Objectives:

This study assesses the incidence and analyzes hemodynamic, procedural and anatomical predictors for post-dilatation during transcatheter aortic valve implantation with the self-expanding ACURATE neo (NEO) transcatheter heart valve (THV).

Background:

Post-dilatation is required in around 40% of cases treated with the NEO and may negatively impact valve durability and carries a certain risk of valve embolization or even destruction of the leaflets. Therefore, it is desirable to minimize post-dilatation. The identification of predictors for post-dilatation is an important step to achieve this aim.

Methods:

A total of 1771 patients treated with the ACURATE neo at two centers were included in the present analysis. Patients with missing CT data (n=40), previous SAVR or TAVR (n=2), a valve embolisation (n=28) or with the requirement of multiple valves (n=30) were excluded from analysis. The covariates for multivariable models were selected using least absolute shrinkage and selection operator (LASSO) regression analysis. Predictor variables were dichotomized using the optimal cut-off in receiver operating characteristic (ROC) curve analysis and the Youden index. A multivariate logistic regression analysis was performed to identify independent predictors for post-dilatation using NEO. 

Results:

Mean age was 82 and median logistic Euroscore was 16.8% (10.7-25.3%). Post-dilation was required in 32.5% (575/1771) of the cases. Lack of pre-dilatation as a procedural characteristic was a strong independent predictor for post-dilatation (21.3% (97/456) vs. 36.3% (478/1315); OR 2.11, 95% CI [1.64-2.72], p<0.001). Therefore, patients without pre-dilatation were excluded from subsequent analyses (see table 1). In patients with pre-dilatation (n=1315 ), independent predictors of post-dilatation were mean pre-interventional transaortic gradient (Cut-Off 43 mmHg; OR 2.23, 95% CI [1.75-2.84], p<0.001), no oversizing (OR 1.39, 95% CI [1.13-1.73], p = 0.002), the ratio between minimum diameter and balloon size used for pre-dilatation (CutOff 12.61 %; OR 1.48, 95% CI [1.20-1.84], p < 0.001), THV size 25 (OR 1.67; 95% CI [1.26-2.21], p < 0.001) as well as aortic cusp calcification (Cut-Off 2312; OR 1.92, 95% CI [1.51-2.43]; p < 0.001). Procedural outcome showed differences in patients without compared with post-dilatation concerning correct positioning (97.9 vs. 93.7%; p=0.006), intended performance (98.6 vs. 95.1%, p=0.011), paravalvular leakage (Grade II+) (3.1 vs. 6.7%, p=0.001) as well as device failure (4.7 vs. 8.9%, p=0.001).

Conclusions:

In addition to pre-dilatation, mean transaortic gradient, lack of oversizing, a smaller ratio of balloon-to-annulus diameter, size 25 THV and the calcification of the aortic cusps were independent predictors for post-dilation with NEO. Procedural outcome was worse in patients requiring post-dilatation. Whether or not the rate of post-dilatation may be ameliorated using more THV oversizing and a more aggressive pre-dilatation approach needs to be determined by future studies.