Comparison of 30-day complications between a tine-based and a screw-in helix fixation single-chamber ventricular leadless pacemaker. Results of a propensity-matched analysis from a multicentre, nationwide registry.

Background: Medtronic Micra VR and Abbott Aveir VR are two single-chamber ventricular leadless pacemakers (L-PMs) currently available in clinical practice. They differ in their design, fixation mechanism (tine-based fixation for Micra VR, screw-in helix fixation for Aveir VR), and implantation technique. Little comparative safety data are available for these LPMs.

Objective: To compare the rate of acute procedure-related complications between patients undergoing Aveir VR versus Micra VR implantation.

Methods: A prospective, multicentre, observational registry enrolled consecutive patients who underwent Aveir VR or Micra VR implantation. The rate and nature of device-related complications at 30-day follow-up were analyzed and compared between the two groups. Individual 1:1 propensity matching of baseline characteristics was performed.

Results: A total of 1,141 patients (75.9±14.8 years, 60.2% male) were enrolled: 211 Aveir VR, and 930 Micra VR. Propensity matching yielded 189 matched pairs. In the matched cohort, the risk of device-related complications at 30 days of follow-up of the two L-PMs was similar (2.1 vs. 2.1%; p=1.000). Device migration (1.6 vs. 0.5%; p=0.315) and vascular complications (0.5 vs. 1.1%; p=0.562) were the most frequent complications with no significant differences between the two groups. Cardiac perforation was rare (1 case in the Micra VR group, no cases in the Aveir VR group).

Conclusions: The risk of acute device-related complications associated with Aveir VR and Micra VR L-PMs implantation was similar. These findings suggest that, despite differences in design, fixation mechanism and implantation technique, these two devices appear to have a similar short-term safety profile.