Objectives: This study sought to elucidate the underlying mechanism through which drug-eluting balloons (DEB) restore coronary blood flow, by assessing the coronary vessel before, immediately after, and at 6-month follow-up with angiography, optical coherence tomography (OCT), and fractional flow reserve (FFR).
Background: In-stent restenosis (ISR) treatment remains challenging. Drug-eluting balloons have been shown to be a valid treatment option in several studies. These studies focused on efficiency of the device, whereas the mechanisms of action of DEB in ISR treatment have not been investigated.
Methods: In this prospective, single-center observational study, patients with ISR were treated with a second-generation DEB. Serial angiographic, OCT, and FFR measurements were performed before and after the procedure, as well as at 6-month follow-up.
Results: Twenty-five patients were assigned to DEB treatment, with an angiographic and device success of 100% and 92%, respectively. Late luminal loss was 0.01 ± 0.43 mm. Median percent changes [interquartile range] between pre-and post-procedure, and post-procedure and follow-up were, respectively: lumen volume 75.1% increase [43.7 to 115.0], and 8% increase [-14.0 to 25.8]; stent volume 23.7% increase [15.5 to 40.0], and -1.2% decrease [-6.9 to 5.9]; and neointimal volume -14.4% decrease [-29.2 to -9.5], and -15.8% decrease [-38.1 to 28.3]. The FFR gradient along the treated stent (difference in FFR between the distal and the proximal stent edge) was 0.37 ± 0.18 pre-procedure, 0.06 ± 0.04 post-procedure, and 0.05 ± 0.05 at follow-up. In all post-procedural OCT images, intrastent dissections were seen, which were sealed at follow-up OCT.
Conclusions: DEB restore coronary blood flow by means of a short-term mechanical effect, causing an increase in lumen and stent volumes and compression of neointimal hyperplasia (with intra-stent dissections). Due to the local drug effect, patency persists and may even improve at follow-up, with further increase in lumen volume, decrease in neointimal volume, and complete sealing of neointimal dissections.
Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.