Stent implantation in the superficial femoral artery: short thrombelastometry-derived coagulation times identify patients with late in-stent restenosis.

Introduction: The mechanisms of restenosis, the recurrence of luminal narrowing, are complex and incompletely understood to date. Thrombin, the pivotal enzyme in haemostasis, presumably contributes to the formation of in-stent restenosis (ISR). It was therefore the aim of our study to investigate whether blood coagulation/thrombin generation plays a critical role in the formation of ISR in peripheral artery disease patients with stent angioplasty in the superficial femoral artery.

Materials And Methods: We aimed to examine in this retrospective study whether patients with high-degree restenosis (50-75% lumen diameter reduction, n=20) are in a hypercoaguable state implying enhanced readiness to generate thrombin compared to patients with low-degree restenosis (<50% lumen diameter reduction, n=14).

Results: The coagulation tests calibrated automated thrombography, activated partial thromboplastin time, platelet aggregation, platelet adhesion, fibrinogen, and microparticles' procoagulant activity did not indicate a different coagulation status in the two patient groups. However, the thrombelastometry-derived value Coagulation Time (CT) was significantly shorter in the high-degree restenosis group (p=0.012), indicating a hypercoagulable state of patients with high-degree restenosis. Under our experimental conditions, CTs shorter than 444.5s identify patients at high risk (sensitivity=95%) for luminal narrowing.

Conclusions: Our study supports the assumption that blood coagulation/thrombin generation plays a critical role in the development of ISR in peripheral arteries after stent insertion and that the thrombelastometry-derived CT might be a suitable value to identify peripheral artery disease patients at risk for development of high-degree in-stent restenosis in the superficial femoral artery.