Efficacy and safety of pimecrolimus-eluting stents in porcine coronary arteries

ObjectiveWe aimed to evaluate an effective dosage and safety profile of pimecrolimus as an anti-inflammatory drug for drug-eluting stents.MethodsIn the dose finding study, coronary arteries of 20 domestic swine were randomly implanted with bare metal stents (ProKinetic and Guidant Vision), the ProKinetic stent with polylactic acid (PLLA), and pimecrolimus-eluting stents (32, 75, and 120 μg) over a period of 4 weeks. In addition, pimecrolimus (75 μg) and ProKinetic stents were randomly implanted into six swine over 3 months. In the safety study, the ProKinetic stent, the ProKinetic stent with PLLA, mid- (45 μg) and high-dose pimecrolimus (120 μg), and overlapping mid-dose stents were implanted over a period of 4 weeks. Mid-dose, ProKinetic stent, and ProKinetic stent with PLLA were implanted over a period of 3 months.ResultsThe dose finding study revealed excellent luminal patency with low percent occlusion (≈29% vs. ≈41%), injury (0.53–0.59 vs. 1.25), and inflammation (0.78–0.97 vs. 1.08) for the pimecrolimus group compared with the vision group. The safety study arm showed similar angiographic results for all tested groups, with a significantly larger minimal lumen diameter for pimecrolimus stents compared to PLLA stents. Except for the high-dose group and overlapping area of the overlapping group, promising morphometric results were found for pimecrolimus compared to bare metal stents.ConclusionsPresent data suggest that pimecrolimus-eluting stents are safe and have a similar healing profile to bare metal stents. They may suppress inflammation, leading to a reduced intimal response and a milder inflammatory reaction in a porcine model.