Impact of out-stent plaque volume on in-stent intimal hyperplasia: Results from serial volumetric analysis with high-gain intravascular ultrasound☆

Abstract Background Changes in out-stent plaque volume can be related to in-stent intimal hyperplasia. However, few data exist regarding the impact of out-stent plaque volume on in-stent intimal hyperplasia. Methods We prospectively performed volumetric intravascular ultrasound in 46 stable coronary patients (34 males, mean age of 66years) immediately as well as 18months after stenting. From the high-gain ultrasound images, out-stent plaque volume was calculated by extracting the stent volume from the external elastic membrane volume. Volumes of in-stent intimal hyperplasia and reference plaque were also evaluated. Results Out-stent plaque volume increased from 177.3±100.8mm 3 to 190.7±111.1mm 3 (p Conclusions These results indicate that irrespective of LDL-C level, changes in out-stent plaque volume correlate with those in in-stent intimal hyperplasia. We suggest that silorimus-eluting stent can suppress in-stent intimal hyperplasia partially by affecting out-stent plaque, although further large-scale studies are required to define the role of out-stent plaque in the occurrence of in-stent intimal hyperplasia.