Short‐ and mid‐term influence of drug‐coated stent implantation on structural and functional vascular healing response: An optical coherence tomography and acetylcholine testing study

Abstract

Objective This study investigated the effect of a drug‐coated stent (DCS) that has a novel microporous abluminal surface without a polymer on 1‐month and 1‐year functional and morphological healing response as assessed using acetylcholine (Ach) testing and optical coherence tomography (OCT). Background DCS is expected to induce favorable morphological and physiological arterial healing after its implantation. Methods A total of 11 patients who underwent vascular response examinations 1‐month and 1‐year after the index PCI with DCS implantation were enrolled. The vascular response was evaluated by the functional response test by acetylcholine infusion, the morphological response test by OCT. Results Although 94.5% of the DCS struts were covered by homogeneous smooth neointima at 1 month, the percentage of neointimal coverage increased to 98.5% at 1 year (p = .02). Conversely, the proportion of uncovered struts and malapposed struts at 1 year were 1.2 and 0.7%, respectively. Furthermore, the coronary vasomotor response to incremental doses of Ach were impaired especially in the distal segments at each period, although the responses to Ach at 10−6 mol/L in the distal segment tended to improve over time from baseline to 1 month and 1 year later (−19 ± 20%, −9 ± 17%, and −5 ± 14%, respectively; p = .27). Conclusions The morphological assessment of DCS with OCT revealed a high degree of strut coverage and apposition at 4 weeks after implantation. The impaired endothelium‐dependent vasomotor response tended to improve chronologically from baseline to 1 month and 1 year later.