Morphological characteristics of severe aortic stenosis in China: imaging corelab observations from the first Chinese transcatheter aortic valve trial.

OBJECTIVES: We sought to describe the morphological characteristics of aortic valve disease in a Chinese population presenting for transcatheter aortic valve replacement (TAVR).
BACKGROUND: Racial and regional differences are known to exist in aortic stenosis (AS), but limited data exist comparing the specific anatomical variations between populations.
METHODS: Patients were prospectively evaluated in a Chinese population presenting for TAVR in the Venus A-Valve trial, the first trial evaluating TAVR in China. A systematic anatomical assessment protocol employed contrast-enhanced computed tomography (CT) in all the cases.
RESULTS: A total of 120 consecutive patients were studied. Of these, 61 (50.7%) were patients with tricuspid, 57 (47.5%) bicuspid, and 2 (1.7%) unicuspid valve morphologies. Of the 57 cases with bicuspid valve, 31 (54.4%) had no raphe (Sievers classification, type 0) and 26 (45.6%) were of raphe type. Although the incidence of bicuspid valve morphology was more than a third in the northern Chinese population, this was lower than the eastern Chinese population (P = 0.035), in whom the incidence was more than half. A comparison of tricuspid morphologies in China versus a Western series of 229 consecutive patients undergoing TAVR assessed with CT showed a threefold excess of leaflet calcium burden in China, with a leaflet calcium volume of 421 mm(3) (IQR, 188-688 mm(3) ) versus 142 mm(3) (IQR, 58-267 mm(3) ).
CONCLUSIONS: Patients presenting for TAVR in China have a very high frequency of bicuspid valve morphology. Even in tricuspid disease, there are clear differences to Western patients, with a high calcium burden, which presents challenges for TAVR in this population (ClinicalTrials.gov NCT01683474).