Definition and outcome measures
The MS was defined as the thinnest part of the interventricular septum
on the perpendicular annular plane image, and MS length was measured as
the distance from the annular plane to the vertex of the muscular septum
in stretched vessel image (18 ). Leaflet calcification and LVOT
calcification severity were semi-quantitatively measured as previously
defined (21, 22 ). The implantation depth was measured with
fluoroscopy images by using institutional imaging software. The
implantation depth was defined as the distance between the bottom of the
non-coronary cusp (NCC) to the ventricular end of the valve stent frame
in the final angiogram after the valve deployment (Figure 2 ).
The angle of the image was normally perpendicular deployment view, but
it can be adjusted by the attending physician.
To evaluate CD following TAVR, we set the primary endpoint as
in-hospital new CD (new-onset LBBB or new PPI). The indication of PPI
following TAVR was decided by the heart team at each hospital. Also, the
hemodynamic outcome measured by ultrasound and in-hospital complications
based on VARC-2 criteria (23 ) were collected. The preoperative
risk was evaluated by calculating the Society of Thoracic Surgeons
predicted risk of mortality (STS-PROM) score. The baseline
characteristics, procedural characteristics, complications, and results
were compared between the patients without CD and with CD following
TAVR. Also, CD and hemodynamic results were compared between the 2
groups based on implantation depth and MS length (implantation depth
> MS length and implantation depth ≤ MS length groups).