Vascular Response Occurring at 3 Months After Everolimus-Eluting Cobalt-Chromium Stent Implantation in Patients With ST-Segment Elevation Myocardial Infarction vs. Stable Coronary Artery Disease

Comparison of MECHANISM of early and late vascular responses following treatment of ST-elevation acute myocardial infarction with two different everolimus-eluting stents: a randomized controlled trial of biodegradable versus durable polymer stents

The early and mid-term arterial healing profile of biodegradable polymer-coated everolimus-eluting stents (BP-EES) is unclear, especially in ST-segment elevation myocardial infarction (STEMI) culprit lesions. This study aimed to compare early- and mid-term arterial healing between durable polymer-coated everolimus-eluting stents (DP-EES) and BP-EES in STEMI patients. In a prospective, multicenter, non-inferiority trial, STEMI patients were randomized to receive BP-EES (n = 60) or DP-EES (n = 60). The primary endpoint of this study was the mean percentage of covered struts (%covered struts) on FD-OCT 2 weeks post-PCI. Key secondary endpoints included the percentage of uncovered struts, frequency of abnormal intra-stent tissue, and percentage of malapposed struts by FD-OCT 2 weeks and 12 months post-PCI. They underwent serial frequency-domain optical coherence tomography (FD-OCT) evaluations immediately after percutaneous coronary intervention, and at 2 weeks and at 12 months after the procedure. The primary endpoint of %covered struts at 2 weeks was 71.4% in BP-EES and 72.3% in DP-EES [risk difference - 0.94%, lower limit of one-sided 95% confidence interval (CI) - 5.6; P_{non-inferiority} = 0.0756]. At 12 months, the mean percentage of uncovered struts was significantly lower [1.73% (95% CI 0.28-3.17) vs. 4.81% (95% CI 3.52-6.09); p = 0.002], and the average malapposed volume was significantly smaller in the BP-EES group than in the DP-EES group (p = 0.002). At 12 months, BP-EES had a significantly larger average neointimal area with a significantly smaller average intra-stent tissue unevenness score than DP-EES, suggesting more uniform neointimal coverage with BP-EES. Strut coverage was comparable between BP-EES and DP-EES at 2 weeks. Non-inferiority could not be proven because of an insufficient sample size. The significantly better arterial healing with BP-EES at 12 months suggests a safer profile for STEMI culprit lesions.Trial registration: jRCTs022180024 https://jrct.niph.go.jp/en-latest-detail/jRCTs022180024.

Early vascular healing of ultra-thin strut polymer-free sirolimus-eluting stents in acute coronary syndrome: USUI-ACS study

Ultra-thin strut polymer-free sirolimus-eluting stent (UPF-SES) have two novel characteristics, ultra-thin strut and polymer-free coating, which have the potential to achieve early re-endotherialization. However, a little is known whether early vascular healing of UPF-SES can be achieved in patients with acute coronary syndrome (ACS). The aim of this study was to evaluate the vascular healing after an implantation of UPF-SES in patients with ACS using optical coherence tomography (OCT) at 3 months after the stent implantation. From September 2020 and January 2021, a total of 31 consecutive patients presenting with ACS who underwent OCT-guided percutaneous coronary intervention (PCI) and 3 month follow-up OCT examination were enrolled in the USUI-ACS study. The endpoints of this study were neointimal strut coverage, malapposition, and mean neointimal hyperplasia (NIH) thickness at 3 month follow-up. Over a mean follow-up of 91 days after the initial PCI, the follow-up OCT was examined. The median percentage of covered struts was 98.4% and malapposed struts 0%, and the mean NIH thickness was 80 μm. UPF-SES exhibited an excellent early vascular healing at 3 months in patients with ACS.

A serial optical frequency-domain imaging study of early and late vascular responses to bioresorbable-polymer sirolimus-eluting stents for the treatment of acute myocardial infarction and stable coronary artery disease patients: results of the MECHANISM-ULTIMASTER study

The purpose of this study was to assess early and late vascular healing in response to bioresorbable-polymer sirolimus-eluting stents (BP-SESs) for the treatment of patients with ST-elevation myocardial infarction (STEMI) and stable coronary artery disease (CAD). A total of 106 patients with STEMI and 101 patients with stable-CAD were enrolled. Optical frequency-domain images were acquired at baseline, at 1- or 3-month follow-up, and at 12-month follow-up. In the STEMI and CAD cohorts, the percentage of uncovered struts (%US) was significantly and remarkably decreased during early two points and at 12-month (the STEMI cohort: 1-month: 18.75 ± 0.78%, 3-month: 10.19 ± 0.77%, 12-month: 1.80 ± 0.72%; p < 0.001, the CAD cohort: 1-month: 9.44 ± 0.78%, 3-month: 7.78 ± 0.78%, 12-month: 1.07 ± 0.73%; p < 0.001 respectively). The average peri-strut low-intensity area (PLIA) score in the STEMI cohort was significantly decreased during follow-up period (1.90 ± 1.14, 1.18 ± 1.25, and 1.01 ± 0.72; p ≤ 0.001), whereas the one in the CAD cohort was not significantly changed (0.89 ± 1.24, 0.67 ± 1.07, and 0.64 ± 0.72; p = 0.59). In comparison with both groups, differences of %US and PLIA score at early two points were almost disappeared or close at 12 months. The strut-coverage and healing processes in the early phase after BP-SES implantation were significantly improved in both cohorts, especially markedly in STEMI patients. At 1 year, qualitatively and quantitatively consistent neointimal coverage was achieved in both pathogenetic groups.