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 stimulus for neointimal hyperplasia and if excessive can result in stent thrombosis. We tested the hypothesis that local delivery of an antithrombin drug from a polymeric‐metallic stent inhibits platelet thrombus formation. An uncoated metal slotted tube, a jellyroll slotted metal stent with an Argatroban‐loaded polymeric sleeve, and a jellyroll slotted metal stent with a drug‐leached polymeric sleeve were randomly deployed into the coronary arteries of eight juvenile farm swine. Platelet deposition in the stented segments was determined at 2 hr using autologous 111Indium oxime‐labeled platelets. Platelet deposition was significantly less in the Argatroban‐loaded stents compared to the Argatroban‐leached stents (1.40 × 108 platelets/cm2 vs. 26.8 × 108 platelets/cm2; P = 0.005). When corrected for differences in the metal surface area exposed to blood, platelet deposition was significantly lower in the Argatroban‐loaded stent (1.74 ± 1.95 × 108/cm2) compared to the Argatroban‐leached stent (33.5 ± 39.1 × 108/cm2; P = 0.005) and the uncoated metal stent (36.2 ± 73.3 × 108/cm2; P = 0.006). In this coronary stent thrombosis model Argatroban has local antithrombotic properties when delivered with a polymer‐metallic stent. Improved polymeric designs may reduce risk of thrombus deposition at the site of stent implantation. Cathet. Cardiovasc. Intervent. 46:503–507, 1999. © 1999 Wiley‐Liss, Inc.