A real‐world experience of atrioventricular synchronous pacing with leadless ventricular pacemakers

Abstract

Aims: The Micra TM transcatheter pacing system (TPS) (Medtronic) is the only leadless pacemaker that promotes atrioventricular (AV) synchrony via accelerometer-based atrial sensing. Data regarding the real-world experience with this novel system are scarce. We sought to characterize patients undergoing Micra TM -AV implants, describe percentage AV synchrony achieved, and analyze the causes for suboptimal AV synchrony. Methods:In this retrospective cohort study, electronic medical records from 56 consecutive patients undergoing Micra TM -AV implants at the Mayo Clinic sites in Minnesota, Florida, and Arizona with a minimum follow-up of 3 months were reviewed. Demographic data, comorbidities, echocardiographic data, and clinical outcomes were compared among patients with and without atrial synchronous ventricular pacing (AsVP) ≥ 70%.Results: Sixty-five percent of patients achieved AsVP ≥ 70%. Patients with adequate AsVP had smaller body mass indices, a lower proportion of congestive heart failure, and prior cardiac surgery. Echocardiographic parameters and procedural characteristics were similar across the two groups. Active device troubleshooting was associated with higher AsVP. The likely reasons for low AsVP were small A4-wave amplitude, high ventricular pacing burden, and inadequate device reprogramming.Importantly, in patients with low AsVP, subjective clinical worsening was not noted during follow-up. Conclusion:With the increasing popularity of leadless pacemakers, it is paramount for device implanting teams to be familiar with common predictors of AV synchrony and troubleshooting with Micra TM -AV devices.

Efficacy and Safety of Leadless Pacemakers for Atrioventricular Synchronous Pacing: A Systematic Review and Meta-Analysis

“…Of these articles, 75 studies related to leadless pacemakers were excluded because they did not report atrioventricular synchrony or combined other interventions, and 4 studies because they used the same cohort as other included studies. Ultimately, eight studies met the inclusion criteria for the meta-analysis [ 6 , 7 , 8 , 9 , 10 , 14 , 15 , 16 ]. The PRISMA flow chart is displayed in Figure 1 .…”

“…This approval substantially broadened the spectrum of patients eligible for leadless pacing. Subsequently, several observational studies reported on the early experience with this novel technology in patients with different pacing indications, including atrioventricular block, sinus node dysfunction, and atrial fibrillation with bradycardia [ 8 , 9 , 10 ]. However, the results of these studies varied.…”

“…However, the results of these studies varied. For instance, in a real-world study, the atrioventricular synchrony was much lower than in the initial MARVEL 2 study (62.9% vs 94.3%) [ 9 ]. Nevertheless, conclusions are limited due to the small sample sizes.…”

Novel method of atrial mechanical sensing for leadless atrioventricular synchronous pacing

“… 3 In this study, 95% of patients had >70% AV synchrony at rest. 3 However, 2 previous retrospective studies about Micra AV 4 , 5 demonstrated that only 65% of the patients had >70% AV synchrony, especially during a higher heart rate. These studies showed the importance of appropriate patient selection for the Micra AV and the importance of active device programming.…”

Implantation of a leadless pacemaker in young adults

“…10 With extensive programming optimization, the proportion of patients in whom AV synchrony can be achieved at rest with this technology can reach 65%-95%. 11,12 However, AV synchrony is lost during physical activity as the device switches to VVI-R mode at higher heart rates. Therefore, in its current iteration, this technology is not expected to provide major incremental benefits in exercise tolerance or performance over single-chamber leadless pacemakers.…”