2018 Volume 43 Issue 2 Pages 147-156
Purpose: The standard test for identifying the number of aortic leaflets is transthoracic echocardiography (TTE); however, it is well-known that the diagnostic accuracy of TTE in patients with severe aortic valve stenosis (AS) is limited. The aim of this study was to investigate the diagnostic accuracy of TTE for identifying the number of aortic leaflets.
Subjects and Methods: We enrolled 227 patients (126 men and 101 women; mean age, 76.0±9.5 years) diagnosed with severe AS and who were scheduled to undergo aortic valve replacement or transcatheter aortic valve implantation. 1) We determined the number of aortic valves based on surgery records or computed tomography (CT) findings and analyzed the diagnostic accuracy, such as sensitivity and specificity. Furthermore, we tried to determine the cause of misidentification in patients whose bicuspid aortic valve (BAV) had been diagnosed as a tricuspid aortic valve (TAV). 2) According to the final diagnosis, we divided the patients into two groups, namely, the TAV and BAV groups and compared background and TTE measurement data.
Results and Discussion: 1) Of the 227 patients, BAV was found in 46 patients. The sensitivity of TTE for diagnosing BAV was only 35%. CT findings indicated the presence of echocardiographic specific artifacts, such as acoustic shadows and multiple reflections which originated from heavily calcified valves, commissures, and raphe, as causes of the misidentification of the leaflet numbers. 2) A multivariable logistic analysis indicated age [OR, 0.86; 95% confidence interval (CI), 0.80–0.91; p＜0.001), left atrial dimension (OR, 0.88; 95% CI, 0.81–0.94; p＜0.001), and ascending aorta (OR, 1.40; 95% CI, 1.25–1.61; p＜0.001) to be independent predictive parameters of BAV. Optimum cut-off points for age and the maximum aortic diameter were 72 years and 40 mm, respectively, for predicting diagnostic accuracy with a receiver operating curve (specificity 77%, sensitivity 89%, and accuracy 80%).
Conclusions: The sensitivity of TTE for identifying BAV was not high because of the presence of severe calcification and artifacts. Multiple windows, including right parasternal, suprasternal, and subcostal approaches, should, therefore, be employed for improving the sensitivity of TTE.
