Introduction:

The Micra™ leadless intracardiac pacing system recently has been introduced and implemented into clinical routine. Feasibility, implantation safety and acute success have been proven in the setting of controlled studies. Even apart from controlled studies, this new technology was beneficial for the individual patient. Therefore, we aimed to report our single center follow-up (FU) data in comparison with the results of the prospective controlled Micra™ study.

Methods:

In 150 patients (98 men; age: 80±9 y) successful Micra™ implantation was performed.

Pacemaker interrogation was performed one to seven days after implantation and during FU (1; 3; 6, then every 6 month) up to 60 months. Data were assessed in a real-life setting and compared with existing data of a controlled prospective trial.

Results:

The implantation was successful in all 150 attempts without procedure or device-related major complications. During Follow up there were two patients developing severe heart failure symptoms resulting in an implantation of a CRT-device and switching of the leadless pacemaker system.

The average acute thresholds, sensing and impedance after system release were: 0.62±0.45V@0.24ms; 10,55±3,61mV and 697±178Ohm. During follow up of up to 5 years neither, pacemaker failure, nor infections were reported. Measurements were reevaluated for long-term thresholds, sensing and impedance: 0.45 ± 0.06V @ 0.24 ms; 17,05 ±4,65 mV and 562 ± 79 Ohm. During five years, no significant changes from acute to long-term measurements were detectable.  In comparison to the controlled trial, our measurements of thid real-life cohort were very similar.

Conclusion:

In a real life setting, the implantation of the leadless Micra™ system demonstrates high rate of implant success without major complications. We were also able to show stable long-term system parameters in the clinical setting of up to five years of follow up.