Hormone thERapy Effects on BRAin-HEART Health During the Menopausal Transition

The goal of this clinical trial is to learn whether it is feasible to conduct a larger study comparing transdermal menopausal hormone therapy (MHT) versus no hormone therapy in menopausal women with vasomotor symptoms (hot flashes and night sweats) and at least one cardiovascular risk factor. The main questions it aims to answer are: * What proportion of eligible women agree to be randomly assigned to either receive MHT or not? * How many participants complete the 12-month follow-up, including repeat heart imaging? * Does transdermal MHT affect early changes in heart muscle tissue as measured by cardiac MRI? Researchers will compare immediate initiation of transdermal estradiol (a skin gel or patch) to a no-hormone therapy strategy to see if MHT influences early cardiovascular and brain-vascular changes over 12 months. Participants will: * Be randomly assigned to start transdermal MHT within 2 weeks, or to use no hormone therapy for at least the first 3 months * Undergo a cardiac MRI and retinal eye imaging at the start of the study and again at 12 months * Complete cognitive testing and questionnaires about symptoms, sleep, and stress at both visits * Provide a blood sample for storage and future analysis of heart and brain health markers * Receive follow-up phone calls at 3, 6, and 9 months to review symptoms, medications, and any health changes