Experience with malfunctioning leadless pacemakers: Troubleshooting and management during medium-term follow-up

BACKGROUND The Nanostim leadless pacemaker (LP) was launched in 2012. However, the use of Nanostim LP was suspended because of safety concerns. OBJECTIVE The aim of this study was to report our experience with the management of malfunctioning Nanostim LPs, including premature battery depletion. METHODS Fifty-one consecutive patients (mean age 83610 years; 65% male) who underwent Nanostim LP implantation between 2014 and 2016 at Isala Clinics were identified. Two patients were excluded from the analysis because of incomplete follow-up. The mean follow-up duration was 1114 +/- 560 days. RESULTS Nanostim LP malfunction occurred in 20 of 49 patients (40.8%). Premature LP battery failure was observed in 18 of 20 affected patients (90%). Furthermore, malpacing/malsensing was observed in 1 patient and mechanical dislocation of the Nanostim LP occurred in 1 patient. Of note, 17 of 18 Nanostim LPs with premature battery depletion (94%) showed normal device parameters 3 months before the diagnosis of (impending) premature battery failure. In 12 patients, Nanostim LPs with a mean device age at the time of extraction of 10406467 days was successfully extracted without complications. Implantation of another LP or a transvenous device was successfully performed in all 20 patients with Nanostim LP malfunction. All known cases of early-life battery failure were identified during the 3-monthly follow-up consultations. CONCLUSION The incidence of Nanostim LP early-life battery failure was higher than previously reported. Nanostim LP extraction in an older population seems to be safe and effective. Three-monthly follow-up seems to be effective at preventing in-between Nanostim LP-related hospitalization.