Cardiovascular disease is the leading cause of death and disproportionately prevalent in patients with kidney disease. Spironolactone has been shown to improve survival in the general population with heart failure by up to 30%. We wish to study the safety and tolerability of aldosterone blockade with spironolactone on cardiac function in a high risk population of patients on hemodialysis. We will study and closely monitor subjects over a period of 12 months, during which they will be receiving spironolactone for a period of 6 months.

• End Stage Renal Disease
• Congestive Heart Failure

Inclusion Criteria:

• They must be at least 18 years of age.
• They must understand the study purpose and give their written informed consent.
• They must have been stable on chronic hemodialysis for at least three months before enrollment into the study.
• Hemodialysis subjects will be included if they have had a left ventricular ejection fraction measured within the past six months with a value no more than 45 percent. A repeat, standardized echocardiogram will be used to confirm left ventricular ejection fraction.

Exclusion Criteria:

• Subjects with primary operable valvular heart disease.
• Subjects with a congenital heart disease.
• Subjects with unstable angina.
• Subjects with primary hepatic failure.
• Subjects with active cancer or any life-threatening disease (other than heart failure or end-stage renal disease).
• Subjects who have undergone heart transplantation or who are awaiting heart transplantation are also ineligible.
• Subjects on a renal transplant list will be accepted into the study until the time of successful renal transplantation and termination of dialysis.
• Subjects with habitually difficult to control hyperkalemia (serum potassium >6.0 meq/L) in the previous month while on dialysis will be excluded.
• The inability to complete the 6-minute walk test will not be a reason to exclude subjects from this study.