The mineralocorticoid receptor antagonists spironolactone and eplerenone have become part of standard medical therapy for heart failure (HF). Randomized clinical trials have shown the clinical efficacy of spironolactone and eplerenone, which lead to lower death rates in patients with systolic HF. Whether these two drugs are equivalent and able to exert a positive effect in patients with clinical HF, including chronic HF with retained left ventricular systolic function remains to be answered.