Role of Eplerenone in Reducing Recurrence of Atrial Fibrillation in Patients With Structural Heart Disease

This study is testing whether a medication called eplerenone (a blood pressure and heart drug) can reduce the chance of atrial fibrillation coming back after a patient's heart rhythm has been successfully restored to normal. It focuses on people with structural heart problems like a stiff or weakened heart. **You may be eligible if...** - You have non-valvular atrial fibrillation (irregular heartbeat not caused by a heart valve problem) - Your heart rhythm was successfully reset to normal through electrical cardioversion, medication, or spontaneously - Your heart pumping function (ejection fraction) is 40% or higher **You may NOT be eligible if...** - You have rheumatic heart disease - You have an overactive or underactive thyroid - You have Wolff-Parkinson-White syndrome - You have kidney impairment or high potassium levels - You had a recent heart attack - You are pregnant - You are already taking eplerenone Talk to your doctor to see if this trial is right for you.