Mechanisms of Lead Failure by Recall Status and Manufacturer: Results From the Pacemaker and Implantable Defibrillator Leads Survival Study ("PAIDLESS").

OBJECTIVES: The aim of this study was to determine the differences in lead failure mechanisms across the major United States implantable defibrillator lead manufacturers (Boston Scientific, Medtronic, and St. Jude Medical), between all non-recalled and recalled leads, and between two recalled lead families (Medtronic Sprint Fidelis and the St. Jude Medical Riata and Riata ST). METHODS: This was a single-center, non-randomized, retrospective study analyzing 3802 patients with 4078 leads who underwent implantable defibrillator lead implantation between February 1, 1996 and December 31, 2011. Lead failure mechanisms were defined as lead fracture, insulation defect, and other. RESULTS: A total of 153 leads (3.8%) failed during the trial period. Failed Medtronic and St. Jude Medical leads presented predominantly as lead fractures (75.8% and 52.8%, respectively). Failed Boston Scientific leads displayed greater variability, although many also failed by fracture (44.4%). The majority of failed non-recalled and recalled leads presented as fractures (50.7% and 82.9%, respectively). The recalled Medtronic Sprint Fidelis and St. Jude Medical Riata/Riata ST leads primarily presented as fractures (89.3% and 65.0%, respectively). Patients whose lead failed via an insulation defect or other mechanism appeared to have a faster time to mortality following lead failure than patients whose lead failed via fracture (P<.01 and P=.02, respectively). CONCLUSIONS: Lead fracture is the most common form of lead failure regardless of the failure points previously identified in these leads. Patients who experienced a lead failure as a result of an insulation defect or other mechanism appeared to die faster than patients whose lead failed via fracture.

Differences in Approaches and Outcomes of Defibrillator Lead Implants Between High-Volume and Low-Volume Operators: Results From the Pacemaker and Implantable Defibrillator Leads Survival Study ("PAIDLESS").

OBJECTIVES: The purpose of this study was to investigate the relationship between operator volume and implantable defibrillator lead failure and patient mortality at a single large implanting center. METHODS: This study analyzed the differences between high-volume and low-volume defibrillator implanters in the Pacemaker and Implantable Defibrillator Lead Survival Study ("PAIDLESS") between February 1, 1996 and December 31, 2011 at NYU Winthrop Hospital. "High-volume" was defined as performing ≥500 implants over the study period, while "low-volume" was defined as performing <500 implants. Comparisons between the procedure volume groups were performed using Fisher's Exact test, Wilcoxon rank-sum test, and Kaplan-Meier analysis as appropriate. RESULTS: Eight operators participated in the study, four of whom were high-volume operators. Of 3801 patients, a total of 3149 (83%) were operated upon by high-volume operators. Low-volume operators implanted fewer recalled leads (12% vs 42%; P<.001) and more often obtained venous access through the cephalic vein cutdown approach (63% vs 38%; P<.001) than high-volume operators. Kaplan-Meier analysis revealed shorter time to lead failure in the low-volume group (P=.02). Time to mortality was not significantly different between the high-volume and low-volume groups (P=.18). When adjusted for lead recall status, patients of high-volume operators were 43% less likely to experience lead failure compared to patients of low-volume operators. CONCLUSIONS: High-volume defibrillator implanters selected a higher percentage of recalled leads, but their patients were less likely to encounter lead failure when adjusted for lead recall status compared to low-volume operators.

The Number of Recalled Leads is Highly Predictive of Lead Failure: Results From the Pacemaker and Implantable Defibrillator Leads Survival Study ("PAIDLESS").

OBJECTIVES: The purpose of this study was to determine if implantation of multiple recalled defibrillator leads is associated with an increased risk of lead failure. BACKGROUND: The authors of the Pacemaker and Implantable Defibrillator Leads Survival Study ("PAIDLESS") have previously reported a relationship between recalled lead status, lead failure, and patient mortality. This substudy analyzes the relationship in a smaller subset of patients who received more than one recalled lead. The specific effects of having one or more recalled leads have not been previously examined. METHODS: This study analyzed lead failure and mortality of 3802 patients in PAIDLESS and compared outcomes with respect to the number of recalled leads received. PAIDLESS includes all patients at Winthrop University Hospital who underwent defibrillator lead implantation between February 1, 1996 and December 31, 2011. Patients with no recalled ICD leads, one recalled ICD lead, and two recalled ICD leads were compared using the Kaplan-Meier method and log-rank test. Sidak adjustment method was used to correct for multiple comparisons. All calculations were performed using SAS 9.4. P-values <.05 were considered statistically significant. RESULTS: This study included 4078 total ICD leads implanted during the trial period. There were 2400 leads (59%) in the no recalled leads category, 1620 leads (40%) in the one recalled lead category, and 58 leads (1%) in the two recalled leads category. No patient received more than two recalled leads. Of the leads categorized in the two recalled leads group, 12 experienced lead failures (21%), which was significantly higher (P<.001) than in the no recalled leads group (60 failures, 2.5%) and one recalled lead group (81 failures; 5%). Multivariable Cox's regression analysis found a total of six significant predictive variables for lead failure including the number of recalled leads (P<.001 for one and two recalled leads group). CONCLUSIONS: The number of recalled leads is highly predictive of lead failure. Lead-based multivariable Cox's regression analysis produced a total of six predictive variable categories for lead failure, one of which was the number of recalled leads. Kaplan-Meier analysis showed that the leads in the two recalled leads category failed faster than both the no recalled lead and one recalled lead groups. The greater the number of recalled leads to which patients are exposed, the greater the risk of lead failure.

Gender-Related and Age-Related Differences in Implantable Defibrillator Recipients: Results From the Pacemaker and Implantable Defibrillator Leads Survival Study ("PAIDLESS").

OBJECTIVES: The purpose of this study was to investigate the influences of gender and age on defibrillator lead failure and patient mortality. BACKGROUND: The specific influences of gender and age on defibrillator lead failure have not previously been investigated. METHODS: This study analyzed the differences in gender and age in relation to defibrillator lead failure and mortality of patients in the Pacemaker and Implantable Defibrillator Leads Survival Study ("PAIDLESS"). PAIDLESS includes all patients at Winthrop University Hospital who underwent defibrillator lead implantation between February 1, 1996 and December 31, 2011. Male and female patients were compared within each age decile, beginning at 15 years old, to analyze lead failure and patient mortality. Statistical analyses were performed using Wilcoxon rank-sum test, Fisher's exact test, Kaplan-Meier analysis, and multivariable Cox regression models. P<.05 was considered statistically significant. No correction for multiple comparisons was performed for the subgroup analyses. RESULTS: A total of 3802 patients (2812 men and 990 women) were included in the analysis. The mean age was 70 ± 13 years (range, 15-94 years). Kaplan-Meier analysis found that between 45 and 54 years of age, leads implanted in women failed significantly faster than in men (P=.03). Multivariable Cox regression models were built to validate this finding, and they confirmed that male gender was an independent protective factor of lead failure in the 45 to 54 years group (for male gender: HR, 0.37; 95% confidence interval, 0.14-0.96; P=.04). Lead survival time for women in this age group was 13.4 years (standard error, 0.6), while leads implanted in men of this age group survived 14.7 years (standard error, 0.3). Although there were significant differences in lead failure, no differences in mortality between the genders were found for any ages or within each decile. CONCLUSIONS: This study is the first to compare defibrillator lead failure and patient mortality in relation to gender and age deciles at a single large implanting center. Within the 45 to 54 years group, leads implanted in women failed faster than in men. Male gender was found to be an independent protective factor in lead survival. This study emphasizes the complex interplay between gender and age with respect to implantable defibrillator lead failure and mortality.