Edge Vascular Response After Polymer-Free vs. Polymer-Based Paclitaxel-Eluting Stent Implantation - Serial Intravascular Ultrasound Study From the Late Incomplete Stent Apposition Evaluation (LISA) Trial

Background: It is unknown if lack of polymer can provoke a different edge response in drug-eluting stents. The aim of this study was to compare edge vascular response between polymer-free paclitaxel-eluting stent (PF-PES) and polymer-based paclitaxel-eluting stents (PB-PES). Methods and Results: A total of 165 eligible patients undergoing percutaneous coronary intervention were prospectively randomized 1: 1 to receive either PF-PES or PB-PES. Those patients with paired intravascular ultrasound (IVUS) after procedure and at 9-month follow-up were included in this analysis. Seventy-six patients with 84 lesions, divided into PB-PES (38 patients, 41 lesions) and PF-PES groups (38 patients, 43 lesions) had paired post-procedure and 9-month follow-up IVUS and were therefore included in this substudy. There was a significant lumen decrease at the proximal edge of PF-PES (from 9.02 +/- 3.06 mm(2) to 8.47 +/- 3.05 mm(2); P=0.040), and a significant plaque increase at the distal edges of PF-PES (from 4.39 +/- 2.73 mm(2) to 4.78 +/- 2.63 mm(2); P=0.004). At the distal edge there was a significant plaque increase in the PF-PES compared to PB-PES (+8.0% vs. -0.6%, respectively; P=0.015) with subsequent lumen reduction (-5.2% vs. +6.0%, respectively; P=0.024). Conclusions: PF-PES had significant plaque increase and lumen reduction at the distal edge as compared to PB-PES, probably due to difference in polymer-based drug-release kinetics between the 2 platforms.