Conduction disorders are frequent after transcatheter aortic valve replacement (TAVR) and there is a lack of consensus on the way to manage them, so they can prolong the hospital length of stay. However, membranous septum length assessed by computed tomography (CT) and valve implantation depth at the final angio, have been identified as strong predictors of new permanent pacemaker implantation after TAVR. We aimed to investigate how these data could help to identify the only patients who are at high risk of high degree AV block after TAVR.

In this aim, we conducted a retrospective observational monocentric study which included 216 consecutive patients scheduled to undergo a TAVR procedure. Among them, we excluded valve-in-valve procedures or patients with pre-existing pacemaker. On the 162 remaining patients, 124 only had sufficient good-quality CT for MS length assessment.

In our cohort, 34 patients (27,4%) received a PPM. After adjustment of pre- and post-procedural parameters, multivariable logistic regression revealed that the difference between MS length and implantation depth is the most powerful independent predictor of PPM implantation (OR: 1.5, 95% CI: 1.3 to 1.7, P<0.001). Predictive probabilities were generated using logistic regression model. Using the difference between MS length and implantation depth as the only parameter, the c-statistic of the model of PPM showed an area under the curve of 0.89.

The lone difference between MS length and implantation depth, seems to be able to select high-risk patients for PPM implantation. These results could reduce length of stay after TAVI, selecting low risk patients for whom an early discharge is allowed. This has to be now validated by a prospective study.