Primary aldosteronism (PA) is a common cause of secondary hypertension in Australia(1). Adrenal vein sampling (AVS) is considered gold standard to lateralise surgically curable disease (2). Our large tertiary referral hospital covers a local health district population of nearly one million people. We identified a need for a local AVS service to meet referral demand and reduce travel costs for patients.
Aim: A quality improvement audit of a new multi-disciplinary supported protocolised AVS service, John Hunter Hospital (Newcastle, NSW).
Method: Prospective data was collected from November 2021 to August 2023. Diagnosis of PA was defined as per Australian and International guidelines(2, 3). AVS was performed after overnight recumbency via sequential cannulation with continuous IV ACTH-infusion (50mcg/hr). Point-of-care rapid cortisol assay was used to predict adrenal vein cannulation success. Successful AVS defined as selectivity index (SI)≥5.0 (adrenal vein cortisol:peripheral vein cortisol). Unilateral aldosterone secretion was defined as lateralisation index ≥4 (dominant aldosterone:cortisol (A:C)/non-dominant A:C) with contralateral suppression <1.0 (non-dominant A:C/peripheral A:C). Patients were treated as per routine standards of care and followed up 3-12 months post-operatively.
Results: Baseline characteristics and results shown Table. 1. Of thirty-two AVS procedures performed to date, overall success rate was 78% (n=25) with no complications. 60% (n=15) of successful procedures demonstrated lateralisation. Those who lateralised were more likely to have hypokalaemia (60% versus 0%,p<0.01,Fisher’s Exact Test) and adrenal nodule on imaging (60% versus 33%,p=0.04,Fisher’s Exact Test) compared to bilateral. AVS and imaging were discordant in 24% (n=6). Following MDT confirmation of AVS results, 16 have been referred for adrenalectomy. Ten have undergone adrenalectomy. Six are ≥ 3 months post-operation. All have biochemical cure and 3 have clinical cure.
Conclusion: We have demonstrated successful establishment of an AVS service with procedural success rates comparable to centres worldwide and good preliminary surgical cure data(4, 5).