579 Pre-operative computed tomography evaluation of suprarenal aortic burden predicts post-procedural acute kidney injury after transcatheter aortic valve replacement: the spread-AKI study
Authors: Marzo Vincenzo De , Seitun Sara , Viglino Umberto , Matos Joao Gavina , Pigati Maria , Vercellino Matteo , Crimi Gabriele , Balbi Manrico , Porto Italo 
Published: December 2021

Abstract

Aims
Acute kidney injury (AKI) is a potential complication of transcatheter aortic valve replacement (TAVR). Athero-embolization linked to catheter manipulation in the supra-renal aorta is a possible pathogenetic mechanism of AKI after TAVR. We sought to determine the impact of supra-renal aortic atheroma burden (AB) on AKI, and the potential role of pre-operative multislice computed tomography (PO-MSCT) in evaluating the supra-renal aortic atherosclerosis and the pre-operative risk of AKI.

Methods and results
We collected PO-MSCT, as well as baseline, procedural, and post-procedural characteristics of 222 consecutive patients who underwent TAVR from January 2018 to December 2020 at a single, high-volume, Italian centre. PO-MSCT was performed using a dedicated TAVR protocol with an ECG-triggered high-pitch spiral acquisition. The non-contrast aortic valve calcium score (AV-CS) was calculated by a dedicated software. Angiographic data were analysed on a dedicated 3D workstation. Bidimensional measurements, total renal volume (TRV), and presence of significant (≥50%) renal artery stenosis (RAS) were recorded. The supra-renal AB was quantified using a ‘plaque analysis’ module that automatically segments the entire aortic root, from the sino-tubular junction to the renal arteries, by drawing a centreline across the aortic lumen and delineating the inner and outer vessel walls (including the plaque). Manual correction was applied. A set of Hounsfield unit (HU) intensity ranges were defined and mapped to a color overlay to visualize the various elements of atherosclerotic lesion by using the plaque density classification of the Society of Cardiovascular Computed Tomography (necrotic core, fibro-fatty, fibrous, and calcified plaque); calcified plaque were subcategorized on a voxel-level basis into three strata: low- (351–700 HU), mid- (701–1000 HU), and high-calcium (&gt;1000 HU, termed 1K plaque). Post-procedural complications were defined according to Valve Academic Research Consortium (VARC-3) criteria. Mean age was 83.3 ± 5.7 years, and 95 (42.8%) patients were males. AKI occurred in 67/222 (30.2%). Patients who developed AKI had higher supra-renal AB (17.6 ± 5.1% vs. 13.9 ± 4.3%, P &lt; 0.001), TRV indexed for body surface area (TRVBSA; 153.7 ± 43.1 vs. 134.9 ± 38.7, P = 0.002), mid-calcium plaque (2.2 ± 1.5% vs. 1.3 ± 1.1%, P &lt; 0.001), 1K plaque (5.4 ± 3.7% vs. 2.4 ± 2.4%, P &lt; 0.001) and suffered more post-procedural major/life-threatening (severe) bleedings [9/67 (13.4%) vs. 5/155 (3.2%), P = 0.004], whereas there was no difference in AV-CS (P = 0.691) and RAS (P = 0.077). Multivariate logistic regression analysis adjusted for other univariate predictors (male sex, baseline eGFR, baseline ejection fraction, baseline mean aortic gradient, and RAS) showed percent supra-renal AB (HR: 1.15, 95% CI: 1.06–1.26, P = 0.002), mid-to-high calcium plaque (HR: 5.67, 95% CI: 2.49–13.77, P &lt; 0.001), severe bleedings (HR: 4.93, 95% CI: 1.09–24.69, P = 0.043), and TRVBSA (HR: 1.015, 95% CI: 1.01–1.02, P = 0.021) as independent predictors of AKI. Finally, a 3-knots spline curve analysis identified percent of supra-renal AB &gt; 15.0% as the optimal threshold to predict an increased risk of AKI.

Conclusions
Suprarenal AB is associated with the occurrence of AKI, and this association is strengthened as the percentage of calcified plaque increases. Quantitative and qualitative pre-operative MSCT assessment of aortic atherosclerosis may help in early identification of patients at high-risk for AKI who could benefit from higher peri-operative surveillance.