SPC365

CT-Derived Extracellular Volume for Risk Stratification in Severe Aortic Stenosis

Session: Sessão de Comunicações Orais 16 – Imagiologia avançada para estratificação de risco: do ECV à RMC em contexto de vida real
Speaker: André Filipe Silva Pereira Martins Lobo

Congress: CPC 2026
Topic: B. Imaging
Theme: 03. Imaging
Subtheme: 03.2 Computed Tomography
Session Type: Comunicações Orais
FP Number: ---
Authors: Andre Lobo; Marta Catarina Almeida; José Cavadas; Carolina Castro; Rafael Teixeira; Mariana Brandão; Pedro Braga; Nuno Dias Ferreira; Francisco Sampaio; Ricardo Fontes-Carvalho

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Aptos,sans-serif"><span style="font-family:&quot;Calibri&quot;,sans-serif">Introduction: Extracellular volume (ECV) reflects diffuse myocardial fibrosis and has been increasingly associated with adverse outcomes in severe aortic stenosis (AS). Dual-energy computed tomography (CT) technology allows reliable ECV quantification during routine pre-transcatheter aortic valve implantation (TAVI) assessment. We aimed to evaluate the prognostic value of CT-derived ECV in severe AS, with particular focus on pre-intervention outcomes.</span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Aptos,sans-serif"><span style="font-family:&quot;Calibri&quot;,sans-serif">Methods: Retrospective cohort of patients with severe AS undergoing pre-TAVI CT (April 2024&ndash;April 2025). A delayed dual-energy acquisition was performed for ECV quantification. Global ECV was defined as the mean of basal and mid-ventricular short-axis values. Patients were included irrespective of subsequent management strategy. Primary outcomes were all-cause and pre-treatment mortality. Secondary outcomes included post-intervention mortality, unplanned cardiovascular hospitalization, and urgent aortic valve replacement.</span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Aptos,sans-serif"><span style="font-family:&quot;Calibri&quot;,sans-serif">Results: 253 patients were included (median age 81 years; 48.6% male). Median follow-up was 11 months [9-15]. 146 patients underwent valve implantation (136 TAVI, 10 SAVR), and 107 were managed conservatively. Median ECV was 30.4% [27.55 &ndash; 33.70%]. ECV did not differ between management strategies (p = 0.118). </span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Aptos,sans-serif"><span style="font-family:&quot;Calibri&quot;,sans-serif">During follow-up, 21 deaths occurred (8.3%). ECV was higher in non-survivors (33.8% vs. 30.0%; p &lt; 0.001). ECV was associated with increased overall mortality (HR 1.157, 95% CI: 1.069 &ndash; 1.252, p &lt; 0.001) and remained significant after multivariable adjustment (HR 1.163, 95% CI: 1.063 &ndash; 1.272, p &lt; 0.001). &nbsp;Survival analysis stratified by the median ECV showed lower survival in patients with ECV &gt;30.4% - 16.81 months (95% CI 15.85&ndash;17.76) vs 19.62 months (95% CI 19.19&ndash;20.05), p &lt; 0.001.</span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Aptos,sans-serif"><span style="font-family:&quot;Calibri&quot;,sans-serif">In the pre-intervention period, 15 deaths occurred; ECV was a significant predictor of pre-treatment mortality (HR 1.154, 95% CI 1.056&ndash;1.262; p = 0.002) and remained independently associated after multivariable adjustment (HR 1.157, 95% CI 1.042&ndash;1.284; p = 0.006).</span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Aptos,sans-serif"><span style="font-family:&quot;Calibri&quot;,sans-serif">Among treated patients, ECV was not significantly associated with mortality (HR 1.137, 95% CI 0.973&ndash;1.331; p = 0.107). Treatment was associated with a reduction in mortality, independently of ECV (HR 0.317, 95% CI 0.122&ndash;0.823; p = 0.018).</span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Aptos,sans-serif"><span style="font-family:&quot;Calibri&quot;,sans-serif">ECV predicted pre-treatment unplanned cardiovascular hospitalization (OR 1.12, 95% CI 1.04&ndash;1.22; p = 0.005) and urgent aortic valve replacement (OR 1.24, 95% CI 1.11&ndash;1.38; p &lt; 0.001).</span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Aptos,sans-serif"><span style="font-family:&quot;Calibri&quot;,sans-serif">CONCLUSIONS: CT-derived ECV is a marker of adverse prognosis in severe AS, particularly in the pre-intervention period. Higher ECV identified patients at increased risk of death, hospitalization, and urgent valve intervention. These findings support the potential role of ECV in routine pre-TAVI evaluation for improved risk stratification.</span></span></span></p>