Predictors and Trends of New Permanent Pacemaker Implantation: A Subanalysis of the International Navitor IDE Study

Background: The Navitor Investigational Device Exemption (IDE) study is a prospective, multicenter, global study assessing the safety and effectiveness of the Navitor valve in a population with severe, symptomatic aortic stenosis who are at high and extreme surgical risk. The impact of pre-existing conduction abnormalities and implantation technique on new permanent pacemaker implantation (PPI) for the Navitor platform is not fully understood. Therefore, the goal of this analysis was to investigate the associations between patient and procedural factors and the 30-day new PPI rate. Methods: A total of 260 patients who underwent implantation of a Navitor valve in the Navitor IDE study were reviewed. Patients with preprocedural permanent pacemakers (n = 28) were excluded. Baseline risk factors were assessed for statistical significance. Multivariable logistic regression analyses were performed to identify independent predictors of new PPI. Results: Mean age of the pacemaker-naïve population was 83.3 ± 5.2 years, 58.6% were female, average Society of Thoracic Surgeons score was 3.8% ± 1.9%, median frailty score was 1 (interquartile range 1, 2), and 17.7% were deemed at extreme surgical risk. Pre-existing first-degree atrioventricular block and right bundle branch block significantly increased the risk of new PPI postimplantation, whereas left bundle branch block did not. Membranous septum length in relation to noncoronary cusp implant depth was a significant predictor of new PPI, with higher rates of new PPI observed when noncoronary cusp implant depth exceeded membranous septum length. Analysis of implant depth alone revealed deeper implants were associated with a higher rate of new PPI, regardless of patient baseline conduction abnormality. Conclusions: The 30-day rate of new PPI in the Navitor IDE study is associated with patient pre-existing baseline conduction disturbances and implantation depth.