Abstract 17924: Four-Month QCA and IVUS Results of the PAX-A Trial: A Randomized Comparison with Serial QCA and IVUS of the Novel Polymer-Free Amazonia Pax® Paclitaxel-Eluting Stent System versus the Taxus® Liberté Stent
Background: Durable polymers in 1st-generation DES have been linked to local inflammatory reactions. Stent thrombosis (ST) secondary to positive vessel remodeling and late-acquired incomplete stent apposition (ISA) is a possible clinical translation of this local adverse effect. The novel Amazonia PAX® (MINVASYS, France) comprises a cobalt chromium stent, a well-tested anti-proliferative agent (paclitaxel, ∼ loading dose 67 μg) and the polymer-free PAX technology. The drug is carried into the vessel by an abluminal coating. The kinetics of paclitaxel includes a burst release and a 100% drug elution within 45 days of the procedure. We sought to compare, by means of surrogate endpoints, this novel device to the first-generation Taxus® Liberté stent.
Methods: PAX-A is a single-center trial comprising 30 patients randomized (1:1) to receive either Amazonia PAX® or Taxus® Liberté stent. We enrolled patients with single, de novo lesion, up to 20mm in length in a native coronary of 2.5 to 3.5mm in diameter. Immediately after the procedure, all patients were submitted to IVUS, which was repeated at four months. Sample size calculation was based on a non-inferiority of the novel device in comparison to the Taxus® Liberté regarding % of in-stent NIH (IVUS). Secondarily, in-stent late lumen loss (LLL) by QCA) at four months was compared.
Results: Mean age was 58 years with 35% of women and 39% of diabetics. Mean reference vessel diameter and lesion length were 2.9±0.4mm and 14.8±3.7mm. There were no differences regarding baseline clinical and angiographic characteristics between groups. In all cases the stents were successfully deployed with no complication. Four-month invasive FU was obtained for all patients. % of in-stent NIH was 6% for the Taxus cohort vs. 19% for the Amazonia Pax (p=0.08) while in-stent LLL was 0.42mm for Taxus vs. 0.77mm for Amazonia Pax (p=0.2). There was a single case of late acquired incomplete stent apposition in the Amazonia group vs. 3 in the control group. Up to six-months there was 1 TLR in the Amazonia cohort vs. 2 in the Taxus, with no case of death or MI.
Conclusions: In this first-in-man assessment of the novel PAX polymer free technology, the novel device failed to achieve the expected efficacy when compared with the first-generation Taxus DES.
- © 2010 by American Heart Association, Inc.