Faculty Bibliography

BACKGROUND:Patients go without pacemaker, defibrillator, and cardiac resynchronization therapies (devices) each year due to the prohibitive costs of devices. OBJECTIVE:We sought to examine data available from studies regarding contemporary risks of reused devices in comparison with new devices. METHODS:We searched online indexing sites to identify recent studies. Peer-reviewed manuscripts reporting infection, malfunction, premature battery depletion, and device related death with reused devices were included. The primary study outcome was the composite risk of infection, malfunction, premature battery depletion, and death. Secondary outcomes were the individual risks. RESULTS:Nine observational studies (published 2009 - 2017) were identified totaling 2 302 devices (2 017 pacemakers, 285 defibrillators). Five controlled trials were included in meta-analysis (2 114 devices; 1 258 new versus 856 reused). All device reuse protocols employed interrogation to confirm longevity and functionality, disinfectant therapy and, usually, additional biocidal agents, packaging and ethylene oxide gas sterilization. Demographic characteristics, indications for pacing, and median follow-up were similar. There were no device-related deaths reported and no statistically significant difference in risk between new versus reused devices for the primary outcome (2.23% versus 3.86% respectively, p = 0.807, OR = 0.76). There were no significant differences seen in the secondary outcomes for the individual risks of infection, malfunction, and premature battery depletion. CONCLUSIONS:Device reuse utilizing modern protocols did not significantly increase risk of infection, malfunction, premature battery depletion or device related death in observational studies. This data provides rationale for proceeding with a prospective multi-center non-inferiority randomized control trial.

BACKGROUND:The Biotronik DX lead is an attractive option due to its floating atrial bipole and its noninferiority compared to dual-chamber defibrillators. METHODS:We describe the case of atrial undersensing by the DX lead resulting in failure of the device to appropriately treat a slow ventricular tachycardia. CONCLUSION/CONCLUSIONS:This case underlies the importance of understanding the limitations to each lead technology as well as the underlying assumptions inherent to detection enhancement algorithms.

Aims: Benefits of automatic remote home monitoring (HM) among implantable cardioverter defibrillator (ICD) patients may require high transmission frequency. However, transmission reliability and effects on battery longevity remain uncertain. We hypothesized that HM would have high transmission success permitting punctual guideline based follow-up, and improve battery longevity. This was tested in the prospective randomized TRUST trial. Methods and results: Implantable cardioverter defibrillator patients were randomized post-implant 2:1 to HM (n = 908) (transmit daily) or to Conventional in-person monitoring [conventional management (CM), n = 431 (HM disabled)]. In both groups, five evaluations were scheduled every 3 months for 15 months. Home Monitoring technology performance was assessed by transmissions received vs. total possible, and number of scheduled HM checks failing because of missed transmissions. Battery longevity was compared in HM vs. CM at 15 months, and again in HM 3 years post-implant using continuously transmitted data. Transmission success per patient was 91% (median follow-up of 434 days). Overall, daily HM transmissions were received in 315 795 of a potential 363 450 days (87%). Only 55/3759 (1.46%) of unsuccessful scheduled evaluations in HM were attributed to transmission loss. Shock frequency and pacing percentage were similar in HM vs. CM. Fifteen month battery longevity was 12% greater in HM (93.2 +/- 8.8% vs. 83.5 +/- 6.0% CM, P < 0.001). In extended follow-up of HM patients, estimated battery longevity was 50.9 +/- 9.1% (median 52%) at 36 months. Conclusion: Automatic remote HM demonstrated robust transmission reliability. Daily transmission load may be sustained without reducing battery longevity. Home Monitoring conserves battery longevity and tracks long term device performance. Clinical trial registration: ClinicalTrials.gov; NCT00336284.

Management of patients with cardiac implantable electronic devices (CIEDs) has become complex given the complications that can occur with implanted lead systems. Clinical problems such as infection, lead failure, and occluded vessels create situations that demand intervention to remove leads. Due to adhesions that occur in the venous system and at the endomyocardial attachment site, simple traction to remove a lead is often not sufficient. Infection is a mandatory reason to remove the entire CIED system. Tools and techniques are now available that enable a skilled operator to extract leads with a great deal of efficacy and safety.

OBJECTIVES/OBJECTIVE:The MultiPoint Pacing (MPP) trial assessed the safety and efficacy of pacing 2 left ventricular sites with a quadripolar lead in patients with heart failure indicated for a CRT-D device. BACKGROUND:Cardiac resynchronization therapy nonresponse is a complex problem where stimulation of multiple left ventricular sites may be a solution. METHODS:Enrolled patients were indicated for a CRT-D system. Bi-ventricular (Bi-V) pacing was activated at implant. Three months later, clinical response was assessed and the patient was randomized (1:1) to receive Bi-V pacing or MPP. Patients were followed for 6 months post-randomization and clinical response was again assessed. RESULTS:The CRT-D system was successfully implanted in 455 of 469 attempted implants (97%). A total of 381 patients were randomized to Bi-V or MPP at 3 months. The primary safety endpoint was met with freedom from system-related complications of 93.2%. The primary efficacy endpoint of the noninferiority comparison of nonresponder rates between the 2 arms was met. Patients randomized to MPP arm and programmed to pace from anatomically distant poles (MPP-AS) responded to therapy at significantly higher rates than MultiPoint pacing-other programmed settings (MPP-Other). Within this group, 87% were responders at 9 months, 100% designated as nonresponders at 3 months converted to responders at 9 months, and 54% experienced an incremental response compared to MPP-Other. Also within MPP-AS, 92% of patients with de novo CRT-D implant were classified as responders compared with patients with MPP-Other. CONCLUSIONS:MPP is safe and effective for treating heart failure. The study met the pre-specified hypothesis that response to MPP is noninferior to Bi-V pacing with a quadripolar left ventricular lead. (MultiPoint Pacing IDE Study [MPP IDE]; NCT01786993).

BACKGROUND: Although the majority of Class III congestive heart failure (HF) patients treated with cardiac resynchronization therapy (CRT) show a clinical benefit, up to 40% of patients do not respond to CRT. This paper reports the design of the MultiPoint Pacing (MPP) trial, a prospective, randomized, double-blind, controlled study to evaluate the safety and efficacy of CRT using MPP compared to standard biventricular (Bi-V) pacing. METHODS: A maximum of 506 patients with a standard CRT-D indication will be enrolled at up to 50 US centers. All patients will be implanted with a CRT-D system (Quartet LV lead Model 1458Q with a Quadra CRT-D, Abbott) that can deliver both MPP and Bi-V pacing. Standard Bi-V pacing will be activated at implant. At 3 months postimplant, patients in whom the echocardiographic parameters during MPP are equal or better than during Bi-V pacing are randomized (1:1) to either an MPP or Bi-V arm. RESULTS: The primary safety endpoint is freedom from system-related complications at 9 months. Each patient's response to CRT will be evaluated using a heart-failure clinical composite score, consisting of a change in NYHA functional class, patient global assessment score, HF events, and cardiovascular death. The primary efficacy endpoint is the proportion of responders in the MPP arm compared with the Bi-V arm between 3 and 9 months. CONCLUSION: This trial seeks to evaluate whether MPP via a single quadripolar LV lead improves hemodynamic and clinical responses to CRT, both in clinical responders and nonresponders.

BACKGROUND: The design of pacemaker leads has continued to evolve; ease of lead handling, improved electrical performance and MRI conditional aspects have become more important, while safety remains critical. The INGEVITY family leads was designed to provide MRI conditional aspects, decreased diameter, and improved performance of pacemaker leads. The INGEVITY study is an investigational device exemption trial evaluating the acute and chronic safety and effectiveness of these leads. METHODS: Consecutive patients were included in 77 institutions worldwide, where 1657 leads (846 right ventricular active fixation leads, 213 right ventricular passive fixation leads, 121 right atrial passive fixation pre-formed J-leads and 477 right atrial active fixation leads) were implanted or attempted in 1060 subjects. RESULTS: At 3 month follow up, the electrical performance were: mean pacing threshold 0.67V at 0.5 ms pulse width, pacing impedance 773 ohms, mean P-wave amplitude 4.8 mV and R-wave amplitude 16.5 +/- 6.5 mV. Over a median follow-up of 31 months, 93 subjects died and 33 subjects reported lead-related complications. Lead-related complication-free rate from 0 to 3 months and 3 to 12 months for all leads was 98.4% and 99.7% respectively. The hazard of lead-related complications was observed to be decelerating over the course of follow-up (Weibull shape = 0.23). The overall lead dislodgment rate observed in the study was 1.3%, the perforation rate was 0.0% and the pericardial effusion rate 0.3%. CONCLUSIONS: The clinical performance of the INGEVITY lead demonstrated a high lead-related complication-free rate over 12 months of follow-up and excellent electrical characteristics.