and User Facility Device Experience database search found 133 deaths; of these, 22 were caused by Riata or Riata ST lead failure and 5 were caused by Quattro Secure lead failure. Riata and Riata ST lead failure deaths were typically caused by short circuits between high-voltage components. No death was due to externalized conductors. CONCLUSIONS Riata and Riata ST implantable cardioverter-defibrillator leads are prone to high-voltage failures that have resulted in death. These failures appeared to have been caused by insulation defects that resulted in short circuiting between high-voltage components. Externalized conductors were not a factor in these deaths. KEYWORDS Implantable cardioverter-defibrillator; Lead; Insulation; Complications; Failure ABBREVIATIONS ETFE ethylene tetrafluoroethylene; ICD implantable cardioverter-defibrillator; MAUDE Manufacturers and User Facility Device Experience (Heart Rhythm 2012;9: ) 2012 Heart Rhythm Society. All rights reserved. Introduction Riata and Riata ST implantable cardioverter-defibrillator (ICD) leads (St Jude Medical, Sylmar, CA) were removed from the market by the manufacturer in 2010 and subsequently recalled in ,2 These multilumen silicone leads are prone to a unique inside-out insulation defect caused by the movement of the conductor cables within their lumens. 2,3 While much interest has been directed toward externalized conductors, 4 6 it is an electrical, such as failure to pace or defibrillate, that poses the greatest risk to patients. These s may not be heralded by detectable signs of failure, 3 and they can result in failure to deliver life-supporting or lifesaving therapy. We therefore queried the US Food and Drug Administration s Manufacturers and User Facility Device Experience (MAUDE) database to assess deaths that may have been caused by Riata and Riata ST lead failure. To provide context, we also This study was funded by grants from the Minneapolis Heart Institute Foundation and the Abbott Northwestern Hospital Foundation. Address for reprint requests and correspondence: Dr Robert G. Hauser, MD, FHRS, Minneapolis Heart Institute Foundation,920 28th St, Suite 500, Minneapolis, MN address: rhauser747@aol.com. evaluated MAUDE database reports for deaths of patients who had Quattro Secure model 6947 ICD leads (Medtronic, Inc, Minneapolis, MN). Methods Riata and Riata ST leads The 8-F Riata and 7-F Riata ST leads were released in the US market in 2002 and 2005, respectively. These were removed from the market in 2010 after approximately 227,000 Riata and Riata ST leads had been sold worldwide, including 96,000 Riata and 45,000 Riata ST leads in the United States. Of the 141,000 Riata and Riata US implants, approximately 79,000 remain active. 2 The multilumen dualcoil construction is illustrated in Figure 1A; the high-voltage and 2 pace-sense cables were extruded with ethylene tetrafluoroethylene (ETFE), and the pace-sense conductor coil was strung through a tube of polytetrafluoroethylene. Single-coil Riata and Riata ST models were also available. The Sprint Quattro Secure model 6947 lead The Quattro Secure model 6947 (Quattro) is an 8.6-F dualcoil multilumen silicone ICD lead that has an outer sleeve of polyurethane (Figure 1B). Since its introduction in 2001, /$ -see front matter 2012 Heart Rhythm Society. All rights reserved.

2 1228 Heart Rhythm, Vol 9, No 8, August 2012 the circumstances were unclear, or evidence of a lead defect was not provided; a not lead-related death was a death that was nonsudden or expected for reasons related to the patient s health status and/or there was no evidence that the lead s performance contributed to the patient s demise. Deaths due to perforation or occurring during or as the result of a lead extraction procedure were considered indirect causes of death, and therefore not lead-related. Lead is failure of the device to meet its performance specifications or otherwise perform as intended. 7 A high-voltage conductor short circuit occurs if the silicone and the ETFE insulation break down and there is contact between the conductive metal surfaces of the highvoltage cables, a high-voltage and low-voltage conductor, or a high-voltage cable and a shocking coil or pulse generator can. Externalized conductors are cables that have breached the outer insulation and are visible outside the lead body. Inside-out abrasion is an insulation defect caused by the motion of the cables within the lead insulation lumen. A can abrasion is an insulation defect caused by contact in the pocket between the lead and the pulse generator can (housing). Figure 1 A: Cross-section of a Riata dual-coil high-voltage implantable cardioverter-defibrillator lead. The redundant cables are coated in ethylene tetrafluoroethylene, which are shown in blue, and the central coil pacesense conductor with stylet lumen is encased in a tube of polytetrafluoroethylene, shown in green. B: Cross-section of a Quattro Secure model 6947 dual-coil high-voltage implantable cardioverter-defibrillator lead. This lead has one ethylene tetrafluoroethylene coated cable per lumen and the pacesense coil, which is encased in a tube of polytetrafluoroethylene, is offset from the center of the lead. 485,000 Quattro Secure leads have been sold worldwide, including 332,000 in the United States; of these, an estimated 231,000 are active. In contrast to Riata and Riata ST leads, the Quattro Secure has a single cable in each lumen and the pace-sense coil is offset. Definitions A lead-related death was defined as a sudden or unexpected death accompanied by evidence of a lead defect; an indeterminate death was a death that was either nonsudden or Food and Drug Administration MAUDE database The MAUDE database contains reports of adverse events involving medical devices reported to US manufacturers by users worldwide. In our experience, 3,8 10 the majority of reports originate from manufacturers and 5% are submitted by user facilities or other observers. We searched the MAUDE database on February 10, 2012, for reports of deaths suffered by patients who had a Riata, Riata ST, or Sprint Quattro Secure model 6947 ICD lead, using the simple search feature and the terms Riata death and Quattro Secure death. The results of the Quattro Secure search were refined to include model 6947 leads. Reports were excluded from the study if there was no known lead problem or allegation of lead and if a returned product analysis found no anomalies that were not caused by the explant procedure. Lead implant time was estimated by subtracting 3 months from the lead age, which is the date the lead was manufactured or shipped. Results The MAUDE database search returned 133 deaths that met our study criteria; the results are summarized in Table 1. All the MAUDE reports in this study originated from the manufacturers. The failure of a Riata or Riata ST lead caused 22 deaths, while Quattro lead failures resulted in the deaths of 5 patients. Riata lead-related deaths occurred later on average than either Riata ST or Quattro lead-related deaths (61 21 months vs 36 7 and months; P.012). All Riata and 2 of the 4 Riata ST lead-related deaths involved dual-coil models. The cause was indeterminate in 38% of the deaths (50 of 133). Of the 56 not lead-related deaths, 16 were procedural 8 perforations and 8 deaths associated with lead extraction.

3 Hauser et al Deaths Caused by Failure of Riata and Riata ST ICD Leads 1229 Table 1 Results of MAUDE database search Riata Riata ST Quattro Secure n % Implanted (mo), mean SD n % Implanted (mo), mean SD n % Implanted (mo), mean SD Total deaths Lead-related Indeterminate Not lead-related Perforation Extraction-related MAUDE Manufacturers and User Facility Device Experience. Lead-related deaths Twenty-seven of the 133 deaths (20%) were caused by ICD lead failure (Table 2). Of the 71 deaths involving Riata and Riata ST leads, 31% (22 of 71) were lead-related while 5 of the 62 (8%) deaths involving Quattro leads were leadrelated (P.0022). Four of the 18 Riata (22%) and 3 of the 4 Riata ST (75%) lead-related deaths were associated with can abrasions; these 7 insulation defects resulted in short circuits and failure to deliver therapy. None of the 62 Quattro leads in this study had can abrasions or a death caused by a documented insulation defect. Abnormal high-voltage impedances were the hallmark of catastrophic Riata and Riata ST lead failure, often resulting in failure to defibrillate. Excluding can abrasions, 13 Riata and Riata ST lead-related deaths involved high-voltage conductors as signified by a high or low impedance. One patient (Table 2, Riata patient number 13) was successfully rescued by his device but died the next day after the home monitor reported out-of-range impedances. Another patient (Table 2, Riata patient number 18) reportedly was induced into ventricular fibrillation by a lead integrity check and was not rescued because the high-voltage conductor was fractured. Oversensing and lead noise was observed less frequently. Three Quattro lead-related deaths were associated with oversensing, indicating pace-sense conductor failure, and 2 patients (Table 2, Quattro patient numbers 2 and 3) were not rescued because of high-voltage conductor defects. Indeterminate lead deaths Overall 50 of the 133 study deaths (38%) did not satisfy the criteria for lead-related death, but there was either clinical or lead data suggesting that death may have been lead-related (Table 3). In many of these cases, the MAUDE report contained a complaint such as an allegation that the lead had ed (Table 3, Riata patient number 5), but no data were available to support the allegation, and the lead was not returned to the manufacturer for analysis. In other cases (Table 3, Riata patient number 6), a lead was returned to the manufacturer and found out of specification but no clinical information was available. Two leads (Table 3, Riata patient number 14 and Riata ST patient number 4) had externalized conductors but neither had ed. Some lead failures were associated with pulse generator abnormalities (Table 3, Riata patient numbers 11 and 18 and Riata ST patient number 1) that may have been caused by a shorted lead, but evidence of lead was lacking. One alleged fixation failure (Table 3, Quattro patient number 6) appeared to have caused tamponade, but analysis of the returned lead revealed no abnormality. Not lead-related deaths Fifty-six deaths (42%) were not lead-related (Table 1). Sixteen of these deaths were the result of either lead extraction (n 8) or lead perforation (n 8). All but one extraction was performed because the lead was ing. Fourteen deaths were reported to the Food and Drug Administration without allegation of lead. Of the 12 leads returned for analysis, 1 had a minor insulation abrasion, which did not expose the conductors, and 11 were within specification. Discussion Our analysis of the MAUDE database suggests that Riata and Riata ST leads are prone to high-voltage failure, which caused the deaths of 22 patients in this study. None of these failures or deaths could be attributed to externalized conductors. The signs of failure were typical of insulation defects that resulted in short circuiting between 2 or more high-voltage components, including the high-voltage cables, shocking coils, and pulse generator can. This mechanism of failure was concisely described by the manufacturer in its MAUDE report regarding Riata patient number 1 (Table 2), namely, Analysis found insulation abrasion resulting in an electrical short. Electrical shorts are particularly lethal because they may occur abruptly during shock delivery, and thus failure to defibrillate may be the first and only sign of lead failure. That these defects may not be detectable by routine monitoring is underscored by a case report showing that even intraoperative testing may fail to identify a shorted Riata lead. 11 Seven of the 22 Riata and Riata ST lead-related deaths were due to can abrasions that resulted in short circuiting between exposed high-voltage cables and the pulse generator. In these and other high-voltage failures, the pulse generator sustained electrical overstress and was unable to

4 1230 Heart Rhythm, Vol 9, No 8, August 2012 Table 2 Lead-related deaths Model number Implanted (mo) Lead problem Observations indicating lead-related death Riata Failure to defibrillate Abnormal HV impedance Sudden death. HV alert. Device failed to deliver correct energy. Insulation defect caused electrical short Oversensing Sudden death. Noise on EGMs consistent Failure to defibrillate Low impedance Failure to defibrillate Abnormal HV impedance Failure to defibrillate Failure to defibrillate Failure to defibrillate High HV impedance Failure to defibrillate Failure to defibrillate Lead noise Failure to treat VT Lead noise Suspected fracture with an anomalous lead. Death due to untreated arrhythmia. HV cable melted. Damage consistent with can abrasion. Device detected VF and attempted to charge several times, but failed. A VF episode occurred and the device did not deliver HV therapy and the patient expired. Interrogation revealed that the HV impedance was 10. Data showed that patient experienced VF. Shock failed to defibrillate. Low lead impedance found. The device was unable to convert VF and the patient expired. HV lead impedance was high. Patient expired because of VF arrest. Device interrogation revealed attempt to deliver HV shock but failed to defibrillate because of low HV impedance. Patient in VF upon arrival of EMS. CPR unsuccessful. Device interrogation revealed it delivered 2 unsuccessful HV shocks. After the second shock, the device reported low HV lead impedance and circuit damage. Patient collapsed during VT and the device did not deliver therapy. Interrogation revealed that the patient had received HV therapy previously because of lead noise. The HV lead impedance was zero. Sudden death 1 d after noise discovered on lead in clinic. Patient had been sent home because INR was too high for surgery Abnormal HV impedance Out of-hospital cardiac arrest. Multiple insulation abrasions on outer insulation exposing conductors and causing a short between HV conductors, melting SVC and shock cables. Abrasions were caused by constant bending and friction Abnormal lead impedance Patient had VF and was shocked successfully. The following day, out-of-range lead impedances were observed via home monitor. The patient could not be reached and expired later that evening Failure to defibrillate Oversensing Unknown Failure to defibrillate High lead impedance HV cable fractured because of can abrasion. The device charged and delivered therapy. It is believed that the lead arced to the ICD can at this time. Interrogation revealed attempted therapy for VF, but therapies were truncated because of a high lead impedance. Visual examination found damage consistent with friction to the can.

5 Hauser et al Deaths Caused by Failure of Riata and Riata ST ICD Leads 1231 Table 2 Continued Model number Failure to defibrillate HV lead issue Failure to defibrillate Failure to defibrillate High HV impedance Device-induced VF Riata ST Failure to defibrillate Fracture Failure to defibrillate High HV lead impedance Low impedance Fracture Unknown Failure to defibrillate Quattro Secure Inappropriate shocks High impedance Oversensing Failure to defibrillate Fracture Failure to defibrillate Noise Implanted (mo) Lead problem Observations indicating lead-related death The patient expired 1 h after retiring. EMS CPR was unsuccessful. Device interrogation revealed that the device was in backup mode and there was an HV lead issue. An open circuit defect occurred and the device failed to deliver therapies. During an HV therapy delivery, the lead arced to the can (can abrasion) and shorted the HV output circuit. It is believed that the RV lead was damaged. ICD inappropriately induced the patient into VF as a result of an HV lead integrity check. Interrogation reported an HV impedance of 200. VF induced and not terminated. Patient expired. Device aborted charge because of possible output circuit damage and the patient expired. Visual examination of the lead found an insulation abrasion consistent with friction with the can. The 2 RV cables were fractured at this location. The ICD was attempting therapy for VF, but therapies were truncated because of high lead impedance. Analysis found insulation abrasion at cm from the connector pin. The RV cables were broken in this area, causing high HV lead impedance. Abrasion damage was due to friction to another device. ICD interrogation at hospital found that it was in alert mode due to low impedance. X-ray revealed insulation damage and lead fracture. The patient expired later that day. Analysis found can abrasion with exposed cables. Sudden death jogging. Analysis revealed short circuit due to arcing between abraded lead and the can. Patient went to ED after being shocked. Pacing impedance Oversensing noted on ventricular EGM causing inappropriate shocks. ICD deactivated in the ED. Patient coded while being taken to the OR and died. Cause of death was VF. Physician reported that death was possibly related to a lead. Lead analysis revealed distal conductor fracture. ICD detected VF and charged to 35 J but delivered shocks between 0.6 and 1.5 J; there was decreased impedance; the patient died. Counters showed noise and oversensing.

6 1232 Heart Rhythm, Vol 9, No 8, August 2012 Table 2 Continued Model number Implanted (mo) Lead problem Observations indicating lead-related death Oversensing The ICD on the day of death recorded a patient alert, VF/VT, nonsustained VT episodes, intervals, and oversensing Oversensing Sudden death. Lead out of specification based on save-to-disk file. CPR cardiopulmonary resuscitation; ED emergency department; EGM electrogram; EMS emergency medical services; HV high voltage; ICD implantable cardioverter-defibrillator; INR international normalized ratio; MDR Medical Device Report; OR operation room; RV right ventricle; SVC superior vena cava; VF ventricular fibrillation; VT ventricular tachycardia. deliver further therapy. None of the 57 Quattro leads in this study had can abrasions. s are not detectable by noninvasive monitoring until they produce an electrical abnormality, such as out-of-range impedance, and they may not be evident at pulse generator change. 11 ICD follow-up clinics and monitoring personnel should scrutinize all impedance vectors, for example, coil-to-can, and they should examine coil-to-can electrograms for artifacts that may be caused by a coil-to-can short. Recently, we reported a study of explanted Riata and Riata ST leads that were found to have inside-out insulation abrasions, which are caused by movement of the cables within their lumens. 3 One manifestation of insideout abrasion is externalized conductors. Two patients in our series had externalized conductors (Table 3, Riata patient number 14 and Riata ST patient number 4), but there was no evidence that they had ed or contributed to the deaths of these patients. However, a quarter of inside-out abrasions occur under the Riata or Riata ST shocking coils, where the cables may not externalize. 3 We hypothesize that inside-out insulation defects under the shocking coils are causing high-voltage cables and coils to come into contact and eventually abrade the ETFE that protects and insulates the cables (Figure 1A). Then, during shock delivery, the energy intended to defibrillate is shorted between the cables or coils. If the ETFE is only partially abraded, the first shock may defibrillate but in the process of delivering high energy, the remaining ETFE breaks down and subsequent shocks are shorted, for example, Riata patient number 13 (Table 2). The 5 Quattro lead-related deaths were caused by conductor fractures. Oversensing and lead fracture were also found with some Quattro indeterminate deaths (Table 3). Notably, no Quattro lead in this study had an insulation defect. Compared with Riata and Riata ST leads, Quattro leads have performed well in multicenter studies. 12,13 Procedural complications accounted for 16 deaths 8 perforations resulting in tamponade and 8 extraction-related deaths. We did not consider these deaths lead-related or indeterminate because they were not arrhythmic and not directly caused by lead. Nevertheless, it is sobering to observe that there were 0.6 procedural deaths in our study for every lead-related death. For the tens of thousands of patients worldwide who have Riata and Riata ST leads, there is an urgent need for test methods that are capable of identifying life-threatening defects and a universally accessible monitoring system that promptly alerts patients and caregivers. The manufacturer should conduct studies focused on the behavior of measurable electrical parameters prior to lead failure. Algorithms that can detect electrical abnormalities before short circuits occur are needed. Our study suggests that any Riata or Riata ST electrical abnormality requires immediate attention. Indeed, when a high-risk patient has a ing ICD lead, he or she should be hospitalized and monitored in a unit capable of prompt external defibrillation. The rationale for this precaution is illustrated by Riata patient number 11 (Table 2) who died suddenly at home the day after his lead was found fractured during a clinic visit. Protocols should exist in hospitals and ICD surveillance clinics that specify how patients who have ing leads should be managed. Our study was limited by the absence of clinical data contained in the manufacturers reports, and many leads were not returned to the manufacturer for analysis. Thus, while we believe that the information in the MAUDE database is accurate, it is often incomplete. Consequently, we classified 50 deaths as indeterminate because important information was not reported. Postmarket surveillance in the United States relies on a passive reporting system, and thus adverse events are underreported, particularly by physicians and hospitals. Therefore, the number of deaths in this study likely underestimates the actual number of deaths that have occurred. Since the MAUDE database does not contain denominator data, we used the manufacturers sales data to estimate the number of implants. The results of this study are not definitive; additional confirmatory data are needed. Our findings do not support the prophylactic replacement of normally functioning Riata or Riata ST leads. Physicians and hospitals are encouraged to return failed leads to the manufacturer for analysis together with detailed clinical information, including pulse generator diagnostic data and electrograms.

7 Hauser et al Deaths Caused by Failure of Riata and Riata ST ICD Leads 1233 Table 3 Indeterminate deaths Model Implant (mo) Lead problem complaint Reason for indeterminate cause of death Riata Failure to convert No further information provided Sudden death Undersensed VF No evidence of lead defect provided. Recent implant Unexpected death Undersensed No evidence of lead defect provided. Recent implant. Partial lead normal Malfunction Shocks No evidence of lead defect provided. Returned lead showed explant damage Allegation that lead No information. contributed to death High impedance Noise High impedance at Analysis found can abrasion. Patient found expired in automobile. follow-up Failure to capture The physician did not consider the incident to be caused by the device Oversensing Noise during shock delivery for VF HV output circuit damage Analysis of the ICD revealed HV output damage consistent with a damaged lead. Uncertain if death sudden, unexpected, or arrhythmic Inappropriate shocks Analysis found abrasion Externalized conductors No further information provided Failure to charge No evidence of lead Failure to deliver therapy Increased impedance Oversensing Noise No evidence of lead Failure to defibrillate Unclear if failure was pulse generator or lead. Lead analysis found abrasion Unknown Oversensing Inappropriate shocks Apparent lead-lead interaction Unknown High HV impedance High HV impedance found at implant. The physician deferred replacement and disabled the ICD. Patient died 3 d later of VF. Riata ST No output HV circuit defect. No evidence of lead Multiple inappropriate shocks Failure to detect VT/VF No evidence of lead Externalized conductors No evidence of lead No allegation consistent with short circuit. Uncertain if death sudden, unexpected, or arrhythmic. No evidence of lead. Quattro Secure Oversensing No allegation Oversensing detected 12 d prior to death Rapid heart rate Family reported that patient s heart rate was 227 beats/min at the time of death and the ICD did not shock. No evidence of lead.

8 1234 Heart Rhythm, Vol 9, No 8, August 2012 Table 3 Continued Model Implant (mo) Lead problem complaint Reason for indeterminate cause of death Undersensing Cardiac arrest No allegation of The patient received 30 appropriate shocks and the device failed to shock 14 times before the therapies were exhausted. No evidence of lead Failure to sense VF Analysis of returned lead was normal Fixation failure During repositioning, the helix did not deploy. The lead was replaced. Tamponade ensued. No evidence of lead No allegation of Intermittent continuity on pin cap No allegation of Returned lead tested out of specification Oversensing Low impedance High impedance Fracture Oversensing Malfunction High impedance ICD found to have power-on reset and out-of-range lead impedance. Analysis of returned lead was normal No allegation of Acute heart failure and cardiac arrest. Analysis of returned lead revealed distal fracture. No evidence of ICD Oversensing No allegation of Returned lead tested out of specification. Uncertain if death sudden, unexpected, or arrhythmic Oversensing No allegation of Oversensing detected by ICD. Uncertain if death sudden, unexpected, or arrhythmic Oversensing Inappropriate shocks Oversensing detected by ICD. Uncertain if death sudden, unexpected, or arrhythmic Failure to shock reported by family member Sudden death. No evidence of lead No allegation of No allegation of No allegation of Failure of helix to deploy High impedance Failure to shock Unexpected death. Recent implant. Carelink transmission indicated out-of-range impedances on day of death. Lead not returned for analysis. Postmortem measurements revealed oversensing and high lead impedances on day of death. Uncertain if death sudden, unexpected, or arrhythmic. Recent implant. Fine VF recorded on day of death. ICD did not detect VF. Analysis of lead normal. Uncertain if death sudden, unexpected, or arrhythmic. Analysis of returned lead normal. Unless otherwise stated, the leads were not returned for analysis. HV high voltage; ICD implantable cardioverter-defibrillator; VF ventricular fibrillation; VT ventricular tachycardia. Conclusions Riata and Riata ST ICD leads appear to be prone to highvoltage failures that have resulted in multiple deaths. These failures often occurred abruptly, without warning, and they appeared to be caused by insulation defects that caused short circuiting between high-voltage components. Externalized conductors did not seem to be a factor in these deaths. Studies are needed to determine whether more frequent or different monitoring may detect an impending Riata or Riata ST lead failure before it results in a catastrophic event. References 1. Chester KM. Important product information: St Jude Medical Riata and Riata ST silicone endocardial leads. Sylmar, CA: St Jude Medical; December 15, 2010.

9 Hauser et al Deaths Caused by Failure of Riata and Riata ST ICD Leads Carlson M, Tsung P. Medical device advisory. Sylmar, CA: St Jude Medical; November 28, Hauser RG, McGriff D, Kallinen Retel L. Riata implantable cardioverterdefibrillator failure: analysis of explanted leads with a unique insulation defect. Heart Rhythm 2012;9: Duray GZ, Israel CW, Schmitt J, Hohnloser SH. Implantable cardioverterdefibrillator lead disintegration at the level of the tricuspid valve. Heart Rhythm 2008;5: Krebsbach A, Alhumaid F, Henrickson, CA, Calkins H, Berger RD, Cheng A. Premature failure of a Riata defibrillator lead impedance change or inappropriate sensing: a case report and review of the literature. J Cardiovasc Electrophysiol 2011;22: Erkapic D, Duray GZ, Bauernfeind T, De Rosa S, Hohnloser SH. Insulation defects of thin high-voltage ICD leads: an underestimated problem? J Cardiovasc Electrophysiol 2011;22: Maisel WH, Hauser RG, Hammill SC, et al. Recommendations from the Heart Rhythm Society Task Force on Lead Performance Policies and Guidelines. Heart Rhythm 2009;6: Hauser RG, Katsiyiannis WT, Gornick CC, Almquist AK, Kallinen LM. Deaths and cardiovascular injuries due to device-assisted implantable cardioverterdefibrillator and pacemaker lead extraction. Europace 2010;12: Hauser RG, Kallinen LM, Almquist AK, Gornick CC, Katsiyiannis WT. Early failure of a small-diameter high-voltage implantable cardioverter lead. Heart Rhythm 2007;4: Hauser RG, Hayes DL, Almquist AK, et al. Unexpected ICD pulse generator failure due to electronic circuit damage caused by electrical overstress. Pacing Clin Electrophysiol 2001;24: Leong DP, Van Erven L. Unrecognized failure of a narrow caliber defibrillation lead: the role of defibrillation threshold testing in identifying an unprotected individual. Pacing Clin Electrophysiol. Published online February 6, Hauser RG, Maisel WH, Friedman PA, et al. Longevity of Sprint Fidelis implantable cardioverter-defibrillator leads: implications for patient management. Circulation 2011;123: Keung E. The VA national cardiac device surveillance experience. Available at: Accessed March 2, 2012.