Delayed ischemic stroke after PED placement for aneurysms: optimal duration of dual antiplatelet therapy and risk factors.

Background: Delayed ischemic stroke (DIS) is a rare complication that may occur in patients with cerebral aneurysms treated with the Pipeline Embolization device (PED). This study aims to evaluate the characteristics of DIS following PED placement and to investigate the optimal duration of dual antiplatelet therapy (DAPT) in relation to the incidence of DIS.

Methods: We conducted a multicenter retrospective cohort study on consecutive cases of intracranial aneurysms treated with PED. Patients were divided into two groups based on the timing of DAPT switching to monotherapy: early (<6 months) and late (≥6 months). To adjust for potential biases between the groups, inverse probability of treatment weighting (IPTW) was applied. Kaplan-Meier survival analysis and multivariate Cox regression were used to calculate cumulative DIS rates, and risk factors for DIS.

Results: A total of 1,146 consecutive patients with 1,296 aneurysms were included, of whom 12 (0.96%) who received PED developed DIS. The late-switch group had a lower DIS rate compared to the early-switch group [0.5% (4 of 752 patients) vs. 2.0% (8 of 394 patients),  = 0.018], even after IPTW. Hypertension [hazard ratio (HR) 3.47, 95% CI: 1.045-11.552] and complete occlusion immediately post-procedure (HR 5.48, 95% CI: 3.048-9.868) were significant risk factors for DIS.

Conclusion: DIS is a rare complication among patients treated with PED for cerebral aneurysms. Extending the duration of DAPT to at least six months may safer for the patients with hypertension and immediate complete occlusion.