Increased Left Ventricular Myocardial Extracellular Volume Assessed by Cardiac Computed Tomography as a Consequence of Aortic Stenosis and Coexisting Cardiovascular Risk Factors

<b>Background/Objectives</b>: Extracellular volume (ECV) expansion reflects myocardial fibrosis and may play a role in subjects with severe aortic stenosis (AS) receiving transcatheter aortic valve implantation (TAVI). This study aimed to assess the relationship between cardiovascular risk factors (CVRF), AS severity and left ventricular myocardial ECV measured by cardiac computed tomography (CCT). <b>Methods</b>: 61 patients qualified for TAVI underwent pre-procedural CCT. CVRFs were recorded, including advanced age, male gender, obesity, hypertension, hypercholesterolemia, hypertriglyceridemia, type 2 diabetes, and smoking. The CCT protocol included non-contrast (for aortic valve calcium score, AVCS), angiographic (for vascular access planning), and delayed phases (for left atrial appendage thrombus assessment). ECV was calculated from attenuation values of the interventricular septum and left ventricular cavity assessed in native and delayed phases. Patients were stratified based on the presence/absence of individual CVRFs, median AVCS, and aortic valve area (AVA). <b>Results</b>: Mean ECV was higher in patients with hypertension (28.01% vs. 26.93%, <i>p</i> = 0.03), smokers (28.71% vs. 26.52%, <i>p</i> = 0.01), AVCS ≥ 2975 (28.08% vs. 26.95%, <i>p</i> = 0.02), and AVA < 0.95 cm² (28.63% vs. 26.53%, <i>p</i> = 0.01). Positive correlations were found between ECV and the number of CVRFs (r = 0.49, <i>p</i> = 0.01), BMI (r = 0.30, <i>p</i> = 0.01), systolic BP (r = 0.31, <i>p</i> = 0.02), and AVCS (r = 0.36, <i>p</i> = 0.01); AVA correlated negatively (r = -0.59, <i>p</i> = 0.01). Regression showed that hypertension, smoking, and smaller AVA were independent predictors of higher ECV. <b>Conclusions</b>: Among TAVI candidates, hypertension, smoking, and more advanced AS are independently associated with increased myocardial ECV on CCT. These findings may reflect subclinical myocardial remodeling and support the added diagnostic value of ECV in pre-TAVI assessment.