Atherosclerosis burden of the aortic valve and aorta and risk of acute kidney injury after transcatheter aortic valve implantation

Abstract

Background: Atheroembolic renal disease, due to dislodgement of cholesterol crystals during maneuvering of a large catheter across the aorta and deployment of the transcatheter prosthesis within a calcified aortic valve, may be one of the pathophysiological mechanisms of acute kidney injury (AKI) complicating transcatheter aortic valve implantation (TAVI).

Objective: To investigate the association between the atherosclerotic burden and plaque characteristics of the aortic valve and thoracic aorta, evaluated with multidetector CT (MDCT), and the occurrence of AKI after TAVI.

Methods: Aortic valve calcification, atherosclerosis burden, and plaque characteristics of the thoracic aorta (including aortic root, ascending aorta, aortic arch, and descending aorta) were analyzed in preprocedural MDCT data of 210 TAVI patients (age, 81 ± 7.1 years; 51.4% men). The thoracic aorta was divided into ascending aorta, aortic arch, and descending thoracic aorta which was further divided into 5 to 8 segments according to the posterior intercostal arteries. Each segment where the maximum wall thickness exceeded ≥ 2 mm was defined as diseased segment with atherosclerotic plaque. Aortic atherosclerosis burden was defined as the proportion of thoracic aortic segments with atherosclerosis. AKI was defined by a creatinine level ≥ 1.5 × baseline or ≥ 26.4 μmol/L above baseline. MDCT data were correlated with the occurrence of postprocedural AKI in a multivariate logistic regression model.

Results: Postprocedural AKI occurred in 51 patients (24.3%). In patients with AKI, the burden of overall (87.5% [75%-90%] vs 71.4% [50%-87.5%]; P < .001) and noncalcified atherosclerosis (42.9% [22.2%-62.5%] vs 12.5% [0%-28.6%]; P < .001) and the maximum plaque thickness (5.7 ± 1.8 mm vs 4.5 ± 1.4 mm; P < .001) were larger compared with patients without AKI. The burden of noncalcified atherosclerosis remained independently associated with AKI (odds ratio, 1.03 [per each 1% of increase in aortic segments with noncalcified atherosclerosis]; 95% confidence interval 1.01-1.05; P = .006) after adjusting for baseline renal function, logistic EuroSCORE, and procedural access. In contrast, aortic valve calcification was not independently associated with AKI.

Conclusion: In patients undergoing TAVI, occurrence of postprocedural AKI was associated with the extent of noncalcified atherosclerotic plaque burden of the thoracic aorta.

Keywords: Acute kidney injury; Multidetector row CT; Transcatheter aortic valve implantation.