Pathway of Leadless Pacemaker in Korea: From Now to Future

Leadless intracardiac transcatheter pacing system, or a leadless pacemaker emerged as new cardiac pacing technology designed for deviating from complications related to transvenous cardiac pacing system. Leadless pacemakers are located to right ventricular septum or apex (septal location preferred) via transfemoral venous approach. Therefore, complications related to lead(s), lead insertion or pocket might not be expected. These features made leadless pacing system as preferred option to transvenous pacing system in patients with venous access problem in chest including hemodialysis, complex venous anatomy and high infection risk.

The first leadless pacemaker had a feature of single chamber sensing and pacing (VR type). Recent technical advance made it possible to dual chamber sensing and/or pacing.¹⁾,²⁾ Several years later from the initial leadless pacemaker implantation, Micra™, developed by Medtronic, VR type leadless pacemaker was introduced to Korea. Similar efficacy and safety might be expected for same device implantation at different region. However, Micra VR pacemaker cohort analysis in Korea revealed significantly different results compared to global studies.³⁾,⁴⁾,⁵⁾ Cha et al.⁶⁾ delineated performance and complications in Korean Micra VR pacemaker as well as pointing unique features in Korean implantation.

Success rate of Micra VR pacemaker implantation in Korea was 99% with sustainable capture threshold less than 1.0V at 0.24 ms through 12 months. Even R wave sensing and resistance remained stable. Acute implantation success rate and stable device performance over long-time were excellent and not different among several continents. Notably, acute and long-term complication rate in Korea was only 1.0%,⁶⁾ which is significantly lower than global studies (Figure 1). Even Asian countries showed complication rates as 3.33% and 2.0% in Japan and China.⁷⁾ Of course, favorable patient selection contributed lower complication rate in Korea. However, major advance for leadless pacemaker implantation in Korea was the crucial key for the final excellent efficacy and safety outcomes.

Figure 1. Major complication rates through 12 months by Micra VR study. Comparison of major complication rate between Korean and global (PAR, IDE) studies. Adopted from Cha MJ, Park SJ, Cho Y, et al. Safety and performance of the Micra VR leadless pacemaker in a South Korean cohort: a comparison to global studies. Korean Circ J 2025;55:526-37.⁶⁾ .

CI = confidence interval; HR = hazard ratio; IDE = Micra VR global IDE study; KOR = Micra VR MAP South Korea study; PAR = Micra VR global post-approval registry study.

Simple procedure and no external device visibility with leadless pacemaker increased quality of life (QoL) with higher satisfaction. Through patient-reported outcomes in components of EQ-5D-5L, health status was significantly improved after leadless pacemaker implantation, especially in activity, anxiety and self-care in Korea.⁶⁾ Immediate hospital discharge and return to usual life with simple procedure is another factor for higher satisfaction. Also, no motion limitation and esthetic appearance contribute to increased activity with reduced anxiety. QoL is the major determinant for the pacemaker type selection, even leadless pacemaker. Consistent results for the QoL improvement with leadless pacemaker compared to trans-venous pacemaker across the different continents should be incorporated into detailed discussion with patients.⁸⁾,⁹⁾,¹⁰⁾ Balanced physicians and patient’s preference are needed for the pacemaker type selection.

VR type leadless pacemaker implantation rate in Korean patients with sinus node dysfunction was higher than global studies. Even mean age was younger and combined comorbidities in Korean patients were lower than the other studies. Atrial sensing and pacing are the best option for them. Although VDD type or dual chamber type leadless pacemaker was not available during the initial implantation, careful contemplations might result in different pacemaker type selection.

Fortunately, VDD type leadless pacemaker is available in Korea, and detailed analysis with them is highly expected. Procedure success rate and complication rate with VDD type leadless pacemaker are expected to be as excellent as the current VR type leadless pacemaker. However, indication for implantation is expected to be totally different.

Cha et al.⁶⁾ introduced results of the first leadless pacemaker outcomes in Korea. Now, clinical outcomes of VDD and dual type leadless pacemaker in Korea are required. Also, comparison their result with other studies in different continents and trans-venous type pacemaker is highly required to make leadless pacemaker as the new treatment option in Korea.