Prognostic impact of echocardiographic mean transvalvular gradients in patients with aortic stenosis and low flow undergoing transcatheter aortic valve implantation

• Published in: Catheterization and cardiovascular interventions Vol. 98; no. 6; pp. E922 - E931
• Main Authors: Fischer‐Rasokat, Ulrich, Renker, Matthias, Liebetrau, Christoph, Weferling, Maren, Rolf, Andreas, Doss, Mirko, Hamm, Christian W., Kim, Won‐Keun
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 15-11-2021; Wiley Subscription Services, Inc
• Subjects: Aortic stenosis; Aortic valve; Cardiovascular diseases; Heart; Hemodynamics; low flow; Medical prognosis; prognosis; transcatheter aortic valve replacement; transvalvular gradient; Ventricle
• ISSN: 1522-1946; 1522-726X
• DOI: 10.1002/ccd.29840

Background
Blunted left ventricular hemodynamics reflected by a low stroke volume index (SVI) ≤35 mL/m2 body surface area (low flow [LF]) in patients with severe aortic stenosis (AS) are associated with worse outcomes even after correction of afterload by transcatheter aortic valve implantation (TAVI). These patients can have a low or high transvalvular mean pressure gradient (MPG). We investigated the impact of the pre‐interventional MPG on outcomes after TAVI.
Methods
Patients with LF AS were classified into those with normal (EF ≥ 50%; LF/NEF) or reduced ejection fraction (EF < 50%; LF/REF) and were then stratified according to an MPG < or ≥ 40 mmHg. Patients with SVI >35 mL/m2 (normal flow; NF) served as controls.
Results
597 patients with LF/NEF, 264 patients with LF/REF and 975 patients with NF were identified. Among all groups those patients with a low MPG were characterized by higher cardiovascular risk. In patients with LF/REF, functional improvement post‐TAVI was less pronounced in low‐MPG patients. One‐year survival was significantly worse in LF AS patients with a low vs. high MPG (LF/NEF 16.5% vs. 10.5%, p = 0.022; LF/REF 25.4% vs. 8.0%, p = 0.002), whereas no differences were found in NF patients (8.7% vs. 10.0%, p = 0.550). In both LF AS groups, a low pre‐procedural MPG emerged as an independent predictor of mortality.
Conclusions
In patients with LF AS, an MPG cut‐off of 40 mmHg defines two patient populations with fundamental differences in outcomes after TAVI. Patients with LF AS and a high MPG have the same favorable prognosis as patients with NF AS.