(P132) PREDICTORS OF HIGH PACING PERCENTAGE IN PATIENTS AFTER TRANSCATHETER AORTIC VALVE REPLACEMENT

Background: Transcatheter aortic valve replacement (TAVR) is increasingly performed in patients with severe aortic stenosis. Patients undergoing TAVR may have transient or permanent pacing requirements, necessitating permanent pacemaker (PPM) implantation. Pacing outcomes and persistence of conduction disorders post-TAVR are variable, with limited data on the extent of pacemaker dependency. We reported the rates of pacemaker dependency and predictors of high pacing requirements in patients post-TAVR.

METHODS AND RESULTS: We performed a retrospective review of patients who underwent TAVR and PPM implantation at a tertiary high-volume TAVR center between 2015-2023. For patients who underwent a PPM implantation within 1-month of TAVR, their pacing percentages at baseline (day 1 post-implant) and up to 1-year post-TAVR were documented. Demographics, comorbidities, and left ventricular ejection fraction (LVEF) at 1-year post-TAVR were recorded. Logistic regression models calculated the odds of substantial pacing (ventricular pacing ≥40%), pacemaker dependency (ventricular pacing ≥90%), and LVEF drop (>10%) at 1-year.

2013 patients underwent TAVR between 2015-2023, of which 174 patients (8.6%) underwent PPM implantation within 1-month of TAVR. The mean age was 83.3±6.2 years, 33.9% female, LVEF 57±11%, with baseline electrocardiogram demonstrating right bundle branch block (RBBB; 42.5%) and intraventricular conduction delay (IVCD; 8.6%). Temporary pacing post-TAVR was required in 64.9%, with a median duration between TAVR and PPM implant of 3 days (IQR 2-6 days; mean 6±8 days).

Mean ventricular pacing post-PPM implant was 72.2±39.4%, decreasing to 61.9±42.0%, 57.2±42.4%, and 54.6±43.0% at 6-weeks, 6-months, and 1-year, respectively (Figure 1). Substantial pacing (≥40%) and pacemaker dependency occurred in 56% and 41%, respectively. Mean LVEF was unchanged at 1-year (58±10%, p=0.304), with LVEF drop (>10%) in 9%. There were no pacemaker complications at 1-year.

Univariable predictors of pacemaker dependency at 1-year included pre-existing RBBB (OR 2.67, 95%CI 1.35-5.29), IVCD (OR 3.62, 95%CI 1.06-12.36), and temporary pacing post-TAVR (OR 5.24, 95%CI 2.35-11.66; Table 1). Valve type was not associated with pacemaker dependency. Lower LVEF at 1-year was associated with higher pacing percentages (r=-0.16, p=0.047), with a trend between substantial pacing and reduced LVEF (OR 2.34, 95%CI 0.86-6.39). LVEF decline (>10%) was weakly associated with substantial pacing at 1-year (OR 2.82, 95%CI 0.74-10.73) after accounting for baseline LVEF.

Conclusion: More than half of TAVR patients requiring PPM post-TAVR have substantial pacing or pacemaker dependency at 1-year. Baseline conduction disease and temporary pacing post-TAVR are associated with substantial pacing and pacemaker dependency. Substantial pacing may be associated with lower LVEF or LVEF decline at 1-year post-TAVR.