Background and Objectives

Prosthesis-patient mismatch (PPM) after aortic valve replacement occurs when the effective orifice area (EOA) is too small relative to the patient's body surface area (EOAi). Incidence and clinical impact of PPM differ after surgical aortic valve replacement (SAVR) and transcatheter aortic valve implantation (TAVI), possibly due to differences in the method of determination. PPM is largely defined by reference values after SAVR and by echocardiographic measurements after TAVI. As PPM after SAVR (unlike PPM after TAVI) is clearly associated with increased mortality, normative EOA tables for TAVI have recently been introduced to improve comparability. This is the first study to investigate the frequency of PPM measured by echocardiography (PPMm) and PPM predicted from normative tables (PPMp) after TAVI and their effect on mortality in an international real-world population.

Methods

Retrospectively, 8699 patients from 6 high-volume TAVI centers implanted with a balloon-expandable (BE) or self-expanding (SE) valve between 02/2008 and 10/2022 were evaluated for the presence of PPM. Severe PPM was defined as EOAi ≤0.65cm2 and moderate PPM as EOAi ≤0.85cm2 (≤0.55cm2 and ≤0.7cm2, for BMI ≥30kg/m2). EOA measured by echocardiography at discharge was used to determine PPMm, and published reference values were used to determine PPMp. Cox proportional hazards regression analysis was used to calculate the risk for death from any cause over 1 and 2 years stratified according to presence and absence of PPM. Because of a low incidence of severe PPM, moderate and severe PPM were combined for statistical survival analyses.

Results

PPM data were available for 3850 (PPMm) and 5299 patients (PPMp), respectively. The median follow-up time was 366 days (IQR 46-735). 4152 patients (47.7%) received a BE (2.9 % SAPIEN XT, 36.6% SAPIEN 3, 8.2% SAPIEN 3 Ultra) and 4547 patients (52.3%) a SE valve (0.5% ACURATE TA, 14.8% ACURATE neo, 6.7% ACURATE neo2; 5.9% CoreValve; 18.2 % Evolut R, 5.6% Evolut PRO, 0.6% Evolut PRO+). Moderate/severe PPMm was present in 22.8%/4.1% (BE) and 14.3%/4.1% (SE) and moderate/severe PPMp was present in 10.2%/0.8% (BE) and 3.9%/2.3% (SE) of patients. PPMp was not associated with increased but numerically reduced mortality at 1 (hazard ratio (HR), 0.85; 95% confidence interval (CI), 0.65-1.11, p=0.23) or 2 years (HR, 0.81; 95% CI, 0.65-1.01, p=0.061). PPMm, on the other hand, was associated with higher mortality at 1 year (HR, 1.40; 95% CI, 1.10-1.85, p=0.019), but not at 2 years (HR, 1.21; 95% CI, 0.97-1.51, p=0.095). 

Conclusion

The incidence of PPM in this real-world international patient collective ranges from 6% to 37%, depending on the method of determination (PPMm vs. PPMp) and valve type (BE vs. SE). PPMm was associated with increased mortality at 1 year but not at 2 years, possibly due to insufficient follow-up beyond 1 year. PPMp had no effect on mortality. Therefore, no clinical added benefit of PPMp can be derived from the present data.