Perioperative use of mineralocorticoid receptor antagonists (MRA) in patients with unilateral primary aldosteronism (PA) awaiting surgery is not well standardized. The aim of this study was to compare the risk of postoperative complications and surgical outcomes between PA patients treated with MRA prior to adrenalectomy and those non-pretreated.

Adrenalectomized patients for unilateral PA from the SPAIN-ALDO registry, with clinical, hormonal and treatment information before and after adrenalectomy, were analyzed.

A total of 355 surgically-treated patients were included and 76.9% (n=273) received presurgical treatment with MRA (more commonly spironolactone [64.5%] than eplerenone [35.5%]). Adrenalectomy was guided by lateralization at AVS in 33.5% of the overall cohort, and by imaging in all the other cases. Patients pretreated with MRA had longer duration of hypertension, higher prevalence of hypokalemia and greater aldosterone concentrations than those not pretreated (n=82). No differences in the rate of postsurgical hyperkalemia, hypoaldosteronism, renal function impairment, blood pressure changes and biochemical outcomes were detected between groups in the immediate (≤30 days) and at short-term follow-up (≤90 days) following surgery. At long-term follow-up, patients pretreated with MRA exhibited better postsurgical biochemical outcomes (81.7% had complete biochemical response vs. 57.1% of non-pretreated patients; p=0.004). In the multivariable analysis, the use of MRA prior to adrenalectomy was independently associated with a successful postsurgical biochemical response.

Preoperative MRA therapy can be safely introduced to control blood pressure and potassium levels in patients with PA awaiting surgery, without increasing the risk of postoperative hyperkalemia, hypoaldosteronism, renal impairment, or hypotension.