Determine the Effectiveness of Eplerenone in Reversing Diastolic Dysfunction, Improving Endothelial Function, and Suppressing Natriuretic Peptides and Collagen Turnover in Patients With Diastolic Heart Failure ( PREDICT Study)

The study will be a single center, double-blind, randomized, parallel group trial enrolling a minimum of 80 patients designed to determine the efficacy of eplerenone in subjects with diastolic heart failure. Prior to administration of study medication, a medical history, physical exam, blood draw, electrocardiogram, 2D echocardiogram, and cardiomyopathy questionnaire will be performed. Subjects will then be randomized to receive either eplerenone 25 mg once daily or placebo for 2 weeks. At the Week 2 visit all patients will be titrated up to the next dose (50 mg eplerenone once daily or placebo). Each study arm will have 40 subjects who will participate for 9 months. Follow-up assessments will be completed at 1 week, 2 weeks, 1 month, 3 months, 6 months, and 9 months.

Starting at the Month 1 visit, any subjects with uncontrolled blood pressure will be administered add-on therapy of HCTZ (starting dose of 12.5 mg daily, that may titrate up to 25 mg daily) and/or amlodipine (starting dose at 5 mg daily, that may titrate up to 10 mg daily). Any subject who receives add-on therapy must have their blood pressure checked within 2 weeks. Uncontrolled blood pressure may be treated by either increasing the add-on therapy dose or increasing the add-on therapy regimen to include both add-on drugs. Changes in add-on therapy require blood pressure checks within 2 weeks.