CTA-based planimetry in discordant high-gradient aortic stenosis
S Voegele, M H Hein, J M Minners, P R Ruile, K K Klaus Kaier, S G Sebastian Grundmann, D W Westermann, C S SchlettAbstract
Background
Aortic valve stenosis (AS) severity in high gradient stenosis as assessed by transthoracic echocardiography (TTE) can remain inconclusive when flow velocity (VmaxTTE), mean pressure gradient (MPGTTE), and calculated effective valve area (eAVATTE) are noncongruent. To aid severity classification, we suggest AVA by computed tomography angiography (CTA)-planimetry (aAVACTA) as additional severity criteria marker as part of an integrated approach for heart team discussion.
Methods
Patients who presented to our institution with discordant high gradient (HG) TTE based stenosis findings (eAVATTE ≥1.0cm² despite severe indicative maximum velocity VmaxTTE≥4m/s and mean gradient MPGTTE≥40mmHg) and underwent a pre-TAVI-CTA-scan between 2013 and 2025 were included for analysis. aAVACTA as a 4th severity marker was assessed using recently published aAVACTA severity cut-offs for stratification to CTA planimetry based severe, indeterminate or non-severe stenosis. Invasive hemodynamic measurements (MPGCath) were included when available within 60days of CT-Scan.
Results
Screening yielded a total of 189 cases with discordant HG aortic stenosis of which 168 had additional invasive gradient availability (MPGCath). aAVACTA values indicated severe stenosis (TC<0.95cm², BC<1.08cm²) in 40.7% of total cases (n=77 of 189). This percentage was 43.1% (n=69 of 160) when excluding cases with more than mild Aortic Insufficiency; 39.4% (n=39 of 99) excluding TTE based Stroke Volume Index (SVI) >58ml/m²; 39.6% (n=44 of 111) excluding low invasive MPGCath<35mmHg; and 31.5% (n=23/73) at eAVATTE cut-off raised to ≥1.1cm².
Conclusion
Despite eAVATTE showing a valve area indicative of nonsevere stenosis, aAVACTA confirmed MPGTTE/VmaxTTE severe stenosis in >30% of cases yielding added value to TTE based measurements.