Development of a Quantitative Contrast CT-Based TAVR-Risk Score to Reliably Predict Deformation in Bicuspid Aortic Valves

BACKGROUND: Bicuspid aortic valve (BAV) calcification affects clinical outcomes by causing transcatheter heart valve (THV) deformation after transcatheter aortic valve replacement (TAVR). However, a computed tomography (CT)-based scoring system for grading BAV calcification severity and predicting THV deformation has not been established. OBJECTIVES: This study sought to develop a cardiac CT-based BAV TAVR-risk score for grading BAV calcification severity and predicting THV deformation. METHODS: This single-center retrospective study included consecutive patients with BAV who underwent TAVR using contemporary balloon-expandable valves between January 2016 and December 2024 and who had preprocedural and postprocedural CT imaging. The BAV TAVR-risk score integrated calcification severity and distribution across valve leaflets, raphe, annulus, and left ventricular outflow tract, quantified using a fixed HU-850 threshold of detection on contrast-enhanced CT scans. Score thresholds were derived by receiver operating curve analysis with Youden index optimization. Patients were categorized into low-, intermediate-, and high-risk score groups. RESULTS: Among 321 patients (median follow-up: 1,825 days; Q1-Q3: 765-1,825 days), 56 (17.4%) were classified into the high-risk score group. Both underexpansion and eccentricity of the THV occurred in 49 of the 321 patients (15.3%) and were predominantly observed in the high-risk score group. However, in the low-risk score group, 149 of 155 patients (96.1%) demonstrated no underexpansion or eccentricity of the THV. A high BAV TAVR-risk score independently predicted both underexpansion and eccentricity of the THV (OR: 89.13; 95% CI: 35.02-226.83; P < 0.001). CONCLUSIONS: This CT-based BAV TAVR-risk score provides a systematic method to precisely quantify BAV severity which reliably predicts THV deformation for BAV patients with contemporary balloon-expandable valves and may help guide decision-making in this challenging population.