Clinical and Echocardiographic Characteristics of Flow-Based Classification Following Balloon-Expandable Transcatheter Heart Valve in PARTNER Trials.

Background: Current expected normal echocardiographic measures of transcatheter heart valve (THV) function were derived from pooled cohorts of the randomized trials; however, THV function by flow state before or following transcatheter aortic valve replacement (TAVR) has not been previously reported.
Objectives: This study sought to assess the expected normal echocardiographic hemodynamics for the balloon-expandable THV grouped by stroke volume index (SVI).
Methods: Patients with severe aortic stenosis enrolled in PARTNER (Placement of Aortic Transcatheter Valves) 1 (high/extreme surgical risk), PARTNER 2 (intermediate surgical risk), or PARTNER 3 (low surgical risk) trials with complete core laboratory echocardiography were included. Patients were grouped by low-flow (SVI _LOW  <35 mL/m ² ) and normal-flow (SVI _NORMAL  ≥35 mL/m ² ). Mean gradient, effective orifice area (EOA), and Doppler velocity index (DVI) were collected at baseline and at 30 days post-TAVR. Prosthesis-patient mismatch (PPM) was both calculated and predicted from normative data, using defined criteria.
Results: In the entire population (N = 4,991), mean age was 81.8 years, 58% of patients were male, and 42% had low flow. Compared with patients with baseline SVI _NORMAL , those with SVI _LOW were more likely to be male; have more comorbidities; and lower left ventricular ejection fraction, mean gradient, and EOA. Post-TAVR, SVI _LOW increased to SVI _NORMAL in 17.3% and SVI _NORMAL decreased to SVI _LOW in 12.3% of patients. Using baseline SVI, follow-up EOA, mean gradient, and DVI for patients with SVI _LOW tended to be lower than for patients with SVI _NORMAL . Using the post-TAVR SVI, follow-up EOA, mean gradient, and DVI were significantly lower for patients with SVI _LOW than for those with SVI _NORMAL (P < 0.001 for all). The incidence of calculated, but not predicted, severe PPM was higher in patients with low flow than it was in patients with normal flow, suggesting pseudo-PPM in the presence of low flow.
Conclusions: This study demonstrates that flow affects THV hemodynamics and both baseline and follow-up SVI should be considered when predicting THV hemodynamics prior to TAVR, as well as assessing valve function following valve implantation.
Competing Interests: Funding Support and Author Disclosures Dr Pibarot has received funding from Edwards Lifesciences, Medtronic, Pi-Cardia, and Cardiac Phoenix for echocardiography core laboratory analyses and research studies in the field of transcatheter valve therapies, for which he received no personal compensation; and has received lecture fees from Edwards Lifesciences and Medtronic. Dr Leipsic has served as a consultant to Circle CVI and HeartFlow; and has institutional core laboratory contracts with Edwards Lifesciences, Medtronic, Boston Scientific, Abbott, PI-Cardia, and Conformal. Dr Hahn has received speaker fees from Abbott Vascular, Baylis Medical, and Edwards Lifesciences; has performed institutional consulting for Abbott Structural, Edwards Lifesciences, and Medtronic; has equity in Navigate; and has served as Chief Scientific Officer for the Echocardiography Core Laboratory at the Cardiovascular Research Foundation for multiple industry-sponsored trials, for which she receives no direct industry compensation. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
(Copyright © 2023 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)