Diagnosis of Congenital Unicuspid Aortic Valve in Adult Population: The Value and Limitation of Transesophageal Echocardiography

BACKGROUND: This study aimed to assess the accuracy of two-dimensional echocardiography (echo) in diagnosing unicuspid aortic valve (UAV) and to determine echo features that could improve the diagnosis. METHOD: We reviewed transthoracic/transesophageal echoes (TTE/TEE) from our hospital database for adult patients who had aortic valve surgery with a preoperative echo diagnosis of UAV or equivocal diagnosis of bicuspid aortic valve (BAV) BAV/UAV. Morphological characteristics of AV and ascending aortic dimensions were evaluated. RESULTS: Nineteen patients were identified, 13 (11 Male, 2 Female, mean age 47 ± 10 years) had surgically confirmed diagnosis of UAV, six had BAV. The incidence of UAV was 2.6%. For diagnosing UAV, the sensitivity and specificity of TTE was 27% and 50% and those of TEE was 75% and 86%, respectively. For TTE, positive predictive value (PPV) was 60% and negative predictive value (NPV) was 20%. By TEE, PPV was 90% and the NPV was 67%. In UAV patients, 85% had severe aortic stenosis (mean gradient 45 ± 16 mmHg, AVA: 0.9 ± 0.2 cm²). 46% had ascending aorta aneurysm (mean aortic root, sinutubular junction, ascending aorta dimensions: 36 ± 3 mm, 31 ± 4 mm and 41 ± 8 mm). Patients with ascending aortic aneurysm were younger (41 ± 11 years vs. 52 ± 5 years, P < 0.05) All UAV were unicommissural with a posteriorly positioned commissural attachment, 69% were heavily calcified. Diagnostic accuracy was limited by quality of images, severity, and distribution of calcification. CONCLUSION: TEE is the diagnostic modality of choice in UAV. Identifying several echo features may improve its diagnostic accuracy.