Determinants of the degree of functional aortic regurgitation in patients with anatomically normal aortic valve and ascending thoracic aorta aneurysm. Transoesophageal Doppler echocardiography study

Objectives: To identify functional aortic regurgitation (FAR) determinants in patients with ascending thoracic aortic aneurysm (ATAA) and surgically confirmed normal aortic valve anatomy. Design: Case-control study. Setting: Non-invasive Cardiology and Cardiac Surgery Department. Patients: Eighty-nine patients with ATAA and varying degrees of FAR undergoing surgery, 40 age-matched patients with ATAA without aortic regurgitation and 20 normal control subjects. Interventions: Doppler and two-dimensional transoesophageal echocardiography. Main outcome measures: Vena contracta (VC) of aortic regurgitant jet, diastolic tented area and coaptation height (CH) of aortic valve leaflets, aortic dimension indexes Valsalva sinus, sinotubular junction (STJ), tubular tract, annulus (A), STJ/A ratio. Results: When VC was used, a wide range of FAR was seen (mean (SD) 5.59 (2.59) mm, ranging from 2 to 13 mm). Of the variables tested, the most strongly associated with FAR severity in multivariate analysis was diastolic leaflet tenting, measured as CH (R(2) = 0.69) (sensitivity 98%, specificity 95% using a cut-off value of CH >= 1.1 cm). In turn, the diastolic leaflet tenting was strongly identified by the STJ/A ratio (sensitivity 87%, specificity 71% using a cut-off value of STJ/A > 1.66). Conclusion: The diastolic tenting of aortic leaflets is strongly related to FAR severity in patients with ATAA. The mismatch of STJ/A is significantly associated with diastolic leaflet tenting and its correlated valve regurgitation, independently of the actual ATAA dimension. These findings provide new insight into the mechanism of FAR arising from ATAA.