Safety of antiplatelet medication discontinuation more than 12 months after stent-assisted coil embolization: a non-interventional, multicenter, observational study

Background Antiplatelet maintenance is essential to avoid ischemia following stent-assisted coiling (SAC) procedures. However, indications for antiplatelet medication discontinuation (AMD) remain controversial, and optimal timing of cessation has yet to be determined. Our goal, which we achieved through a multicenter, prospectively enrolled, non-interventional study, was to investigate the safety of AMD conducted more than 12 months after SAC. Methods Data were retrieved from the records of 495 consecutive patients prospectively enrolled at 10 institutions during a 3-year period (between January 2021 and December 2023). Each subject had discontinued antiplatelet therapy >12 months after SAC. Maintenance duration and cessation were both at physician discretion, based on patient clinical status. We investigated clinical outcomes for at least 6 months after AMD. Results A majority of patients engaged in AMD (292/495, 59.0%) were not at high risk for ischemia. Mean±SD time to AMD was 20.0±12.9 months after SAC. Treated aneurysms were largely confined to the internal carotid artery (332/495, 67.1%), followed by the anterior (95/495, 19.2%) and middle (43/495, 8.7%) cerebral arteries. A laser-cut open-cell stent was most often applied (60.5%); laser-cut closed-cell (22.2%) and braided closed-cell (17.3%) stents were used to a lesser extent. Four patients underwent double stenting. Despite sizeable (41.0%) high-risk group representation, there were no ischemic events in relation to AMD. Conclusion Our results suggest that AMD >12 months after SAC procedures is safe in patients who are not at high risk for ischemia. Randomized controlled trials are warranted to confirm these results.