Role of periprocedural HV interval assessment to determine the risk of atrioventricular block after transcatheter aortic valve replacement

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Fondation vaudoise de cardiologie interventionnelle. Background The identification of patients at risk of post-procedural high-grade atrio-ventricular block (HAVB) is one of the major unmet challenges in transcatheter aortic valve replacement (TAVR). Some studies have suggested that periprocedural electrophysiological (EP) testing might help to identify patients at risk, but its role is controversial. Purpose To determine whether the immediate postvalve deployment HV and the Delta-HV interval (difference between post- and prevalve deployment HV interval) are predictive of HAVB and pacemaker (PM) need over 1 year follow-up. Methods We prospectively analysed consecutive patients undergoing TAVR between August 2019 and October 2021, and without prior PM implantation. ECG and standardized HV interval measurements were performed pre- and postvalve deployment with the quadripolar catheter used for rapid pacing. The primary outcome was either documented HAVB beyond 24h after TAVR or ventricular pacing >1% in patients who underwent prophylactic PM implantation because of abnormal EP testing in the days following TAVR. Minimal follow-up was 12 months. Results 97 patients were included. The primary outcome occurred in 8 patients (8.3%): HAVB occurred in 7 patients (5 during hospitalisation and 2 within one month of follow-up), and 1 patient underwent PM implantation because of abnormal EP testing (HV interval≥70 ms) with ventricular pacing up to 11% despite an algorithm to minimize pacing. Among ECG and EP findings, univariate predictors of the primary outcome were the pre- and postvalve deployment PR interval and both the postvalve deployment HV and Delta-HV interval (Table 1). By ROC analysis, a Delta-HV interval ≥18ms predicted HAVB with 50% sensitivity and 90% specificity (AUC=0.708, PPV 31%), and an HV interval ≥ 60ms after TAVR predicted HAVB with 63% sensitivity and 79% specificity (AUC=0.681, PPV 21%) (Figure 1). Conclusion The yield of the periprocedural HV interval assessment alone is limited in ruling out the risk of HAVB since about half of the patients at risk fail to be identified. However, abnormal postvalve deployment HV or Delta-HV interval may identify a subgroup at particularly higher risk, with up to one third of HAVB during follow-up.