Clinical evaluation of a small implantable cardiac monitor with a long sensing vector

INTRODUCTION: We conducted this study to show the safety and efficacy of a new implantable cardiac monitor (ICM), the BioMonitor 2 (Biotronik SE & Co. KG; Berlin, Germany), and to describe the arrhythmia detection performance. METHODS: The BioMonitor 2 has an extended sensing vector and is implanted close to the heart. It can transmit up to six subcutaneous electrocardiogram strips by Home Monitoring each day. We enrolled 92 patients with a standard device indication for an ICM in a single-arm, multicenter prospective trial. Patients were followed for 3 months, and 48-h Holter recordings were used to evaluate the arrhythmia detection performance. RESULTS: One patient withdrew consent and in one patient, the implantation failed. Two study device-related serious adverse events were reported, satisfying the primary safety hypothesis. Implantations took 7.4 ± 4.4 min from skin cut to suture. At 1 week, the R-wave amplitude was 0.75 ± 0.53 mV. In the 82 patients with completed Holter recordings, all patients with arrhythmias were correctly identified. False positive detections of arrhythmia were mostly irregular rhythms wrongly detected as atrial fibrillation (episode-based positive predictive value 72.5%). Daily Home Monitoring transmission was 94.9% successful. CONCLUSION: Safety and efficacy of the new device has been demonstrated. The detected R-wave amplitudes are large, leading to a low level of inappropriate detections due to over- or undersensing.