CT-Defined Prosthesis-Patient Mismatch Downgrades Frequency and Severity, and Demonstrates No Association With Adverse Outcomes After Transcatheter Aortic Valve Replacement.

Objectives: This study sought to determine if indexed effective orifice area (EOAi), using left ventricular outflow tract measured from computed tomography (EOAi _CT ), reclassified prosthesis-patient mismatch (PPM) compared with conventional echocardiogram-defined measurements (EOAi _TTE ).
Background: PPM does not predict mortality following transcatheter aortic valve replacement (TAVR). However, it is unknown if the EOAi _CT of the left ventricular outflow tract improves risk stratification.
Methods: A total of 765 TAVR patients from the PARTNER II (Placement of Aortic Transcatheter Valves II) trial S3i cohort were evaluated. EOAi was calculated using the continuity equation, and the left ventricular outflow tract area was derived from baseline computed tomography. Traditional echocardiographic categories defined PPM: absent (>0.85 cm ² /m ² ), moderate (≥0.65 and ≤0.85 cm ² /m ² ), or severe (≤0.65 cm ² /m ² ). Correlation of EOAi _CT and EOAi _TTE to 1-year outcomes was performed.
Results: The incidence of PPM was 24% with EOA _CT compared with 45% with EOAi _TTE . Only 6% of PPM was graded severe by EOAi _CT compared with 9% by EOAi _TTE . EOAi _TTE , but not EOAi _CT , defined PPM showed association with reduced left ventricular mass regression (p = 0.03 vs. p = 0.52). There was no association between PPM and death or rehospitalization at 1 year with either modality. EOA _CT was associated with minor stroke at 1 year (log-rank p = 0.04), and EOAi _TTE with stroke/transient ischemic attack (log-rank p = 0.030). Furthermore, when subjects with mild or greater paravalvular regurgitation were excluded, the presence of PPM did not show association with any outcome.
Conclusions: EOAi _CT downgrades frequency and severity of PPM in patients after TAVR, and was not associated with mortality 1 year after TAVR. EOAi _TTE , but not EOAi _CT , was associated with less left ventricular mass regression.
(Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)