Cesar Augusto Ferreira Alves Filho

Background and purpose: Flow diverters (FDs) have become one of the primary treatments for intracranial aneurysms (IAs). However, their use in distal IA has been associated with higher complication rates compared with other techniques. The development of coated FDs, in combination with novel antiplatelet regimens, offers promising strategies to improve the safety profile of FDs in this context. This trial aimed to compare mono antiplatelet therapy (MAPT) using prasugrel versus dual antiplatelet therapy (DAPT) with aspirin and prasugrel for the treatment of distal IA using the p48 MW HPC FD (WallabyPhenox). Methods: This was a multicenter, prospective, parallel-group, single-blind, non-inferiority randomized trial. Between February 2021 and February 2025, 140 patients were enrolled. After excluding 11 patients, 129 were included in the final analysis. The primary endpoint was the absence of new neurological deficits, defined as no shift in the modified Rankin Scale (mRS) score. The secondary endpoint was the incidence of any stroke. Results: At the 30-day follow-up, 66 patients (98.5%) in the MAPT group and 59 patients (95.2%) in the DAPT group showed no new neurological deficits. With a predefined non-inferiority margin of 5%, the difference of 3.35% confirmed the non-inferiority of MAPT compared with DAPT (p=0.002). The incidence of any stroke was 4/67 (5.9%) in the MAPT group and 6/62 (9.6%) in the DAPT group (p=0.431). Conclusion: Prasugrel monotherapy for the treatment of distal IAs using the p48 MW HPC was non-inferior to DAPT within the first 30 days following treatment. Clinical trial registration: https://ensaiosclinicos.gov.br/rg/RBR-3q9zb73. UTN code: U1111-1290-2489. Research Ethics Committee of the Hospital das Clínicas de Ribeirão Preto - Universidade de São Paulo. CAAE number: 29848720.0.1001.5440.