ObjectiveTo report the accuracy of preoperative 4D cardiac computed tomography angiogram (CTA), real-time 3D transesophageal echocardiography (TEE) and intraoperative techniques in aortic valve (AV) measurement and phenotype determination in patients undergoing surgery for aortic insufficiency and/or root aneurysm. MethodsThis is a prospective, observational study of preoperative AV imaging for AV repair surgery. Twenty-two patients were accrued over 12 months. Preoperative TEE and CTA were obtained and measurements provided by dedicated imaging cardiologists. Intraoperative measurements were obtained from the arrested heart and reported by the surgeon prior to repair. Intraoperative assessment was considered the gold standard of height measurements, with CTA being the standard assessment for commissural orientation. Correlation coefficients were used to describe agreement of measurements. ResultsBaseline characteristics (Table 1) and assessment of phenotype and measurement of commissural orientation (CO), geometric height (gH) and commissural heights (cH) are reported (Table 2). TEE (κ=0.833, p<0.01) and CTA (κ=0.729, p<0.01) both agreed with intraoperative assessment of AV phenotype. TEE appeared more accurate than intraoperative measurement at predicting CO (rs=0.79, p<0.01 vs rs=0.58, p=0.01). CTA and TEE were unlikely to predict and measured shorter than intraoperative gH measurement. Measurements of cH by CTA did not agree with and were shorter than intraoperative measurement. ConclusionsTEE and CTA both appear accurate in predicting the AV phenotype identified intraoperatively. CTA and TEE predicted shorter heights than intraoperative measurement.