Pharmacologic blockade of the mineralocorticoid receptor (MR) has become a cornerstone of guideline-directed medical therapy for the treatment of heart failure (HF).1-4 Both angiotensin-converting enzyme (ACE) inhibitors and aldosterone receptor blockers (ARBs) provide a cardiovascular mortality benefit but may be insufficient for treating HF on their own, likely because half of patients experience a rebound in plasma aldosterone levels within 6-12 months of initiating ACE inhibitor / ARB therapy.