Electrocardiographic and electrophysiological predictors of atrioventricular block after transcatheter aortic valve...

Electrophysiological predictors of atrioventricular (AV) block after transcatheter aortic valve replacement (TAVR) are unknown.

We sought to assess the value of electrophysiology study before and after TAVR.

Seventy-five consecutive pacemaker-free patients undergoing TAVR at the Montreal Heart Institute were prospectively studied.

Eleven patients (14.7%) developed AV block during the index hospitalization and 3 (4.0%) after hospital discharge over a median follow-up of 1.4 years (interquartile range 0.6-2.1 years). AV block developed in 5 of 6 patients with preprocedural right bundle branch block (83.3%), 8 of 30 patients with new-onset left bundle branch block (LBBB; 26.7%), and 1 of 7 patients with preexisting LBBB (14.3%). In multivariate analysis that considered all patients, the delta-HV interval (HV interval after TAVR minus HV interval before TAVR) was the only factor independently associated with AV block. In the subgroup of patients with new-onset LBBB, the postprocedural HV interval was strongly associated with AV block. By receiver operating characteristic analysis, a delta-HV interval of ≥13 ms predicted AV block with 100.0% sensitivity and 84.4% specificity and an HV interval of ≥65 ms predicted AV block with 83.3% sensitivity and 81.6% specificity. In multivariate analysis, the HV interval after TAVR (hazard ratio 1.073 per ms; 95% confidence interval 1.029-1.119; P = .001) was also independently associated with all-cause mortality.

A prolonged delta-HV interval (≥13 ms) is strongly associated with AV block after TAVR. In patients with new-onset LBBB after TAVR, a postprocedural HV interval of ≥65 ms is likewise predictive of AV block.