Micra TPS implantation in the right ventricular outflow tract yielded a narrower median paced QRS duration (142 ms) compared to mid-septal (159 ms; P<0.001) and apical (181 ms; P<0.001) positions.
Observational (n=133)
No
Does RVOT implantation of the Micra TPS improve paced QRS duration and maintain safety compared to mid-septal and apical positions in patients requiring leadless pacing?
Implantation of the Micra leadless pacemaker in the right ventricular outflow tract is safe and achieves a narrower paced QRS complex compared to mid-septal and apical positions.
Absolute Event Rate: 142% vs 159%
p-value: p=<0.001
BACKGROUND: With its steerable transcatheter delivery system, the Micra can be deployed in nonapical positions within the right ventricle, potentially allowing reduction of the paced QRS width. We sought to evaluate the safety and long-term performance of the right ventricular outflow tract (RVOT) pacing using the Micra transcatheter pacing system (TPS). We also compared the paced QRS between RVOT, mid-septal, and apical implant positions. METHODS: All patients who underwent a Micra TPS implantation at the University Hospitals of Leuven were enrolled in this observational study. Right ventricular (RV) position of the device was assessed on per-procedural ventriculography. Paced QRS was analyzed and follow-up completed at 1 month and then every 6 months. RESULTS: Among the 133 patients included (mean follow-up: 13 ± 11 months), 45 were implanted in the RVOT, 58 midseptally, and 30 at the apex. All implant procedures were successful and no pericardial effusion was encountered within the 30 days post-implant. Two major complications were reported with devices implanted at the apex. Pacing impedance was significantly higher in the RVOT compared to the mid-septal and apical position (P < .001). Pacing threshold and R-wave amplitude did not differ over time in either position. The median narrowest paced QRS duration was observed in the RVOT (142 ms) compared to mid-septal (159 ms; P < .001), and apical position (181 ms; P < .001). CONCLUSION: Implantation of the Micra TPS in the RVOT is safe and feasible. Electrical performance over time was comparable to mid-septal and apical positions. The narrowest paced QRS complexes is achieved with RVOT pacing.
Garweg et al. (Wed,) conducted a observational in Patients requiring Micra TPS implantation (n=133). Micra TPS in right ventricular outflow tract (RVOT) vs. Micra TPS in mid-septal and apical positions was evaluated on Paced QRS duration (p=<0.001). Micra TPS implantation in the right ventricular outflow tract yielded a narrower median paced QRS duration (142 ms) compared to mid-septal (159 ms; P<0.001) and apical (181 ms; P<0.001) positions.