Per PI: "Never went to IRB Never recruited anyone Never resubmitted the score NIH application I am leaving the institution"

Double blind randomized controlled parallel pilot trial of Quercetin vs placebo oral administration in 24 postmenopausal women. The study team will conduct a feasibility pilot in preparation for a larger efficacy trial that will test the protective effects of quercetin against cardiac and skeletal muscle dysfunction and changes in structure induced by estrogen loss and potential mechanistic pathways in post-menopausal women at risk of heart failure with preserved ejection fraction (HFPEF).

Participants receive either oral Quercetin 1000 g/day or placebo for 20 weeks. Quercetin levels, biomarkers, ultrasounds (heart and muscle), functional assessments will be measured on enrollment and after the intervention. The study coordinator will contact participants weekly to monitor safety and ensure compliance. All quercetin administration will be supervised by Claudia L Campos, MD, Associate Professor of Internal Medicine, Medical Director Internal Medicine clinic.

Inclusion Criteria:

• Female, postmenopausal, aged 60 to 74
• Stated willingness to comply with all study procedures and availability for the duration of the study
• High risk of Heart failure with preserved ejection fraction (HFPEF) using web-based Primary Care Physician-HF risk tool (Khan S, et al.10-Year Risk Equations for Incident Heart Failure in the General Population. Information used for calculation include: age, gender, race, hypertension treatment (yes or no), fasting glucose value, smoking status, body mass index, systolic BP, diabetes treatment (yes or no), total cholesterol, HDL cholesterol, and electrocardiogram QRS duration. Prospective participant's with scores >= 10% will be included.
• Electrocardiogram (EKG) on medical record

Exclusion Criteria:

• History of congestive heart failure or use of loop diuretics
• Recent myocardial infarction (MI), stroke, angina, or atrial fibrillation (in the past 6 months), either self-reported and or in the electronic medical record.
• Uncontrolled diabetes mellitus
• Uncontrolled hypertension
• Significant renal insufficiency requiring dialysis or estimated glomerular filtration rate (eGFR) < 15 mL/min
• Liver disease
• Psychiatric disease - uncontrolled major psychoses, depressions, dementia, or personality disorder
• Participants reporting extreme energy intakes >3500 or <500 kcal/day
• Plans to leave area within the study period
• Refuses informed consent

Enrolled participants who complete the pre-treatment assessment will be randomly assigned to Quercetin or placebo. The trial manager who is not involved in any outcome assessments will carry out randomization following the protocol designed by the study biostatistician (Dr. Leng) prior to the study's start. The randomization sequence list will remain concealed from the investigators. Participants will be randomized using a computer-generated, password-protected randomization list, and simple randomization scheme. All staff involved in data collection and management will be kept unaware of the participants' group assignments and will explicitly inform participants that they (staff) are to remain blinded during the course of the study. The biostatistician will also be unaware of treatment assignment.