Safety of discontinuing antiplatelet therapy 12-24 months after stent-assisted coil embolization: a multicenter retrospective study

OBJECTIVE Antiplatelet medication is required after stent-assisted coil embolization (SACE) to avoid thromboembolic complications. Currently, there is no consensus on how long the antiplatelet agent should be maintained. The authors investigated clinical outcomes in patients who discontinued their antiplatelet agent 12-24 months after SACE. METHODS Data were retrieved from a prospective database for 373 consecutive patients with SACE at 6 institutions who discontinued antiplatelet therapy 12-24 months after SACE. Thromboembolic complications associated with discontinuation were defined as neurological or radiographic ischemia that occurred within 6 months after discontinuation of the antiplatelet agent; the lesion had to be correlated with the territory of the stented artery. RESULTS The mean time until discontinuation of the antiplatelet medication was 15.8 +/- 4.7 months after SACE (12-18 months, n = 271; 19-24 months, n = 102). The most common location of treated aneurysms was the internal carotid artery (n = 223, 59.8%). A laser-cut open-cell stent was most commonly applied (n = 236/388, 60.8%), followed by lasercut closed-cell stents (n = 119, 30.7%) and braided closed-cell (n = 33, 8.5%); double stenting was applied in 15 aneurysms. There were no patients who experienced cerebral ischemia related to discontinuation of antiplatelet medications, except for 1 patient at high risk of ischemia (0.27%, 95% CI 0.01%-1.48%). CONCLUSIONS These results suggest that it may be safe to discontinue antiplatelet medication after SACE in patients at low risk for ischemia, and that it appears safe to discontinue the agent at approximately 15 months after the procedure. Large cohort-based prospective studies or randomized clinical trials are warranted to confirm these results.