Rationale and design of the Lead Evaluation for Defibrillation and Reliability study: Safety and efficacy of a novel ICD lead design

High predicted durability for the novel small-diameter OmniaSecure defibrillation lead

BACKGROUND

Defibrillation leads remain the Achilles heel of implantable cardioverter-defibrillators. As patients with implantable cardioverter-defibrillators are living longer and battery longevity increases, more durable leads are needed. The LEADR trial evaluated the novel, lumenless, small-diameter, OmniaSecure defibrillation lead and demonstrated favorable safety and efficacy profile as well as zero fractures through 12.7 ± 4.8 months and remains in clinical follow-up. To augment the clinical trial, advanced cardiac lead reliability modeling was used to project long-term lead durability.

OBJECTIVE

We aimed to project the 10-year fracture-free survival of the OmniaSecure defibrillation lead using reliability modeling.

METHODS

The validated reliability model, which incorporates patient and bench test data, was used to project the 10-year fracture-free survival of the OmniaSecure lead. A subset of LEADR trial patients underwent biplane fluoroscopy imaging during cardiac and patient motion to evaluate the lead's bending curvature in vivo. Bench tests then reproduced these use conditions with greater bending curvatures than observed in patients to exaggerate stress on the lead and to evaluate the lead fatigue strength.

RESULTS

The reliability modeling projects a 98.2% fracture-free survival rate of the OmniaSecure lead at 10 years, including a 10-year fracture-free survival rate of 97.9% in adolescents, exceeding both the modeled and clinical 10-year performance of the highly reliable, larger diameter Sprint Quattro lead.

CONCLUSION

Consistent with early clinical trial experience, modeling projects highly durable 10-year performance of the OmniaSecure lead, including within the active adolescent pediatric population, which may uniquely benefit from a novel 4.7F defibrillation lead designed for reliability.

CLINICALTRIALS

GOV IDENTIFIER

NCT04863664.

Atrioventricular node ablation for atrial fibrillation in the era of conduction system pacing

Despite key advances in catheter-based treatments, the management of persistent atrial fibrillation (AF) remains a therapeutic challenge in a significant subset of patients. While success rates have improved with repeat AF ablation procedures and the concurrent use of antiarrhythmic drugs, the likelihood of maintaining sinus rhythm during long-term follow-up is still limited. Atrioventricular node ablation (AVNA) has returned as a valuable treatment option given the recent developments in cardiac pacing. With the advent of conduction system pacing, AVNA has seen a revival where pacing-induced cardiomyopathy after AVNA is felt to be overcome. This review will discuss the role of permanent pacemaker implantation and AVNA for AF management in this new era of conduction system pacing. Specifically, this review will discuss the haemodynamic consequences of AF and the mechanisms through which 'pace-and-ablate therapy' enhances outcomes, analyse historical and more recent literature across various pacing methods, and work to identify patient groups that may benefit from earlier implementation of this approach.

Safety, efficacy, and reliability evaluation ofa novel small-diameter defibrillation lead: Global LEADR pivotal trial results

BACKGROUND

Implantable cardioverter-defibrillators last longer, and interest in reliable leads with targeted lead placement is growing. The OmniaSecure defibrillation lead is a novel, small-diameter, catheter-delivered lead designed for targeted placement, based on the established SelectSecure SureScan MRI Model 3830 lumenless pacing lead platform.

OBJECTIVE

This trial assessed safety and efficacy of the OmniaSecure defibrillation lead.

METHODS

The worldwide LEADR pivotal clinical trial enrolled patients indicated for de novo implantation of a primary or secondary prevention implantable cardioverter-defibrillator or cardiac resynchronization therapy defibrillator, all of whom received the study lead. The primary efficacy end point was successful defibrillation at implantation per protocol. The primary safety end point was freedom from study lead-related major complications at 6 months. The primary efficacy and safety objectives were met if the lower bound of the 2-sided 95% credible interval was >88% and >90%, respectively.

RESULTS

In total, 643 patients successfully received the study lead, and 505 patients have completed 12-month follow-up. The lead was placed in the desired right ventricular location in 99.5% of patients. Defibrillation testing at implantation was completed in 119 patients, with success in 97.5%. The Kaplan-Meier estimated freedom from study lead-related major complications was 97.1% at 6 and 12 months. The trial exceeded the primary efficacy and safety objective thresholds. There were zero study lead fractures and electrical performance was stable throughout the mean follow-up of 12.7 ± 4.8 months (mean ± SD).

CONCLUSION

The OmniaSecure lead exceeded prespecified primary end point performance goals for safety and efficacy, demonstrating high defibrillation success and a low occurrence of lead-related major complications with zero lead fractures.

Standard Defibrillator Leads for Left Bundle Branch Area Pacing: First-in-Man Experience and Short-Term Follow-Up

The authors report for the first time to their knowledge, implantation of a standard implantable cardioverter-defibrillator lead for permanent delivery of left bundle branch area pacing. Implantation was successful and safe in 11 of 12 patients, with adequate defibrillation testing, good electrical and electrocardiographic parameters, and uneventful device-related short-term follow-up.

Therapeutic potential of conduction system pacing as a method for improving cardiac output during ventricular tachycardia

BACKGROUND

Ventricular tachycardia (VT) reduces cardiac output through high heart rates, loss of atrioventricular synchrony, and loss of ventricular synchrony. We studied the contribution of each mechanism and explored the potential therapeutic utility of His bundle pacing to improve cardiac output during VT.

METHODS

Study 1 aimed to improve the understanding of mechanisms of harm during VT (using pacing simulated VT). In 23 patients with left ventricular impairment, we recorded continuous ECG and beat-by-beat blood pressure measurements. We assessed the hemodynamic impact of heart rate and restoration of atrial and biventricular synchrony. Study 2 investigated novel pacing interventions during clinical VT by evaluating the hemodynamic effects of His bundle pacing at 5 bpm above the VT rate in 10 patients.

RESULTS

In Study 1, at progressively higher rates of simulated VT, systolic blood pressure declined: at rates of 125, 160, and 190 bpm, -22.2%, -42.0%, and -58.7%, respectively (ANOVA p < 0.0001). Restoring atrial synchrony alone had only a modest beneficial effect on systolic blood pressure (+ 3.6% at 160 bpm, p = 0.2117), restoring biventricular synchrony alone had a greater effect (+ 9.1% at 160 bpm, p = 0.242), and simultaneously restoring both significantly increased systolic blood pressure (+ 31.6% at 160 bpm, p = 0.0003). In Study 2, the mean rate of clinical VT was 143 ± 21 bpm. His bundle pacing increased systolic blood pressure by + 14.2% (p = 0.0023). In 6 of 10 patients, VT terminated with His bundle pacing.

CONCLUSIONS

Restoring atrial and biventricular synchrony improved hemodynamic function in simulated and clinical VT. Conduction system pacing could improve VT tolerability and treatment.

Severe Tricuspid Regurgitation in a Patient with a Transvenous Dual-chamber Pacemaker: Considerations for Diagnosis and Management

Cardiac implantable electronic device leads can contribute to tricuspid regurgitation and also complicate surgical and transcatheter interventions to manage tricuspid regurgitation. Here we present a case of a patient with sinus node dysfunction and complete heart block who underwent extraction of a right ventricular pacing lead before tricuspid valve surgery. We review the data regarding the contribution of leads to tricuspid regurgitation and the benefits of lead extraction, risks of jailing leads during tricuspid interventions, and pacing considerations around tricuspid valve procedures.