Aortoventricular annulus shape as a predictor of pacemaker implantation following transcatheter aortic valve replacement

Aims: Conduction abnormalities following transcatheter aortic valve replacement (TAVR) are caused by damage of the aortoventricular conduction tissue during positioning of the valve. Therefore, our aim was to assess whether a higher difference between the long and short diameters of the elliptic aortoventricular annulus will possess higher forces on the annulus, and thus will be a predictor of pacemaker need following TAVR. Methods: We retrospectively analyzed 123 patients who had the aortoventricular annulus measured by computed tomography angiography. The difference between maximal (D_max) and minimal (D_min) 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 pacemaker and the group without the need for a pacemaker. Then, using univariate and multivariate models adjusted for other confounders predicting the need for a pacemaker, we sought to evaluate whether a higher ELFA is a predictor of pacemaker implantation. Results: Mean age was 82.2±6.4 years, and 62.6% were women. Average D_max, D_min and ELFA were 25.8, 20.8 and 5mm, respectively. Fourteen patients (11.4%) underwent pacemaker implantation. Those patients had an ELFA of 5.9mm compared with 4.9mm in those who did not receive a pacemaker (P<0.01). In multivariate analysis, a higher ELFA remained a statistically significant and independent predictor for the need of a pacemaker (P=0.046). Conclusion: A high ELFA is an independent and significant predictor of the need for pacemaker implantation after TAVR and suggests further investigation whether it should be considered as a factor in managing TAVR patients.