Anti-seizure medications in patients with post-stroke epilepsy: A survival analysis study

Objective: The role of antiseizure medications (ASMs) in patients with post-stroke epilepsy (PSE) is still debated. Although a few studies have compared the efficacy of different ASMs on mortality in patients with PSE, overall evidence on the impact of ASM use on survival is limited. This study aimed to evaluate the association between ASM use and all-cause mortality in patients with PSE. Methods: A cohort study was conducted using health care administrative database of Health Protection Agency of Bergamo (Italy). Individuals with a diagnosis of stroke followed by epilepsy onset between January 1, 2014 and December 31, 2017 were included. The date of epilepsy was considered as Index date (ID). Patients were followed from the ID until death, disenrollment, or end of follow-up, whichever occurred first. Exposure to ASMs was defined as at least one dispensing within 30 days of the ID; patients without ASM dispensing during this period were considered non-exposed. All-cause mortality was analyzed using Cox proportional hazards models, with non-exposure as the reference. Two analytical approaches were adopted: an intention-to-treat analysis and a time-dependent analysis. Results: A total of 145 patients met the inclusion criteria: 107 ASM users and 38 non-users. In the intention-to-treat analysis, ASM use was associated with a lower risk of all-cause mortality (adjusted hazard ratio [HR]: 0.56; 95% confidence interval [CI]: 0.33-0.95). Consistent findings were observed in the time-dependent analysis (adjusted HR: 0.39; 95% CI: 0.23-0.65). The sensitivity analyses confirmed the robustness of the results. Significance: In this population-based cohort study, ASM use in patients with PSE was associated with a significantly reduced risk of all-cause mortality compared to non-use. These findings support the hypothesis that ASM treatment might be associated with positive effect in this high-risk population.