Inclusion Criteria:

• Patient is 18 years of age or older.
• Patient has CHF for > 2 months
• Patient has LVEF > 50% within 2 months
• Patient with NYHA class II or III
• BNP > 62 pg/ml within 2 months of screening
• Patient on ACEI or ARB therapy for at least 1 month
• BP no more than 150/95
• Patient able to walk
• Signed informed consent.

Exclusion Criteria:

• Current treatment with spironolactone.
• Severe hepatic impairment.
• Creatinine > 2.5 mg/dl
• Potassium > 5.0 mEq/L
• Intolerance to spironolactone in the past.
• Significant valvular heart disease, pericardial disease, or severe COPD.
• Unstable angina or MI within the past 4 weeks.
• Severe vascular disease.
• Pregnant or lactating females.
• History of alcohol or substance abuse.
• History of cancer.
• Participation in any other drug trial within 30 days prior to randomization.
• Inability to provide informed consent.
• Patient on any CYP3A4s.