Abstract 15943: Impact of Stent Patency on Proximal and Distal Vessel Segments After Various Drug-Eluting Stent Implantation: Pooled Intravascular Ultrasound Analyses
Background: Several drug-eluting stent (DES) studies have shown favorable effects in the distal stent edge. While possible mechanisms include direct drug effects on the adjacent downstream segment, animal studies have shown that flow dynamics and shear stress can also affect the vessel response. This IVUS study aimed to investigate the vascular response at reference segments with respect to the stent patency and the various types of DES.
Methods: Serial (post-procedure and 6-9 months) 3D IVUS was evaluated in 609 patients treated with bare metal (BMS: n=85), sirolimus- (n=90), paclitaxel- (n=169), zotarolimus- (n=209) or everolimus- (n=56) eluting stents. Volume index (VI: volume/length, mm3/mm) was measured for lumen (LVI), vessel and plaque within the stented segment and at up to 5-mm proximal and distal adjacent segments. Patients were divided into 2 groups based on the minimum lumen area (MLA) ≥3 or <3 mm2 within the stent at follow up.
Results: In the large MLA group, lumen reduction was similar between DES and BMS in both reference segments (%ΔLVI: -2.3% vs. -1.7%, p=0.84 at distal; -6.0% vs. -6.4%, p=0.85 at proximal). In contrast, in the small MLA group, DES showed less lumen reduction at reference segments compared with BMS (%ΔLVI: -9.3% vs. -19.9%, p=0.01 at distal; -5.2% vs. -17.8%, p<0.01 at proximal). In the distal reference, both BMS and DES showed significantly greater lumen reduction and plaque proliferation in the small MLA group than in the large MLA group, which was not apparent in the proximal reference segment (Figure). No differential vessel remodeling was detected with respect to stent type and patency. The characteristic arterial responses observed at the distal reference showed no interaction for the type of DES.
Conclusions: The primary determinant of the distal arterial response appears to be upstream stent patency, rather than the type of DES used. Maintaining proximal laminar flow may result in preventing downstream disease in both BMS and DES.
- © 2013 by American Heart Association, Inc.