Abstract 4140136: Aortic Valve Calcification Density Performs Better Compared to Absolute Aortic Valve Calcification in Aortic Stenosis Risk Stratification

Aortic valve calcification (AVC) scores can be used to stratify aortic stenosis (AS) severity. Current practice guidelines recommend use of absolute AVC scores without considering body surface area or aortic annulus size. We investigated whether size variation in aortic annular area should be considered in identifying optimal AVC cutoffs for patients with severe AS. This was a retrospective analysis of AS patients that underwent AVC assessment during 2018-2023. Outcomes were composite of valve intervention or all-cause mortality. AVC density was defined by dividing AVC by echo-derived left ventricular tract area. Receiver operator curve analysis determined optimal AVC density scores. Absolute AVC cutoffs of >1200AU for females and >2000AU for males were used to identify severe AS. The study included 749 patients (mean age 78 years, 46% female). Median CT-annulus area was larger for males compared with females (532mm 2 [Q1, Q3: 479, 582] vs. 413mm 2 [370, 458], p<0.001). There was a strong association of absolute AVC with CT-annulus area for both males and females (Spearman coefficient: 0.87 and 0.83, p<0.01 each) respectively (Figure 1). The optimal AVC density cutoffs for males and females were 427 and 326, respectively (accuracy 76%, sensitivity 83%, specificity 51%). Composite outcomes were better differentiated with AVC density (males: HR 2.48, 95% CI: 1.82-3.37, p<0.001; females: HR 2.37 (1.71-3.28), p<0.001) compared with absolute AVC scores (males: HR 1.81 (1.43-2.30), p<0.001; females: HR 2.11 (1.62-2.74), p<0.001) (Figure 2). AVC is strongly associated with CT-annulus area and risk stratification is improved with the use of AVC density compared with absolute AVC. This may be especially helpful in patients with extremes of annulus area sizes.