Persistent Renin Suppression After Unilateral Adrenalectomy for Primary Aldosteronism: Implications for Adverse Outcome?

CONTEXT: Suppressed renin concentrations in medically treated patients with primary aldosteronism (PA) are associated with a worse cardiometabolic outcome compared to patients with normalized renin levels. No similar study has been conducted in patients with PA after unilateral adrenalectomy. OBJECTIVE: This study investigates the prevalence and impact of persistent renin suppression after unilateral adrenalectomy in patients with lateralized PA. METHODS: We retrospectively included 77 patients who underwent adrenalectomy for lateralized PA. All patients had postoperative renin levels available. Patients were divided into tertiles based on their direct renin concentrations (DRC) (<8 mU/L, 8-16 mU/L, >16 mU/L) at the first follow-up, approximately 6 months after surgery. Study endpoints included histopathology using CYP11B2 staining according to HISTALDO consensus, biochemical and clinical outcomes according to the PASO criteria and improvement of comorbidities and end-organ damage at short- and long-term follow-up up to 3 years postoperatively. RESULTS: Patients with DRC <8 mU/L showed a higher prevalence of non-classical histopathology compared to the other 2 tertiles (8/26 [30.8%] vs 1/25 [4%] vs 3/26 [11.5%]; P = .024) and more frequently absent or partial biochemical remission at their first follow-up (9/26 [34.6%] vs 3/25 [12.0%] vs 2/26 [7.7%]; P = .036). Nonetheless, 65.4% achieved complete biochemical remission. Clinical outcomes, including end-organ damage and comorbidities, did not differ across the tertiles. CONCLUSION: Persistent renin suppression is common 6 months after adrenalectomy and associated with worse biochemical but not clinical outcomes. More than 60% of patients with DRC <8 mU/L achieved full biochemical remission.