Primary aldosteronism (PA) is the commonest cause of endocrine hypertension. Unilateral subtypes of the disease may be effectively cured through adrenalectomy, however challenges implementing with current diagnostic guidelines can result in significant treatment delay.
This retrospective study audits the diagnostic pipeline for PA in the North Sydney Local Health District (NSLHD), including baseline demographics. biochemistry (potassium, aldosterone-renin ratio (ARR)), saline suppression tests (SSTs), adrenal vein sampling (AVS), surgery and histopathology spanning a ten-year period (July 2013 to June 2023). We aimed to identify clinical characteristics associated with unilateral disease at screening outset.
Data was extracted from electronic medical records, local pathology, imaging and surgical databases and divided into stepwise cohorts along the diagnostic pipeline. For the purposes of this study, unilateral PA was defined as lateralization on AVS together with histopathology consistent with an aldosterone-producing lesion. Both univariate and multivariate logistic regression were performed to identify significant characteristics associated with unilateral PA.
191 SSTs, 191 AVSs and 124 adrenalectomies were included in the study. On multivariate analysis, lower serum potassium level (OR 3.97; 95% CI 1.50-11.73) and higher ARR (OR 0.996; 95% CI 0.993-0.998) were both independently associated with unilateral PA. Area under the receiver operating characteristic curve of this combined model was 0.80 (CI 0.72-0.88).
The biochemical characteristics of ARR and serum potassium were identified as significantly associated with unilateral disease. These findings may inform the future development of clinical decision-making tools to accelerate surgically curable patients through the diagnostic pipeline.