Long term outcomes of dual chamber leadless pacemaker insights from European patients data
C Garweg, P Defaye, P Neuzil, J Fernandez Concha, G Hindricks, M Bongiorni, J Deharo, S M Delgado, L Ganz, A Bulusu, R KnopsAbstract
Background
One-year results from the pivotal clinical study on dual-chamber leadless pacemakers (LP) demonstrated favorable safety and performance. To expand these findings and assess outcomes over time of these novel devices, extended follow-up data are required.
Purpose
To assess the long-term safety and efficacy up to 2 years following implantation of a dual-chamber LP in a European cohort of patients.
Methods
The dual-chamber LP system safety and performance were evaluated in a prospective, multicenter, single-arm study of patients indicated for dual-chamber pacing. The clinical trial had pre-specified endpoints at 3- and 12-months follow-up. Exploratory analyses were evaluated through 2-years follow-up for patients enrolled at European centers. The analyses reported herein with 2-year data were not pre-specified or powered. Freedom from device or procedure-related serious adverse device effects (referred to as complications) was estimated using Kaplan-Meier analysis. Electrical measurements and implant-to-implant (i2i) communication success (a lower-bound surrogate for atrioventricular synchrony) were summarized as the mean ± standard deviation at implantation and each follow-up visit. The estimated battery longevity was summarized at the 24-month visit.
Results
A total of 99 patients had an attempted de novo dual-chamber LP implantation at 12 sites in Europe (across Italy, Austria, Belgium, Czech Republic, France, the Netherlands, Spain and the United Kingdom). All 99 patients were successfully implanted with a right atrial (RA) and right ventricular (RV) LP with i2i communication established and dual-chamber (DDD(R)) pacing programmed. The complication free rate on the day of the implant was 97.0% (95% CI 90.9%, 99.0%). At 365 days the complication free rate was 92.9% (95% CI 85.7%, 96.5%) and at 720 days it was 91.3% (95% CI 83.2%, 95.6%). A total of 8 patients experienced 8 complications, of which atrial fibrillation and threshold elevation were the most common. The majority of complications (62.5%, 5/8) occurred within 90 days; of these early complications, 80% (4/5) occurred within the first 24 hours following the implantation procedure (Figure 1). Figure 2 illustrates a declining pacing capture threshold (at 0.4 ms pulse width), increasing p-wave amplitude, and stable impedance for the RA LP over 24 months. Mean i2i communication success from the RA to RV and RV to RA improved from discharge to 6 months (93.5±7.2% and 90.0±10.7% respectively at 6 months). The i2i communication remained further stable and high through 24 months (92.9±7.4% from RA to RV and 89.2±11.1% RV to RA at 24 months). The total battery longevity for all pacing modes, calculated based on the estimated remaining longevity at 24 months, was 6.9±4.3 and 10.5±3.7 years for the RA and RV LPs respectively.
Conclusions
These results demonstrate the 2-year safety, electrical performance and high i2i communication of a dual-chamber LP in a European cohort of patients.Complication Free RateElectrical Measurements