EWISE: Study of Eplerenone in Women With Chest Pain, Coronary Vascular Dysfunction and Evidence of Myocardial Ischemia

Inclusion Criteria: * Non-pregnant women with chest discomfort who are 21 to 75 years of age and from diverse racial/ethnic groups. * Suspected ischemic heart disease (IHD) but no severe coronary stenosis (\> 50% diameter reduction) on coronary angiography used to qualify for WISE. * Endothelial dysfunction, defined as failure to dilate to intracoronary acetylcholine (\< 5% increase in mean lumen diameter). * If possible, patients should be taking stable, maximally tolerated dose of either an angiotensin-converting enzyme inhibitor \[ACEI\] (or an angiotensin II receptor blocker \[ARB\] if ACEI intolerant) Exclusion Criteria: * Women who are breast-feeding or who are pregnant. Women of childbearing potential may be enrolled but must agree not to become pregnant during the course of the study and must practice a method of birth control considered reliable by the investigator. If established on hormonal contraceptives for more than 3 months, patients will be allowed to participate provided that this therapy remains constant throughout the study. If a patient becomes pregnant or begins breast-feeding during the study, she must be withdrawn immediately. * Acute ischemic syndrome defined as acute myocardial infarction \[MI\] (by enzyme or electrocardiogram \[ECG\] criteria) or unstable angina within 1 month of entry. * Uncontrolled moderate hypertension: sitting blood pressure \> 160/95mmHg with measurements recorded on at least 2 occasions (for blood pressure control patients must first be stabilized, preferably with a diuretic, and remain on that dosing regimen throughout participation in the study). * Severe heart failure defined as New York Heart Association (NYHA) Class III or IV on treatment. * Coronary revascularization by either coronary artery bypass grafting (CABG) or percutaneous transluminal coronary angioplasty (PTCA) or stent placement. * Conditions likely to influence outcomes independent of IHD: severe lung, renal (creatinine \>1.8 or creatinine clearance \[CrCl\] ≤ 50ml/min) or hepatic disease; surgically uncorrected significant congenital or valvular heart disease; and other diseases likely to be fatal or require frequent hospitalizations within the next six months. * Adherence or retention reasons: recent alcoholism or drug abuse; psychiatric illness including severe depression; dementia; active participation in any other research trial other than WISE; or unwilling to complete follow-up evaluations including repeat testing. * Hypersensitivity to any medications to be used in the study * Documented obstructive hypertrophic cardiomyopathy. * Aortic stenosis (valve area \< 1.5cm). * Left ventricular (LV) dysfunction (ejection fraction \<= 35%). * History of significant cocaine or amphetamine abuse. * Serum potassium \> 5.0meq/l at baseline * Taking potent CYP3A4 inhibitors (ketoconazole, itraconazole, nefazodone, troleandomycin, clarithromycin, ritonavir, nelfinavir) * Intolerance to ACEI and ARB medications * Use of potassium supplements or potassium sparing diuretics