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.