Adrenal Insufficiency After Unilateral Adrenalectomy in Primary Aldosteronism: Long-Term Outcome and Clinical Impact

Context: Primary aldosteronism (PA) represents a secondary form of arterial hypertension that can be cured by surgery. Evidence of adrenal insufficiency (AI) was recently found in patients with PA who had undergone unilateral adrenalectomy (uADX). Objective: To study the incidence and long-term outcome of postoperative Al after uADX for PA. Design: Prospective registry study (August 2014 until the end of 2018). Setting: Tertiary referral center. Patients: One hundred consecutive patients undergoing uADX for PA were included. All patients underwent postoperative ACTH stimulation testing. Intervention: Postoperative ACTH stimulation testing to identify patients with Al. Main Outcome Measures: Incidence of patients with postoperative Al and definition of long-term outcome. Results: Twenty-seven percent of patients developed postoperative Al. Of these, 48% had postoperative ACTH stimulation serum cortisol levels <= 13.5 mu g/dL (severe AI); 52% were classified into the group with moderate Al (stimulated serum cortisol levels: 13.5 to 17 mu g/dL). Patients with severe Al required significantly longer hydrocortisone replacement therapy than the moderate group (median [25th, 75th percentiles]: 353 [294, 476] days; 95% CI: 284 to 322 days; vs 74 [32, 293] days; 95% CI: 11 to 137 days; P = 0.016). One patient with severe Al was hospitalized for an acute adrenal crisis. With a cumulative follow-up of 14.5 years, this produced an incidence rate of 6.9 adrenal crises per 100 patient-years. Conclusion: We suggest performing postoperative ACTH stimulation tests in all patients who undergo uADX for PA.