Spontaneous Remission of Primary Aldosteronism with Mineralocorticoid Receptor Antagonism

Introduction: Primary aldosteronism (PA) is considered the most common cause of secondary hypertension. Though the specific etiology behind primary hyperaldosteronism is multifactorial, mineralocorticoid receptor antagonists (MRA) are the mainstay of medical management. Rare cases of spontaneous remission of PA due to bilateral adrenal hyperplasia have been reported after medical management with MRAs including potassium canrenoate and spironolactone. Here we describe a patient with PA entering spontaneous remission after mineralocorticoid receptor antagonist treatment. Case Description: A 66-year-old male with a past medical history of hypertension (HTN), hyperlipidemia, chronic pain treated with long-term NSAID use was initially referred to treat chronic kidney disease. The patient had a 25-year history of resistant HTN for 5 years prior to presentation and an increase in baseline creatinine from 0.8 to 1.6 over a year. Imaging showed a left adrenal adenoma with no lateralization or contralateral suppression with adrenal vein sampling. Plasma aldosterone/renin ratio was elevated at that time. Initial lab results showed hypokalemia and treatment with potassium (K+) and eplerenone was initiated. K+ normalized with medical management and after 18 months was stopped due to hyperkalemia. Eplerenone was replaced with spironolactone at that time. After 2 years, hyperkalemia developed despite subsequent reduction of spironolactone with no effect on the patient's HTN. Eventually, the MRA was stopped and blood pressure remained controlled without hypokalemia. Repeat aldosterone/renin ratio demonstrated normalization, suggesting spontaneous resolution. Discussion: Cases of PA have been reported to resolve spontaneously after treatment with MRA; remission is associated with K+ levels and length of treatment. Some studies report remission rate at 5.4% of participants, with complete remission being half of that. This low rate of remission emphasizes the need for further investigation. Here, adrenal vein sampling was consistent with bilateral adrenal hyperplasia, leading to medical management. Treatment with an MRA, lead to biochemical remission for 4 years after ending therapy. Our findings add to reports identifying patients with spontaneous partial or complete remission of PA with MRA use and highlight the importance of continued surveillance of possible spontaneous remission in these patients.