Hauser, Robert G.

Knowledge of major adverse clinical events (MACE) associated with ICD and pacemaker (PM) pulse generator (PG) and lead performance may be important for managing patients who have these devices. The aim of our study was to assess MACE in our Multicenter Registry. Participating centers prospectively reported ICD and PM PG and lead failures, and PG replaced for normal battery depletion (NBD). Data included dates of implant and removal, failure signs including the elective replacement indicator (ERI), clinical consequences, and reason for removal. MACE were death, inappropriate shocks (IAS), syncope, heart failure, ischemia, sustained tachyarrhythmias, and replacement of a normally functioning PG or lead due to a manufacturers recall. Since 1998, 6,291 ICD and PM PG and leads were removed from service. Of 5,212 ICD and PM PGs, 4,562 (88%) were removed for NBD, 346 (7%) for a recall, and 304 (5%) for component defects. MACE are shown in the Table . The deaths (n=2) were due to component defects causing an ICD PG to short-circuit and a PM PG to deliver high rate pacing. Thus, of the 304 component defects in our database, 2 resulted in death (0.7%). No deaths were associated with ICD or PM lead failure, but 2 deaths occurred following PM lead extraction. The ERI, signifying NBD, resulted in 48 MACE, primarily syncope (67%). Most MACE are due to replacement of normally functioning recalled devices. However, our experience suggests that death due to ICD and PM PG component or lead failure is rare; this finding may be important for managing patients who have recalled devices. Overall, MACE may be substantially reduced by improving high voltage lead reliability, and by providing physiologic ERIs.

Background— Postmarket medical device surveillance in the United States depends largely on voluntary reporting of adverse events. Consequently, early safety signals may be missed, exposing patients to potentially hazardous products. The aim of this study was to assess the feasibility of using an automated safety surveillance tool to detect early signals that a marketed implantable cardiac device was underperforming. Methods and Results— For this purpose, we performed simulated prospective monthly full-cohort and propensity-matched comparative survival analyses on our 3-center database of Sprint Fidelis and Quattro Secure implantable cardioverter-defibrillator leads, using a commercially available automated surveillance tool that was preset to trigger an alert if the log rank probability value was <0.05. During the study, 84 of 1035 Fidelis (8.1%) and 23 of 1675 Quattro (1.4%) leads failed. The simulated full-cohort analysis triggered a sustained alert for Fidelis leads beginning 13 months after the first implant and 2 years before Fidelis leads were removed from the market. Of the 1035 patients who had Fidelis leads, up to 969 (93.6%) were successfully matched to Quattro patients. In the propensity-matched analysis, the alert triggered 22 months after the first Fidelis implant and more than 1 year before the lead was recalled. Conclusions— An active automated safety surveillance system could have identified this implantable cardiovascular device problem substantially sooner than was achieved through existing postmarket surveillance methods. Such a tool, when applied to clinical registries and remote monitoring databases, may limit the exposure of large populations to underperforming and potentially hazardous cardiovascular devices.

Background— Sprint Fidelis (Fidelis) implantable cardioverter-defibrillator leads are prone to fractures that have caused adverse events, primarily inappropriate shocks, and a few reported deaths. More than 100 000 patients have Fidelis leads. No independent multicenter long-term performance information exists for this lead, and single-center studies suggest that certain patients are at increased risk for Fidelis failure. Our aim was to assess the longevity of Fidelis leads and to evaluate clinical variables and adverse events associated with Fidelis failure. The results were compared with like data for Quattro Secure (Quattro) implantable cardioverter-defibrillator leads implanted at our centers. Methods and Results— This 3-center study included adults ≥18 years of age who received Fidelis or Quattro leads for the prevention of sudden cardiac death. From November 2001 to January 2009,1023 Fidelis and 1668 Quattro leads were implanted and followed up. The failure rate for Fidelis leads was 2.81%/y compared with 0.43%/y for Quattro leads ( P <0.0001). No deaths or injuries occurred as a result of lead failure, but 42% of fractures caused inappropriate shocks. The survival of Fidelis leads at 4 years was 87.0% (95% confidence interval, 83.6 to 90.1) compared with 98.7% (95% confidence interval, 97.9 to 99.4) for Quattro leads ( P <0.0001). Multivariate predictors of Fidelis failure were younger age (hazard ratio, 0.98; 95% confidence interval, 0.96 to 0.99), female gender (hazard ratio, 0.61; 95% confidence interval, 0.40 to 1.00), and cardiac disease ( P =0.041). Conclusions— Compared with Quattro leads, the survival of Fidelis leads continues to decline, and Fidelis failure is notably higher in younger patients, women, individuals with hypertrophic cardiomyopathy, and patients with arrhythmogenic right ventricular dysplasia or channelopathies. These findings have significant implications for the management of patients who have Fidelis leads, and they demonstrate the importance of weighing clinical variables in assessments of implantable cardioverter-defibrillator lead performance.