Biological effect on drug distribution and vascular healing via paclitaxel‐coated balloon technology in drug eluting stent restenosis swine model

OBJECTIVES: To evaluate the biological effect of a paclitaxel‐coated balloon (PCB) technology on vascular drug distribution and healing in drug eluting stent restenosis (DES‐ISR) swine model. BACKGROUND: The mechanism of action and healing response via PCB technology in DES‐ISR is not completely understood. METHODS: A total of 27 bare metal stents were implanted in coronary arteries and 30 days later the in‐stent restenosis was treated with PCB. Treated segments were harvested at 1 hr, 14 days and 30 days post treatment for the pharmacokinetic analysis. In addition, 24 DES were implanted in coronary arteries for 30 days, then all DES‐ISRs were treated with either PCB (n = 12) or uncoated balloon (n = 12). At day 60, vessels were harvested for histology following angiography and optical coherence tomography (OCT). RESULTS: The paclitaxel level in neointimal tissue was about 18 times higher (P = 0.0004) at 1 hr C (max), and retained about five times higher (P = 0.008) at day 60 than that in vessel wall. A homogenous distribution of paclitaxel in ISR was demonstrated by using fluorescently labeled paclitaxel. Notably, in DES‐ISR, both termination OCT and quantitative coronary angioplasty showed a significant neointimal reduction and less late lumen loss (P = 0.05 and P = 0.03, respectively) post PCB versus post uncoated balloon. The PES‐ISR + PCB group displayed higher levels of peri‐strut inflammation and fibrin scores compared to the ‐limus DES‐ISR + PCB group. CONCLUSIONS: In ISR, paclitaxel is primarily deposited in neointimal tissue and effectively retained over time following PCB use. Despite the presence of metallic struts, a uniform distribution was characterized. PCB demonstrated an equivalent biological effect in DES‐ISR without significantly increasing inflammation. © 2015 Wiley Periodicals, Inc.