What Is An Aldosterone Antagonist?

— -- Question: What is an aldosterone antagonist, how does it work, and when is it used to treat heart failure?

Answer: Aldosterone is a hormone that the body normally produces. It's present in all of us. It's important because it helps us hold on to salt and water.

Patients with heart failure, particularly those with more severe heart failure, produce excess amounts of adolsterone. As a result, they hold on to large amounts of salt and water, and that's responsible for some of the congestive symptoms that people with heart failure have.

Also, people with heart failure with high levels of aldosterone waste potassium and magnesium in the urine, and that makes them more susceptible to certain arrhythmias.

Aldosterone causes fibrosis or scarring within blood vessels making them more stiff. This increases the work that the diseased heart has to do.

Finally, aldosterone causes scarring within the heart that makes it stiff. It also leads to progressive enlargement and progressive dysfunction of an already weakened heart.

Aldosterone antagonists are drugs that block the effective aldosterone by binding to receptors in the heart and on blood vessels thus blunting the action of this harmful hormone.

We give out aldosterone antagonists to people with moderate to severe chronic systolic heart failure. Systolic heart failure is heart failure due to decreased pumping ability of the heart. We also give aldosterone antagonists to people who have heart failure in the days following a heart attack.