In vitro thrombogenicity of drug-eluting and bare metal stents

Aims: We sought to investigate the thrombogenicity of different DES and BMS in an in vitro system of stent perfusion. Material and methods: The experimental model consisted of a peristaltic pump connected to 4 parallel silicone tubes in which different stents were deployed. Blood was drawn from healthy volunteers and the amount of stent surfaced-induced thrombus deposition was determined using ¹²⁵I-fibrinogen. Results: Compared to Resolute, Biomatrix and Vision, Xience was associated with the lowest amount of stent surface-induced thrombus formation, with a significant difference compared to Vision (¹²⁵I-fibrinogen median value deposition [IQ range]: 50 ng [25–98] versus 560 ng [320–1520], respectively, p < 0.05), but not to other DES. In the second set of experiments Fluoropolymer-coated BMS not eluting drug was associated with a significant 3-fold reduction in ¹²⁵I-fibrinogen deposition (245 ng [80–300]) compared to Vision (625 ng [320–760], p < 0.05), but a 7-fold increase compared to Xience (35 ng [20–60], p < 0.05). Finally Xience was associated with a significantly greater absorption of albumin compared to BMS. Conclusions: In an in vitro system of stent perfusion, Xience was associated with the lowest amount of stent surface-induced thrombus formation compared with Resolute, Biomatrix and Vision, with a noted synergistic effect between the fluoropolymer and the drug.