Diagnosis of bicuspid aortic valves: CT vs. TTE

Bicuspid aortic valfves (BAV) are a relatively common cardiac abnormality, with an associated risk of aortic stenosis, aortic regurgitation and aortopathy. First-line diagnosis is via transthoracic echocardiography (TTE), which may be impacted by valve calcification and operator variability. Electrocardiogram-gated computed tomography (CT) offers an alternative form of assessment. The aim of this systematic review and meta-analysis is to evaluate the diagnostic performance of TTE versus CT for BAV. Eligible studies were retrieved from inception through to March 2024 on OVID Medline, Embase and Cochrane Library. All primary studies regarding the diagnostic performance of TTE and/or CT with regards to BAV were included. The QUADAS-2 tool was utilized for quality assessment. Sensitivity and specificity data were statistically analyzed. Of 4698 records, 19 were eligible for inclusion, and 16 had sufficient data for inclusion in the meta-analysis. There was only data regarding TTE vs. retrospectively ECG-gated CT. There was a significant difference between the sensitivity of retrospectively ECG-gated cardiac CT (95.5% (95% CI: [91.3-97.5%]) and TTE (79.7%, 95% CI: [71.6-86.0%]) for identifying BAV. The specificity was high and not significantly different for both CT and TTE (96%, 95% CI: [92.5-98.2%] and 91.3%, 95% CI: [87.3-93.8%], respectively). Retrospectively ECG-gated CT demonstrates greater sensitivity for diagnosis of BAV compared to TTE. Both modalities are non-invasive and demonstrate good specificity for excluding BAV. Given that CT scans are easily accessible, they offer a reasonable second-line investigation for diagnosis of BAV when an initial TTE is inconclusive.