B-po01-025 a real-world multicenter experience of atrioventricular synchronous pacing with leadless ventricular pacemakers

Recent advances in leadless pacing include atrioventricular (AV) synchrony. The Micra-AV transcatheter pacing system (TPS) uses accelerometer-based atrial sensing to ensure atrial synchronous ventricular pacing (AsVP). Data regarding the real-world experience of this novel system is lacking. Characterize patients undergoing Micra-AV implants, describe percentage AsVP achieved, and analyze the causes for lack of AV synchrony. In this retrospective study, medical records from 50 patients undergoing Micra-AV implants at the 3 Mayo Clinic (MN, FL, and AZ) sites with a minimum follow-up of 3 months were reviewed. Demographics, comorbidities, echocardiography, and clinical outcomes were compared among patients with and without AsVP ≥70%. Fifty-six percent patients achieved AsVP ≥ 70%. Patients with higher percentage of AsVP had smaller body habitus, lower proportion of congestive heart failure, and pulmonary hypertension. No significant differences were observed in other comorbidities, echocardiographic data, and procedural aspects (Table). Patients with lower AsVP were followed longer indicating implant date early after FDA approval. The most common etiology of high AsVP was active device troubleshooting, and the most common reasons for low AsVP were small atrial amplitudes, persistent atrial arrhythmias, and inadequate device programming. Importantly, in patients with low AsVP, subjective clinical worsening was not noted during follow-up. Real-world AV synchrony with Micra-AV TPS is lower than the original trial. Patient selection is critical, and there exists a learning curve to optimize AV synchrony.