Preclinical randomised safety, efficacy and physiologic study of the silicon dioxide inert-coated Axetis and bare metal stent: short-, mid- and long-term outcome

AIMS: To evaluate the short-, mid- and long-term safety, efficacy and vascular physiology of Axetis silicon dioxide (SiO2, abrading the micropores) inert-coated stent implantation in a randomised preclinical setting. METHODS AND RESULTS: Coronary arteries of domestic pigs were randomised to receive either Axetis or BMS (same design) stents with one-, three- and six-month follow-up (FUP), controlled by coronary angiography, optical coherence tomography (OCT), intravascular ultrasound (IVUS) and histology (n=32). The time-dependent vasomotor reaction of coronary arteries to stenting was measured using modified myography (n=12). Complete endothelialisation of the Axetis stent was confirmed by OCT, IVUS and histology at one-month FUP. Histopathology revealed continuous healing of the vessel wall with a gradual reduction of inflammation and fibrin score during the six-month FUP in both stent types. Significantly smaller neointimal area and %area stenosis were measured in Axetis stents compared with BMS at each FUP time point. Vascular reactivity measurements showed significantly better endothelium-dependent vasodilation of stented arteries with Axetis implantation. CONCLUSIONS: Implantation of the Axetis SiO2-coated stent resulted in a significantly better safety, efficacy and vessel physiology profile compared with BMS of the same design with a continuous decrease in vessel inflammation during the six-month FUP.