Incidence of infranodal conduction delay in patients with left bundle branch block after transcatheter aortic valve replacement: impact of the 2021 ESC guidelines for cardiac pacing

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background Left bundle branch block (LBBB) remains the most frequent conduction disorder after transcatheter aortic valve replacement (TAVR). Electrophysiological (EP) testing is recommended in the 2021 ESC Guidelines for cardiac pacing with a IIa indication in patients with new LBBB with QRS ≥ 150ms or PR ≥ 240ms or with pre-existing LBBB with a delta of QRS/PR intervals of ≥ 20ms after TAVR. A cut-off for the HV interval of ≥ 70ms to consider pacemaker implantation was proposed. However, evidence for these proposed cutoffs is scarce in LBBB patients after TAVR. Aims To assess the incidence of infranodal conduction delay in patients with LBBB after TAVR and assess safety of predefined criteria for PR and QRS width to identify infranodal conduction delay. Methods We analyzed a consecutively included cohort of patients who underwent TAVR between August 2014 and May 2022. A 12-lead surface electrocardiogram (ECG) was available in all patients before and the day after TAVR. Patients with LBBB also received an EP testing the following day, irrespective of surface ECG measurements. Results Of 1033 patients who received TAVR between August 2014 and May 2022, 708 were included in the study (Figure). Mean age was 82 years, 53% were female. The used valve types were homogenously distributed. Among 708 patients, 180 patients demonstrated LBBB (25%) the next day (86%new-onset LBBB). Infranodal conduction delay, defined as a HV interval ≥ 70ms, was observed in 18/180 patients (10%) with LBBB on the day after TAVR. Using the new ESC guidelines, EP testing was indicated in 86 of 177 patients (49%) with LBBB after TAVR, with 14 of 18 (78%) being identified with an HV interval of ≥ 70ms (sensitivity 78%, negative predictive value 94%). Thus, in 4 patients (3 men) with new LBBB, the HV interval of ≥ 70ms would have been missed based on surface ECG readings suggested by current guidelines. Stratified by sex, the predefined criteria for PR and QRS demonstrated a sensitivity and negative predictive value of 86% and 98% in women and 72% and 90% in men, respectively. Conclusion In patients with LBBB after TAVR the incidence of infranodal conduction delay defined as a HV interval ≥ 70ms is 10%. Predefined surface ECG criteria offer excellent safety for rule out of infranodal conduction delay, especially in women, while caution might be advisable using the same criteria in men.