Leadless Micra pacemakers: Estimating long-term longevity. A real word data analysis

Background: Although leadless pacemakers have demonstrated satisfactory safety and efficacy, there is limited published data regarding the estimated lifespan in real word clinical scenarios. Methods: Between May 2015 and September 2023, all consecutive patients who underwent implantation of a single-chamber leadless Micra pacemaker were included in the One Hospital ClinicalService project and systematically tracked through remote monitoring at 15 Italian cardiology sites. Data on procedures, complications, electrical parameters, and estimated battery longevity were collected at baseline and annually during follow-up (FU). Additionally, virtual battery longevity (VBL) was calculated as the sum of the actual battery life consumed and the predicted remaining longevity (VBL = months consumed + months predicted), providing an estimate of the device's total battery lifespan. Results: Patient and device data were gathered from 391 patients. Over a median follow-up period of 33.9 months (with interquartile range from 17.5 to 52.0 months), one patient experienced battery depletion. When examining VBL across all patients, the median VBL at baseline was 172 months (with a I-III interquartile range of 146 to 200 months), and VBL remained consistent or greater from the time of implantation up to seven years post-implant. The strongest predictor of VBL depletion within 8 years was capture threshold at implant greater than 1 V @ 0.24 ms. Conclusion: In clinical practice, leadless pacemakers appear to have a median expected longevity ranging from 14 to 17 years. Having a stimulation threshold less than or equal to 1 V @ 0.24 ms seems to be an excellent predictor of increased longevity.