Leadless vs. transvenous single-chamber pacing - propensity-matched comparison of outcomes

Abstract Background Clinical Trials have demonstrated the safety and efficacy of the leadless pacemaker. However, real-world outcome comparisons between patients receiving conventional VVI and leadless pacemakers are still scarce. The aim of this study was to evaluate short and long-term complications of patients receiving leadless pacemakers in comparison to a population of conventional VVI. Methods We conducted a single-centre retrospective study of patients receiving the leadless or a conventional VVI between 2014 and 2022. Propensity score matching was performed on 725 patients (156 leadless and 569 conventional) and according to age, sex, coronary artery disease (CAD), chronic kidney disease (CKD), haemodialysis and AF, with a 1:1 matching protocol without replacement (matching tolerance 5%). Complications that occurred up to one month after implantation were considered acute and included access site BARC ≥ 3 bleeding events, pacemaker pocket hematoma requiring medical intervention (either drainage o antibiotic therapy), femoral access infection, pneumothorax, pericardial effusion, cardiac tamponade, and dysfunction of the implanted device. Long-term complications were defined as those occurring at least one month after implantation and included device infection, need for reintervention, and device upgrades due to left ventricular dysfunction. The primary outcome was a composite of acute and long-term complications. Results A total of 312 patients (80 [73 - 86] years, 63% male, 79% with AF and 7% on dialysis) were included, 156 within each group. The main indication for PM implantation was AF with low ventricular rate (48%), followed by atrioventricular block (31%) and sick sinus syndrome (13%). In total, 19 patients (16%) had a previously implanted device, and 14 (4%) had previously been submitted to lead extraction, of which 10 (71%) were due to device-related infection. All of these were more frequent in patients receiving the leadless pacemaker (p = 0.001). During a median follow-up of 26 [11 - 47] months, a total of 32 patients (10%) had a complication related to the implantation of the device – table 1. While intra-hospital complications showed only a tendency towards higher incidence in the VVI group (5% vs 3%; p = 0.124), overall complications (16% vs 5%) and long-term complications (12% vs 2%) were higher in the VVI group (p < 0.001 for both). The Kaplan-Meier curves for the primary outcome showed a significantly lower event-rate for patients receiving the leadless pacemaker – Figure 1. Conclusions In this propensity-matched study, leadless pacemaker implantation was associated with a lower incidence of complications during follow-up, in comparison to conventional VVI pacemaker.