QWISE - Study of Quinapril in Women With Chest Pain, Coronary Flow Reserve Limitations and Evidence of Myocardial Ischemia

Inclusion Criteria: 1. Non pregnant women with chest discomfort 21 to 75 years of age from diverse racial/ethnic groups. 2. Suspected ischemic heart disease (IHD) but no severe coronary stenosis (\> 50% diameter reduction) on coronary angiography used to qualify for WISE. 3. Coronary flow reserve limitation (\<3.0 velocity). Exclusion Criteria: 1. 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 providing this therapy remains constant throughout the study. If a patient becomes pregnant or begins breast-feeding during the study, she must be withdrawn immediately. 2. Acute ischemic syndrome defined as acute myocardial infarction (MI) (by enzyme or electrocardiogram (ECG) criteria) or unstable angina within 1 month of entry. 3. 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 kept on that dosing regimen throughout participation in the study). 4. Severe heart failure defined as New York Heart Association (NYHA) Class III or IV on treatment. 5. Coronary revascularization by either coronary artery bypass grafting (CABG) or percutaneous transluminal coronary angioplasty (PTCA) or Stent Placement. 6. Conditions likely to influence outcomes independent of IHD: Severe lung, renal (creatinine \>3.0) or hepatic disease, surgically uncorrected significant congenital or valvular heart disease and other disease likely to be fatal or require frequent hospitalization within the next six months. 7. 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, unwilling to complete follow-up evaluation including repeat testing. 8. Hypersensitivity to any medications to be used in the study (e.g. angioedema to ACE-I). 9. Documented obstructive hypertrophic cardiomyopathy. 10. Aortic stenosis (valve area \<1.5cm). 11. LV dysfunction (ejection fraction \<=35%). 12. History of cocaine or amphetamine abuse. 13. ACE-I or angiotension 1 (AT-1) receptor blocker use within 30 days or need for continued ACEI/AT-1RB use.