1Kerckhoff Klinik GmbH Abteilung für Kardiologie Bad Nauheim, Deutschland; 2Kerckhoff Klinik GmbH Herzchirurgie Bad Nauheim, Deutschland; 3Universitätsklinikum Gießen und Marburg GmbH Medizinische Klinik I - Kardiologie und Angiologie Gießen, Deutschland
Background: Leadless pacemakers have been used clinically for about 10 years. The single-chamber devices are indicated for bradyarrhythmia due to permanent atrial fibrillation or to prevent syncope. In comparison to conventional transvenous systems the leadless technology avoids lead- and device pocket-related complications. The implantation is performed transvenously via a femoral vascular access. One of the main advantages of the new leadless pacemaker "AVEIR™ VR" is the possibility of mapping before it is finally screwed in. Further advantages are the long-lasting battery with up to twice the battery life of the "Micra™ VR" and the possibility to remove the device at the end of battery life. This study presents our experiences with the “AVEIR™ VR”.
Methods: Since licensing in Europe in September 2023, 36 “AVEIR™ VR” have already been implanted in 13 German hospitals. Of these, 9 implantations were performed in our center. We analyzed these with regard to operating time, the need to reposition, contrast agent consumption and radiation exposure. In addition, we compared values measured peri- and postinterventionally and analyzed the selected programming, the expected battery duration and complications.
Results: We included 9 men with bradycardic atrial fibrillation (mean age: 82 yr). The median total operating time was 102 min (range 82-157) and the median implantation time, defined as the time between correct catheter lock position and pacemaker release, was 27 min (range 16-88). On average, the device had to be repositioned 6 times, however, repositioning after screwing in was only necessary in one case. Except for two cases with anatomy-dependent difficulties (procedures 3 and 4) and one unsuccessful implantation attempt (kinking of IVC), a learning curve with decreasing frequency of repositioning over time can be seen (Figure 1). We observed a positive correlation between the number of repositioning and procedure duration (Pearson correlations coefficient (r) = 0.93, p < 0.001). X-ray time (r = 0.89, p = 0.003) and contrast agent consumption (r = 0.86, p = 0.006) also correlate positively with the required repositioning. As expected, the peri- and postoperative difference in the measured impedance and stimulus threshold decreased. The final measurement resulted in an average impedance of 620 Ω (SD 174), average sensing of 10.7 mV (SD 5) and a median stimulus threshold (at 0.4 ms) of 0.5 mV. The basal heartrate was set at 50-65 bpm, resulting in a ventricular pacing rate between 1% (patient with planned AVN ablation) and 91% (mean 31%). There is a negative correlation with the expected battery life (r = -0.83, p = 0.17), which was 19.3 years on average. With regard to complications, there was one Proglide® failure with postoperative hematoma, without need for intervention.
Conclusion: We can report good experiences and a satisfactory learning curve from our first “AVEIR™ VR” implantations. Noteworthy is the possibility of mapping before screw fixation, which facilitates implantation in patients with endocardial fibrosis (e.g. chronic Lyme disease). According to the current guidelines, we consider the leadless pacemaker to be indicated for permanent bradyarrhythmia and for patients with stenosis of superior veins. Another advantage of the “AVEIR™ VR” could be the upgrade option to the announced dual-chamber system “AVEIR™ DR”, which will soon be approved in the USA and is expected to be approved in Europe in summer of 2024.