Safety and efficacy of different paclitaxel-eluting balloons in a porcine model.

Introduction and objectives: Paclitaxel-eluting balloons have shown high antiproliferative efficacy in the treatment and prevention of restenosis. Nevertheless, not all available devices are equally effective, which makes it interesting to compare results in a preclinical model. Our objective was to assess the preclinical efficacy and safety of different devices. Methods: We implanted 51 metallic stents (Architect W, iVascular) in 17 domestic swine (mean, 25 [ 3] kg), inserting 1 stent per major coronary artery. Stent postdilatation was performed with different control balloons (n = 10) or paclitaxel-eluting balloons: paclitaxel-eluting balloon 1 (iVascular) (n = 15); paclitaxeleluting balloon 2 (iVascular) (n = 16) and In. Pact Falcon W (Medtronic) (n = 10). The restenosis rate (using angiography and histomorphometry) and vascular healing parameters (balloon-related vascular injury score, endothelialization rate, and fibrin and inflammation scores) were analyzed at 28 days. Results: The distinct paclitaxel-eluting balloons showed a similar degree of stenosis at follow-up, which was significantly lower than that in the control group: diameter stenosis was 9% (12%) vs 34% (18%) by angiography (P <.0001) and was 22% (8%) vs 51% (18%) by histomorphometry (P <.0001). Scores for vascular injury (mean, 0.6 [ 0.5]) and inflammation (mean, 0.8 [ 0.3]) were uniformly low across all groups. Drug effect markers differed significantly between the paclitaxel-eluting balloons and control groups, with lower endothelialization rates (87% [ 10%] vs 99% [ 2%]; P =.0007) and higher fibrin scores (2.1 [ 0.7] vs 0.4 [ 0.5]; P <.0001) in the paclitaxel-eluting balloons groups. There were no differences between the different paclitaxel-eluting balloons. Conclusions: In this preclinical model, the paclitaxel-eluting balloons studied significantly reduced instent restenosis compared with the control balloons. Although there were no findings of persistent vascular injury or inflammation, delayed endothelialization and fibrin aggregate suggest a drug deposition response. (C) 2013 Sociedad Espanola de Cardiologia. Published by Elsevier Espanoa, S. L. All rights reserved.