CT-based evaluation of patient-prosthesis mismatch after transcatheter aortic valve implantation and its influence on outcome.

Background: Patient-prosthesis mismatch (PPM) after trans-catheter aortic valve implantation (TAVI) is a risk factor for heart failure and mortality. Assessment of PPM using transthoracic echocardiography (TTE) and presence of hypo-attenuated leaflet thickening (HALT) may lead to overestimation. Our study aimed to assess the incidence of PPM using TTE and CTA after exclusion of patients with HALT and to evaluate predictors analyzing stent geometry.

Methods: 444 patients were analyzed. PPM was calculated using the continuity equation from TTE (TTE-PPM) and CTA (CT-PPM). Regression analyses were conducted for the endpoint effective orifice area (EOA) as surrogate for PPM.

Results: Severe PPM was detected in 4.5% using TTE-PPM and in 0.5% using CT-PPM. Body mass index (BMI) was identified as a predictor for a smaller EOA in each model (p < 0.001). Using TTE-PPM and CT-PPM, a smaller valve diameter was associated with a smaller effective orifice area (EOA) (p < 0.001). Presence of a balloon-expanding valve was associated with a smaller EOA using CT-PPM (p = 0.033). Stent geometry did not influence the EOA (p > 0.05 each model). EOA did not influence overall survival (p > 0.05 each model).

Conclusions: The incidence of severe PPM was very low and only predicted by BMI in each assessment model. Stent geometry did not influence the incidence of PPM. Overall survival was not influenced by a smaller EOA.