Utility of ECG-gated computed tomography angiography for the improved diagnosis of bicuspid aortic valve disease prior to transcatheter aortic valve replacement
Hughes CL, Lee J, Coriasso N, Alalwan Y, Aljamal A, Wang DD, Pantelic M, Song T, Eng MH, Frisoli T, Villablanca P, Wyman JF, O'Neill WW, and Abdelrahim E. Utility of ECG-gated computed tomography angiography for the improved diagnosis of bicuspid aortic valve disease prior to transcatheter aortic valve replacement. Catheterization and Cardiovascular Interventions 2020; 95:S118-S119.
Catheterization and cardiovascular interventions
Background: Diagnosis of a bicuspid aortic valve (BAV) morphology has important prognostic implications due to early valve degeneration and an associated aortopathy. Presence of a BAV also has technical implications for transcatheter aortic valve replacement (TAVR) procedural planning and implantation. BAV is often first identified on transthoracic echocardiography (TTE), but diagnosis may be limited by imaging windows, operator skill, and valve calcification. ECG-gated computed tomography angiography (CTA) may improve identification of BAV.
Methods: 335 patients who underwent TAVR between 5/1/18 and 12/20/18 were retrospectively evaluated. Routine pre-procedure planning retrospectively ECG-gated CTA studies were performed with reconstruction phases at 10% increments through the R-R cycle. 50% or greater commissural fusion was categorized as a BAV. Valve morphology from the preprocedural TTE reports was also abstracted. Of 335 patients, 17 patients had prosthetic valves. Of the remaining 318 patients, 267 (52.4% male, age 79 ± 27) had TTE grading of aortic valve morphology.
Results: BAV was identified by TTE in 23 patients (8.6% of cohort, age 75 ± 20 years) whereas CTA identified 26 patients (9.7% of cohort, age 74 ± 21 years) with a bicuspid valve. Direct correlation between CTA and TTE was modest (R-value = 0.38). With CTA as the reference standard, TTE had a sensitivity, specificity, positive predictive value and negative predictive value of 88.5%, 100%, 100% and 98.8% respectively. The age of patients with tricuspid vs BAV was 80 ± 28 years vs 74 ± 21 years, respectively. Aortic size in tricuspid vs BAV patients was 34.2 ± 15 vs 37.9 ± 30 mm (p=0.001). In BAV patients, 82% of the patients had no aortic dilation greater than 40mm.
Conclusions: In patients referred for TAVR, CTA is valuable tool for diagnosis of BAV and associated aortopathies, particularly when valve morphology cannot be characterized by TTE. In our cohort, BAV patients were older and rarely had significant aortopathy, suggesting an increased prevalence of degenerative valve fusion relative to congenital BAV disease. Further study is required to categorize and distinguish BAV sub-types and their effect on TAVR procedure results.