Comparison of two different paclitaxel-coated balloon catheters in the porcine coronary restenosis model.

Background: Drug-eluting balloon (DEB) catheters coated with paclitaxel in a water-soluble matrix have shown beneficial effects in the treatment and prevention of restenosis in the porcine coronary overstretch model and in clinical trials. Adherence of paclitaxel, same dose, on another recently introduced coated percutaneous coronary intervention (PCI) catheter (DIOR) is mediated by a roughened balloon surface. Only scarce experimental and clinical data has been published on the new coating method. The aim of the present study was to compare the safety and efficacy of the two coatings in the porcine model.

Methods And Results: Twenty-eight stainless steel stents were implanted in the left anterior descending and circumflex coronary arteries of 14 domestic pigs using either matrix-coated (n = 8), roughened DEB (n = 9), or uncoated PCI catheters, which served as control (n = 11). After 28 days, quantitative angiography and histomorphometry of the stented arteries were performed. Matrix-coated DEB led to a highly significant (P < 0.01) reduction of all parameters indicating neointimal proliferation compared to both, uncoated control and the roughened DEB; late lumen loss in-segment was 0.4 +/- 0.2, 1.9 +/- 0.5, and 1.4 +/- 0.5 mm, respectively. In contrast, the roughened DEB failed to produce statistically significant effects on angiographic measures of stenosis or morphometric parameters such as maximal neointimal thickness and luminal area, except for neointimal area (5.7 +/- 1.5 mm(2) in the control group, 4.1 +/- 1.7 mm(2) roughened DEB, P < 0.05 vs. control, and 2.5 +/- 0.8 mm(2) matrix-coated DEB, P < 0.01 vs. control).

Conclusion: Inhibition of neointimal proliferation in the porcine coronary overstretch model by paclitaxel depends critically on the coating method.