Local drug delivery of argatroban from a polymeric-metallic composite stent reduces platelet deposition in a swine coronary model

Thrombus formation after intracoronary stent implantation provides a stimul us for neointimal hyperplasia and if excessive can result in stent thrombos is. We tested the hypothesis that local delivery of an antithrombin drug fr om a polymeric-metallic stent inhibits platelet thrombus formation. An unco ated metal slotted tube, a jellyroll slotted metal stent with an Argatroban -loaded polymeric sleeve, and a jellyroll slotted metal stent with a drug-l eached polymeric sleeve were randomly deployed into the coronary arteries o f eight juvenile farm swine. Platelet deposition in the stented segments wa s determined at 2 hr using autologous (111)Indium oxime-labeled platelets. Platelet deposition was significantly less in the Argatroban-loaded stents compared to the Argatroban-leached stents (1.40 x 10(8) platelets/cm(2) vs. 26.8 x 10(8) platelets/cm(2); P = 0.005). When corrected for differences i n the metal surface area exposed to blood, platelet deposition was signific antly lower in the Argatroban-loaded stent (1.74 +/- 1.95 x 10(8)/cm(2)) co mpared to the Argatroban-leached stent (33.5 +/- 39.1 x 10(8)/cm(2); P = 0. 005) and the uncoated metal stent (36.2 +/- 73.3 x 10(8)/cm(2); P = 0.006). In this coronary stent thrombosis model Argatroban has local antithromboti c properties when delivered with a polymer-metallic stent. Improved polymer ic designs may reduce risk of thrombus deposition at the site of stent impl antation. Cathet. Cardiovasc. Intervent 46:503-507, 1999. (C) 1999 Wiley-Li ss, Inc.