2.1 Patient population
Patients with severe symptomatic AS scheduled to undergo TAVR at
Flinders Medical Centre between March 2013 and June 2015, who had both
3D TEE and MSCT images available were included in this study. During
this period all patients who underwent TAVR had general anaesthesia and
peri-procedural TEE performed. However, our current default protocol
particularly for transfemoral TAVR is conscious sedation with the use of
periprocedural transthoracic echocardiogram (TTE). Peri-procedural TEE
is now only performed in a few select cases especially those of
alternate vascular access. A balloon expandable Edwards SAPIEN XT
transcatheter heart valve was implanted in all cases. TAVR sizes were
predicted using standard measurements for Edwards Lifesciences SAPIEN
transcatheter heart valves. The final sizing of the prosthesis was
determined by the implanting physician using all available data. MSCT
was performed 17.0 ± 11.0 weeks prior to TAVR. TEE was performed
peri-procedurally. 3D TEE images were analysed offline. 3D TEE and MSCT
measurements were performed separately in a blinded fashion. 3D TEE
measurements were performed by cardiologists with expertise in
echocardiography. The cardiologists were blinded from the MSCT
measurements to eliminate measurement bias thereby ensuring validity of
the comparisons between these imaging modalities. MSCT measurements were
performed by an experienced radiologist. Informed consent was obtained
from each patient and the study protocol conforms to the ethical
guidelines of the 1975 Declaration of Helsinki as reflected in a priori
approval by the Southern Adelaide Clinical Human Research Ethics
Committee.