Introduction:

The Micra AV™ intracardiac leadless pacing system has been introduced recently and implemented into clinical routine. Size and composition of this second-generation leadless pacemaker are the same as the available MICRA VVI system. Feasibility, implantation safety and procedural success are assumed to be similar than proven in the setting of controlled studies with the first generation device. Therefore, we aimed to report our first single center follow-up (FU) data in comparison with the results of the prospective controlled Micra VR™ study and the results of our own Micra VR™ population.

Methods:

After MicraAV™ implantation pacemaker interrogation was performed one to seven days after implantation and during FU (one and three months). Data were assessed in a real-life setting and compared with existing data of a controlled prospective trial and the own data of the first generation VVI-device. Furthermore, we investigated the rate of AV-synchronous Stimulation (AVSR).

Results:

The MicraAV™ implantation was successful in 15/15 patients (53% male; mean age: 76±8 y) without procedure or device-related major complications.

The average acute thresholds, sensing and impedance after system release were: 0.66±0.45V@0.24ms; 8,9±3,61mV and 724±178Ohm. During follow up of up to 3 months, neither pacemaker failure nor infections were reported. Measurements were reevaluated for “long-term” thresholds, sensing and impedance: 0.44 ± 0.06V @ 0.24 ms; 12,00 ±4,65 mV and 552 ± 69 Ohm. During three months of FU, no significant changes were detectable.  

In three patients with increased RV-pacing (due to AV-block II° or III°), we had three months of follow up data with an AV-synchronous stimulation rate (AVSR) of 86%.

Conclusion:

In a real-life setting, the implantation of the leadless Micra AV™ system demonstrated a high rate of implantatiom success without major complications. We were also able to show stable system parameters in the clinical setting during short term follow up. We were able to reconfirm the positive results of the IDE trial in this clinical scenario.