Abstract 1148: Local Hypercoagulability and Endothelial Dysfunction after Sirolimus-Eluting Stent Implantation: Implication for Late Stent Thrombosis
Endothelial dysfunction is known to cause hypercoagulability. The long-term effects of sirolimus-eluting stent (SES) on endothelial function are not known. We evaluated endothelial function and local hypercoagulability more than six months following SES or bare metal stent (BMS) implantation. Forty-three patients treated six months earlier with a coronary stenting for isolated proximal left anterior descending (LAD) stenosis, with no evidence of restenosis, were studied. Sixteen patients had been stented with BMS, and 27 had been with SES. Changes in diameter at distal site of the stented LAD in response to intracoronary acetylcholine infusions (30μg/min) were assessed by quantitative angiography. We also measured plasma levels of prothrombin fragment F1+2 (F1+2) and D-dimer sampled in coronary sinus (CS) and sinus of Valsalva (V). The mean percent change in the diameter of the stented LAD was significantly more in the SES group than in the BMS group (−33.4±5.9 vs. −19.8±6.0%, p<0.05). The translesional F1+2 gradient [F1+2(CS) minus F1+2(V)] and D-dimer gradient were greater in the SES group than in the BMS group (0.52±0.68 vs. −0.10±0.29 nmol/l, p<0.05 and 0.22 ±0.38 vs. −0.12±0.35 μg/ml, p<0.05, respectively). An increased local coagulative response and more severe endothelial dysfunction were observed long term after SES implantation as compared to BMS. In the SES group, delay of endothelial regrowth might be associated with our findings.