Ap-452680-1 clinical, anatomical and pacing characteristics associated with follow-up pacing burden of prophylactic permanent pacemaker for transcatheter aortic valve implantation patients

Prophylactic implantation of permanent pacemaker (PPM) prior to transcatheter aortic valve implant (TAVI) is an option for patients at high-risk of atrioventricular block. The long-term follow-up ventricular pacing (VP) burden and associated clinical features of this group are not well known due to pre-existing PPM commonly being excluded by studies assessing TAVI patient outcomes. To identify features associated with longer-term VP in TAVI patients receiving prophylactic PPM. Using our prospectively maintained institutional TAVI database, we identified patients who had a PPM implanted up to 100-days before TAVI (Pre-TAVI), on the TAVI date (Same-day), and up to 30-days after TAVI (Post-TAVI) and evaluated their medical history, clinical parameters and pacing follow-up data up until 31st December 2020. Pre-TAVI patients receiving prophylactic PPM, due to baseline conduction abnormality, also had additional measurement of TAVI implant depth (ID) and membranous septum (MS) length performed by blinded investigators from preprocedural computed tomography (CT) and intraoperative fluoroscopic imaging. Of 681 TAVI procedures, we identified 122 (17.9%) patients (n=79 male; median age 85 [IQR 81-88] years old) who received PPM (including n=47 pre-TAVI), with a total median follow-up after TAVI of 751 days (IQR 323 – 1311). At first PPM check after TAVI (1 day, IQR 1-48 days after TAVI), 32% of patients (34 of 107) had not used VP (<1% burden, “Nil-VP”), with the remaining 73 patients (68% of 107) having used VP (≥1% burden). Nil-VP at first check after TAVI were 6 times more likely to have baseline LBBB (OR 6.79, 95%CI 1.13-40.84, p=.035). At the end of follow-up, there were 27 patients (25% of 107) who did not use VP (<1% burden). Among Pre-TAVI, there were 15 patients with <1% VP burden both before and after TAVI (nil-group), and 13 who had a sudden VP% increase after TAVI (change-group). The nil-group had significantly longer membranous septum ‘MS’ length (5.47 ± 1.7mm vs 2.94 ± 1.28mm, p=.024), shallower implant depth ‘ID’ (1mm [IQR 0-2.5] vs 5mm [IQR 3.5-10], p=.009) and different deltaMSID (4.13 ± 2.50mm vs -3.46 ± 3.69mm p=.007). A quarter of TAVI patients receiving periprocedural PPM did not use VP from their PPM throughout follow-up. The presence of long MS and an intraoperatively measured shallow ID with resultant positive deltaMSID may be features that warrant only periprocedural temporary pacing wire, rather than PPM due to low usage of VP during follow-up.