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.