Conduction disturbance recovery after permanent pacemaker implantation post-transcatheter aortic valve implantation: substudy of the LANDMARK trial

Background Permanent pacemaker implantation (PPI) remains a common complication after transcatheter aortic valve implantation (TAVI). It is known that some patients remain dependent on pacing, while others recover conduction function over time and become pacemaker-independent during follow-up. Purpose The aim of this study is to report the incidence and predictors of 1-year pacemaker dependency in the randomized LANDMARK trial. Methods This is a post-hoc subanalysis of the LANDMARK trial. The LANDMARK trial is a randomized, open-label, multi-centre, non-inferiority trial that compares clinical outcomes of a Myval transcatheter heart valve (THV) series with the contemporary THVs (Sapien and Evolut series). A total of 768 patients with severe symptomatic native aortic stenosis were assigned in a 1:1 ratio either to receive a Myval (n=368) or contemporary THV (n=368). Patients in the contemporary group were further randomized (1:1) to the Sapien or Evolut group. We aimed to obtain 1-year pacemaker follow-up data retrospectively in patients who received a permanent pacemaker within 30 days after TAVI. In case 1-year follow-up data were not available, the follow-up data closest to the 1-year timepoint was collected. Patients were excluded from this subanalysis if they did not undergo TAVI, were converted to SAVR, had a pre-procedure pacemaker, died within 1 year after TAVI, had no available pacemaker follow-up data, or were implanted with cardiac resynchronization therapy (CRT). Recovery of conduction disturbances was defined as ventricular pacing (VP) rate≦1%. Results Permanent pacemakers were implanted in 122 (15.9% of 768 randomized) patients within 30 days after TAVI. Excluding the patients who died within 1 year (n=10), had missing follow-up data (n=10), or received CRT (n=3), 99 patients were eligible for this subanalysis. The median time from pacemaker implantation to follow-up was 413 (280-588) days and the median VP rate was 28% (3-95%). Conduction recovery occurred in 18% (18/99). The recovery group was younger than the non-recovery group (78.6±3.0 vs 81.1±5.1 years, p=0.045). The implantation depth did not differ significantly (5.7±3.5 vs 5.8±2.8 mm, p=0.94). Recovery rates by THV type were: Myval 24% (11/46), Sapien 19% (5/26), and Evolut 7% (2/27), with no significant difference among groups (Figure 1). In univariable logistic regression, older age showed a borderline association with lower odds of recovery (odds ratio 0.90, 95% CI 0.80-1.00, p=0.05). Conclusion In the randomized LANDMARK trial, the recovery of conduction disturbances (VP≦1%) was observed in 18% of the patients who received a permanent pacemaker, which is consistent with previous studies.For image description, please refer to the figure legend and surrounding text.