Impact of Interventricular membranous septum length on pacemaker need with different Transcatheter aortic valve implantation systems.

Background The need for new permanent pacemaker implantation (PPI) after Transcatheter Aortic Valve Implantation (TAVI) remains a critical issue. Membranous Septum (MS) length is associated with PPI after TAVI. The aim of this study was to identify different MS thresholds for the contemporary THV-platforms. Methods This retrospective, case-control study enrolled all patients who underwent a successful TAVI procedure with contemporary THV-platforms in the Erasmus University Medical Center between January 2016 and March 2020. The follow-up period for new PPI was 30 days. MS-length was determined by Computed Tomography. Results The study consisted 653 TAVI patients with median age 80.6 years (IQR 74.7–84.8). New PPI occurred in 120 patients (18.4%). Patients with new PPI had a shorter MS-length (2.9 mm (IQR 2.3–4.3) vs. 4.2 mm (IQR 2.9–5.7), p < 0.001). MS-length < 3 mm identified a high-risk phenotype with 30.3% PPI-rate (OR 6.5 [95%CI 2.9–14.9]), MS-length 3–6 mm an intermediate-risk phenotype with 15.4% PPI-rate (OR 2.7 [95%CI 1.2–6.2]) and MS > 6 mm a low-risk phenotype with a 6.3% PPI-rate (reference). For the Lotus valve, there was no significant difference in PPI-rates between the high-risk (45.8%, OR 3.5 [95%CI 0.8–15.1]) and low-risk group (20%). By multivariate analysis MS-length, Agatston-score, use of Lotus valve, and ECG with first-degree AV block, RBBB or bifascular block were independent predictors for new PPI. Conclusion MS-length was an independent predictor for new PPI post-TAVI. Three phenotypes were found based on MS-length. MS < 3 mm was universally associated with a high risk for new PPI (>30%). MS > 6 mm represented a low-risk phenotype with PPI-rate < 10%. PPI-rate varied per THV type in the intermediate phenotype. PPI-rate with Lotus was high regardless of MS-length. • The length of the membranous interventricular septum is an independent predictor for pacemaker implantation post-TAVI. • MS length is an argument to choose between the different valve platforms to minimize the risk for new pacemaker post-TAVI. • MS length < 3 mm gives a high risk for pacemaker (>30%) regardless of the valve platform. • The pacemaker-rate varied per valve platform by a MS length > 3 mm. [ABSTRACT FROM AUTHOR]