Table 1 Definition of study variables.

Variable	Definition
Absolute stent recoil	(Balloon diameter by angiography) − (stent diameter by IVUS after stent placement)
Achieved balloon‐to‐artery ratio	(Maximum stent balloon diameter by angiography in a single view) ÷ (mean prestent vessel diameter by IVUS)
Cross‐sectional area stenosis at stent minimum LD	(1 − (Minimum in‐stent lumen area)/(stent area)) × 100
Immediate LD gain	(Minimum LD immediately after stent placement) − (minimum LD before stent placement)
In‐stent volume stenosis	(1 − (stent lumen volume)/(in‐stent neointimal volume + stent lumen volume)) × 100
Late‐loss index	(Late lumen loss) ÷ (immediate lumen gain)
Late lumen loss	(Minimum LD immediately after stent placement) − (minimum LD at day 28)
Neointima beyond the stent edges	Total distance from proximal and distal stent edges that displayed neointimal thickness of ⩾0.25 mm by IVUS at day 28
Neointimal thickness	Average neointimal thickness based on four measurements made every 1 mm along the length of the stent
Net lumen diameter change	(Minimum LD at day 28) − (prestent LD)
Percentage cross‐sectional area stenosis	(1 −(average cross‐sectional area at stent minimum LD by IVUS at day 28) ÷ (average prestent vessel area by IVUS)) × 100
Percentage LD stenosis	(Average of major and minor axes at the lesion minimum LD by IVUS at day 28) ÷ (average prestent vessel diameter by IVUS) × 100
Prestent vessel diameter by IVUS	Average of major and minor axis measurements, from external elastic membrane to external elastic membrane in the mid‐portion of the region where stent placement was intended
Relative stent recoil	(Absolute stent recoil) ÷ (balloon diameter by angiography)
Stent symmetry index	(Minor axis stent minimum LD) ÷ (major axis stent minimum LD). Measured at the stent mid‐length

IVUS, intravascular ultrasound; LD, lumen diameter.