aAVA CTA cutoff values for severe aortic stenosis were ≤0.95 cm² for tricuspid and ≤1.08 cm² for bicuspid valves, with high sensitivity and specificity.
Does CTA-based planimetry of anatomic aortic valve area provide reliable severity cutoffs for bicuspid and tricuspid aortic stenosis compared to echocardiography?
CTA-based planimetry of aortic valve area provides feasible severity cutoffs for aortic stenosis, which differ between bicuspid (≤1.08 cm²) and tricuspid (≤0.95 cm²) valves, and can aid in reclassifying low-gradient cases.
Absolute Event Rate: 0% vs 0%
BACKGROUND: Computed tomography based planimetric assessment of the anatomic aortic valve area (aAVA CTA ) in aortic stenosis is routinely performed. Unlike transthoracic echocardiography-based effective AVA by transthoracic echocardiography, it lacks clearly defined severity cutoff values, limiting clinical utility. METHODS: In this retrospective single-center analysis with computed tomography angiography data from 2013 to 2025, cutoffs were determined from 1294 transthoracic echocardiography-based conclusive severe or nonsevere patients by congruence of maximum velocity, mean pressure gradient, and effective AVA by transthoracic echocardiography. In separate receiver operator curves analyses for tricuspid and bicuspid valves, the severe stenosis likely cutoff was defined by Youden index and the unlikely cutoff by a negative likelihood ratio <0.1. Cutoffs were internally validated in 480 patients, compared with the Agatston score by net reclassification index, and tested in 190 separate normal flow-low gradient-aortic stenosis cases. RESULTS: Correlation between aAVA CTA and effective AVA by transthoracic echocardiography was moderate and strong in tricuspid and bicuspid valves, respectively (Pearson r 0.67 and 0.78; P <0.001). Severe stenosis was likely in tricuspid valves at aAVA CTA ≤0.95 cm² (sensitivity 87%, specificity 78.9%) and unlikely at ≥1.10 cm² (negative likelihood ratio, 0.092). In bicuspid valves severe stenosis was likely at aAVA CTA ≤1.08 cm² (sensitivity 88.3%, specificity 77.3%) and unlikely at ≥1.20cm 2 (negative likelihood ratio, 0.091). Validation showed comparable results. Net reclassification index compared with the Agatston score was 0.16 for likely and 0.17 for unlikely cutoffs ( P <0.001). Cutoffs were applied to 190 suspected severe low-gradient cases. Adding aAVA CTA as an additional severity marker led to reclassification to nonsevere in 5.8% of cases. CONCLUSIONS: Direct planimetry of AVA is feasible and shows utility in low gradient-aortic stenosis. However, as the hemodynamic effect is impacted by valve shape, cutoff values should differentiate between tricuspid and bicuspid valves.
Voegele et al. (Thu,) reported a other. aAVA CTA cutoff values for severe aortic stenosis were ≤0.95 cm² for tricuspid and ≤1.08 cm² for bicuspid valves, with high sensitivity and specificity.