Paradoxical Effects of Aurintricarboxylic Acid and RG-13577: Acute Thrombosis and In-Stent Stenosis in a Passive-Coated Stent

Purpose: To investigate if a platelet inhibitor (aurintricarboxylic acid [ATA]) and a heparin-mimicking antagonist (RG-13577) of basic fibroblast growth factor 2 (bFGF2) could be combined as a stable compound and attached to conventional bare metal stents to hinder thrombus formation and inflammatory reactions of stenting. Methods: Fifteen domestic pigs were stented with RG-13577/ATA—coated (n=6), ATA-coated (n = 12), and bare metal stents (n = 12) in the left anterior descending (LAD) and left circumflex (LCX) coronary arteries. All surviving pigs were evaluated with contrast angiography and intravascular ultrasonography (IVUS) after 4 weeks. Histological analysis of the stented arteries was performed after hematoxylin-eosin staining. Tissue factor (TF) staining and scanning electron microscopy (SEM) were performed in animals with acute stent thrombosis. Results: Five of the 6 animals receiving an RG-13577/ATA—coated stent experienced acute stent thrombosis, while no adverse events occurred in the animals of the other 2 groups. Follow-up angiography did not show significant in-stent stenosis in either bare or ATA-coated stents. However, histomorphometry revealed larger neointimal area (3.54±0.69 mm2 versus 1.82±0.27 mm2, p