Evolution of Tined Leadless Pacemaker Implantation: Patient Selection, Implant Volume, Center Characteristics, and Safety Trends

BACKGROUND: As leadless pacing approaches a decade in clinical practice, we sought to assess how device complications have changed over time, and how variations in patient, implanter volume, and facility characteristics are associated with these changes. OBJECTIVE: To examine rates of cardiac perforations after leadless pacemaker implantation over time, and the associations between patient, implanter volume, and facility characteristics with these outcomes, including the extent of variation attributable to implanters and facilities. METHODS: Medicare claims linked to a manufacturer's device registration data were used to identify patients implanted with a tined leadless pacemaker from 2017 to 2024. Patient selection across implanters and facilities was evaluated by examining differences in patient characteristics and their impact on patient-adjusted model estimates. Random-intercept models were fitted to estimate variation attributable to implanters and facilities. RESULTS: Among 46,698 implants, 19,446 (41.6%) were Micra AV; patients had a mean age of 80.4 years and a high Charlson Comorbidity Index (4.7±3.4). Cardiac perforation rates declined over time (adjusted Coefficient -0.13, 95% CI -0.19 - -0.06, p-value<0.01). Higher implanter volume was associated with fewer perforations (OR 0.93 per additional 10 implants, 95% CI 0.88-0.98; p-value<0.01). Differences in patient characteristics across providers and facilities were observed; however, adjustment for these differences did not materially alter the associations between implanters and facility and perforation rates. CONCLUSION: In Medicare patients with tined leadless pacemakers, cardiac perforation rates declined over time and were lower in those implanted by more experienced implanters. Variation in outcomes was more closely associated with implanters than facilities.