Abstract Body (Do not enter title and authors here): Background
Leadless pacemaker has emerged as a promising alternative to traditional transvenous pacemaker (PM) among elderly patients who are at high risk of complications.

Objective
This study aims to assess and compare 5-year clinical outcomes of leadless PM versus transvenous single-chamber PM in elderly patients using a multi-national dataset.


Methods
Using the TriNetX Analytics Research Network, we included patients aged ≥65 years who underwent leadless versus transvenous single-chamber PM implantation between 1/1/2014 and 1/1/2020. Propensity score matching (PSM) was performed by using patient’s demographic, LVEF, cardiac comorbidities, and medications. The study outcomes included all-cause mortality and adverse cardiovascular events over a 5-year follow-up period.

Results
After PSM, 7,501 patients in each group were analyzed. Leadless PM was associated with a significantly lower odds of 5-year all-cause mortality (odds ratio [OR]: 0.534; 95% confidence interval [CI]: 0.497-0.575), heart failure exacerbation (OR: 0.779, 95% CI: 0.721-0.841), major bleeding (OR: 0.666, 95% CI: 0.604-0.734), cardiac arrest (OR: 0.747, 95% CI: 0.646-0.864) and stroke (OR: 0.825, 95% CI: 0.750-0.908) compared to transvenous single-chamber PM. No significant difference was observed between the two groups in all-cause hospitalization (OR: 1.006, 95%CI: 0.938-1.079), cardiac thrombus (OR: 1.077, 95%CI: 0.791-1.465) or venous thromboembolism (OR: 1.028, 95%CI: 0.916-1.153).

Conclusion
Leadless PM was associated with significantly improved mortality and cardiovascular outcomes compared to transvenous single-chamber PM in elderly patients. These findings support the strong consideration of leadless pacing as a strategy to reduce mortality and improve clinical outcomes in this high-risk population.