Abstract Number: Esoc2026a568 Multivitamin Supplementation and Increased Long-Term Mortality Among Young Stroke Survivors: A Cohort Study

Background and aims Whether multivitamin supplements improve prognosis after ischemic event remains unclear. We aim to associate multivitamin use and long-term mortality among stroke survivors. Methods We sifted patients from a prospective cohort including patients with cerebrovascular diseases between 2002 and 2007, at the Department of Neurology, Ren Ji Hospital, and followed annually from enrollment to the date of death or December 31, 2023. Patients were excluded if they had (1)age<18 years; (2)hemorrhagic stroke; (3)history of cancer; (4)no information on multivitamin use at baseline. Demographics, multivitamin use and other variables were collected. Primary outcome was all-cause death. Cox regression analyses were employed to associate multivitamin use with long-term and cause-specific mortality, and analyze the interaction between multivitamin use and other variables for the outcomes. Subgroup analyses were conducted based on interaction analysis, with the same methods. Results Among 972 eligible patients (605 [62.2%] males, median age 68 [IQR 57-74] years), 656 (67.5%) reported multivitamin use at enrollment. Primary outcome was observed in 428 (44.0%) patients, with the median follow-up time of 17 (IQR 10-19) years. No association was identified between multivitamin use and long-term mortality. A significant age-multivitamin use interaction on the long-term mortality (p=0.046) was observed. In those aged<60 years, multivitamin use may increase long-term mortality (HR 2.59, 95% CI 1.01-6.62; p=0.047). Specifically, multivitamin users suffered a higher risk of cancer-related death than non-users (4.9% versus 0.0%; Log-rank p=0.054). Conclusions Multivitamin may not improve long-term survival in stroke patients, but elevate mortality in young survivors, possibly by promoting cancer. Conflict of interest Nothing to disclose