Longitudinal Follow-Up of Implantable Cardioverter Defibrillator Leads
2013; Elsevier BV; Volume: 113; Issue: 1 Linguagem: Inglês
10.1016/j.amjcard.2013.08.046
ISSN1879-1913
AutoresJeffrey Liu, Genevieve Brumberg, Rishi Rattan, Divyang Patel, Evan Adelstein, Sandeep Jain, Samir Saba,
Tópico(s)Cardiomyopathy and Myosin Studies
ResumoAlthough implantable cardioverter defibrillator (ICD) leads are prone to failure and Food and Drug Administration recall, comprehensive longitudinal studies investigating contemporary ICD lead survival rate in the United States are lacking. All patients receiving Medtronic, Boston Scientific, or St. Jude Medical transvenous ICD leads at the hospitals of the University of Pittsburgh Medical Center from 2000 to 2012 were included. Leads were classified as (1) functional lead, patient deceased; (2) functional lead, replaced; (3) failed lead, replaced; or (4) functional lead, active. Kaplan-Meier survival curves were constructed for all lead models separately and in aggregate. We followed 5,288 patients (1,020 Quattro, 623 Fidelis, 627 Riata, 828 Durata, and 2,190 Reliance) over 3.7 ± 3.3 years. Functional leads that were replaced included 30 Quattro (3%), 99 Fidelis (16%), 24 Riata (4%), 24 Durata (3%), and 62 Reliance (3%). Leads replaced because of failure included 11 Quattro (1%), 47 Fidelis (8%), 38 Riata (6%), 18 Durata (2%), and 26 Reliance (1%; p <0.001 for Food and Drug Administration recalled vs nonrecalled leads). Overall survival rate of all leads was 89.3% at 5 years. Survival curves of Riata and Fidelis diverged from nonrecalled leads at approximately 2 years. In conclusion, the overall survival rate of ICD leads is nearly 90% at 5 years. Survival curves of recalled leads diverge from nonrecalled leads after 2 years of implantation. These data have important implications on postmarket release monitoring of ICD leads and physicians' choice of leads. Although implantable cardioverter defibrillator (ICD) leads are prone to failure and Food and Drug Administration recall, comprehensive longitudinal studies investigating contemporary ICD lead survival rate in the United States are lacking. All patients receiving Medtronic, Boston Scientific, or St. Jude Medical transvenous ICD leads at the hospitals of the University of Pittsburgh Medical Center from 2000 to 2012 were included. Leads were classified as (1) functional lead, patient deceased; (2) functional lead, replaced; (3) failed lead, replaced; or (4) functional lead, active. Kaplan-Meier survival curves were constructed for all lead models separately and in aggregate. We followed 5,288 patients (1,020 Quattro, 623 Fidelis, 627 Riata, 828 Durata, and 2,190 Reliance) over 3.7 ± 3.3 years. Functional leads that were replaced included 30 Quattro (3%), 99 Fidelis (16%), 24 Riata (4%), 24 Durata (3%), and 62 Reliance (3%). Leads replaced because of failure included 11 Quattro (1%), 47 Fidelis (8%), 38 Riata (6%), 18 Durata (2%), and 26 Reliance (1%; p 5 years after lead implantation.3Alter P. Waldhans S. Plachta E. Moosdorf R. Grimm W. Complications of implantable cardioverter defibrillator therapy in 440 consecutive patients.Pacing Clin Electrophysiol. 2005; 28: 926-932Crossref PubMed Scopus (218) Google Scholar, 4Kleemann T. Becker T. Doenges K. Vater M. Senges J. Schneider S. Saggau W. Weisse U. Seidl K. Annual rate of transvenous defibrillation lead defects in implantable cardioverter-defibrillators over a period of >10 years.Circulation. 2007; 115: 2474-2480Crossref PubMed Scopus (513) Google Scholar Two ICD leads—the Sprint Fidelis (Medtronic Inc., Minneapolis, Minnesota) and the Riata (St. Jude Medical, Sylmar, California)—have been recalled by the Food and Drug Administration (FDA) in 2007 and 2011, respectively, after observed high rates of premature lead failure. Despite these FDA recalls, comprehensive studies investigating the overall ICD lead survival rate in the United States (US) are scarce. We therefore investigated the overall ICD lead survival rate of lead models from 3 major manufacturers implanted at the hospitals of the University of Pittsburgh Medical Center from 2000 to 2012.MethodsAll patients receiving a Medtronic, Boston Scientific, or St. Jude Medical transvenous ICD lead at the University of Pittsburgh Medical Center from November 2000 to March 2012 were included. Patients were followed in the outpatient device clinic with no <1 clinic visit and 3 remote checks/year or 2 clinic visits/year in patients with no remote home monitoring. Leads were classified as (1) functional lead, patient deceased (from any cause); (2) functional lead replaced for any reason other than lead failure (e.g., infection, heart transplantation, prophylactically after recall); (3) electrically failed lead, replaced; or (4) functional lead, active. Prophylactic replacement of recalled leads was performed on patient request and was offered primarily to high-risk patients (pacemaker-dependent or secondary prevention). Lead failure was defined as electrical malfunction resulting in lead extraction or replacement with a new ICD lead. Although no standard definition of ICD lead failure exists, we used criteria similar to those of previous reports.5Abdelhadi R.H. Saba S.F. Ellis C.R. Mason P.K. Kramer D.B. Friedman P.A. Gura M.T. DiMarco J.P. Mugglin A.S. Reynolds M.R. Bazaz R.R. Retel L.K. Hayes D.L. Hauser R.G. Independent multicenter study of Riata and Riata ST implantable cardioverter-defibrillator leads.Heart Rhythm. 2012; 10: 361-365Abstract Full Text Full Text PDF PubMed Scopus (62) Google Scholar Specifically, electrical malfunction was defined as abnormal pace-sense or high-voltage impedance values, decrease in R-wave amplitude, increase in pacing threshold necessitating lead replacement; or the presence of electrical noise leading to inappropriate ICD therapy. Leads demonstrating mechanical failure (e.g., cable externalization in Riata leads) with normal electrical function were not classified as lead failures in the present study. Kaplan-Meier survival curves were constructed for all leads in aggregate and for each lead model separately.All continuous variables are presented as mean ± SD and were compared using the Student t test. All categorical variables are presented as absolute numbers and percentages and were compared using the chi-square test. Lead survival rate was evaluated using the Kaplan-Meier method and compared between lead models using the log-rank test. A 2-sided p-value of 0.05 was considered statistically significant. All statistical analyses were performed on SPSS, version 19.0.0 (IBM Inc., Armonk, New York).ResultsA total of 5,288 patients (1,020 Sprint Quattro [models 6947 and 6935] [Medtronic Inc., Minneapolis, Minnesota], 623 Sprint Fidelis [model 6949], 627 Riata [models 1580 to 1582, 1590, 7000, 7001, 7011, and 7041], 828 Durata [models 7120 to 7122] [Saint Jude Medical, Sylmar, California], and 2,190 Reliance [models 0185 and 0158] [Boston Scientific, Natick, Massachusetts]) were included and followed for a mean of 3.7 ± 3.3 years. Baseline characteristics of all patients are detailed in Table 1. Functional leads that were replaced included 30 Quattro (3%), 99 Fidelis (16%), 24 Riata (4%), 24 Durata (3%), and 62 Reliance (3%). Leads replaced for electrical failure included 11 Quattro (1%), 47 Fidelis (8%), 38 Riata (6%), 18 Durata (2%), and 26 Reliance (1%; p <0.001 for comparison of Fidelis and Riata with other lead models) as listed in Table 2. Mode of lead failure is included in Table 2.Table 1Baseline characteristicsCharacteristicQuattroFidelisRiataDurataRelianceNumber of leads1,0206236278282,190Age (yrs)64 ± 1466 ± 1366 ± 1468 ± 1572 ± 12Men (%)7875767578CRT (%)3841364438Follow-up (yrs)3.5 ± 2.72.7 ± 1.33.2 ± 2.12.3 ± 1.24.6 ± 2.7CRT = cardiac resynchronization therapy devices. Open table in a new tab Table 2Failed ICD leadsLead OutcomeQuattroFidelisRiataDurataRelianceFunctional lead, patient deceased, n (%)264 (26)77 (12)198 (32)46 (6)847 (39)Functional leads replaced, n (%)30 (3)99 (16)24 (4)24 (3)62 (3)Failed leads replaced, n (%)11 (1)47 (8)38 (6)18 (2)26 (1)Mode of electrical failure Sensing/noise32815213 Impedance change75200 High threshold04726 Perforation/dislodgement014134 High-voltage failure00413 Unknown mechanism19600 Open table in a new tab Overall survival rate of all leads was 89.3% at 5 years (Figure 1). Individual failure-free survival curves were also generated for each ICD lead model, separately (Figure 2). Survival curves for the 2 ICD leads under FDA recall (Riata and Sprint Fidelis) diverged from the other curves after nearly 2 years on the overall survival and failure-free survival Kaplan-Meier plots. Furthermore, lead models with the longest follow-up time, that is, Sprint Quattro and Endotak Reliance, exhibited 8-year survival rates of 98.3% and 98.5%, respectively.Figure 2Failure-free ICD lead survival for 5 major lead models from 3 manufacturers.View Large Image Figure ViewerDownload Hi-res image Download (PPT)DiscussionThis study represents a comprehensive retrospective review of ICD lead survival rate from major US lead manufacturers. Our data demonstrate that failure-free survival curves of recalled ICD leads diverge from those of nonrecalled leads 2 years after implantation. Furthermore, an overall ICD lead survival rate on the order of 90% is seen at 5 years.Before an ICD lead is brought to market in the United States, rigorous premarketing testing is required to demonstrate its safety, quality, and reliability. These tests generally involve 3 separate phases: bench testing, animal testing, and human trials. Bench testing is performed to simulate the mechanical stresses that ICD leads are subject to by virtue of their intracardiac placement. An ICD lead may be subject to 500 million repetitive cardiac cycles over its lifetime, and thus, leads must demonstrate the ability to withstand such stresses ex vivo before animal and human studies. Subsequently, animal testing allows for assessment of lead handling and evaluation of in vivo performance before proceeding to investigational human trials. However, despite rigorous premarket release testing, the Riata lead (St. Jude Medical) demonstrated premature failure and cable externalization after market release, leading to a class I FDA recall and the withdrawal of the lead from the US market roughly 10 years after its release. The Sprint Fidelis (Medtronic) was not even subjected to premarket clinical testing because of its perceived similarity in design and structure to the Sprint Quattro (model 6947) lead, and thus, clinical data from the model 6947 lead supported the safety and efficacy of model 6949 lead.6Available at: http://manuals.medtronic.com.Google Scholar In the case of the Fidelis, the lead was recalled by the FDA 3 years after its US market release. The limitations of premarket release ICD lead testing highlight the importance of adequate postmarket release monitoring.In a 2007 editorial in Circulation, Maisel7Maisel W.H. Transvenous implantable cardioverter-defibrillator leads: the weakest link.Circulation. 2007; 115: 2461-2463Crossref PubMed Scopus (57) Google Scholar highlighted the inadequacies of ICD lead performance reporting and concluded that "… better designed lead monitoring… and more timely reporting of ICD lead performance must be required of manufacturers by the US Food and Drug Administration." Currently, there are no uniform guidelines for postmarket release ICD lead surveillance. The approach to postmarket release surveillance has been multifaceted, involving FDA, device manufacturers, and independent registries. FDA maintains all reported adverse events into the Manufacturer and User Device Experience (MAUDE) database. In addition, the HeartNet subset of the Medical Product Safety Network (MedSun) focuses on problems with medical devices, specifically used in the electrophysiology lab.8Available at: http://www.fda.gov/MedicalDevices/Safety/MedSunMedicalProductSafetyNetwork.Google Scholar Device manufacturers are not currently required to provide longitudinal lead performance studies, but most have chosen to do so, independently.Despite this multifaceted approach to ICD lead monitoring, there remain inadequacies in the present system. Our data show similar failure-free survival of the Riata and the Fidelis lead; however, the Riata lead was on the market for about 10 years before FDA recall compared with only 3 years for the Fidelis.9Liu J. Brumberg G. Rattan R. Jain S. Saba S. Class I recall of defibrillator leads: a comparison of the Sprint Fidelis and Riata families.Heart Rhythm. 2012; 9: 1251-1255Abstract Full Text Full Text PDF PubMed Scopus (49) Google Scholar This may be partially explained by the clinical manifestations of lead failure of each lead.10Liu J. Rattan R. Adelstein E. Barrington W. Bazaz R. Brode S. Jain S. Mendenhall G.S. Nemec J. Razak E. Shalaby A. Schwartzman D. Voigt A. Wang N.C. Saba S. Fluoroscopic screening of asymptomatic patients implanted with the recalled Riata lead family.Circ Arrhythm Electrophysiol. 2012; 5: 809-814Crossref PubMed Scopus (42) Google Scholar, 11Liu J. Qin D. Rattan R. Bazaz R. Adelstein E. Jain S.K. Saba S. Longitudinal follow-up of externalized Riata leads.Am J Cardiol. 2013; 112: 1616-1618Abstract Full Text Full Text PDF PubMed Scopus (12) Google Scholar, 12Brumberg G.E. Kaseer B. Shah H. Saba S. Jain S. Biventricular defibrillator patients have higher complication rates after revision of recalled leads.Pacing Clin Electrophysiol. 2012; 35: 665-671Crossref PubMed Scopus (6) Google Scholar, 13Liu J. Patel D. Rattan R. Brumberg G. Saini A. Vaghasia N. Bazaz R. Adelstein E. Jain S. Saba S. Failure-free survival of the Durata defibrillator lead.Europace. 2013; 15: 1002-1006Crossref PubMed Scopus (19) Google Scholar Fractured Fidelis leads often present with inappropriate ICD shocks from sensed noise, whereas externalized Riata leads are less likely to present with inappropriate shocks and thus its failure may not be readily apparent to patients or providers. Our data also show that the failure-free survival curves of the Fidelis and Riata diverge from that of nonrecalled leads at approximately 2 years. This finding has important implications on the duration of postmarketing surveillance of ICD leads by FDA and on the choice of lead models made by implanting physician, favoring models with longer track records. Defibrillator lead recalls have far reaching clinical ramifications, including increased cost to the health-care system for lead revisions and other procedures and increased risks to patients who have recalled leads. Based on our present study, newly developed ICD leads that are released to the market should be followed closely and intensely scrutinized for no 5 years after lead implantation.3Alter P. Waldhans S. Plachta E. Moosdorf R. Grimm W. Complications of implantable cardioverter defibrillator therapy in 440 consecutive patients.Pacing Clin Electrophysiol. 2005; 28: 926-932Crossref PubMed Scopus (218) Google Scholar, 4Kleemann T. Becker T. Doenges K. Vater M. Senges J. Schneider S. Saggau W. Weisse U. Seidl K. Annual rate of transvenous defibrillation lead defects in implantable cardioverter-defibrillators over a period of >10 years.Circulation. 2007; 115: 2474-2480Crossref PubMed Scopus (513) Google Scholar Two ICD leads—the Sprint Fidelis (Medtronic Inc., Minneapolis, Minnesota) and the Riata (St. Jude Medical, Sylmar, California)—have been recalled by the Food and Drug Administration (FDA) in 2007 and 2011, respectively, after observed high rates of premature lead failure. Despite these FDA recalls, comprehensive studies investigating the overall ICD lead survival rate in the United States (US) are scarce. We therefore investigated the overall ICD lead survival rate of lead models from 3 major manufacturers implanted at the hospitals of the University of Pittsburgh Medical Center from 2000 to 2012. MethodsAll patients receiving a Medtronic, Boston Scientific, or St. Jude Medical transvenous ICD lead at the University of Pittsburgh Medical Center from November 2000 to March 2012 were included. Patients were followed in the outpatient device clinic with no <1 clinic visit and 3 remote checks/year or 2 clinic visits/year in patients with no remote home monitoring. Leads were classified as (1) functional lead, patient deceased (from any cause); (2) functional lead replaced for any reason other than lead failure (e.g., infection, heart transplantation, prophylactically after recall); (3) electrically failed lead, replaced; or (4) functional lead, active. Prophylactic replacement of recalled leads was performed on patient request and was offered primarily to high-risk patients (pacemaker-dependent or secondary prevention). Lead failure was defined as electrical malfunction resulting in lead extraction or replacement with a new ICD lead. Although no standard definition of ICD lead failure exists, we used criteria similar to those of previous reports.5Abdelhadi R.H. Saba S.F. Ellis C.R. Mason P.K. Kramer D.B. Friedman P.A. Gura M.T. DiMarco J.P. Mugglin A.S. Reynolds M.R. Bazaz R.R. Retel L.K. Hayes D.L. Hauser R.G. Independent multicenter study of Riata and Riata ST implantable cardioverter-defibrillator leads.Heart Rhythm. 2012; 10: 361-365Abstract Full Text Full Text PDF PubMed Scopus (62) Google Scholar Specifically, electrical malfunction was defined as abnormal pace-sense or high-voltage impedance values, decrease in R-wave amplitude, increase in pacing threshold necessitating lead replacement; or the presence of electrical noise leading to inappropriate ICD therapy. Leads demonstrating mechanical failure (e.g., cable externalization in Riata leads) with normal electrical function were not classified as lead failures in the present study. Kaplan-Meier survival curves were constructed for all leads in aggregate and for each lead model separately.All continuous variables are presented as mean ± SD and were compared using the Student t test. All categorical variables are presented as absolute numbers and percentages and were compared using the chi-square test. Lead survival rate was evaluated using the Kaplan-Meier method and compared between lead models using the log-rank test. A 2-sided p-value of 0.05 was considered statistically significant. All statistical analyses were performed on SPSS, version 19.0.0 (IBM Inc., Armonk, New York). All patients receiving a Medtronic, Boston Scientific, or St. Jude Medical transvenous ICD lead at the University of Pittsburgh Medical Center from November 2000 to March 2012 were included. Patients were followed in the outpatient device clinic with no <1 clinic visit and 3 remote checks/year or 2 clinic visits/year in patients with no remote home monitoring. Leads were classified as (1) functional lead, patient deceased (from any cause); (2) functional lead replaced for any reason other than lead failure (e.g., infection, heart transplantation, prophylactically after recall); (3) electrically failed lead, replaced; or (4) functional lead, active. Prophylactic replacement of recalled leads was performed on patient request and was offered primarily to high-risk patients (pacemaker-dependent or secondary prevention). Lead failure was defined as electrical malfunction resulting in lead extraction or replacement with a new ICD lead. Although no standard definition of ICD lead failure exists, we used criteria similar to those of previous reports.5Abdelhadi R.H. Saba S.F. Ellis C.R. Mason P.K. Kramer D.B. Friedman P.A. Gura M.T. DiMarco J.P. Mugglin A.S. Reynolds M.R. Bazaz R.R. Retel L.K. Hayes D.L. Hauser R.G. Independent multicenter study of Riata and Riata ST implantable cardioverter-defibrillator leads.Heart Rhythm. 2012; 10: 361-365Abstract Full Text Full Text PDF PubMed Scopus (62) Google Scholar Specifically, electrical malfunction was defined as abnormal pace-sense or high-voltage impedance values, decrease in R-wave amplitude, increase in pacing threshold necessitating lead replacement; or the presence of electrical noise leading to inappropriate ICD therapy. Leads demonstrating mechanical failure (e.g., cable externalization in Riata leads) with normal electrical function were not classified as lead failures in the present study. Kaplan-Meier survival curves were constructed for all leads in aggregate and for each lead model separately. All continuous variables are presented as mean ± SD and were compared using the Student t test. All categorical variables are presented as absolute numbers and percentages and were compared using the chi-square test. Lead survival rate was evaluated using the Kaplan-Meier method and compared between lead models using the log-rank test. A 2-sided p-value of 0.05 was considered statistically significant. All statistical analyses were performed on SPSS, version 19.0.0 (IBM Inc., Armonk, New York). ResultsA total of 5,288 patients (1,020 Sprint Quattro [models 6947 and 6935] [Medtronic Inc., Minneapolis, Minnesota], 623 Sprint Fidelis [model 6949], 627 Riata [models 1580 to 1582, 1590, 7000, 7001, 7011, and 7041], 828 Durata [models 7120 to 7122] [Saint Jude Medical, Sylmar, California], and 2,190 Reliance [models 0185 and 0158] [Boston Scientific, Natick, Massachusetts]) were included and followed for a mean of 3.7 ± 3.3 years. Baseline characteristics of all patients are detailed in Table 1. Functional leads that were replaced included 30 Quattro (3%), 99 Fidelis (16%), 24 Riata (4%), 24 Durata (3%), and 62 Reliance (3%). Leads replaced for electrical failure included 11 Quattro (1%), 47 Fidelis (8%), 38 Riata (6%), 18 Durata (2%), and 26 Reliance (1%; p <0.001 for comparison of Fidelis and Riata with other lead models) as listed in Table 2. Mode of lead failure is included in Table 2.Table 1Baseline characteristicsCharacteristicQuattroFidelisRiataDurataRelianceNumber of leads1,0206236278282,190Age (yrs)64 ± 1466 ± 1366 ± 1468 ± 1572 ± 12Men (%)7875767578CRT (%)3841364438Follow-up (yrs)3.5 ± 2.72.7 ± 1.33.2 ± 2.12.3 ± 1.24.6 ± 2.7CRT = cardiac resynchronization therapy devices. Open table in a new tab Table 2Failed ICD leadsLead OutcomeQuattroFidelisRiataDurataRelianceFunctional lead, patient deceased, n (%)264 (26)77 (12)198 (32)46 (6)847 (39)Functional leads replaced, n (%)30 (3)99 (16)24 (4)24 (3)62 (3)Failed leads replaced, n (%)11 (1)47 (8)38 (6)18 (2)26 (1)Mode of electrical failure Sensing/noise32815213 Impedance change75200 High threshold04726 Perforation/dislodgement014134 High-voltage failure00413 Unknown mechanism19600 Open table in a new tab Overall survival rate of all leads was 89.3% at 5 years (Figure 1). Individual failure-free survival curves were also generated for each ICD lead model, separately (Figure 2). Survival curves for the 2 ICD leads under FDA recall (Riata and Sprint Fidelis) diverged from the other curves after nearly 2 years on the overall survival and failure-free survival Kaplan-Meier plots. Furthermore, lead models with the longest follow-up time, that is, Sprint Quattro and Endotak Reliance, exhibited 8-year survival rates of 98.3% and 98.5%, respectively. A total of 5,288 patients (1,020 Sprint Quattro [models 6947 and 6935] [Medtronic Inc., Minneapolis, Minnesota], 623 Sprint Fidelis [model 6949], 627 Riata [models 1580 to 1582, 1590, 7000, 7001, 7011, and 7041], 828 Durata [models 7120 to 7122] [Saint Jude Medical, Sylmar, California], and 2,190 Reliance [models 0185 and 0158] [Boston Scientific, Natick, Massachusetts]) were included and followed for a mean of 3.7 ± 3.3 years. Baseline characteristics of all patients are detailed in Table 1. Functional leads that were replaced included 30 Quattro (3%), 99 Fidelis (16%), 24 Riata (4%), 24 Durata (3%), and 62 Reliance (3%). Leads replaced for electrical failure included 11 Quattro (1%), 47 Fidelis (8%), 38 Riata (6%), 18 Durata (2%), and 26 Reliance (1%; p <0.001 for comparison of Fidelis and Riata with other lead models) as listed in Table 2. Mode of lead failure is included in Table 2. CRT = cardiac resynchronization therapy devices. Overall survival rate of all leads was 89.3% at 5 years (Figure 1). Individual failure-free survival curves were also generated for each ICD lead model, separately (Figure 2). Survival curves for the 2 ICD leads under FDA recall (Riata and Sprint Fidelis) diverged from the other curves after nearly 2 years on the overall survival and failure-free survival Kaplan-Meier plots. Furthermore, lead models with the longest follow-up time, that is, Sprint Quattro and Endotak Reliance, exhibited 8-year survival rates of 98.3% and 98.5%, respectively. DiscussionThis study represents a comprehensive retrospective review of ICD lead survival rate from major US lead manufacturers. Our data demonstrate that failure-free survival curves of recalled ICD leads diverge from those of nonrecalled leads 2 years after implantation. Furthermore, an overall ICD lead survival rate on the order of 90% is seen at 5 years.Before an ICD lead is brought to market in the United States, rigorous premarketing testing is required to demonstrate its safety, quality, and reliability. These tests generally involve 3 separate phases: bench testing, animal testing, and human trials. Bench testing is performed to simulate the mechanical stresses that ICD leads are subject to by virtue of their intracardiac placement. An ICD lead may be subject to 500 million repetitive cardiac cycles over its lifetime, and thus, leads must demonstrate the ability to withstand such stresses ex vivo before animal and human studies. Subsequently, animal testing allows for assessment of lead handling and evaluation of in vivo performance before proceeding to investigational human trials. However, despite rigorous premarket release testing, the Riata lead (St. Jude Medical) demonstrated premature failure and cable externalization after market release, leading to a class I FDA recall and the withdrawal of the lead from the US market roughly 10 years after its release. The Sprint Fidelis (Medtronic) was not even subjected to premarket clinical testing because of its perceived similarity in design and structure to the Sprint Quattro (model 6947) lead, and thus, clinical data from the model 6947 lead supported the safety and efficacy of model 6949 lead.6Available at: http://manuals.medtronic.com.Google Scholar In the case of the Fidelis, the lead was recalled by the FDA 3 years after its US market release. The limitations of premarket release ICD lead testing highlight the importance of adequate postmarket release monitoring.In a 2007 editorial in Circulation, Maisel7Maisel W.H. Transvenous implantable cardioverter-defibrillator leads: the weakest link.Circulation. 2007; 115: 2461-2463Crossref PubMed Scopus (57) Google Scholar highlighted the inadequacies of ICD lead performance reporting and concluded that "… better designed lead monitoring… and more timely reporting of ICD lead performance must be required of manufacturers by the US Food and Drug Administration." Currently, there are no uniform guidelines for postmarket release ICD lead surveillance. The approach to postmarket release surveillance has been multifaceted, involving FDA, device manufacturers, and independent registries. FDA maintains all reported adverse events into the Manufacturer and User Device Experience (MAUDE) database. In addition, the HeartNet subset of the Medical Product Safety Network (MedSun) focuses on problems with medical devices, specifically used in the electrophysiology lab.8Available at: http://www.fda.gov/MedicalDevices/Safety/MedSunMedicalProductSafetyNetwork.Google Scholar Device manufacturers are not currently required to provide longitudinal lead performance studies, but most have chosen to do so, independently.Despite this multifaceted approach to ICD lead monitoring, there remain inadequacies in the present system. Our data show similar failure-free survival of the Riata and the Fidelis lead; however, the Riata lead was on the market for about 10 years before FDA recall compared with only 3 years for the Fidelis.9Liu J. Brumberg G. Rattan R. Jain S. Saba S. Class I recall of defibrillator leads: a comparison of the Sprint Fidelis and Riata families.Heart Rhythm. 2012; 9: 1251-1255Abstract Full Text Full Text PDF PubMed Scopus (49) Google Scholar This may be partially explained by the clinical manifestations of lead failure of each lead.10Liu J. Rattan R. Adelstein E. Barrington W. Bazaz R. Brode S. Jain S. Mendenhall G.S. Nemec J. Razak E. Shalaby A. Schwartzman D. Voigt A. Wang N.C. Saba S. Fluoroscopic screening of asymptomatic patients implanted with the recalled Riata lead family.Circ Arrhythm Electrophysiol. 2012; 5: 809-814Crossref PubMed Scopus (42) Google Scholar, 11Liu J. Qin D. Rattan R. Bazaz R. Adelstein E. Jain S.K. Saba S. Longitudinal follow-up of externalized Riata leads.Am J Cardiol. 2013; 112: 1616-1618Abstract Full Text Full Text PDF PubMed Scopus (12) Google Scholar, 12Brumberg G.E. Kaseer B. Shah H. Saba S. Jain S. Biventricular defibrillator patients have higher complication rates after revision of recalled leads.Pacing Clin Electrophysiol. 2012; 35: 665-671Crossref PubMed Scopus (6) Google Scholar, 13Liu J. Patel D. Rattan R. Brumberg G. Saini A. Vaghasia N. Bazaz R. Adelstein E. Jain S. Saba S. Failure-free survival of the Durata defibrillator lead.Europace. 2013; 15: 1002-1006Crossref PubMed Scopus (19) Google Scholar Fractured Fidelis leads often present with inappropriate ICD shocks from sensed noise, whereas externalized Riata leads are less likely to present with inappropriate shocks and thus its failure may not be readily apparent to patients or providers. Our data also show that the failure-free survival curves of the Fidelis and Riata diverge from that of nonrecalled leads at approximately 2 years. This finding has important implications on the duration of postmarketing surveillance of ICD leads by FDA and on the choice of lead models made by implanting physician, favoring models with longer track records. Defibrillator lead recalls have far reaching clinical ramifications, including increased cost to the health-care system for lead revisions and other procedures and increased risks to patients who have recalled leads. Based on our present study, newly developed ICD leads that are released to the market should be followed closely and intensely scrutinized for no <2 years after market release to evaluate for early signs of premature failure.In our present study, an overall ICD lead survival rate of 89.3% was seen at 5 years. Previous independent studies from Europe have estimated ICD lead survival rate to range from 85% to 98% at 5 years,14Goette A. Cantu F. van Erven L. Geelen P. Halimi F. Merino J.L. Morgan J.M. Scientific Initiative Committee of the European Heart Rhythm AssociationPerformance and survival of transvenous defibrillation leads: need for a European data registry.Europace. 2009; 11: 31-34Crossref PubMed Scopus (25) Google Scholar which is comparable with the 5-year survival rate that we report. Additionally, our data show a sharper decrease of ICD lead survival rate over the first 4 years of follow-up before the survival curve exhibits a plateau. This is explained by prophylactic lead replacement toward recalled leads. A very high number of functional Fidelis leads (16%) were replaced despite no electrical failure. The mean dwell time of all replaced Fidelis leads was 2.6 ± 1.2 years. Thus, the plateau effect of the overall ICD lead survival after 4 years is due to most prophylactic Fidelis lead replacements occurring before 4-year follow-up time.The present study is a single-center retrospective analysis and may therefore not be completely reflective of the experience at other institutions. Retrospective data collection may have introduced bias for which we cannot account. However, this study included all leads implanted at a high-volume center with multiple operators, which would minimize referral and/or selection bias. Smaller changes in lead parameters involving known recalled leads may have resulted in a lower threshold to replace these leads compared with nonrecalled leads. This study represents a comprehensive retrospective review of ICD lead survival rate from major US lead manufacturers. Our data demonstrate that failure-free survival curves of recalled ICD leads diverge from those of nonrecalled leads 2 years after implantation. Furthermore, an overall ICD lead survival rate on the order of 90% is seen at 5 years. Before an ICD lead is brought to market in the United States, rigorous premarketing testing is required to demonstrate its safety, quality, and reliability. These tests generally involve 3 separate phases: bench testing, animal testing, and human trials. Bench testing is performed to simulate the mechanical stresses that ICD leads are subject to by virtue of their intracardiac placement. An ICD lead may be subject to 500 million repetitive cardiac cycles over its lifetime, and thus, leads must demonstrate the ability to withstand such stresses ex vivo before animal and human studies. Subsequently, animal testing allows for assessment of lead handling and evaluation of in vivo performance before proceeding to investigational human trials. However, despite rigorous premarket release testing, the Riata lead (St. Jude Medical) demonstrated premature failure and cable externalization after market release, leading to a class I FDA recall and the withdrawal of the lead from the US market roughly 10 years after its release. The Sprint Fidelis (Medtronic) was not even subjected to premarket clinical testing because of its perceived similarity in design and structure to the Sprint Quattro (model 6947) lead, and thus, clinical data from the model 6947 lead supported the safety and efficacy of model 6949 lead.6Available at: http://manuals.medtronic.com.Google Scholar In the case of the Fidelis, the lead was recalled by the FDA 3 years after its US market release. The limitations of premarket release ICD lead testing highlight the importance of adequate postmarket release monitoring. In a 2007 editorial in Circulation, Maisel7Maisel W.H. Transvenous implantable cardioverter-defibrillator leads: the weakest link.Circulation. 2007; 115: 2461-2463Crossref PubMed Scopus (57) Google Scholar highlighted the inadequacies of ICD lead performance reporting and concluded that "… better designed lead monitoring… and more timely reporting of ICD lead performance must be required of manufacturers by the US Food and Drug Administration." Currently, there are no uniform guidelines for postmarket release ICD lead surveillance. The approach to postmarket release surveillance has been multifaceted, involving FDA, device manufacturers, and independent registries. FDA maintains all reported adverse events into the Manufacturer and User Device Experience (MAUDE) database. In addition, the HeartNet subset of the Medical Product Safety Network (MedSun) focuses on problems with medical devices, specifically used in the electrophysiology lab.8Available at: http://www.fda.gov/MedicalDevices/Safety/MedSunMedicalProductSafetyNetwork.Google Scholar Device manufacturers are not currently required to provide longitudinal lead performance studies, but most have chosen to do so, independently. Despite this multifaceted approach to ICD lead monitoring, there remain inadequacies in the present system. Our data show similar failure-free survival of the Riata and the Fidelis lead; however, the Riata lead was on the market for about 10 years before FDA recall compared with only 3 years for the Fidelis.9Liu J. Brumberg G. Rattan R. Jain S. Saba S. Class I recall of defibrillator leads: a comparison of the Sprint Fidelis and Riata families.Heart Rhythm. 2012; 9: 1251-1255Abstract Full Text Full Text PDF PubMed Scopus (49) Google Scholar This may be partially explained by the clinical manifestations of lead failure of each lead.10Liu J. Rattan R. Adelstein E. Barrington W. Bazaz R. Brode S. Jain S. Mendenhall G.S. Nemec J. Razak E. Shalaby A. Schwartzman D. Voigt A. Wang N.C. Saba S. Fluoroscopic screening of asymptomatic patients implanted with the recalled Riata lead family.Circ Arrhythm Electrophysiol. 2012; 5: 809-814Crossref PubMed Scopus (42) Google Scholar, 11Liu J. Qin D. Rattan R. Bazaz R. Adelstein E. Jain S.K. Saba S. Longitudinal follow-up of externalized Riata leads.Am J Cardiol. 2013; 112: 1616-1618Abstract Full Text Full Text PDF PubMed Scopus (12) Google Scholar, 12Brumberg G.E. Kaseer B. Shah H. Saba S. Jain S. Biventricular defibrillator patients have higher complication rates after revision of recalled leads.Pacing Clin Electrophysiol. 2012; 35: 665-671Crossref PubMed Scopus (6) Google Scholar, 13Liu J. Patel D. Rattan R. Brumberg G. Saini A. Vaghasia N. Bazaz R. Adelstein E. Jain S. Saba S. Failure-free survival of the Durata defibrillator lead.Europace. 2013; 15: 1002-1006Crossref PubMed Scopus (19) Google Scholar Fractured Fidelis leads often present with inappropriate ICD shocks from sensed noise, whereas externalized Riata leads are less likely to present with inappropriate shocks and thus its failure may not be readily apparent to patients or providers. Our data also show that the failure-free survival curves of the Fidelis and Riata diverge from that of nonrecalled leads at approximately 2 years. This finding has important implications on the duration of postmarketing surveillance of ICD leads by FDA and on the choice of lead models made by implanting physician, favoring models with longer track records. Defibrillator lead recalls have far reaching clinical ramifications, including increased cost to the health-care system for lead revisions and other procedures and increased risks to patients who have recalled leads. Based on our present study, newly developed ICD leads that are released to the market should be followed closely and intensely scrutinized for no <2 years after market release to evaluate for early signs of premature failure. In our present study, an overall ICD lead survival rate of 89.3% was seen at 5 years. Previous independent studies from Europe have estimated ICD lead survival rate to range from 85% to 98% at 5 years,14Goette A. Cantu F. van Erven L. Geelen P. Halimi F. Merino J.L. Morgan J.M. Scientific Initiative Committee of the European Heart Rhythm AssociationPerformance and survival of transvenous defibrillation leads: need for a European data registry.Europace. 2009; 11: 31-34Crossref PubMed Scopus (25) Google Scholar which is comparable with the 5-year survival rate that we report. Additionally, our data show a sharper decrease of ICD lead survival rate over the first 4 years of follow-up before the survival curve exhibits a plateau. This is explained by prophylactic lead replacement toward recalled leads. A very high number of functional Fidelis leads (16%) were replaced despite no electrical failure. The mean dwell time of all replaced Fidelis leads was 2.6 ± 1.2 years. Thus, the plateau effect of the overall ICD lead survival after 4 years is due to most prophylactic Fidelis lead replacements occurring before 4-year follow-up time. The present study is a single-center retrospective analysis and may therefore not be completely reflective of the experience at other institutions. Retrospective data collection may have introduced bias for which we cannot account. However, this study included all leads implanted at a high-volume center with multiple operators, which would minimize referral and/or selection bias. Smaller changes in lead parameters involving known recalled leads may have resulted in a lower threshold to replace these leads compared with nonrecalled leads. DisclosureThe authors have no conflicts of interest to disclose. The authors have no conflicts of interest to disclose.
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