Comparison of the Safety of Aspirin Monotherapy and Aspirin and P2Y12 Inhibitor Combination Therapy in Patients Post Coil Embolization During Admission: A Cross-Sectional Study Using a Nationwide Inpatient Database.

Background: Some aspects regarding the use of antiplatelet agents after coil embolization for subarachnoid hemorrhage during admission remain unclear. This study used diagnostic procedure combination (DPC) data to investigate the safety and prognostic effects of aspirin monotherapy and aspirin and P2Y12 inhibitor combination therapy on bleeding events.

Methods: This cross-sectional study used Japanese DPC data to assess patients who were hospitalized with subarachnoid hemorrhage and received aspirin monotherapy and aspirin and P2Y12 inhibitor combination therapy between April 2016 and March 2020 (n = 4421). The aspirin monotherapy (A group, n = 2848) and aspirin and P2Y12 inhibitor combination therapy (AP group, n = 1573) groups were compared. The primary and secondary endpoints were the incidence of bleeding events and proportion of patients with a modified Rankin Scale (mRS) score ≤ 2 at discharge, respectively. Data was analyzed using multivariable adjusted logistic regression (significance level, 5%).

Results: The adjusted odds ratio in AP group, with A group as the reference, for bleeding events and the proportion of patients with mRS score ≤ 2 at discharge were 0.97 (95% confidence interval [95% CI]: 0.75-1.26, p = 0.839) and 1.09 (95% CI: 0.92-1.29, p = 0.302), respectively.

Conclusions: There are no differences in the incidence of bleeding events or good clinical outcomes (mRS score ≤ 2 at discharge) between aspirin monotherapy and aspirin and P2Y12 inhibitor combination therapy.