European experience with a first totally leadless cardiac resynchronization therapy pacemaker system

Area of Science:

• Cardiology
• Medical Devices
• Electrophysiology

Background:

• Conventional cardiac resynchronization therapy (CRT) systems face limitations in certain patient populations.
• Leadless pacing systems like Micra offer advantages but may require upgrade for CRT.
• Heart failure patients with specific pacing needs or contraindications for traditional CRT benefit from innovative solutions.

Purpose of the Study:

• To assess the technical feasibility, safety, and efficacy of combining Micra and WiSE-CRT systems for totally leadless CRT.
• To evaluate acute QRS duration reduction and procedural success.
• To explore mid-term outcomes including ejection fraction and heart failure class.

Main Methods:

• Eight patients indicated for Micra upgrade or unsuitable for conventional CRT underwent implantation of the WiSE-CRT system synchronized with an existing Micra pacemaker.
• Technical success was defined by successful WiSE-CRT implantation and synchronized pacing.
• Primary endpoints included acute QRS duration reduction and freedom from major adverse events.

Main Results:

• All eight WiSE-CRT devices successfully detected Micra pacing and delivered synchronized left ventricular (LV) pacing.
• Significant acute reduction in QRS duration was observed (204.38 ms to 137.5 ms, P=0.012).
• At 6 months, a significant increase in LV ejection fraction (28.43% to 39.71%, P=0.018) was noted, without significant changes in LV reverse remodeling or NYHA class.

Conclusions:

• The combination of Micra and WiSE-CRT systems enables successful totally leadless CRT delivery.
• The WiSE-CRT system offers a unique solution for upgrading Micra patients to CRT capability without device replacement.
• Future advancements in leadless pacing may further expand the application of this combined approach.