Safety and Efficacy of Leadless Pacemakers: A Systematic Review and Meta-Analysis

Area of Science:

• Cardiology
• Biomedical Engineering
• Medical Devices

Background:

• Leadless pacemakers represent a novel advancement in cardiac rhythm management.
• Evidence regarding the safety and efficacy of leadless pacemakers, particularly those implanted in the right ventricle, requires further elucidation.

Purpose of the Study:

• To conduct a systematic review and meta-analysis evaluating the safety and efficacy of leadless pacemakers.
• To specifically examine complication rates and pacing capture thresholds for Nanostim and Micra devices.

Main Methods:

• A comprehensive search of PubMed and Embase databases was performed for studies published before June 6, 2020.
• Included studies were observational, focusing on Nanostim and Micra leadless pacemakers.
• Primary safety outcome was major complications; primary efficacy endpoint was acceptable pacing capture threshold (≤2 V). Pooled estimates were calculated using the Freedman-Tukey double arcsine transformation.

Main Results:

• The Micra leadless pacemaker demonstrated a pooled complication incidence of 0.46% at 90 days and 1.77% at 1 year.
• Compared to transvenous pacemakers, Micra was associated with 51% lower odds of complications (OR, 0.49; 95% CI, 0.34-0.70).
• At 1 year, 98.96% of patients with Micra achieved good pacing capture thresholds. Nanostim showed higher complication rates and variable capture thresholds.

Conclusions:

• The Micra leadless pacemaker exhibits a favorable safety profile with low complication rates and effective electrical performance up to one year post-implantation.
• While promising, further data from randomized controlled trials are necessary to support the broad clinical adoption of leadless pacemakers.