Impact of implantation depth on outcomes of new-generation balloon-expandable transcatheter heart valves

Background: Little is known about the impact of the ID on outcomes and device success using balloon-expandable devices. This study sought to analyze the impact of implantation depth (ID) on procedural outcomes.

Methods: In consecutive patients (n = 969) undergoing transfemoral TAVR with new-generation balloon-expandable prostheses, the mean ID (ID_Mean) was determined by aortography and categorized into low, correct, and high device position. Outcomes of interest were device success (VARC-2), paravalvular regurgitation (PVR) ≥ moderate, severe prosthesis-patient mismatch (PPM), permanent pacemaker implantation (PPI), and the composite of the three latter outcome measures (COMP_PPP).

Results: ID_Mean was greater among patients with PPI (median 4.0 [interquartile range 2.0; 4.0] vs. 3.5 [1.5; 5.5] mm; p = 0.002), severe PPM (3.5 [1.5; 5.0] vs. 4.0 [2.0; 6.0] mm; p = 0.028), and COMP_PPP (4.0 [2.0; 6.0] vs. 3.0 [1.5; 5.5] mm; p < 0.001) when compared with the respective groups without these complications. There was no significant association between ID_Mean and device success or PVR ≥ moderate. Categorization into low (7.3%), correct (90.7%), and high (2.0%) device position showed significant discrimination with an increase of severe PPM, PPI, and COMP_PPP with lower position, whereas device success was not significantly affected by position. Only PVR ≥ moderate showed an asymmetric distribution with highest rates in the high and low position group, which was non-significant. However, among patients without correct position the rate of device success was 45.6%.

Conclusions: A higher device position was associated with improved outcomes. Malpositioning without functional impairment should not be classified as device failure. The odds ratio of ID_Mean was calculated by univariate logistic regression for each outcome variable, showing that with higher values of ID_Mean (i.e., low implantation depth), the risk of severe PPM, PPI, and COMP_PPP increases. The bar charts under the heading "Position category" denote the frequency of each outcome measure across patients with high, correct, and low device position. The p values are derived from chi-squared test.