Endocrine Abstracts

Aim: Review of clinical presentation of primary hyperaldosteronism (PHA) and identify unique features in our cohort.

Method: Patients with PHA were identified from patients who underwent adrenal vein sampling (AVS) at our centre until October 2014.

Results: 45 PHA patients (32 males, mean age of 50 years, 33 older than 45 years) were identified after confirmation with high aldosterone:renin ratio >15 and/or positive saline suppression test. All had hypertension and 41/45 (91.1%) presented with hypokalaemia. CT adrenal findings were; 31/45 (68.9%) unilateral nodule (one had two nodules unilaterally), 5/45 (11.1%) bilateral nodules, 7/45 no nodules, 1/45 bilateral bulky adrenals, and 1/45 left adrenal limb thickening. The mean tumour size on CT was 1.41 (0.7–2.3) cm. All underwent AVS (four had repeat investigation). Based on biochemical criteria, 61% (30/49) of cases were successfully cannulated bilaterally. Final diagnosis of PHA was established after evaluating both CT and AVS findings (ratio of higher over lower aldosterone/cortisol of >4 for aldosterone producing adenoma (APA) and <3 for bilateral adrenal hyperplasia (BAH)) by the primary clinician: 18 had APA, 16 had BAH, and 11 were inconclusive. 17/45 (37.8%) patients underwent surgery (all confirmed as APA on histology). After surgery, hypokalemia normalised in all, 15/17 (88.2%) BP improved and 3/17 (17.6%) were cured of hypertension. Among 27 patients treated medically, 25/27 (92.6%) had normalisation of potassium, 25/27 (92.6%) BP improved and 2/27 (7.4%) were cured of hypertension. One patient declined treatment.

Discussion: The prevalence of BAH is higher in our cohort compared to reported series but this could be due to selection of cases through AVS procedure as some cases of APA may have been missed because they did not undergo AVS. The prevalence of inconclusive diagnosis after AVS was higher, which could be related to the expertise in our centre.