Impact of Measured and Predicted Prosthesis-Patient Mismatch After Transcatheter Aortic Valve Replacement

Background: Prosthesis-patient mismatch after transcatheter aortic valve replacement (TAVR) can be measured echocardiographically (measured prosthesis-patient mismatch [PPMm]) or predicted (predicted prosthesis-patient mismatch [PPMp]) using published effective orifice area (EOA) reference values. However, the clinical implications of PPM post-TAVR remain unclear. Objectives: This study aimed to elucidate the prevalence of PPMm and PPMp post-TAVR and their impact on mortality in a large international cohort. Methods: The IMPPACT TAVR (Impact of Measured or Predicted Prosthesis-pAtient mismatCh after TAVR) registry included 38,808 TAVR patients from 26 international centers. Valve Academic Research Consortium 3 criteria were used to define prosthesis-patient mismatch severity. EOA was determined echocardiographically (PPMm) or predicted (PPMp) based on core lab–derived EOA reference values. The primary endpoint was 2-year all-cause mortality. Results: The prevalence of PPMp (moderate: 6.8%, severe: 0.6%) was significantly lower than that of PPMm (moderate: 20.7%, severe: 4.3%; P < 0.001) with negligible correlation between the 2 methods (Kendall's tau c correlation coefficient: 0.063; P < 0.001). In unadjusted analyses, severe PPMm adversely influenced 2-year survival (HR: 1.22; 95% CI: 1.02-1.45; P = 0.027), whereas severe PPMp was not associated with outcomes (HR: 0.81; 95% CI: 0.55-1.19; P = 0.291). After adjusting for confounders, neither PPMm nor PPMp had a significant effect on 2-year all-cause mortality. Conclusions: PPMm and PPMp were associated with different patient characteristics, with PPMm tending toward worse (especially low flow) and PPMp toward better (especially women) survival. After adjusting for confounders, neither PPMm nor PPMp significantly affected 2-year all-cause mortality. Hence, valve selection should not solely be based on hemodynamics but rather on a holistic approach, including patient and procedural specifics.