Impact of Drug-Eluting Stent Expansion on Saphenous Vein Graft Percutaneous Intervention

Background: We intended to evaluate the effects of stent expansion in percutaneous coronary intervention (PCI) on saphenous vein graft (SVG) lesions and compare over-expansion and under-expansion between SVG stents in the case of major adverse cardiac events (MACE). Methods: Totally, 196 SVG lesions were treated with drug-eluting stents. The ratio of the stent diameter to the diameter of the normal part of the SVG (which was without lesions and considered the reference part of the SVG) was measured by quantitative coronary angiography. Subsequently, the patients were divided into 3 groups: Group I (<0.90 expansion: undersized stents), Group II (0.90-1.0 expansion: normal-sized stents), and Group III (>1.0: oversized stents). MACE rates during PCI, hospitalization length, and follow-up findings were compared between the groups. Additionally, the effects of the embolic protection device (EPD) on MACE were assessed. Results: Oversized stenting was associated with increased cardiac enzymes (P=0.035) during hospitalization but was not associated with more MACE or restenosis on follow-up. Statistical analysis demonstrated nonsignificant more revascularization in the oversized group mainly due to unknown vessel revascularization and non-target vessel revascularization (P=0.167 and P=0.108, respectively). There were no differences in other MACE outcomes. The EPD was used in 25% of the patients. By comparison with the group without the EPD, there was no decrease in MACE components except a higher incidence of heart failure in the EPD group (P=0.03). Conclusions: Aggressive stent expansion in SVG lesions resulted in higher myocardial injury; and unlike native arteries, there was no improvement in target vessel revascularization rates at follow-up.