Geometry of the Aorto-Ventricular Annulus as a Predictor of Pacemaker Implantation Following Transcatheter Aortic Valve Replacement – A Proof-of-Concept Study

Background: Conduction abnormalities following transcatheter aortic valve replacement (TAVR) are caused by disruption of the aorto-ventricular (AV) conduction tissue during positioning of the valve. We sought to evaluate whether a higher difference between the long and short diameters of the elliptic AV annulus will possess higher forces on the annulus and thus will be a predictor of pacemaker (PM) need following TAVR.

Methods: We retrospectively analyzed 123 patients who had the AV annulus measured by CT angiography. The difference between maximal (Dmax) and minimal (Dmin) diameters of the annulus was considered the elliptic factor (ELFA), which was analyzed using t-test to evaluate whether it differs between the group who received a PM and the group without the need for a PM. Then, using univariate and multivariate models adjusted for other confounders predicting the need for a PM, we sought to evaluate whether a higher ELFA is a predictor of PM implantation.

Results: Mean age was 82.2±6.4 and 62.6% were women. Average Dmax, Dmin and ELFA were 25.8mm, 20.8mm and 5mm, respectively. Fourteen patients (11.4%) underwent PM implantation. Those patients had an ELFA of 5.9mm compared to 4.9mm in those who did not receive a PM (p<0.01). In multivariate analysis, a higher ELFA remained a statistically significant and independent predictor for the need of a PM (p=0.04).

Conclusions: A high ELFA is an independent and significant predictor of the need for PM implantation after TAVR, and suggests further investigation whether it should be considered as a factor in managing TAVR patients.