Recommendations from the Heart Rhythm Society Task Force on Lead Performance Policies and Guidelines

Same-day discovery of implantable cardioverter defibrillator dysfunction in the TRUST remote monitoring trial: influence of contrasting messaging systems

Aims

Assess whether automatic remote home monitoring (HM) permits same-day evaluation of implantable cardioverter defibrillator (ICD) system dysfunction.

Methods and results

Compromised ICD system integrity (generator/lead) demands prompt evaluation. Home monitoring promises earlier discovery but may be limited by technological differences and follow-up mechanism. We tested whether HM enabled event review within 24 h, and contrasted differing messaging mechanisms. Nine hundred and eight patients in the TRUST prospective multicentre trial were followed by HM for 15 months. ICD system problems automatically triggered notifications: repeatedly (‘redundant’) for impedance deviations and elective replacement indication (ERI), but only a single transmission for ‘30 J ineffective’. Detection time from event onset to physician evaluation was measured. Forty-three system-related alerts occurred; 42% were asymptomatic, 42% were actionable, and 22 of 43 (51%) were viewed within 24 h. Redundant notifications were: 1 ERI, 9 shock impedance, 2 ventricular and 6 atrial pacing impedance. Most (11/18; 61%) were detected in <24 h. Others elicited daily notifications without interruption until resolution. For single transmissions, 11 of 25 (44%) events were detected on the same day. Most (56%, 14/25) were detected between 1 and 39 days (mean 10.0 ± 13.0 days). Ten of 14 events were detected by HM and 4 at the time of office visits. These observations suggest single transmissions were vulnerable to detection failure. Mean detection time of redundant events was 1.1 ± 1.8 vs. single transmission 5.6 ± 10.9 days (P = 0.05). Hence, redundant notification avoided late detection.

Conclusion

Same-day discovery of ICD dysfunction, even if asymptomatic, was achievable. For those events not evaluated within 24 h, repetitive messaging promoted earlier discovery. Reorganization of clinical follow-up methods may maintain early reaction ability.

Clinical Trials registration information

ClinicalTrials.gov; NCT00336284.

Telemedicine and cardiac implants: what is the benefit?

Cardiac implantable electronic devices are increasing in prevalence. The post-implant follow-up is important for monitoring both device function and patient condition. However, practice is inconsistent. For example, ICD follow-up schedules vary from 3 monthly to yearly according to facility and physician preference and availability of resources. Recommended follow-up schedules impose significant burden. Importantly, no surveillance occurs between follow-up visits. In contrast, implantable devices with automatic remote monitoring capability provide a means for performing constant surveillance, with the ability to identify salient problems rapidly. Remote home monitoring reduces the volume of device clinic visits and provides early detection of patient and/or system problems.

Use of remote monitoring in the management of system-related complications in implantable defibrillator patients

Remote monitoring of implantable defibrillators (ICDs) is designed to minimise regular follow-up visits and to facilitate early detection of adverse events. With the increased rate of ICD implantations in today's clinical setting and multiple device advisories, which pose management challenges, this approach becomes very attractive. The aim of this article is to present the role of remote monitoring in the detection of system-related complications, its potential benefits and its barriers in the outpatient management of ICD patients.

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

BACKGROUND

Riata and Riata ST leads (St Jude Medical, Sylmar, CA) were recalled in 2011. These leads are prone to externalized conductors. However, it is electrical malfunctions 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 malfunction. 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 malfunction; an indeterminate death was a death that was nonsudden or evidence of lead malfunction was not provided; a not lead-related 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.

Early Detection of an Underperforming Implantable Cardiovascular Device Using an Automated Safety Surveillance Tool

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.

Introduction of new industry standards for cardiac implantable electronic devices: balancing benefits and unexpected risks

The DF-4 connector is a novel industry standard for the connection of a defibrillator lead to the generator. It aims at reducing the bulk created by two or three pins at the proximal end of the defibrillator lead and its corresponding ports at the header of the device. Having only one connection port between the lead and the device reduces the material in the pocket, the risk of lead-to-port mismatch, may lower the risk of lead abrasion, and probably makes the implantation procedure a little easier since only one set screw is required. However, all these conceived benefits are related to convenience rather than to a medical need.

After the recent experiences with the possible negative clinical impact of ‘minor’ changes like simply downsizing a defibrillator lead, a word of caution is warranted. The lead is the weakest part of the defibrillator system, complex in design and undergoing constant stress through movement. It is very hard to predict which issues may evolve over time with the changes in lead design. Does the perceived benefit really outweigh an unpredictable risk in a sensitive medical product like a defibrillator? This article tries to address the possible issues of the new spring contacts instead of set screws, the proximity of the low- and high-voltage connections as well as the inability of adding a pace/sense or an additional shock lead without a special adaptor, and advocates a measured speed in the introduction of this technology.

Longevity of Sprint Fidelis Implantable Cardioverter-Defibrillator Leads and Risk Factors for Failure

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.

An appropriate defibrillation threshold obtained by the combined connection between two shock leads and ICD generator

A 60-year-old man with arrhythmogenic right ventricular cardiomyopathy was readmitted for the battery exchange of his implantable cardioverter-defibrillator (ICD). Since (i) he had been treated with a dual-coil shock lead (Sprint Fidelis, Medtronic) and (ii) pre-operative venography showed mild collateral flow to the left subclavian vein, a single-coil lead was additionally implanted. However, the single-coil defibrillation system was unable to terminate the induced ventricular fibrillation (VF), thus dual defibrillation shock pathways were created using the connection to the superior vena cava coil of the Fidelis lead. The combined connections of the two shock leads provided an appropriate margin of the defibrillation threshold.

Automatic remote monitoring of implantable cardioverter-defibrillator lead and generator performance: the Lumos-T Safely RedUceS RouTine Office Device Follow-Up (TRUST) trial

BACKGROUND

Monitoring performance of implantable cardioverter-defibrillator (ICD) generators and leads is important. Methods available are with in-person evaluations or by automatic remote home monitoring (HM). These were prospectively evaluated and compared in the TRUST trial. The HM technology tested performed daily self-checks and databasing with rapid event notifications for out-of-range (including asymptomatic) conditions.

METHODS AND RESULTS

Patients (n=1339) were randomly assigned after ICD implant 2:1 to HM or to conventional groups. Both groups underwent scheduled checks every 3 months and were followed for 15 months. In HM, in-person office visits were scheduled at 3 and 15 months. At 6, 9, and 12 months, HM only was used with subsequent office visits if necessary. Between these time points, ICDs triggered event notifications for system integrity problems. Patients randomly assigned to conventional follow-up were evaluated with office visits only. HM and conventional patients were similar (age, 63.3±12.8 versus 64.0±12.1 years; 72.0% versus 73.1% male; New York Heart Association II class, 55.9% versus 60.4%; left ventricular ejection fraction, 29.0±10.7% versus 28.5±9.8%; coronary artery disease, 64.8% versus 71.7%; primary prevention, 72.2% versus 73.8%; DDD devices, 57.8% versus 56.6%). Four patients crossed over from conventional to HM because of advisories. Scheduled checks were more successfully accomplished in HM (92.7% versus 89.2% in conventional, P<0.001). Sixty-two device-related events (53 in HM versus 9 in conventional) were observed in 46 patients (40 [4.4%] in HM versus 6 [1.39%] in conventional, P=0.004). Forty-seven percent were asymptomatic. HM detected generator and lead problems earlier (HM versus conventional: median, 1 versus 5 days; P=0.05). A total of 20 device problems (eg, lead fracture, elective replacement indicators) requiring surgical revision (0.012 per patient-year) were found, 15 in HM and 5 in the conventional groups. Other events were managed nonsurgically (eg, reprogramming, initiation of antiarrhythmics).

CONCLUSIONS

ICD lead and generator malfunction was infrequent and often asymptomatic. Only a minority of detected events required surgical intervention. Automatic HM enhanced discovery, permitted prompt detection, and facilitated management decisions. Longitudinal parameter trending, with component function evaluated daily by remote monitoring, may enable long-term performance assessment.

CLINICAL TRIAL REGISTRATION

URL: http://clinicaltrials.gov. Unique identifier: NCT00336284.

Efficacy and safety of automatic remote monitoring for implantable cardioverter-defibrillator follow-up: the Lumos-T Safely Reduces Routine Office Device Follow-up (TRUST) trial

BACKGROUND

Monitoring implantable cardiac device function and patient condition is important. The Lumos-T Safely Reduces Routine Office Device Follow-Up (TRUST) trial tested the hypothesis that remote home monitoring with automatic daily surveillance (HM) is safe and effective for implantable cardioverter-defibrillator follow-up for 1 year and enables rapid physician evaluation of significant events.

METHODS AND RESULTS

In total, 1339 patients were randomized 2:1 to HM or conventional follow-up. Follow-up checks occurred at 3, 6, 9, 12, and 15 months after implantation. HM was used before office visits at 3 and 15 months in the HM group. At 6, 9, and 12 months, HM only was used but was followed by office visits if necessary. Conventional patients were evaluated with office visits only. Scheduled office visits and unscheduled evaluations, incidence of morbidity, and time elapsed from first event occurrence in each patient to physician evaluation were tracked for each group. HM and conventional patients were similar (age, 63.3+/-12.8 versus 64.0+/-12.1 years; gender, 72.0% versus 73.1% male; New York Heart Association class II, 55.9% versus 60.4%; pathology: left ventricular ejection fraction, 29.0+/-10.7% versus 28.5+/-9.8%; coronary artery disease, 64.8% versus 71.7%; primary prevention indication, 72.2% versus 73.8%; and dual-chamber implants, 57.8% versus 56.6%). HM reduced total in-hospital device evaluations by 45% without affecting morbidity. In the HM group, 85.8% of all 6-, 9-, and 12-month follow-ups were performed remotely only, indicating that HM provided sufficient assessment in the majority. Median time to evaluation was <2 days in the HM group compared with 36 days in the conventional group (P<0.001) for all arrhythmic events.

CONCLUSIONS

HM is safe and allows more rapid detection of actionable events compared with conventional monitoring in patients with implantable electronic cardiac devices.

Safety and efficacy of a new magnetic resonance imaging-compatible pacing system: early results of a prospective comparison with conventional dual-chamber implant outcomes

BACKGROUND

A new pacing system has been designed and tested preclinically for safe use in the magnetic resonance imaging (MRI) environment. Experience with this innovative system has not yet been reported.

OBJECTIVE

The purpose of this study was to verify the safety and effectiveness of this newly designed system compared to conventional DDD implant outcomes.

METHODS

Over an 11-month period, 107 consecutive patients (71 men and 36 women; age 72.6 +/- 8.5 years) were implanted with either the MRI system (n = 50; MRI group) or a dual-chamber, active-fixation lead (Medtronic 4076) non-MRI system (n = 57; DDD group). Data were collected at implant and during postoperative follow-up at 1, 3, 6, and 12 months. Procedural and fluoroscopic times at implant, as well as lead measurements, handling characteristics, and procedural-related complications, were prospectively analyzed.

RESULTS

The implantation success rate in both groups was 100%. Cephalic access was 63% for MRI patients and 70% for DDD patients (P = NS). Follow-up was obtained for all patients (median 6.8 months, range 3-12 months). At implant and at the end of follow-up, stimulation thresholds, sensing, and impedance were acceptable. No cases of high pacing thresholds or inadequate sensing were noted. No complications occurred, and no patient experienced subsequent lead displacement.

CONCLUSION

This prospective, controlled study provides strong evidence that the feasibility and safety of this novel technology compare favorably with those of the conventional technique.

ICD Lead Design and the Management of Patients with Lead Failure

The implantable cardioverter defibrillator (ICD) lead is critical to the function of the ICD system. The mortality reduction associated with ICDs implanted for primary prevention indications has been made possible by the development of effective and reliable transvenous ICD leads. Mortality rates for implantation of transvenous ICD lead systems are currently less than 0.5%. The reliability and functional characteristics of a lead are often not known until it has been in widespread use. An understanding of the mechanism of lead failure is essential for proper patient management. This article describes the design and construction of ICD leads, discusses lead failure, and reviews subsequent management of patients.