PROJECT ABSTRACT Cardiovascular disease (CVD) is the leading cause of death in women worldwide and despite declines in all other age groups, mortality rates attributed to CVD are increasing in women of childbearing age. Preeclampsia is a well-established risk factor for CVD across diverse patient populations, however, there are currently no evidence-based interventions targeting this at-risk patient population. While blood pressure control is the cornerstone of postpartum management, emerging evidence suggests that management of hypertension alone does not fully mitigate CVD risk after preeclampsia. The overall goal of this line of research is to begin to develop and test novel pharmacologic interventions for postpartum management following preeclampsia, representing a paradigm shift focused on endothelial recovery postpartum in addition to blood pressure control. In this application, the objective is to conduct a single-site pilot trial to assess the feasibility and effect of low- dose aspirin to augment vascular recovery in the immediate postpartum period after preeclampsia through two specific aims: to pilot test the feasibility of conducting a randomized controlled trial of postpartum low-dose aspirin vs. placebo, and 2) to assess the effect of postpartum aspirin on endothelial function and blood pressure. Our central hypothesis is that postpartum administration of low-dose aspirin following preeclampsia will be feasible, improve endothelial function, and lower BP at 6 months postpartum. The research proposed in this application is innovative in its novel adaptation of an evidence-based strategy to improve vascular function and postpartum blood pressure in an understudied population with significant morbidity during a critical time period. This proposal is significant as it will provide an opportunity to assess the feasibility and explore the effect of low-dose aspirin on vascular function in addition to blood pressure. Effective interventions to improve postpartum hypertension care and reduce long-term cardiovascular risk have broad implications for improving maternal morbidity and reducing disparities in care. Our findings will provide a valuable framework to inform a subsequent large-scale randomized trial of low-dose aspirin in the postpartum period following preeclampsia. Successful completion of this line of research would represent a transformation in postpartum management of women with hypertensive disorders of pregnancy and have a direct impact to improve hypertension and cardiovascular-related maternal morbidity and mortality.